new file mode 100644
@@ -0,0 +1,31 @@
+BSD License
+
+Copyright (c) 2020, Google LLC
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+* Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+
+* Neither the name of Google LLC nor the names of its contributors may
+be used to endorse or promote products derived from this software
+without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
new file mode 100644
@@ -0,0 +1,19 @@
+
+The source code in this directory comes from https://github.com/google/reftable.
+
+The VERSION file keeps track of the current version of the reftable library.
+
+To update the library, do:
+
+ ((cd reftable-repo && git fetch origin && git checkout origin/master ) ||
+ git clone https://github.com/google/reftable reftable-repo) && \
+ cp reftable-repo/c/*.[ch] reftable/ && \
+ cp reftable-repo/LICENSE reftable/ &&
+ git --git-dir reftable-repo/.git show --no-patch origin/master \
+ > reftable/VERSION && \
+ echo '/* empty */' > reftable/config.h
+ rm reftable/*_test.c reftable/test_framework.*
+ git add reftable/*.[ch]
+
+Bugfixes should be accompanied by a test and applied to upstream project at
+https://github.com/google/reftable.
new file mode 100644
@@ -0,0 +1,5 @@
+commit e7c3fc3099d9999bc8d895f84027b0e36348d5e6
+Author: Han-Wen Nienhuys <hanwen@google.com>
+Date: Thu Feb 6 20:17:40 2020 +0100
+
+ C: use inttypes.h header definitions
new file mode 100644
@@ -0,0 +1,196 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "basics.h"
+
+#include "system.h"
+
+void put_u24(byte *out, uint32_t i)
+{
+ out[0] = (byte)((i >> 16) & 0xff);
+ out[1] = (byte)((i >> 8) & 0xff);
+ out[2] = (byte)((i)&0xff);
+}
+
+uint32_t get_u24(byte *in)
+{
+ return (uint32_t)(in[0]) << 16 | (uint32_t)(in[1]) << 8 |
+ (uint32_t)(in[2]);
+}
+
+void put_u32(byte *out, uint32_t i)
+{
+ out[0] = (byte)((i >> 24) & 0xff);
+ out[1] = (byte)((i >> 16) & 0xff);
+ out[2] = (byte)((i >> 8) & 0xff);
+ out[3] = (byte)((i)&0xff);
+}
+
+uint32_t get_u32(byte *in)
+{
+ return (uint32_t)(in[0]) << 24 | (uint32_t)(in[1]) << 16 |
+ (uint32_t)(in[2]) << 8 | (uint32_t)(in[3]);
+}
+
+void put_u64(byte *out, uint64_t v)
+{
+ int i = 0;
+ for (i = sizeof(uint64_t); i--;) {
+ out[i] = (byte)(v & 0xff);
+ v >>= 8;
+ }
+}
+
+uint64_t get_u64(byte *out)
+{
+ uint64_t v = 0;
+ int i = 0;
+ for (i = 0; i < sizeof(uint64_t); i++) {
+ v = (v << 8) | (byte)(out[i] & 0xff);
+ }
+ return v;
+}
+
+void put_u16(byte *out, uint16_t i)
+{
+ out[0] = (byte)((i >> 8) & 0xff);
+ out[1] = (byte)((i)&0xff);
+}
+
+uint16_t get_u16(byte *in)
+{
+ return (uint32_t)(in[0]) << 8 | (uint32_t)(in[1]);
+}
+
+/*
+ find smallest index i in [0, sz) at which f(i) is true, assuming
+ that f is ascending. Return sz if f(i) is false for all indices.
+*/
+int binsearch(int sz, int (*f)(int k, void *args), void *args)
+{
+ int lo = 0;
+ int hi = sz;
+
+ /* invariant: (hi == sz) || f(hi) == true
+ (lo == 0 && f(0) == true) || fi(lo) == false
+ */
+ while (hi - lo > 1) {
+ int mid = lo + (hi - lo) / 2;
+
+ int val = f(mid, args);
+ if (val) {
+ hi = mid;
+ } else {
+ lo = mid;
+ }
+ }
+
+ if (lo == 0) {
+ if (f(0, args)) {
+ return 0;
+ } else {
+ return 1;
+ }
+ }
+
+ return hi;
+}
+
+void free_names(char **a)
+{
+ char **p = a;
+ if (p == NULL) {
+ return;
+ }
+ while (*p) {
+ free(*p);
+ p++;
+ }
+ free(a);
+}
+
+int names_length(char **names)
+{
+ int len = 0;
+ for (char **p = names; *p; p++) {
+ len++;
+ }
+ return len;
+}
+
+/* parse a newline separated list of names. Empty names are discarded. */
+void parse_names(char *buf, int size, char ***namesp)
+{
+ char **names = NULL;
+ int names_cap = 0;
+ int names_len = 0;
+
+ char *p = buf;
+ char *end = buf + size;
+ while (p < end) {
+ char *next = strchr(p, '\n');
+ if (next != NULL) {
+ *next = 0;
+ } else {
+ next = end;
+ }
+ if (p < next) {
+ if (names_len == names_cap) {
+ names_cap = 2 * names_cap + 1;
+ names = realloc(names,
+ names_cap * sizeof(char *));
+ }
+ names[names_len++] = strdup(p);
+ }
+ p = next + 1;
+ }
+
+ if (names_len == names_cap) {
+ names_cap = 2 * names_cap + 1;
+ names = realloc(names, names_cap * sizeof(char *));
+ }
+
+ names[names_len] = NULL;
+ *namesp = names;
+}
+
+int names_equal(char **a, char **b)
+{
+ while (*a && *b) {
+ if (strcmp(*a, *b)) {
+ return 0;
+ }
+
+ a++;
+ b++;
+ }
+
+ return *a == *b;
+}
+
+const char *error_str(int err)
+{
+ switch (err) {
+ case IO_ERROR:
+ return "I/O error";
+ case FORMAT_ERROR:
+ return "FORMAT_ERROR";
+ case NOT_EXIST_ERROR:
+ return "NOT_EXIST_ERROR";
+ case LOCK_ERROR:
+ return "LOCK_ERROR";
+ case API_ERROR:
+ return "API_ERROR";
+ case ZLIB_ERROR:
+ return "ZLIB_ERROR";
+ case -1:
+ return "general error";
+ default:
+ return "unknown error code";
+ }
+}
new file mode 100644
@@ -0,0 +1,37 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef BASICS_H
+#define BASICS_H
+
+#include "system.h"
+
+#include "reftable.h"
+
+#define true 1
+#define false 0
+
+void put_u24(byte *out, uint32_t i);
+uint32_t get_u24(byte *in);
+
+uint64_t get_u64(byte *in);
+void put_u64(byte *out, uint64_t i);
+
+void put_u32(byte *out, uint32_t i);
+uint32_t get_u32(byte *in);
+
+void put_u16(byte *out, uint16_t i);
+uint16_t get_u16(byte *in);
+int binsearch(int sz, int (*f)(int k, void *args), void *args);
+
+void free_names(char **a);
+void parse_names(char *buf, int size, char ***namesp);
+int names_equal(char **a, char **b);
+int names_length(char **names);
+
+#endif
new file mode 100644
@@ -0,0 +1,401 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "block.h"
+
+#include "system.h"
+
+#include "blocksource.h"
+#include "constants.h"
+#include "record.h"
+#include "reftable.h"
+#include "zlib.h"
+
+int block_writer_register_restart(struct block_writer *w, int n, bool restart,
+ struct slice key);
+
+void block_writer_init(struct block_writer *bw, byte typ, byte *buf,
+ uint32_t block_size, uint32_t header_off, int hash_size)
+{
+ bw->buf = buf;
+ bw->hash_size = hash_size;
+ bw->block_size = block_size;
+ bw->header_off = header_off;
+ bw->buf[header_off] = typ;
+ bw->next = header_off + 4;
+ bw->restart_interval = 16;
+ bw->entries = 0;
+}
+
+byte block_writer_type(struct block_writer *bw)
+{
+ return bw->buf[bw->header_off];
+}
+
+/* adds the record to the block. Returns -1 if it does not fit, 0 on
+ success */
+int block_writer_add(struct block_writer *w, struct record rec)
+{
+ struct slice empty = {};
+ struct slice last = w->entries % w->restart_interval == 0 ? empty :
+ w->last_key;
+ struct slice out = {
+ .buf = w->buf + w->next,
+ .len = w->block_size - w->next,
+ };
+
+ struct slice start = out;
+
+ bool restart = false;
+ struct slice key = {};
+ int n = 0;
+
+ record_key(rec, &key);
+ n = encode_key(&restart, out, last, key, record_val_type(rec));
+ if (n < 0) {
+ goto err;
+ }
+ out.buf += n;
+ out.len -= n;
+
+ n = record_encode(rec, out, w->hash_size);
+ if (n < 0) {
+ goto err;
+ }
+
+ out.buf += n;
+ out.len -= n;
+
+ if (block_writer_register_restart(w, start.len - out.len, restart,
+ key) < 0) {
+ goto err;
+ }
+
+ free(slice_yield(&key));
+ return 0;
+
+err:
+ free(slice_yield(&key));
+ return -1;
+}
+
+int block_writer_register_restart(struct block_writer *w, int n, bool restart,
+ struct slice key)
+{
+ int rlen = w->restart_len;
+ if (rlen >= MAX_RESTARTS) {
+ restart = false;
+ }
+
+ if (restart) {
+ rlen++;
+ }
+ if (2 + 3 * rlen + n > w->block_size - w->next) {
+ return -1;
+ }
+ if (restart) {
+ if (w->restart_len == w->restart_cap) {
+ w->restart_cap = w->restart_cap * 2 + 1;
+ w->restarts = realloc(
+ w->restarts, sizeof(uint32_t) * w->restart_cap);
+ }
+
+ w->restarts[w->restart_len++] = w->next;
+ }
+
+ w->next += n;
+ slice_copy(&w->last_key, key);
+ w->entries++;
+ return 0;
+}
+
+int block_writer_finish(struct block_writer *w)
+{
+ int i = 0;
+ for (i = 0; i < w->restart_len; i++) {
+ put_u24(w->buf + w->next, w->restarts[i]);
+ w->next += 3;
+ }
+
+ put_u16(w->buf + w->next, w->restart_len);
+ w->next += 2;
+ put_u24(w->buf + 1 + w->header_off, w->next);
+
+ if (block_writer_type(w) == BLOCK_TYPE_LOG) {
+ int block_header_skip = 4 + w->header_off;
+ struct slice compressed = {};
+ uLongf dest_len = 0, src_len = 0;
+ slice_resize(&compressed, w->next - block_header_skip);
+
+ dest_len = compressed.len;
+ src_len = w->next - block_header_skip;
+
+ if (Z_OK != compress2(compressed.buf, &dest_len,
+ w->buf + block_header_skip, src_len, 9)) {
+ free(slice_yield(&compressed));
+ return ZLIB_ERROR;
+ }
+ memcpy(w->buf + block_header_skip, compressed.buf, dest_len);
+ w->next = dest_len + block_header_skip;
+ }
+ return w->next;
+}
+
+byte block_reader_type(struct block_reader *r)
+{
+ return r->block.data[r->header_off];
+}
+
+int block_reader_init(struct block_reader *br, struct block *block,
+ uint32_t header_off, uint32_t table_block_size,
+ int hash_size)
+{
+ uint32_t full_block_size = table_block_size;
+ byte typ = block->data[header_off];
+ uint32_t sz = get_u24(block->data + header_off + 1);
+
+ if (!is_block_type(typ)) {
+ return FORMAT_ERROR;
+ }
+
+ if (typ == BLOCK_TYPE_LOG) {
+ struct slice uncompressed = {};
+ int block_header_skip = 4 + header_off;
+ uLongf dst_len = sz - block_header_skip;
+ uLongf src_len = block->len - block_header_skip;
+
+ slice_resize(&uncompressed, sz);
+ memcpy(uncompressed.buf, block->data, block_header_skip);
+
+ if (Z_OK != uncompress_return_consumed(
+ uncompressed.buf + block_header_skip,
+ &dst_len, block->data + block_header_skip,
+ &src_len)) {
+ free(slice_yield(&uncompressed));
+ return ZLIB_ERROR;
+ }
+
+ block_source_return_block(block->source, block);
+ block->data = uncompressed.buf;
+ block->len = dst_len; /* XXX: 4 bytes missing? */
+ block->source = malloc_block_source();
+ full_block_size = src_len + block_header_skip;
+ } else if (full_block_size == 0) {
+ full_block_size = sz;
+ } else if (sz < full_block_size && sz < block->len &&
+ block->data[sz] != 0) {
+ /* If the block is smaller than the full block size, it is
+ padded (data followed by '\0') or the next block is
+ unaligned. */
+ full_block_size = sz;
+ }
+
+ {
+ uint16_t restart_count = get_u16(block->data + sz - 2);
+ uint32_t restart_start = sz - 2 - 3 * restart_count;
+
+ byte *restart_bytes = block->data + restart_start;
+
+ /* transfer ownership. */
+ br->block = *block;
+ block->data = NULL;
+ block->len = 0;
+
+ br->hash_size = hash_size;
+ br->block_len = restart_start;
+ br->full_block_size = full_block_size;
+ br->header_off = header_off;
+ br->restart_count = restart_count;
+ br->restart_bytes = restart_bytes;
+ }
+
+ return 0;
+}
+
+static uint32_t block_reader_restart_offset(struct block_reader *br, int i)
+{
+ return get_u24(br->restart_bytes + 3 * i);
+}
+
+void block_reader_start(struct block_reader *br, struct block_iter *it)
+{
+ it->br = br;
+ slice_resize(&it->last_key, 0);
+ it->next_off = br->header_off + 4;
+}
+
+struct restart_find_args {
+ struct slice key;
+ struct block_reader *r;
+ int error;
+};
+
+static int restart_key_less(int idx, void *args)
+{
+ struct restart_find_args *a = (struct restart_find_args *)args;
+ uint32_t off = block_reader_restart_offset(a->r, idx);
+ struct slice in = {
+ .buf = a->r->block.data + off,
+ .len = a->r->block_len - off,
+ };
+
+ /* the restart key is verbatim in the block, so this could avoid the
+ alloc for decoding the key */
+ struct slice rkey = {};
+ struct slice last_key = {};
+ byte unused_extra;
+ int n = decode_key(&rkey, &unused_extra, last_key, in);
+ if (n < 0) {
+ a->error = 1;
+ return -1;
+ }
+
+ {
+ int result = slice_compare(a->key, rkey);
+ free(slice_yield(&rkey));
+ return result;
+ }
+}
+
+void block_iter_copy_from(struct block_iter *dest, struct block_iter *src)
+{
+ dest->br = src->br;
+ dest->next_off = src->next_off;
+ slice_copy(&dest->last_key, src->last_key);
+}
+
+/* return < 0 for error, 0 for OK, > 0 for EOF. */
+int block_iter_next(struct block_iter *it, struct record rec)
+{
+ if (it->next_off >= it->br->block_len) {
+ return 1;
+ }
+
+ {
+ struct slice in = {
+ .buf = it->br->block.data + it->next_off,
+ .len = it->br->block_len - it->next_off,
+ };
+ struct slice start = in;
+ struct slice key = {};
+ byte extra;
+ int n = decode_key(&key, &extra, it->last_key, in);
+ if (n < 0) {
+ return -1;
+ }
+
+ in.buf += n;
+ in.len -= n;
+ n = record_decode(rec, key, extra, in, it->br->hash_size);
+ if (n < 0) {
+ return -1;
+ }
+ in.buf += n;
+ in.len -= n;
+
+ slice_copy(&it->last_key, key);
+ it->next_off += start.len - in.len;
+ free(slice_yield(&key));
+ return 0;
+ }
+}
+
+int block_reader_first_key(struct block_reader *br, struct slice *key)
+{
+ struct slice empty = {};
+ int off = br->header_off + 4;
+ struct slice in = {
+ .buf = br->block.data + off,
+ .len = br->block_len - off,
+ };
+
+ byte extra = 0;
+ int n = decode_key(key, &extra, empty, in);
+ if (n < 0) {
+ return n;
+ }
+ return 0;
+}
+
+int block_iter_seek(struct block_iter *it, struct slice want)
+{
+ return block_reader_seek(it->br, it, want);
+}
+
+void block_iter_close(struct block_iter *it)
+{
+ free(slice_yield(&it->last_key));
+}
+
+int block_reader_seek(struct block_reader *br, struct block_iter *it,
+ struct slice want)
+{
+ struct restart_find_args args = {
+ .key = want,
+ .r = br,
+ };
+
+ int i = binsearch(br->restart_count, &restart_key_less, &args);
+ if (args.error) {
+ return -1;
+ }
+
+ it->br = br;
+ if (i > 0) {
+ i--;
+ it->next_off = block_reader_restart_offset(br, i);
+ } else {
+ it->next_off = br->header_off + 4;
+ }
+
+ {
+ struct record rec = new_record(block_reader_type(br));
+ struct slice key = {};
+ int result = 0;
+ int err = 0;
+ struct block_iter next = {};
+ while (true) {
+ block_iter_copy_from(&next, it);
+
+ err = block_iter_next(&next, rec);
+ if (err < 0) {
+ result = -1;
+ goto exit;
+ }
+
+ record_key(rec, &key);
+ if (err > 0 || slice_compare(key, want) >= 0) {
+ result = 0;
+ goto exit;
+ }
+
+ block_iter_copy_from(it, &next);
+ }
+
+ exit:
+ free(slice_yield(&key));
+ free(slice_yield(&next.last_key));
+ record_clear(rec);
+ free(record_yield(&rec));
+
+ return result;
+ }
+}
+
+void block_writer_reset(struct block_writer *bw)
+{
+ bw->restart_len = 0;
+ bw->last_key.len = 0;
+}
+
+void block_writer_clear(struct block_writer *bw)
+{
+ FREE_AND_NULL(bw->restarts);
+ free(slice_yield(&bw->last_key));
+ /* the block is not owned. */
+}
new file mode 100644
@@ -0,0 +1,71 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef BLOCK_H
+#define BLOCK_H
+
+#include "basics.h"
+#include "record.h"
+#include "reftable.h"
+
+struct block_writer {
+ byte *buf;
+ uint32_t block_size;
+ uint32_t header_off;
+ int restart_interval;
+ int hash_size;
+
+ uint32_t next;
+ uint32_t *restarts;
+ uint32_t restart_len;
+ uint32_t restart_cap;
+ struct slice last_key;
+ int entries;
+};
+
+void block_writer_init(struct block_writer *bw, byte typ, byte *buf,
+ uint32_t block_size, uint32_t header_off, int hash_size);
+byte block_writer_type(struct block_writer *bw);
+int block_writer_add(struct block_writer *w, struct record rec);
+int block_writer_finish(struct block_writer *w);
+void block_writer_reset(struct block_writer *bw);
+void block_writer_clear(struct block_writer *bw);
+
+struct block_reader {
+ uint32_t header_off;
+ struct block block;
+ int hash_size;
+
+ /* size of the data, excluding restart data. */
+ uint32_t block_len;
+ byte *restart_bytes;
+ uint32_t full_block_size;
+ uint16_t restart_count;
+};
+
+struct block_iter {
+ struct block_reader *br;
+ struct slice last_key;
+ uint32_t next_off;
+};
+
+int block_reader_init(struct block_reader *br, struct block *bl,
+ uint32_t header_off, uint32_t table_block_size,
+ int hash_size);
+void block_reader_start(struct block_reader *br, struct block_iter *it);
+int block_reader_seek(struct block_reader *br, struct block_iter *it,
+ struct slice want);
+byte block_reader_type(struct block_reader *r);
+int block_reader_first_key(struct block_reader *br, struct slice *key);
+
+void block_iter_copy_from(struct block_iter *dest, struct block_iter *src);
+int block_iter_next(struct block_iter *it, struct record rec);
+int block_iter_seek(struct block_iter *it, struct slice want);
+void block_iter_close(struct block_iter *it);
+
+#endif
new file mode 100644
@@ -0,0 +1,20 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef BLOCKSOURCE_H
+#define BLOCKSOURCE_H
+
+#include "reftable.h"
+
+uint64_t block_source_size(struct block_source source);
+int block_source_read_block(struct block_source source, struct block *dest,
+ uint64_t off, uint32_t size);
+void block_source_return_block(struct block_source source, struct block *ret);
+void block_source_close(struct block_source source);
+
+#endif
new file mode 100644
new file mode 100644
@@ -0,0 +1 @@
+/* empty */
new file mode 100644
@@ -0,0 +1,27 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef CONSTANTS_H
+#define CONSTANTS_H
+
+#define SHA1_SIZE 20
+#define SHA256_SIZE 32
+#define VERSION 1
+#define HEADER_SIZE 24
+#define FOOTER_SIZE 68
+
+#define BLOCK_TYPE_LOG 'g'
+#define BLOCK_TYPE_INDEX 'i'
+#define BLOCK_TYPE_REF 'r'
+#define BLOCK_TYPE_OBJ 'o'
+#define BLOCK_TYPE_ANY 0
+
+#define MAX_RESTARTS ((1 << 16) - 1)
+#define DEFAULT_BLOCK_SIZE 4096
+
+#endif
new file mode 100644
@@ -0,0 +1,97 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "system.h"
+
+#include "reftable.h"
+
+static int dump_table(const char *tablename)
+{
+ struct block_source src = {};
+ int err = block_source_from_file(&src, tablename);
+ if (err < 0) {
+ return err;
+ }
+
+ struct reader *r = NULL;
+ err = new_reader(&r, src, tablename);
+ if (err < 0) {
+ return err;
+ }
+
+ {
+ struct iterator it = {};
+ err = reader_seek_ref(r, &it, "");
+ if (err < 0) {
+ return err;
+ }
+
+ struct ref_record ref = {};
+ while (1) {
+ err = iterator_next_ref(it, &ref);
+ if (err > 0) {
+ break;
+ }
+ if (err < 0) {
+ return err;
+ }
+ ref_record_print(&ref, 20);
+ }
+ iterator_destroy(&it);
+ ref_record_clear(&ref);
+ }
+
+ {
+ struct iterator it = {};
+ err = reader_seek_log(r, &it, "");
+ if (err < 0) {
+ return err;
+ }
+ struct log_record log = {};
+ while (1) {
+ err = iterator_next_log(it, &log);
+ if (err > 0) {
+ break;
+ }
+ if (err < 0) {
+ return err;
+ }
+ log_record_print(&log, 20);
+ }
+ iterator_destroy(&it);
+ log_record_clear(&log);
+ }
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ int opt;
+ const char *table = NULL;
+ while ((opt = getopt(argc, argv, "t:")) != -1) {
+ switch (opt) {
+ case 't':
+ table = strdup(optarg);
+ break;
+ case '?':
+ printf("usage: %s [-table tablefile]\n", argv[0]);
+ return 2;
+ break;
+ }
+ }
+
+ if (table != NULL) {
+ int err = dump_table(table);
+ if (err < 0) {
+ fprintf(stderr, "%s: %s: %s\n", argv[0], table,
+ error_str(err));
+ return 1;
+ }
+ }
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,97 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "system.h"
+
+#include "block.h"
+#include "iter.h"
+#include "record.h"
+#include "reftable.h"
+#include "tree.h"
+
+struct file_block_source {
+ int fd;
+ uint64_t size;
+};
+
+static uint64_t file_size(void *b)
+{
+ return ((struct file_block_source *)b)->size;
+}
+
+static void file_return_block(void *b, struct block *dest)
+{
+ memset(dest->data, 0xff, dest->len);
+ free(dest->data);
+}
+
+static void file_close(void *b)
+{
+ int fd = ((struct file_block_source *)b)->fd;
+ if (fd > 0) {
+ close(fd);
+ ((struct file_block_source *)b)->fd = 0;
+ }
+
+ free(b);
+}
+
+static int file_read_block(void *v, struct block *dest, uint64_t off,
+ uint32_t size)
+{
+ struct file_block_source *b = (struct file_block_source *)v;
+ assert(off + size <= b->size);
+ dest->data = malloc(size);
+ if (pread(b->fd, dest->data, size, off) != size) {
+ return -1;
+ }
+ dest->len = size;
+ return size;
+}
+
+struct block_source_vtable file_vtable = {
+ .size = &file_size,
+ .read_block = &file_read_block,
+ .return_block = &file_return_block,
+ .close = &file_close,
+};
+
+int block_source_from_file(struct block_source *bs, const char *name)
+{
+ struct stat st = {};
+ int err = 0;
+ int fd = open(name, O_RDONLY);
+ if (fd < 0) {
+ if (errno == ENOENT) {
+ return NOT_EXIST_ERROR;
+ }
+ return -1;
+ }
+
+ err = fstat(fd, &st);
+ if (err < 0) {
+ return -1;
+ }
+
+ {
+ struct file_block_source *p =
+ calloc(sizeof(struct file_block_source), 1);
+ p->size = st.st_size;
+ p->fd = fd;
+
+ bs->ops = &file_vtable;
+ bs->arg = p;
+ }
+ return 0;
+}
+
+int fd_writer(void *arg, byte *data, int sz)
+{
+ int *fdp = (int *)arg;
+ return write(*fdp, data, sz);
+}
new file mode 100644
@@ -0,0 +1,229 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "iter.h"
+
+#include "system.h"
+
+#include "block.h"
+#include "constants.h"
+#include "reader.h"
+#include "reftable.h"
+
+bool iterator_is_null(struct iterator it)
+{
+ return it.ops == NULL;
+}
+
+static int empty_iterator_next(void *arg, struct record rec)
+{
+ return 1;
+}
+
+static void empty_iterator_close(void *arg)
+{
+}
+
+struct iterator_vtable empty_vtable = {
+ .next = &empty_iterator_next,
+ .close = &empty_iterator_close,
+};
+
+void iterator_set_empty(struct iterator *it)
+{
+ it->iter_arg = NULL;
+ it->ops = &empty_vtable;
+}
+
+int iterator_next(struct iterator it, struct record rec)
+{
+ return it.ops->next(it.iter_arg, rec);
+}
+
+void iterator_destroy(struct iterator *it)
+{
+ if (it->ops == NULL) {
+ return;
+ }
+ it->ops->close(it->iter_arg);
+ it->ops = NULL;
+ FREE_AND_NULL(it->iter_arg);
+}
+
+int iterator_next_ref(struct iterator it, struct ref_record *ref)
+{
+ struct record rec = {};
+ record_from_ref(&rec, ref);
+ return iterator_next(it, rec);
+}
+
+int iterator_next_log(struct iterator it, struct log_record *log)
+{
+ struct record rec = {};
+ record_from_log(&rec, log);
+ return iterator_next(it, rec);
+}
+
+static void filtering_ref_iterator_close(void *iter_arg)
+{
+ struct filtering_ref_iterator *fri =
+ (struct filtering_ref_iterator *)iter_arg;
+ free(slice_yield(&fri->oid));
+ iterator_destroy(&fri->it);
+}
+
+static int filtering_ref_iterator_next(void *iter_arg, struct record rec)
+{
+ struct filtering_ref_iterator *fri =
+ (struct filtering_ref_iterator *)iter_arg;
+ struct ref_record *ref = (struct ref_record *)rec.data;
+
+ while (true) {
+ int err = iterator_next_ref(fri->it, ref);
+ if (err != 0) {
+ return err;
+ }
+
+ if (fri->double_check) {
+ struct iterator it = {};
+
+ int err = reader_seek_ref(fri->r, &it, ref->ref_name);
+ if (err == 0) {
+ err = iterator_next_ref(it, ref);
+ }
+
+ iterator_destroy(&it);
+
+ if (err < 0) {
+ return err;
+ }
+
+ if (err > 0) {
+ continue;
+ }
+ }
+
+ if ((ref->target_value != NULL &&
+ !memcmp(fri->oid.buf, ref->target_value, fri->oid.len)) ||
+ (ref->value != NULL &&
+ !memcmp(fri->oid.buf, ref->value, fri->oid.len))) {
+ return 0;
+ }
+ }
+}
+
+struct iterator_vtable filtering_ref_iterator_vtable = {
+ .next = &filtering_ref_iterator_next,
+ .close = &filtering_ref_iterator_close,
+};
+
+void iterator_from_filtering_ref_iterator(struct iterator *it,
+ struct filtering_ref_iterator *fri)
+{
+ it->iter_arg = fri;
+ it->ops = &filtering_ref_iterator_vtable;
+}
+
+static void indexed_table_ref_iter_close(void *p)
+{
+ struct indexed_table_ref_iter *it = (struct indexed_table_ref_iter *)p;
+ block_iter_close(&it->cur);
+ reader_return_block(it->r, &it->block_reader.block);
+ free(slice_yield(&it->oid));
+}
+
+static int indexed_table_ref_iter_next_block(struct indexed_table_ref_iter *it)
+{
+ if (it->offset_idx == it->offset_len) {
+ it->finished = true;
+ return 1;
+ }
+
+ reader_return_block(it->r, &it->block_reader.block);
+
+ {
+ uint64_t off = it->offsets[it->offset_idx++];
+ int err = reader_init_block_reader(it->r, &it->block_reader,
+ off, BLOCK_TYPE_REF);
+ if (err < 0) {
+ return err;
+ }
+ if (err > 0) {
+ /* indexed block does not exist. */
+ return FORMAT_ERROR;
+ }
+ }
+ block_reader_start(&it->block_reader, &it->cur);
+ return 0;
+}
+
+static int indexed_table_ref_iter_next(void *p, struct record rec)
+{
+ struct indexed_table_ref_iter *it = (struct indexed_table_ref_iter *)p;
+ struct ref_record *ref = (struct ref_record *)rec.data;
+
+ while (true) {
+ int err = block_iter_next(&it->cur, rec);
+ if (err < 0) {
+ return err;
+ }
+
+ if (err > 0) {
+ err = indexed_table_ref_iter_next_block(it);
+ if (err < 0) {
+ return err;
+ }
+
+ if (it->finished) {
+ return 1;
+ }
+ continue;
+ }
+
+ if (!memcmp(it->oid.buf, ref->target_value, it->oid.len) ||
+ !memcmp(it->oid.buf, ref->value, it->oid.len)) {
+ return 0;
+ }
+ }
+}
+
+int new_indexed_table_ref_iter(struct indexed_table_ref_iter **dest,
+ struct reader *r, byte *oid, int oid_len,
+ uint64_t *offsets, int offset_len)
+{
+ struct indexed_table_ref_iter *itr =
+ calloc(sizeof(struct indexed_table_ref_iter), 1);
+ int err = 0;
+
+ itr->r = r;
+ slice_resize(&itr->oid, oid_len);
+ memcpy(itr->oid.buf, oid, oid_len);
+
+ itr->offsets = offsets;
+ itr->offset_len = offset_len;
+
+ err = indexed_table_ref_iter_next_block(itr);
+ if (err < 0) {
+ free(itr);
+ } else {
+ *dest = itr;
+ }
+ return err;
+}
+
+struct iterator_vtable indexed_table_ref_iter_vtable = {
+ .next = &indexed_table_ref_iter_next,
+ .close = &indexed_table_ref_iter_close,
+};
+
+void iterator_from_indexed_table_ref_iter(struct iterator *it,
+ struct indexed_table_ref_iter *itr)
+{
+ it->iter_arg = itr;
+ it->ops = &indexed_table_ref_iter_vtable;
+}
new file mode 100644
@@ -0,0 +1,56 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef ITER_H
+#define ITER_H
+
+#include "block.h"
+#include "record.h"
+#include "slice.h"
+
+struct iterator_vtable {
+ int (*next)(void *iter_arg, struct record rec);
+ void (*close)(void *iter_arg);
+};
+
+void iterator_set_empty(struct iterator *it);
+int iterator_next(struct iterator it, struct record rec);
+bool iterator_is_null(struct iterator it);
+
+struct filtering_ref_iterator {
+ struct reader *r;
+ struct slice oid;
+ bool double_check;
+ struct iterator it;
+};
+
+void iterator_from_filtering_ref_iterator(struct iterator *,
+ struct filtering_ref_iterator *);
+
+struct indexed_table_ref_iter {
+ struct reader *r;
+ struct slice oid;
+
+ /* mutable */
+ uint64_t *offsets;
+
+ /* Points to the next offset to read. */
+ int offset_idx;
+ int offset_len;
+ struct block_reader block_reader;
+ struct block_iter cur;
+ bool finished;
+};
+
+void iterator_from_indexed_table_ref_iter(struct iterator *it,
+ struct indexed_table_ref_iter *itr);
+int new_indexed_table_ref_iter(struct indexed_table_ref_iter **dest,
+ struct reader *r, byte *oid, int oid_len,
+ uint64_t *offsets, int offset_len);
+
+#endif
new file mode 100644
@@ -0,0 +1,286 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "merged.h"
+
+#include "system.h"
+
+#include "constants.h"
+#include "iter.h"
+#include "pq.h"
+#include "reader.h"
+
+static int merged_iter_init(struct merged_iter *mi)
+{
+ int i = 0;
+ for (i = 0; i < mi->stack_len; i++) {
+ struct record rec = new_record(mi->typ);
+ int err = iterator_next(mi->stack[i], rec);
+ if (err < 0) {
+ return err;
+ }
+
+ if (err > 0) {
+ iterator_destroy(&mi->stack[i]);
+ record_clear(rec);
+ free(record_yield(&rec));
+ } else {
+ struct pq_entry e = {
+ .rec = rec,
+ .index = i,
+ };
+ merged_iter_pqueue_add(&mi->pq, e);
+ }
+ }
+
+ return 0;
+}
+
+static void merged_iter_close(void *p)
+{
+ struct merged_iter *mi = (struct merged_iter *)p;
+ int i = 0;
+ merged_iter_pqueue_clear(&mi->pq);
+ for (i = 0; i < mi->stack_len; i++) {
+ iterator_destroy(&mi->stack[i]);
+ }
+ free(mi->stack);
+}
+
+static int merged_iter_advance_subiter(struct merged_iter *mi, int idx)
+{
+ if (iterator_is_null(mi->stack[idx])) {
+ return 0;
+ }
+
+ {
+ struct record rec = new_record(mi->typ);
+ struct pq_entry e = {
+ .rec = rec,
+ .index = idx,
+ };
+ int err = iterator_next(mi->stack[idx], rec);
+ if (err < 0) {
+ return err;
+ }
+
+ if (err > 0) {
+ iterator_destroy(&mi->stack[idx]);
+ record_clear(rec);
+ free(record_yield(&rec));
+ return 0;
+ }
+
+ merged_iter_pqueue_add(&mi->pq, e);
+ }
+ return 0;
+}
+
+static int merged_iter_next(struct merged_iter *mi, struct record rec)
+{
+ struct slice entry_key = {};
+ struct pq_entry entry = merged_iter_pqueue_remove(&mi->pq);
+ int err = merged_iter_advance_subiter(mi, entry.index);
+ if (err < 0) {
+ return err;
+ }
+
+ record_key(entry.rec, &entry_key);
+ while (!merged_iter_pqueue_is_empty(mi->pq)) {
+ struct pq_entry top = merged_iter_pqueue_top(mi->pq);
+ struct slice k = {};
+ int err = 0, cmp = 0;
+
+ record_key(top.rec, &k);
+
+ cmp = slice_compare(k, entry_key);
+ free(slice_yield(&k));
+
+ if (cmp > 0) {
+ break;
+ }
+
+ merged_iter_pqueue_remove(&mi->pq);
+ err = merged_iter_advance_subiter(mi, top.index);
+ if (err < 0) {
+ return err;
+ }
+ record_clear(top.rec);
+ free(record_yield(&top.rec));
+ }
+
+ record_copy_from(rec, entry.rec, mi->hash_size);
+ record_clear(entry.rec);
+ free(record_yield(&entry.rec));
+ free(slice_yield(&entry_key));
+ return 0;
+}
+
+static int merged_iter_next_void(void *p, struct record rec)
+{
+ struct merged_iter *mi = (struct merged_iter *)p;
+ if (merged_iter_pqueue_is_empty(mi->pq)) {
+ return 1;
+ }
+
+ return merged_iter_next(mi, rec);
+}
+
+struct iterator_vtable merged_iter_vtable = {
+ .next = &merged_iter_next_void,
+ .close = &merged_iter_close,
+};
+
+static void iterator_from_merged_iter(struct iterator *it,
+ struct merged_iter *mi)
+{
+ it->iter_arg = mi;
+ it->ops = &merged_iter_vtable;
+}
+
+int new_merged_table(struct merged_table **dest, struct reader **stack, int n)
+{
+ uint64_t last_max = 0;
+ uint64_t first_min = 0;
+ int i = 0;
+ for (i = 0; i < n; i++) {
+ struct reader *r = stack[i];
+ if (i > 0 && last_max >= reader_min_update_index(r)) {
+ return FORMAT_ERROR;
+ }
+ if (i == 0) {
+ first_min = reader_min_update_index(r);
+ }
+
+ last_max = reader_max_update_index(r);
+ }
+
+ {
+ struct merged_table m = {
+ .stack = stack,
+ .stack_len = n,
+ .min = first_min,
+ .max = last_max,
+ .hash_size = SHA1_SIZE,
+ };
+
+ *dest = calloc(sizeof(struct merged_table), 1);
+ **dest = m;
+ }
+ return 0;
+}
+
+void merged_table_close(struct merged_table *mt)
+{
+ int i = 0;
+ for (i = 0; i < mt->stack_len; i++) {
+ reader_free(mt->stack[i]);
+ }
+ FREE_AND_NULL(mt->stack);
+ mt->stack_len = 0;
+}
+
+/* clears the list of subtable, without affecting the readers themselves. */
+void merged_table_clear(struct merged_table *mt)
+{
+ FREE_AND_NULL(mt->stack);
+ mt->stack_len = 0;
+}
+
+void merged_table_free(struct merged_table *mt)
+{
+ if (mt == NULL) {
+ return;
+ }
+ merged_table_clear(mt);
+ free(mt);
+}
+
+uint64_t merged_max_update_index(struct merged_table *mt)
+{
+ return mt->max;
+}
+
+uint64_t merged_min_update_index(struct merged_table *mt)
+{
+ return mt->min;
+}
+
+static int merged_table_seek_record(struct merged_table *mt,
+ struct iterator *it, struct record rec)
+{
+ struct iterator *iters = calloc(sizeof(struct iterator), mt->stack_len);
+ struct merged_iter merged = {
+ .stack = iters,
+ .typ = record_type(rec),
+ .hash_size = mt->hash_size,
+ };
+ int n = 0;
+ int err = 0;
+ int i = 0;
+ for (i = 0; i < mt->stack_len && err == 0; i++) {
+ int e = reader_seek(mt->stack[i], &iters[n], rec);
+ if (e < 0) {
+ err = e;
+ }
+ if (e == 0) {
+ n++;
+ }
+ }
+ if (err < 0) {
+ int i = 0;
+ for (i = 0; i < n; i++) {
+ iterator_destroy(&iters[i]);
+ }
+ free(iters);
+ return err;
+ }
+
+ merged.stack_len = n, err = merged_iter_init(&merged);
+ if (err < 0) {
+ merged_iter_close(&merged);
+ return err;
+ }
+
+ {
+ struct merged_iter *p = malloc(sizeof(struct merged_iter));
+ *p = merged;
+ iterator_from_merged_iter(it, p);
+ }
+ return 0;
+}
+
+int merged_table_seek_ref(struct merged_table *mt, struct iterator *it,
+ const char *name)
+{
+ struct ref_record ref = {
+ .ref_name = (char *)name,
+ };
+ struct record rec = {};
+ record_from_ref(&rec, &ref);
+ return merged_table_seek_record(mt, it, rec);
+}
+
+int merged_table_seek_log_at(struct merged_table *mt, struct iterator *it,
+ const char *name, uint64_t update_index)
+{
+ struct log_record log = {
+ .ref_name = (char *)name,
+ .update_index = update_index,
+ };
+ struct record rec = {};
+ record_from_log(&rec, &log);
+ return merged_table_seek_record(mt, it, rec);
+}
+
+int merged_table_seek_log(struct merged_table *mt, struct iterator *it,
+ const char *name)
+{
+ uint64_t max = ~((uint64_t)0);
+ return merged_table_seek_log_at(mt, it, name, max);
+}
new file mode 100644
@@ -0,0 +1,34 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef MERGED_H
+#define MERGED_H
+
+#include "pq.h"
+#include "reftable.h"
+
+struct merged_table {
+ struct reader **stack;
+ int stack_len;
+ int hash_size;
+
+ uint64_t min;
+ uint64_t max;
+};
+
+struct merged_iter {
+ struct iterator *stack;
+ int hash_size;
+ int stack_len;
+ byte typ;
+ struct merged_iter_pqueue pq;
+} merged_iter;
+
+void merged_table_clear(struct merged_table *mt);
+
+#endif
new file mode 100644
@@ -0,0 +1,114 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "pq.h"
+
+#include "system.h"
+
+int pq_less(struct pq_entry a, struct pq_entry b)
+{
+ struct slice ak = {};
+ struct slice bk = {};
+ int cmp = 0;
+ record_key(a.rec, &ak);
+ record_key(b.rec, &bk);
+
+ cmp = slice_compare(ak, bk);
+
+ free(slice_yield(&ak));
+ free(slice_yield(&bk));
+
+ if (cmp == 0) {
+ return a.index > b.index;
+ }
+
+ return cmp < 0;
+}
+
+struct pq_entry merged_iter_pqueue_top(struct merged_iter_pqueue pq)
+{
+ return pq.heap[0];
+}
+
+bool merged_iter_pqueue_is_empty(struct merged_iter_pqueue pq)
+{
+ return pq.len == 0;
+}
+
+void merged_iter_pqueue_check(struct merged_iter_pqueue pq)
+{
+ int i = 0;
+ for (i = 1; i < pq.len; i++) {
+ int parent = (i - 1) / 2;
+
+ assert(pq_less(pq.heap[parent], pq.heap[i]));
+ }
+}
+
+struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq)
+{
+ int i = 0;
+ struct pq_entry e = pq->heap[0];
+ pq->heap[0] = pq->heap[pq->len - 1];
+ pq->len--;
+
+ i = 0;
+ while (i < pq->len) {
+ int min = i;
+ int j = 2 * i + 1;
+ int k = 2 * i + 2;
+ if (j < pq->len && pq_less(pq->heap[j], pq->heap[i])) {
+ min = j;
+ }
+ if (k < pq->len && pq_less(pq->heap[k], pq->heap[min])) {
+ min = k;
+ }
+
+ if (min == i) {
+ break;
+ }
+
+ SWAP(pq->heap[i], pq->heap[min]);
+ i = min;
+ }
+
+ return e;
+}
+
+void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, struct pq_entry e)
+{
+ int i = 0;
+ if (pq->len == pq->cap) {
+ pq->cap = 2 * pq->cap + 1;
+ pq->heap = realloc(pq->heap, pq->cap * sizeof(struct pq_entry));
+ }
+
+ pq->heap[pq->len++] = e;
+ i = pq->len - 1;
+ while (i > 0) {
+ int j = (i - 1) / 2;
+ if (pq_less(pq->heap[j], pq->heap[i])) {
+ break;
+ }
+
+ SWAP(pq->heap[j], pq->heap[i]);
+
+ i = j;
+ }
+}
+
+void merged_iter_pqueue_clear(struct merged_iter_pqueue *pq)
+{
+ int i = 0;
+ for (i = 0; i < pq->len; i++) {
+ record_clear(pq->heap[i].rec);
+ free(record_yield(&pq->heap[i].rec));
+ }
+ FREE_AND_NULL(pq->heap);
+ pq->len = pq->cap = 0;
+}
new file mode 100644
@@ -0,0 +1,34 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef PQ_H
+#define PQ_H
+
+#include "record.h"
+
+struct pq_entry {
+ struct record rec;
+ int index;
+};
+
+int pq_less(struct pq_entry a, struct pq_entry b);
+
+struct merged_iter_pqueue {
+ struct pq_entry *heap;
+ int len;
+ int cap;
+};
+
+struct pq_entry merged_iter_pqueue_top(struct merged_iter_pqueue pq);
+bool merged_iter_pqueue_is_empty(struct merged_iter_pqueue pq);
+void merged_iter_pqueue_check(struct merged_iter_pqueue pq);
+struct pq_entry merged_iter_pqueue_remove(struct merged_iter_pqueue *pq);
+void merged_iter_pqueue_add(struct merged_iter_pqueue *pq, struct pq_entry e);
+void merged_iter_pqueue_clear(struct merged_iter_pqueue *pq);
+
+#endif
new file mode 100644
@@ -0,0 +1,708 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "reader.h"
+
+#include "system.h"
+
+#include "block.h"
+#include "constants.h"
+#include "iter.h"
+#include "record.h"
+#include "reftable.h"
+#include "tree.h"
+
+uint64_t block_source_size(struct block_source source)
+{
+ return source.ops->size(source.arg);
+}
+
+int block_source_read_block(struct block_source source, struct block *dest,
+ uint64_t off, uint32_t size)
+{
+ int result = source.ops->read_block(source.arg, dest, off, size);
+ dest->source = source;
+ return result;
+}
+
+void block_source_return_block(struct block_source source, struct block *blockp)
+{
+ source.ops->return_block(source.arg, blockp);
+ blockp->data = NULL;
+ blockp->len = 0;
+ blockp->source.ops = NULL;
+ blockp->source.arg = NULL;
+}
+
+void block_source_close(struct block_source *source)
+{
+ if (source->ops == NULL) {
+ return;
+ }
+
+ source->ops->close(source->arg);
+ source->ops = NULL;
+}
+
+static struct reader_offsets *reader_offsets_for(struct reader *r, byte typ)
+{
+ switch (typ) {
+ case BLOCK_TYPE_REF:
+ return &r->ref_offsets;
+ case BLOCK_TYPE_LOG:
+ return &r->log_offsets;
+ case BLOCK_TYPE_OBJ:
+ return &r->obj_offsets;
+ }
+ abort();
+}
+
+static int reader_get_block(struct reader *r, struct block *dest, uint64_t off,
+ uint32_t sz)
+{
+ if (off >= r->size) {
+ return 0;
+ }
+
+ if (off + sz > r->size) {
+ sz = r->size - off;
+ }
+
+ return block_source_read_block(r->source, dest, off, sz);
+}
+
+void reader_return_block(struct reader *r, struct block *p)
+{
+ block_source_return_block(r->source, p);
+}
+
+const char *reader_name(struct reader *r)
+{
+ return r->name;
+}
+
+static int parse_footer(struct reader *r, byte *footer, byte *header)
+{
+ byte *f = footer;
+ int err = 0;
+ if (memcmp(f, "REFT", 4)) {
+ err = FORMAT_ERROR;
+ goto exit;
+ }
+ f += 4;
+
+ if (memcmp(footer, header, HEADER_SIZE)) {
+ err = FORMAT_ERROR;
+ goto exit;
+ }
+
+ {
+ byte version = *f++;
+ if (version != 1) {
+ err = FORMAT_ERROR;
+ goto exit;
+ }
+ }
+
+ r->block_size = get_u24(f);
+
+ f += 3;
+ r->min_update_index = get_u64(f);
+ f += 8;
+ r->max_update_index = get_u64(f);
+ f += 8;
+
+ r->ref_offsets.index_offset = get_u64(f);
+ f += 8;
+
+ r->obj_offsets.offset = get_u64(f);
+ f += 8;
+
+ r->object_id_len = r->obj_offsets.offset & ((1 << 5) - 1);
+ r->obj_offsets.offset >>= 5;
+
+ r->obj_offsets.index_offset = get_u64(f);
+ f += 8;
+ r->log_offsets.offset = get_u64(f);
+ f += 8;
+ r->log_offsets.index_offset = get_u64(f);
+ f += 8;
+
+ {
+ uint32_t computed_crc = crc32(0, footer, f - footer);
+ uint32_t file_crc = get_u32(f);
+ f += 4;
+ if (computed_crc != file_crc) {
+ err = FORMAT_ERROR;
+ goto exit;
+ }
+ }
+
+ {
+ byte first_block_typ = header[HEADER_SIZE];
+ r->ref_offsets.present = (first_block_typ == BLOCK_TYPE_REF);
+ r->ref_offsets.offset = 0;
+ r->log_offsets.present = (first_block_typ == BLOCK_TYPE_LOG ||
+ r->log_offsets.offset > 0);
+ r->obj_offsets.present = r->obj_offsets.offset > 0;
+ }
+ err = 0;
+exit:
+ return err;
+}
+
+int init_reader(struct reader *r, struct block_source source, const char *name)
+{
+ struct block footer = {};
+ struct block header = {};
+ int err = 0;
+
+ memset(r, 0, sizeof(struct reader));
+ r->size = block_source_size(source) - FOOTER_SIZE;
+ r->source = source;
+ r->name = strdup(name);
+ r->hash_size = SHA1_SIZE;
+
+ err = block_source_read_block(source, &footer, r->size, FOOTER_SIZE);
+ if (err != FOOTER_SIZE) {
+ err = IO_ERROR;
+ goto exit;
+ }
+
+ /* Need +1 to read type of first block. */
+ err = reader_get_block(r, &header, 0, HEADER_SIZE + 1);
+ if (err != HEADER_SIZE + 1) {
+ err = IO_ERROR;
+ goto exit;
+ }
+
+ err = parse_footer(r, footer.data, header.data);
+exit:
+ block_source_return_block(r->source, &footer);
+ block_source_return_block(r->source, &header);
+ return err;
+}
+
+struct table_iter {
+ struct reader *r;
+ byte typ;
+ uint64_t block_off;
+ struct block_iter bi;
+ bool finished;
+};
+
+static void table_iter_copy_from(struct table_iter *dest,
+ struct table_iter *src)
+{
+ dest->r = src->r;
+ dest->typ = src->typ;
+ dest->block_off = src->block_off;
+ dest->finished = src->finished;
+ block_iter_copy_from(&dest->bi, &src->bi);
+}
+
+static int table_iter_next_in_block(struct table_iter *ti, struct record rec)
+{
+ int res = block_iter_next(&ti->bi, rec);
+ if (res == 0 && record_type(rec) == BLOCK_TYPE_REF) {
+ ((struct ref_record *)rec.data)->update_index +=
+ ti->r->min_update_index;
+ }
+
+ return res;
+}
+
+static void table_iter_block_done(struct table_iter *ti)
+{
+ if (ti->bi.br == NULL) {
+ return;
+ }
+ reader_return_block(ti->r, &ti->bi.br->block);
+ FREE_AND_NULL(ti->bi.br);
+
+ ti->bi.last_key.len = 0;
+ ti->bi.next_off = 0;
+}
+
+static int32_t extract_block_size(byte *data, byte *typ, uint64_t off)
+{
+ int32_t result = 0;
+
+ if (off == 0) {
+ data += 24;
+ }
+
+ *typ = data[0];
+ if (is_block_type(*typ)) {
+ result = get_u24(data + 1);
+ }
+ return result;
+}
+
+int reader_init_block_reader(struct reader *r, struct block_reader *br,
+ uint64_t next_off, byte want_typ)
+{
+ int32_t guess_block_size = r->block_size ? r->block_size :
+ DEFAULT_BLOCK_SIZE;
+ struct block block = {};
+ byte block_typ = 0;
+ int err = 0;
+ uint32_t header_off = next_off ? 0 : HEADER_SIZE;
+ int32_t block_size = 0;
+
+ if (next_off >= r->size) {
+ return 1;
+ }
+
+ err = reader_get_block(r, &block, next_off, guess_block_size);
+ if (err < 0) {
+ return err;
+ }
+
+ block_size = extract_block_size(block.data, &block_typ, next_off);
+ if (block_size < 0) {
+ return block_size;
+ }
+
+ if (want_typ != BLOCK_TYPE_ANY && block_typ != want_typ) {
+ reader_return_block(r, &block);
+ return 1;
+ }
+
+ if (block_size > guess_block_size) {
+ reader_return_block(r, &block);
+ err = reader_get_block(r, &block, next_off, block_size);
+ if (err < 0) {
+ return err;
+ }
+ }
+
+ return block_reader_init(br, &block, header_off, r->block_size,
+ r->hash_size);
+}
+
+static int table_iter_next_block(struct table_iter *dest,
+ struct table_iter *src)
+{
+ uint64_t next_block_off = src->block_off + src->bi.br->full_block_size;
+ struct block_reader br = {};
+ int err = 0;
+
+ dest->r = src->r;
+ dest->typ = src->typ;
+ dest->block_off = next_block_off;
+
+ err = reader_init_block_reader(src->r, &br, next_block_off, src->typ);
+ if (err > 0) {
+ dest->finished = true;
+ return 1;
+ }
+ if (err != 0) {
+ return err;
+ }
+
+ {
+ struct block_reader *brp = malloc(sizeof(struct block_reader));
+ *brp = br;
+
+ dest->finished = false;
+ block_reader_start(brp, &dest->bi);
+ }
+ return 0;
+}
+
+static int table_iter_next(struct table_iter *ti, struct record rec)
+{
+ if (record_type(rec) != ti->typ) {
+ return API_ERROR;
+ }
+
+ while (true) {
+ struct table_iter next = {};
+ int err = 0;
+ if (ti->finished) {
+ return 1;
+ }
+
+ err = table_iter_next_in_block(ti, rec);
+ if (err <= 0) {
+ return err;
+ }
+
+ err = table_iter_next_block(&next, ti);
+ if (err != 0) {
+ ti->finished = true;
+ }
+ table_iter_block_done(ti);
+ if (err != 0) {
+ return err;
+ }
+ table_iter_copy_from(ti, &next);
+ block_iter_close(&next.bi);
+ }
+}
+
+static int table_iter_next_void(void *ti, struct record rec)
+{
+ return table_iter_next((struct table_iter *)ti, rec);
+}
+
+static void table_iter_close(void *p)
+{
+ struct table_iter *ti = (struct table_iter *)p;
+ table_iter_block_done(ti);
+ block_iter_close(&ti->bi);
+}
+
+struct iterator_vtable table_iter_vtable = {
+ .next = &table_iter_next_void,
+ .close = &table_iter_close,
+};
+
+static void iterator_from_table_iter(struct iterator *it, struct table_iter *ti)
+{
+ it->iter_arg = ti;
+ it->ops = &table_iter_vtable;
+}
+
+static int reader_table_iter_at(struct reader *r, struct table_iter *ti,
+ uint64_t off, byte typ)
+{
+ struct block_reader br = {};
+ struct block_reader *brp = NULL;
+
+ int err = reader_init_block_reader(r, &br, off, typ);
+ if (err != 0) {
+ return err;
+ }
+
+ brp = malloc(sizeof(struct block_reader));
+ *brp = br;
+ ti->r = r;
+ ti->typ = block_reader_type(brp);
+ ti->block_off = off;
+ block_reader_start(brp, &ti->bi);
+ return 0;
+}
+
+static int reader_start(struct reader *r, struct table_iter *ti, byte typ,
+ bool index)
+{
+ struct reader_offsets *offs = reader_offsets_for(r, typ);
+ uint64_t off = offs->offset;
+ if (index) {
+ off = offs->index_offset;
+ if (off == 0) {
+ return 1;
+ }
+ typ = BLOCK_TYPE_INDEX;
+ }
+
+ return reader_table_iter_at(r, ti, off, typ);
+}
+
+static int reader_seek_linear(struct reader *r, struct table_iter *ti,
+ struct record want)
+{
+ struct record rec = new_record(record_type(want));
+ struct slice want_key = {};
+ struct slice got_key = {};
+ struct table_iter next = {};
+ int err = -1;
+ record_key(want, &want_key);
+
+ while (true) {
+ err = table_iter_next_block(&next, ti);
+ if (err < 0) {
+ goto exit;
+ }
+
+ if (err > 0) {
+ break;
+ }
+
+ err = block_reader_first_key(next.bi.br, &got_key);
+ if (err < 0) {
+ goto exit;
+ }
+ {
+ int cmp = slice_compare(got_key, want_key);
+ if (cmp > 0) {
+ table_iter_block_done(&next);
+ break;
+ }
+ }
+
+ table_iter_block_done(ti);
+ table_iter_copy_from(ti, &next);
+ }
+
+ err = block_iter_seek(&ti->bi, want_key);
+ if (err < 0) {
+ goto exit;
+ }
+ err = 0;
+
+exit:
+ block_iter_close(&next.bi);
+ record_clear(rec);
+ free(record_yield(&rec));
+ free(slice_yield(&want_key));
+ free(slice_yield(&got_key));
+ return err;
+}
+
+static int reader_seek_indexed(struct reader *r, struct iterator *it,
+ struct record rec)
+{
+ struct index_record want_index = {};
+ struct record want_index_rec = {};
+ struct index_record index_result = {};
+ struct record index_result_rec = {};
+ struct table_iter index_iter = {};
+ struct table_iter next = {};
+ int err = 0;
+
+ record_key(rec, &want_index.last_key);
+ record_from_index(&want_index_rec, &want_index);
+ record_from_index(&index_result_rec, &index_result);
+
+ err = reader_start(r, &index_iter, record_type(rec), true);
+ if (err < 0) {
+ goto exit;
+ }
+
+ err = reader_seek_linear(r, &index_iter, want_index_rec);
+ while (true) {
+ err = table_iter_next(&index_iter, index_result_rec);
+ table_iter_block_done(&index_iter);
+ if (err != 0) {
+ goto exit;
+ }
+
+ err = reader_table_iter_at(r, &next, index_result.offset, 0);
+ if (err != 0) {
+ goto exit;
+ }
+
+ err = block_iter_seek(&next.bi, want_index.last_key);
+ if (err < 0) {
+ goto exit;
+ }
+
+ if (next.typ == record_type(rec)) {
+ err = 0;
+ break;
+ }
+
+ if (next.typ != BLOCK_TYPE_INDEX) {
+ err = FORMAT_ERROR;
+ break;
+ }
+
+ table_iter_copy_from(&index_iter, &next);
+ }
+
+ if (err == 0) {
+ struct table_iter *malloced =
+ calloc(sizeof(struct table_iter), 1);
+ table_iter_copy_from(malloced, &next);
+ iterator_from_table_iter(it, malloced);
+ }
+exit:
+ block_iter_close(&next.bi);
+ table_iter_close(&index_iter);
+ record_clear(want_index_rec);
+ record_clear(index_result_rec);
+ return err;
+}
+
+static int reader_seek_internal(struct reader *r, struct iterator *it,
+ struct record rec)
+{
+ struct reader_offsets *offs = reader_offsets_for(r, record_type(rec));
+ uint64_t idx = offs->index_offset;
+ struct table_iter ti = {};
+ int err = 0;
+ if (idx > 0) {
+ return reader_seek_indexed(r, it, rec);
+ }
+
+ err = reader_start(r, &ti, record_type(rec), false);
+ if (err < 0) {
+ return err;
+ }
+ err = reader_seek_linear(r, &ti, rec);
+ if (err < 0) {
+ return err;
+ }
+
+ {
+ struct table_iter *p = malloc(sizeof(struct table_iter));
+ *p = ti;
+ iterator_from_table_iter(it, p);
+ }
+
+ return 0;
+}
+
+int reader_seek(struct reader *r, struct iterator *it, struct record rec)
+{
+ byte typ = record_type(rec);
+
+ struct reader_offsets *offs = reader_offsets_for(r, typ);
+ if (!offs->present) {
+ iterator_set_empty(it);
+ return 0;
+ }
+
+ return reader_seek_internal(r, it, rec);
+}
+
+int reader_seek_ref(struct reader *r, struct iterator *it, const char *name)
+{
+ struct ref_record ref = {
+ .ref_name = (char *)name,
+ };
+ struct record rec = {};
+ record_from_ref(&rec, &ref);
+ return reader_seek(r, it, rec);
+}
+
+int reader_seek_log_at(struct reader *r, struct iterator *it, const char *name,
+ uint64_t update_index)
+{
+ struct log_record log = {
+ .ref_name = (char *)name,
+ .update_index = update_index,
+ };
+ struct record rec = {};
+ record_from_log(&rec, &log);
+ return reader_seek(r, it, rec);
+}
+
+int reader_seek_log(struct reader *r, struct iterator *it, const char *name)
+{
+ uint64_t max = ~((uint64_t)0);
+ return reader_seek_log_at(r, it, name, max);
+}
+
+void reader_close(struct reader *r)
+{
+ block_source_close(&r->source);
+ FREE_AND_NULL(r->name);
+}
+
+int new_reader(struct reader **p, struct block_source src, char const *name)
+{
+ struct reader *rd = calloc(sizeof(struct reader), 1);
+ int err = init_reader(rd, src, name);
+ if (err == 0) {
+ *p = rd;
+ } else {
+ free(rd);
+ }
+ return err;
+}
+
+void reader_free(struct reader *r)
+{
+ reader_close(r);
+ free(r);
+}
+
+static int reader_refs_for_indexed(struct reader *r, struct iterator *it,
+ byte *oid)
+{
+ struct obj_record want = {
+ .hash_prefix = oid,
+ .hash_prefix_len = r->object_id_len,
+ };
+ struct record want_rec = {};
+ struct iterator oit = {};
+ struct obj_record got = {};
+ struct record got_rec = {};
+ int err = 0;
+
+ record_from_obj(&want_rec, &want);
+
+ err = reader_seek(r, &oit, want_rec);
+ if (err != 0) {
+ return err;
+ }
+
+ record_from_obj(&got_rec, &got);
+ err = iterator_next(oit, got_rec);
+ iterator_destroy(&oit);
+ if (err < 0) {
+ return err;
+ }
+
+ if (err > 0 ||
+ memcmp(want.hash_prefix, got.hash_prefix, r->object_id_len)) {
+ iterator_set_empty(it);
+ return 0;
+ }
+
+ {
+ struct indexed_table_ref_iter *itr = NULL;
+ err = new_indexed_table_ref_iter(&itr, r, oid, r->hash_size,
+ got.offsets, got.offset_len);
+ if (err < 0) {
+ record_clear(got_rec);
+ return err;
+ }
+ got.offsets = NULL;
+ record_clear(got_rec);
+
+ iterator_from_indexed_table_ref_iter(it, itr);
+ }
+
+ return 0;
+}
+
+static int reader_refs_for_unindexed(struct reader *r, struct iterator *it,
+ byte *oid, int oid_len)
+{
+ struct table_iter *ti = calloc(sizeof(struct table_iter), 1);
+ struct filtering_ref_iterator *filter = NULL;
+ int err = reader_start(r, ti, BLOCK_TYPE_REF, false);
+ if (err < 0) {
+ free(ti);
+ return err;
+ }
+
+ filter = calloc(sizeof(struct filtering_ref_iterator), 1);
+ slice_resize(&filter->oid, oid_len);
+ memcpy(filter->oid.buf, oid, oid_len);
+ filter->r = r;
+ filter->double_check = false;
+ iterator_from_table_iter(&filter->it, ti);
+
+ iterator_from_filtering_ref_iterator(it, filter);
+ return 0;
+}
+
+int reader_refs_for(struct reader *r, struct iterator *it, byte *oid,
+ int oid_len)
+{
+ if (r->obj_offsets.present) {
+ return reader_refs_for_indexed(r, it, oid);
+ }
+ return reader_refs_for_unindexed(r, it, oid, oid_len);
+}
+
+uint64_t reader_max_update_index(struct reader *r)
+{
+ return r->max_update_index;
+}
+
+uint64_t reader_min_update_index(struct reader *r)
+{
+ return r->min_update_index;
+}
new file mode 100644
@@ -0,0 +1,52 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef READER_H
+#define READER_H
+
+#include "block.h"
+#include "record.h"
+#include "reftable.h"
+
+uint64_t block_source_size(struct block_source source);
+
+int block_source_read_block(struct block_source source, struct block *dest,
+ uint64_t off, uint32_t size);
+void block_source_return_block(struct block_source source, struct block *ret);
+void block_source_close(struct block_source *source);
+
+struct reader_offsets {
+ bool present;
+ uint64_t offset;
+ uint64_t index_offset;
+};
+
+struct reader {
+ struct block_source source;
+ char *name;
+ int hash_size;
+ uint64_t size;
+ uint32_t block_size;
+ uint64_t min_update_index;
+ uint64_t max_update_index;
+ int object_id_len;
+
+ struct reader_offsets ref_offsets;
+ struct reader_offsets obj_offsets;
+ struct reader_offsets log_offsets;
+};
+
+int init_reader(struct reader *r, struct block_source source, const char *name);
+int reader_seek(struct reader *r, struct iterator *it, struct record rec);
+void reader_close(struct reader *r);
+const char *reader_name(struct reader *r);
+void reader_return_block(struct reader *r, struct block *p);
+int reader_init_block_reader(struct reader *r, struct block_reader *br,
+ uint64_t next_off, byte want_typ);
+
+#endif
new file mode 100644
@@ -0,0 +1,1107 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "record.h"
+
+#include "system.h"
+
+#include "constants.h"
+#include "reftable.h"
+
+int is_block_type(byte typ)
+{
+ switch (typ) {
+ case BLOCK_TYPE_REF:
+ case BLOCK_TYPE_LOG:
+ case BLOCK_TYPE_OBJ:
+ case BLOCK_TYPE_INDEX:
+ return true;
+ }
+ return false;
+}
+
+int get_var_int(uint64_t *dest, struct slice in)
+{
+ int ptr = 0;
+ uint64_t val;
+
+ if (in.len == 0) {
+ return -1;
+ }
+ val = in.buf[ptr] & 0x7f;
+
+ while (in.buf[ptr] & 0x80) {
+ ptr++;
+ if (ptr > in.len) {
+ return -1;
+ }
+ val = (val + 1) << 7 | (uint64_t)(in.buf[ptr] & 0x7f);
+ }
+
+ *dest = val;
+ return ptr + 1;
+}
+
+int put_var_int(struct slice dest, uint64_t val)
+{
+ byte buf[10] = {};
+ int i = 9;
+ buf[i] = (byte)(val & 0x7f);
+ i--;
+ while (true) {
+ val >>= 7;
+ if (!val) {
+ break;
+ }
+ val--;
+ buf[i] = 0x80 | (byte)(val & 0x7f);
+ i--;
+ }
+
+ {
+ int n = sizeof(buf) - i - 1;
+ if (dest.len < n) {
+ return -1;
+ }
+ memcpy(dest.buf, &buf[i + 1], n);
+ return n;
+ }
+}
+
+int common_prefix_size(struct slice a, struct slice b)
+{
+ int p = 0;
+ while (p < a.len && p < b.len) {
+ if (a.buf[p] != b.buf[p]) {
+ break;
+ }
+ p++;
+ }
+
+ return p;
+}
+
+static int decode_string(struct slice *dest, struct slice in)
+{
+ int start_len = in.len;
+ uint64_t tsize = 0;
+ int n = get_var_int(&tsize, in);
+ if (n <= 0) {
+ return -1;
+ }
+ in.buf += n;
+ in.len -= n;
+ if (in.len < tsize) {
+ return -1;
+ }
+
+ slice_resize(dest, tsize + 1);
+ dest->buf[tsize] = 0;
+ memcpy(dest->buf, in.buf, tsize);
+ in.buf += tsize;
+ in.len -= tsize;
+
+ return start_len - in.len;
+}
+
+int encode_key(bool *restart, struct slice dest, struct slice prev_key,
+ struct slice key, byte extra)
+{
+ struct slice start = dest;
+ int prefix_len = common_prefix_size(prev_key, key);
+ uint64_t suffix_len = key.len - prefix_len;
+ int n = put_var_int(dest, (uint64_t)prefix_len);
+ if (n < 0) {
+ return -1;
+ }
+ dest.buf += n;
+ dest.len -= n;
+
+ *restart = (prefix_len == 0);
+
+ n = put_var_int(dest, suffix_len << 3 | (uint64_t)extra);
+ if (n < 0) {
+ return -1;
+ }
+ dest.buf += n;
+ dest.len -= n;
+
+ if (dest.len < suffix_len) {
+ return -1;
+ }
+ memcpy(dest.buf, key.buf + prefix_len, suffix_len);
+ dest.buf += suffix_len;
+ dest.len -= suffix_len;
+
+ return start.len - dest.len;
+}
+
+static byte ref_record_type(void)
+{
+ return BLOCK_TYPE_REF;
+}
+
+static void ref_record_key(const void *r, struct slice *dest)
+{
+ const struct ref_record *rec = (const struct ref_record *)r;
+ slice_set_string(dest, rec->ref_name);
+}
+
+static void ref_record_copy_from(void *rec, const void *src_rec, int hash_size)
+{
+ struct ref_record *ref = (struct ref_record *)rec;
+ struct ref_record *src = (struct ref_record *)src_rec;
+ assert(hash_size > 0);
+
+ /* This is simple and correct, but we could probably reuse the hash
+ fields. */
+ ref_record_clear(ref);
+ if (src->ref_name != NULL) {
+ ref->ref_name = strdup(src->ref_name);
+ }
+
+ if (src->target != NULL) {
+ ref->target = strdup(src->target);
+ }
+
+ if (src->target_value != NULL) {
+ ref->target_value = malloc(hash_size);
+ memcpy(ref->target_value, src->target_value, hash_size);
+ }
+
+ if (src->value != NULL) {
+ ref->value = malloc(hash_size);
+ memcpy(ref->value, src->value, hash_size);
+ }
+ ref->update_index = src->update_index;
+}
+
+static char hexdigit(int c)
+{
+ if (c <= 9) {
+ return '0' + c;
+ }
+ return 'a' + (c - 10);
+}
+
+static void hex_format(char *dest, byte *src, int hash_size)
+{
+ assert(hash_size > 0);
+ if (src != NULL) {
+ int i = 0;
+ for (i = 0; i < hash_size; i++) {
+ dest[2 * i] = hexdigit(src[i] >> 4);
+ dest[2 * i + 1] = hexdigit(src[i] & 0xf);
+ }
+ dest[2 * hash_size] = 0;
+ }
+}
+
+void ref_record_print(struct ref_record *ref, int hash_size)
+{
+ char hex[SHA256_SIZE + 1] = {};
+
+ printf("ref{%s(%" PRIu64 ") ", ref->ref_name, ref->update_index);
+ if (ref->value != NULL) {
+ hex_format(hex, ref->value, hash_size);
+ printf("%s", hex);
+ }
+ if (ref->target_value != NULL) {
+ hex_format(hex, ref->target_value, hash_size);
+ printf(" (T %s)", hex);
+ }
+ if (ref->target != NULL) {
+ printf("=> %s", ref->target);
+ }
+ printf("}\n");
+}
+
+static void ref_record_clear_void(void *rec)
+{
+ ref_record_clear((struct ref_record *)rec);
+}
+
+void ref_record_clear(struct ref_record *ref)
+{
+ free(ref->ref_name);
+ free(ref->target);
+ free(ref->target_value);
+ free(ref->value);
+ memset(ref, 0, sizeof(struct ref_record));
+}
+
+static byte ref_record_val_type(const void *rec)
+{
+ const struct ref_record *r = (const struct ref_record *)rec;
+ if (r->value != NULL) {
+ if (r->target_value != NULL) {
+ return 2;
+ } else {
+ return 1;
+ }
+ } else if (r->target != NULL) {
+ return 3;
+ }
+ return 0;
+}
+
+static int encode_string(char *str, struct slice s)
+{
+ struct slice start = s;
+ int l = strlen(str);
+ int n = put_var_int(s, l);
+ if (n < 0) {
+ return -1;
+ }
+ s.buf += n;
+ s.len -= n;
+ if (s.len < l) {
+ return -1;
+ }
+ memcpy(s.buf, str, l);
+ s.buf += l;
+ s.len -= l;
+
+ return start.len - s.len;
+}
+
+static int ref_record_encode(const void *rec, struct slice s, int hash_size)
+{
+ const struct ref_record *r = (const struct ref_record *)rec;
+ struct slice start = s;
+ int n = put_var_int(s, r->update_index);
+ assert(hash_size > 0);
+ if (n < 0) {
+ return -1;
+ }
+ s.buf += n;
+ s.len -= n;
+
+ if (r->value != NULL) {
+ if (s.len < hash_size) {
+ return -1;
+ }
+ memcpy(s.buf, r->value, hash_size);
+ s.buf += hash_size;
+ s.len -= hash_size;
+ }
+
+ if (r->target_value != NULL) {
+ if (s.len < hash_size) {
+ return -1;
+ }
+ memcpy(s.buf, r->target_value, hash_size);
+ s.buf += hash_size;
+ s.len -= hash_size;
+ }
+
+ if (r->target != NULL) {
+ int n = encode_string(r->target, s);
+ if (n < 0) {
+ return -1;
+ }
+ s.buf += n;
+ s.len -= n;
+ }
+
+ return start.len - s.len;
+}
+
+static int ref_record_decode(void *rec, struct slice key, byte val_type,
+ struct slice in, int hash_size)
+{
+ struct ref_record *r = (struct ref_record *)rec;
+ struct slice start = in;
+ bool seen_value = false;
+ bool seen_target_value = false;
+ bool seen_target = false;
+
+ int n = get_var_int(&r->update_index, in);
+ if (n < 0) {
+ return n;
+ }
+ assert(hash_size > 0);
+
+ in.buf += n;
+ in.len -= n;
+
+ r->ref_name = realloc(r->ref_name, key.len + 1);
+ memcpy(r->ref_name, key.buf, key.len);
+ r->ref_name[key.len] = 0;
+
+ switch (val_type) {
+ case 1:
+ case 2:
+ if (in.len < hash_size) {
+ return -1;
+ }
+
+ if (r->value == NULL) {
+ r->value = malloc(hash_size);
+ }
+ seen_value = true;
+ memcpy(r->value, in.buf, hash_size);
+ in.buf += hash_size;
+ in.len -= hash_size;
+ if (val_type == 1) {
+ break;
+ }
+ if (r->target_value == NULL) {
+ r->target_value = malloc(hash_size);
+ }
+ seen_target_value = true;
+ memcpy(r->target_value, in.buf, hash_size);
+ in.buf += hash_size;
+ in.len -= hash_size;
+ break;
+ case 3: {
+ struct slice dest = {};
+ int n = decode_string(&dest, in);
+ if (n < 0) {
+ return -1;
+ }
+ in.buf += n;
+ in.len -= n;
+ seen_target = true;
+ r->target = (char *)slice_as_string(&dest);
+ } break;
+
+ case 0:
+ break;
+ default:
+ abort();
+ break;
+ }
+
+ if (!seen_target && r->target != NULL) {
+ FREE_AND_NULL(r->target);
+ }
+ if (!seen_target_value && r->target_value != NULL) {
+ FREE_AND_NULL(r->target_value);
+ }
+ if (!seen_value && r->value != NULL) {
+ FREE_AND_NULL(r->value);
+ }
+
+ return start.len - in.len;
+}
+
+int decode_key(struct slice *key, byte *extra, struct slice last_key,
+ struct slice in)
+{
+ int start_len = in.len;
+ uint64_t prefix_len = 0;
+ uint64_t suffix_len = 0;
+ int n = get_var_int(&prefix_len, in);
+ if (n < 0) {
+ return -1;
+ }
+ in.buf += n;
+ in.len -= n;
+
+ if (prefix_len > last_key.len) {
+ return -1;
+ }
+
+ n = get_var_int(&suffix_len, in);
+ if (n <= 0) {
+ return -1;
+ }
+ in.buf += n;
+ in.len -= n;
+
+ *extra = (byte)(suffix_len & 0x7);
+ suffix_len >>= 3;
+
+ if (in.len < suffix_len) {
+ return -1;
+ }
+
+ slice_resize(key, suffix_len + prefix_len);
+ memcpy(key->buf, last_key.buf, prefix_len);
+
+ memcpy(key->buf + prefix_len, in.buf, suffix_len);
+ in.buf += suffix_len;
+ in.len -= suffix_len;
+
+ return start_len - in.len;
+}
+
+struct record_vtable ref_record_vtable = {
+ .key = &ref_record_key,
+ .type = &ref_record_type,
+ .copy_from = &ref_record_copy_from,
+ .val_type = &ref_record_val_type,
+ .encode = &ref_record_encode,
+ .decode = &ref_record_decode,
+ .clear = &ref_record_clear_void,
+};
+
+static byte obj_record_type(void)
+{
+ return BLOCK_TYPE_OBJ;
+}
+
+static void obj_record_key(const void *r, struct slice *dest)
+{
+ const struct obj_record *rec = (const struct obj_record *)r;
+ slice_resize(dest, rec->hash_prefix_len);
+ memcpy(dest->buf, rec->hash_prefix, rec->hash_prefix_len);
+}
+
+static void obj_record_copy_from(void *rec, const void *src_rec, int hash_size)
+{
+ struct obj_record *ref = (struct obj_record *)rec;
+ const struct obj_record *src = (const struct obj_record *)src_rec;
+
+ *ref = *src;
+ ref->hash_prefix = malloc(ref->hash_prefix_len);
+ memcpy(ref->hash_prefix, src->hash_prefix, ref->hash_prefix_len);
+
+ {
+ int olen = ref->offset_len * sizeof(uint64_t);
+ ref->offsets = malloc(olen);
+ memcpy(ref->offsets, src->offsets, olen);
+ }
+}
+
+static void obj_record_clear(void *rec)
+{
+ struct obj_record *ref = (struct obj_record *)rec;
+ FREE_AND_NULL(ref->hash_prefix);
+ FREE_AND_NULL(ref->offsets);
+ memset(ref, 0, sizeof(struct obj_record));
+}
+
+static byte obj_record_val_type(const void *rec)
+{
+ struct obj_record *r = (struct obj_record *)rec;
+ if (r->offset_len > 0 && r->offset_len < 8) {
+ return r->offset_len;
+ }
+ return 0;
+}
+
+static int obj_record_encode(const void *rec, struct slice s, int hash_size)
+{
+ struct obj_record *r = (struct obj_record *)rec;
+ struct slice start = s;
+ int n = 0;
+ if (r->offset_len == 0 || r->offset_len >= 8) {
+ n = put_var_int(s, r->offset_len);
+ if (n < 0) {
+ return -1;
+ }
+ s.buf += n;
+ s.len -= n;
+ }
+ if (r->offset_len == 0) {
+ return start.len - s.len;
+ }
+ n = put_var_int(s, r->offsets[0]);
+ if (n < 0) {
+ return -1;
+ }
+ s.buf += n;
+ s.len -= n;
+
+ {
+ uint64_t last = r->offsets[0];
+ int i = 0;
+ for (i = 1; i < r->offset_len; i++) {
+ int n = put_var_int(s, r->offsets[i] - last);
+ if (n < 0) {
+ return -1;
+ }
+ s.buf += n;
+ s.len -= n;
+ last = r->offsets[i];
+ }
+ }
+ return start.len - s.len;
+}
+
+static int obj_record_decode(void *rec, struct slice key, byte val_type,
+ struct slice in, int hash_size)
+{
+ struct slice start = in;
+ struct obj_record *r = (struct obj_record *)rec;
+ uint64_t count = val_type;
+ int n = 0;
+ r->hash_prefix = malloc(key.len);
+ memcpy(r->hash_prefix, key.buf, key.len);
+ r->hash_prefix_len = key.len;
+
+ if (val_type == 0) {
+ n = get_var_int(&count, in);
+ if (n < 0) {
+ return n;
+ }
+
+ in.buf += n;
+ in.len -= n;
+ }
+
+ r->offsets = NULL;
+ r->offset_len = 0;
+ if (count == 0) {
+ return start.len - in.len;
+ }
+
+ r->offsets = malloc(count * sizeof(uint64_t));
+ r->offset_len = count;
+
+ n = get_var_int(&r->offsets[0], in);
+ if (n < 0) {
+ return n;
+ }
+
+ in.buf += n;
+ in.len -= n;
+
+ {
+ uint64_t last = r->offsets[0];
+ int j = 1;
+ while (j < count) {
+ uint64_t delta = 0;
+ int n = get_var_int(&delta, in);
+ if (n < 0) {
+ return n;
+ }
+
+ in.buf += n;
+ in.len -= n;
+
+ last = r->offsets[j] = (delta + last);
+ j++;
+ }
+ }
+ return start.len - in.len;
+}
+
+struct record_vtable obj_record_vtable = {
+ .key = &obj_record_key,
+ .type = &obj_record_type,
+ .copy_from = &obj_record_copy_from,
+ .val_type = &obj_record_val_type,
+ .encode = &obj_record_encode,
+ .decode = &obj_record_decode,
+ .clear = &obj_record_clear,
+};
+
+void log_record_print(struct log_record *log, int hash_size)
+{
+ char hex[SHA256_SIZE + 1] = {};
+
+ printf("log{%s(%" PRIu64 ") %s <%s> %" PRIu64 " %04d\n", log->ref_name,
+ log->update_index, log->name, log->email, log->time,
+ log->tz_offset);
+ hex_format(hex, log->old_hash, hash_size);
+ printf("%s => ", hex);
+ hex_format(hex, log->new_hash, hash_size);
+ printf("%s\n\n%s\n}\n", hex, log->message);
+}
+
+static byte log_record_type(void)
+{
+ return BLOCK_TYPE_LOG;
+}
+
+static void log_record_key(const void *r, struct slice *dest)
+{
+ const struct log_record *rec = (const struct log_record *)r;
+ int len = strlen(rec->ref_name);
+ uint64_t ts = 0;
+ slice_resize(dest, len + 9);
+ memcpy(dest->buf, rec->ref_name, len + 1);
+ ts = (~ts) - rec->update_index;
+ put_u64(dest->buf + 1 + len, ts);
+}
+
+static void log_record_copy_from(void *rec, const void *src_rec, int hash_size)
+{
+ struct log_record *dst = (struct log_record *)rec;
+ const struct log_record *src = (const struct log_record *)src_rec;
+
+ *dst = *src;
+ dst->ref_name = strdup(dst->ref_name);
+ dst->email = strdup(dst->email);
+ dst->name = strdup(dst->name);
+ dst->message = strdup(dst->message);
+ if (dst->new_hash != NULL) {
+ dst->new_hash = malloc(hash_size);
+ memcpy(dst->new_hash, src->new_hash, hash_size);
+ }
+ if (dst->old_hash != NULL) {
+ dst->old_hash = malloc(hash_size);
+ memcpy(dst->old_hash, src->old_hash, hash_size);
+ }
+}
+
+static void log_record_clear_void(void *rec)
+{
+ struct log_record *r = (struct log_record *)rec;
+ log_record_clear(r);
+}
+
+void log_record_clear(struct log_record *r)
+{
+ free(r->ref_name);
+ free(r->new_hash);
+ free(r->old_hash);
+ free(r->name);
+ free(r->email);
+ free(r->message);
+ memset(r, 0, sizeof(struct log_record));
+}
+
+static byte log_record_val_type(const void *rec)
+{
+ return 1;
+}
+
+static byte zero[SHA256_SIZE] = {};
+
+static int log_record_encode(const void *rec, struct slice s, int hash_size)
+{
+ struct log_record *r = (struct log_record *)rec;
+ struct slice start = s;
+ int n = 0;
+ byte *oldh = r->old_hash;
+ byte *newh = r->new_hash;
+ if (oldh == NULL) {
+ oldh = zero;
+ }
+ if (newh == NULL) {
+ newh = zero;
+ }
+
+ if (s.len < 2 * hash_size) {
+ return -1;
+ }
+
+ memcpy(s.buf, oldh, hash_size);
+ memcpy(s.buf + hash_size, newh, hash_size);
+ s.buf += 2 * hash_size;
+ s.len -= 2 * hash_size;
+
+ n = encode_string(r->name ? r->name : "", s);
+ if (n < 0) {
+ return -1;
+ }
+ s.len -= n;
+ s.buf += n;
+
+ n = encode_string(r->email ? r->email : "", s);
+ if (n < 0) {
+ return -1;
+ }
+ s.len -= n;
+ s.buf += n;
+
+ n = put_var_int(s, r->time);
+ if (n < 0) {
+ return -1;
+ }
+ s.buf += n;
+ s.len -= n;
+
+ if (s.len < 2) {
+ return -1;
+ }
+
+ put_u16(s.buf, r->tz_offset);
+ s.buf += 2;
+ s.len -= 2;
+
+ n = encode_string(r->message ? r->message : "", s);
+ if (n < 0) {
+ return -1;
+ }
+ s.len -= n;
+ s.buf += n;
+
+ return start.len - s.len;
+}
+
+static int log_record_decode(void *rec, struct slice key, byte val_type,
+ struct slice in, int hash_size)
+{
+ struct slice start = in;
+ struct log_record *r = (struct log_record *)rec;
+ uint64_t max = 0;
+ uint64_t ts = 0;
+ struct slice dest = {};
+ int n;
+
+ if (key.len <= 9 || key.buf[key.len - 9] != 0) {
+ return FORMAT_ERROR;
+ }
+
+ r->ref_name = realloc(r->ref_name, key.len - 8);
+ memcpy(r->ref_name, key.buf, key.len - 8);
+ ts = get_u64(key.buf + key.len - 8);
+
+ r->update_index = (~max) - ts;
+
+ if (in.len < 2 * hash_size) {
+ return FORMAT_ERROR;
+ }
+
+ r->old_hash = realloc(r->old_hash, hash_size);
+ r->new_hash = realloc(r->new_hash, hash_size);
+
+ memcpy(r->old_hash, in.buf, hash_size);
+ memcpy(r->new_hash, in.buf + hash_size, hash_size);
+
+ in.buf += 2 * hash_size;
+ in.len -= 2 * hash_size;
+
+ n = decode_string(&dest, in);
+ if (n < 0) {
+ goto error;
+ }
+ in.len -= n;
+ in.buf += n;
+
+ r->name = realloc(r->name, dest.len + 1);
+ memcpy(r->name, dest.buf, dest.len);
+ r->name[dest.len] = 0;
+
+ slice_resize(&dest, 0);
+ n = decode_string(&dest, in);
+ if (n < 0) {
+ goto error;
+ }
+ in.len -= n;
+ in.buf += n;
+
+ r->email = realloc(r->email, dest.len + 1);
+ memcpy(r->email, dest.buf, dest.len);
+ r->email[dest.len] = 0;
+
+ ts = 0;
+ n = get_var_int(&ts, in);
+ if (n < 0) {
+ goto error;
+ }
+ in.len -= n;
+ in.buf += n;
+ r->time = ts;
+ if (in.len < 2) {
+ goto error;
+ }
+
+ r->tz_offset = get_u16(in.buf);
+ in.buf += 2;
+ in.len -= 2;
+
+ slice_resize(&dest, 0);
+ n = decode_string(&dest, in);
+ if (n < 0) {
+ goto error;
+ }
+ in.len -= n;
+ in.buf += n;
+
+ r->message = realloc(r->message, dest.len + 1);
+ memcpy(r->message, dest.buf, dest.len);
+ r->message[dest.len] = 0;
+
+ return start.len - in.len;
+
+error:
+ free(slice_yield(&dest));
+ return FORMAT_ERROR;
+}
+
+static bool null_streq(char *a, char *b)
+{
+ char *empty = "";
+ if (a == NULL) {
+ a = empty;
+ }
+ if (b == NULL) {
+ b = empty;
+ }
+ return 0 == strcmp(a, b);
+}
+
+static bool zero_hash_eq(byte *a, byte *b, int sz)
+{
+ if (a == NULL) {
+ a = zero;
+ }
+ if (b == NULL) {
+ b = zero;
+ }
+ return !memcmp(a, b, sz);
+}
+
+bool log_record_equal(struct log_record *a, struct log_record *b, int hash_size)
+{
+ return null_streq(a->name, b->name) && null_streq(a->email, b->email) &&
+ null_streq(a->message, b->message) &&
+ zero_hash_eq(a->old_hash, b->old_hash, hash_size) &&
+ zero_hash_eq(a->new_hash, b->new_hash, hash_size) &&
+ a->time == b->time && a->tz_offset == b->tz_offset &&
+ a->update_index == b->update_index;
+}
+
+struct record_vtable log_record_vtable = {
+ .key = &log_record_key,
+ .type = &log_record_type,
+ .copy_from = &log_record_copy_from,
+ .val_type = &log_record_val_type,
+ .encode = &log_record_encode,
+ .decode = &log_record_decode,
+ .clear = &log_record_clear_void,
+};
+
+struct record new_record(byte typ)
+{
+ struct record rec;
+ switch (typ) {
+ case BLOCK_TYPE_REF: {
+ struct ref_record *r = calloc(1, sizeof(struct ref_record));
+ record_from_ref(&rec, r);
+ return rec;
+ }
+
+ case BLOCK_TYPE_OBJ: {
+ struct obj_record *r = calloc(1, sizeof(struct obj_record));
+ record_from_obj(&rec, r);
+ return rec;
+ }
+ case BLOCK_TYPE_LOG: {
+ struct log_record *r = calloc(1, sizeof(struct log_record));
+ record_from_log(&rec, r);
+ return rec;
+ }
+ case BLOCK_TYPE_INDEX: {
+ struct index_record *r = calloc(1, sizeof(struct index_record));
+ record_from_index(&rec, r);
+ return rec;
+ }
+ }
+ abort();
+ return rec;
+}
+
+static byte index_record_type(void)
+{
+ return BLOCK_TYPE_INDEX;
+}
+
+static void index_record_key(const void *r, struct slice *dest)
+{
+ struct index_record *rec = (struct index_record *)r;
+ slice_copy(dest, rec->last_key);
+}
+
+static void index_record_copy_from(void *rec, const void *src_rec,
+ int hash_size)
+{
+ struct index_record *dst = (struct index_record *)rec;
+ struct index_record *src = (struct index_record *)src_rec;
+
+ slice_copy(&dst->last_key, src->last_key);
+ dst->offset = src->offset;
+}
+
+static void index_record_clear(void *rec)
+{
+ struct index_record *idx = (struct index_record *)rec;
+ free(slice_yield(&idx->last_key));
+}
+
+static byte index_record_val_type(const void *rec)
+{
+ return 0;
+}
+
+static int index_record_encode(const void *rec, struct slice out, int hash_size)
+{
+ const struct index_record *r = (const struct index_record *)rec;
+ struct slice start = out;
+
+ int n = put_var_int(out, r->offset);
+ if (n < 0) {
+ return n;
+ }
+
+ out.buf += n;
+ out.len -= n;
+
+ return start.len - out.len;
+}
+
+static int index_record_decode(void *rec, struct slice key, byte val_type,
+ struct slice in, int hash_size)
+{
+ struct slice start = in;
+ struct index_record *r = (struct index_record *)rec;
+ int n = 0;
+
+ slice_copy(&r->last_key, key);
+
+ n = get_var_int(&r->offset, in);
+ if (n < 0) {
+ return n;
+ }
+
+ in.buf += n;
+ in.len -= n;
+ return start.len - in.len;
+}
+
+struct record_vtable index_record_vtable = {
+ .key = &index_record_key,
+ .type = &index_record_type,
+ .copy_from = &index_record_copy_from,
+ .val_type = &index_record_val_type,
+ .encode = &index_record_encode,
+ .decode = &index_record_decode,
+ .clear = &index_record_clear,
+};
+
+void record_key(struct record rec, struct slice *dest)
+{
+ rec.ops->key(rec.data, dest);
+}
+
+byte record_type(struct record rec)
+{
+ return rec.ops->type();
+}
+
+int record_encode(struct record rec, struct slice dest, int hash_size)
+{
+ return rec.ops->encode(rec.data, dest, hash_size);
+}
+
+void record_copy_from(struct record rec, struct record src, int hash_size)
+{
+ assert(src.ops->type() == rec.ops->type());
+
+ rec.ops->copy_from(rec.data, src.data, hash_size);
+}
+
+byte record_val_type(struct record rec)
+{
+ return rec.ops->val_type(rec.data);
+}
+
+int record_decode(struct record rec, struct slice key, byte extra,
+ struct slice src, int hash_size)
+{
+ return rec.ops->decode(rec.data, key, extra, src, hash_size);
+}
+
+void record_clear(struct record rec)
+{
+ return rec.ops->clear(rec.data);
+}
+
+void record_from_ref(struct record *rec, struct ref_record *ref_rec)
+{
+ rec->data = ref_rec;
+ rec->ops = &ref_record_vtable;
+}
+
+void record_from_obj(struct record *rec, struct obj_record *obj_rec)
+{
+ rec->data = obj_rec;
+ rec->ops = &obj_record_vtable;
+}
+
+void record_from_index(struct record *rec, struct index_record *index_rec)
+{
+ rec->data = index_rec;
+ rec->ops = &index_record_vtable;
+}
+
+void record_from_log(struct record *rec, struct log_record *log_rec)
+{
+ rec->data = log_rec;
+ rec->ops = &log_record_vtable;
+}
+
+void *record_yield(struct record *rec)
+{
+ void *p = rec->data;
+ rec->data = NULL;
+ return p;
+}
+
+struct ref_record *record_as_ref(struct record rec)
+{
+ assert(record_type(rec) == BLOCK_TYPE_REF);
+ return (struct ref_record *)rec.data;
+}
+
+static bool hash_equal(byte *a, byte *b, int hash_size)
+{
+ if (a != NULL && b != NULL) {
+ return !memcmp(a, b, hash_size);
+ }
+
+ return a == b;
+}
+
+static bool str_equal(char *a, char *b)
+{
+ if (a != NULL && b != NULL) {
+ return 0 == strcmp(a, b);
+ }
+
+ return a == b;
+}
+
+bool ref_record_equal(struct ref_record *a, struct ref_record *b, int hash_size)
+{
+ assert(hash_size > 0);
+ return 0 == strcmp(a->ref_name, b->ref_name) &&
+ a->update_index == b->update_index &&
+ hash_equal(a->value, b->value, hash_size) &&
+ hash_equal(a->target_value, b->target_value, hash_size) &&
+ str_equal(a->target, b->target);
+}
+
+int ref_record_compare_name(const void *a, const void *b)
+{
+ return strcmp(((struct ref_record *)a)->ref_name,
+ ((struct ref_record *)b)->ref_name);
+}
+
+bool ref_record_is_deletion(const struct ref_record *ref)
+{
+ return ref->value == NULL && ref->target == NULL &&
+ ref->target_value == NULL;
+}
+
+int log_record_compare_key(const void *a, const void *b)
+{
+ struct log_record *la = (struct log_record *)a;
+ struct log_record *lb = (struct log_record *)b;
+
+ int cmp = strcmp(la->ref_name, lb->ref_name);
+ if (cmp) {
+ return cmp;
+ }
+ if (la->update_index > lb->update_index) {
+ return -1;
+ }
+ return (la->update_index < lb->update_index) ? 1 : 0;
+}
+
+bool log_record_is_deletion(const struct log_record *log)
+{
+ /* XXX */
+ return false;
+}
new file mode 100644
@@ -0,0 +1,79 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef RECORD_H
+#define RECORD_H
+
+#include "reftable.h"
+#include "slice.h"
+
+struct record_vtable {
+ void (*key)(const void *rec, struct slice *dest);
+ byte (*type)(void);
+ void (*copy_from)(void *rec, const void *src, int hash_size);
+ byte (*val_type)(const void *rec);
+ int (*encode)(const void *rec, struct slice dest, int hash_size);
+ int (*decode)(void *rec, struct slice key, byte extra, struct slice src,
+ int hash_size);
+ void (*clear)(void *rec);
+};
+
+/* record is a generic wrapper for differnt types of records. */
+struct record {
+ void *data;
+ struct record_vtable *ops;
+};
+
+int get_var_int(uint64_t *dest, struct slice in);
+int put_var_int(struct slice dest, uint64_t val);
+int common_prefix_size(struct slice a, struct slice b);
+
+int is_block_type(byte typ);
+struct record new_record(byte typ);
+
+extern struct record_vtable ref_record_vtable;
+
+int encode_key(bool *restart, struct slice dest, struct slice prev_key,
+ struct slice key, byte extra);
+int decode_key(struct slice *key, byte *extra, struct slice last_key,
+ struct slice in);
+
+struct index_record {
+ struct slice last_key;
+ uint64_t offset;
+};
+
+struct obj_record {
+ byte *hash_prefix;
+ int hash_prefix_len;
+ uint64_t *offsets;
+ int offset_len;
+};
+
+void record_key(struct record rec, struct slice *dest);
+byte record_type(struct record rec);
+void record_copy_from(struct record rec, struct record src, int hash_size);
+byte record_val_type(struct record rec);
+int record_encode(struct record rec, struct slice dest, int hash_size);
+int record_decode(struct record rec, struct slice key, byte extra,
+ struct slice src, int hash_size);
+void record_clear(struct record rec);
+void *record_yield(struct record *rec);
+void record_from_obj(struct record *rec, struct obj_record *objrec);
+void record_from_index(struct record *rec, struct index_record *idxrec);
+void record_from_ref(struct record *rec, struct ref_record *refrec);
+void record_from_log(struct record *rec, struct log_record *logrec);
+struct ref_record *record_as_ref(struct record ref);
+
+/* for qsort. */
+int ref_record_compare_name(const void *a, const void *b);
+
+/* for qsort. */
+int log_record_compare_key(const void *a, const void *b);
+
+#endif
new file mode 100644
@@ -0,0 +1,399 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef REFTABLE_H
+#define REFTABLE_H
+
+#include "system.h"
+
+typedef uint8_t byte;
+typedef byte bool;
+
+/* block_source is a generic wrapper for a seekable readable file.
+ It is generally passed around by value.
+ */
+struct block_source {
+ struct block_source_vtable *ops;
+ void *arg;
+};
+
+/* a contiguous segment of bytes. It keeps track of its generating block_source
+ so it can return itself into the pool.
+*/
+struct block {
+ byte *data;
+ int len;
+ struct block_source source;
+};
+
+/* block_source_vtable are the operations that make up block_source */
+struct block_source_vtable {
+ /* returns the size of a block source */
+ uint64_t (*size)(void *source);
+
+ /* reads a segment from the block source. It is an error to read
+ beyond the end of the block */
+ int (*read_block)(void *source, struct block *dest, uint64_t off,
+ uint32_t size);
+ /* mark the block as read; may return the data back to malloc */
+ void (*return_block)(void *source, struct block *blockp);
+
+ /* release all resources associated with the block source */
+ void (*close)(void *source);
+};
+
+/* opens a file on the file system as a block_source */
+int block_source_from_file(struct block_source *block_src, const char *name);
+
+/* write_options sets options for writing a single reftable. */
+struct write_options {
+ /* do not pad out blocks to block size. */
+ bool unpadded;
+
+ /* the blocksize. Should be less than 2^24. */
+ uint32_t block_size;
+
+ /* do not generate a SHA1 => ref index. */
+ bool skip_index_objects;
+
+ /* how often to write complete keys in each block. */
+ int restart_interval;
+};
+
+/* ref_record holds a ref database entry target_value */
+struct ref_record {
+ char *ref_name; /* Name of the ref, malloced. */
+ uint64_t update_index; /* Logical timestamp at which this value is
+ written */
+ byte *value; /* SHA1, or NULL. malloced. */
+ byte *target_value; /* peeled annotated tag, or NULL. malloced. */
+ char *target; /* symref, or NULL. malloced. */
+};
+
+/* returns whether 'ref' represents a deletion */
+bool ref_record_is_deletion(const struct ref_record *ref);
+
+/* prints a ref_record onto stdout */
+void ref_record_print(struct ref_record *ref, int hash_size);
+
+/* frees and nulls all pointer values. */
+void ref_record_clear(struct ref_record *ref);
+
+/* returns whether two ref_records are the same */
+bool ref_record_equal(struct ref_record *a, struct ref_record *b,
+ int hash_size);
+
+/* log_record holds a reflog entry */
+struct log_record {
+ char *ref_name;
+ uint64_t update_index;
+ byte *new_hash;
+ byte *old_hash;
+ char *name;
+ char *email;
+ uint64_t time;
+ int16_t tz_offset;
+ char *message;
+};
+
+/* returns whether 'ref' represents the deletion of a log record. */
+bool log_record_is_deletion(const struct log_record *log);
+
+/* frees and nulls all pointer values. */
+void log_record_clear(struct log_record *log);
+
+/* returns whether two records are equal. */
+bool log_record_equal(struct log_record *a, struct log_record *b,
+ int hash_size);
+
+void log_record_print(struct log_record *log, int hash_size);
+
+/* iterator is the generic interface for walking over data stored in a
+ reftable. It is generally passed around by value.
+*/
+struct iterator {
+ struct iterator_vtable *ops;
+ void *iter_arg;
+};
+
+/* reads the next ref_record. Returns < 0 for error, 0 for OK and > 0:
+ end of iteration.
+*/
+int iterator_next_ref(struct iterator it, struct ref_record *ref);
+
+/* reads the next log_record. Returns < 0 for error, 0 for OK and > 0:
+ end of iteration.
+*/
+int iterator_next_log(struct iterator it, struct log_record *log);
+
+/* releases resources associated with an iterator. */
+void iterator_destroy(struct iterator *it);
+
+/* block_stats holds statistics for a single block type */
+struct block_stats {
+ /* total number of entries written */
+ int entries;
+ /* total number of key restarts */
+ int restarts;
+ /* total number of blocks */
+ int blocks;
+ /* total number of index blocks */
+ int index_blocks;
+ /* depth of the index */
+ int max_index_level;
+
+ /* offset of the first block for this type */
+ uint64_t offset;
+ /* offset of the top level index block for this type, or 0 if not
+ * present */
+ uint64_t index_offset;
+};
+
+/* stats holds overall statistics for a single reftable */
+struct stats {
+ /* total number of blocks written. */
+ int blocks;
+ /* stats for ref data */
+ struct block_stats ref_stats;
+ /* stats for the SHA1 to ref map. */
+ struct block_stats obj_stats;
+ /* stats for index blocks */
+ struct block_stats idx_stats;
+ /* stats for log blocks */
+ struct block_stats log_stats;
+
+ /* disambiguation length of shortened object IDs. */
+ int object_id_len;
+};
+
+/* different types of errors */
+
+/* Unexpected file system behavior */
+#define IO_ERROR -2
+
+/* Format inconsistency on reading data
+ */
+#define FORMAT_ERROR -3
+
+/* File does not exist. Returned from block_source_from_file(), because it
+ needs special handling in stack.
+*/
+#define NOT_EXIST_ERROR -4
+
+/* Trying to write out-of-date data. */
+#define LOCK_ERROR -5
+
+/* Misuse of the API:
+ - on writing a record with NULL ref_name.
+ - on writing a ref_record outside the table limits
+ - on writing a ref or log record before the stack's next_update_index
+ - on reading a ref_record from log iterator, or vice versa.
+ */
+#define API_ERROR -6
+
+/* Decompression error */
+#define ZLIB_ERROR -7
+
+const char *error_str(int err);
+
+/* new_writer creates a new writer */
+struct writer *new_writer(int (*writer_func)(void *, byte *, int),
+ void *writer_arg, struct write_options *opts);
+
+/* write to a file descriptor. fdp should be an int* pointing to the fd. */
+int fd_writer(void *fdp, byte *data, int size);
+
+/* Set the range of update indices for the records we will add. When
+ writing a table into a stack, the min should be at least
+ stack_next_update_index(), or API_ERROR is returned.
+ */
+void writer_set_limits(struct writer *w, uint64_t min, uint64_t max);
+
+/* adds a ref_record. Must be called in ascending
+ order. The update_index must be within the limits set by
+ writer_set_limits(), or API_ERROR is returned.
+ */
+int writer_add_ref(struct writer *w, struct ref_record *ref);
+
+/* Convenience function to add multiple refs. Will sort the refs by
+ name before adding. */
+int writer_add_refs(struct writer *w, struct ref_record *refs, int n);
+
+/* adds a log_record. Must be called in ascending order (with more
+ recent log entries first.)
+ */
+int writer_add_log(struct writer *w, struct log_record *log);
+
+/* Convenience function to add multiple logs. Will sort the records by
+ key before adding. */
+int writer_add_logs(struct writer *w, struct log_record *logs, int n);
+
+/* writer_close finalizes the reftable. The writer is retained so statistics can
+ * be inspected. */
+int writer_close(struct writer *w);
+
+/* writer_stats returns the statistics on the reftable being written. */
+struct stats *writer_stats(struct writer *w);
+
+/* writer_free deallocates memory for the writer */
+void writer_free(struct writer *w);
+
+struct reader;
+
+/* new_reader opens a reftable for reading. If successful, returns 0
+ * code and sets pp. The name is used for creating a
+ * stack. Typically, it is the basename of the file.
+ */
+int new_reader(struct reader **pp, struct block_source, const char *name);
+
+/* reader_seek_ref returns an iterator where 'name' would be inserted in the
+ table.
+
+ example:
+
+ struct reader *r = NULL;
+ int err = new_reader(&r, src, "filename");
+ if (err < 0) { ... }
+ struct iterator it = {};
+ err = reader_seek_ref(r, &it, "refs/heads/master");
+ if (err < 0) { ... }
+ struct ref_record ref = {};
+ while (1) {
+ err = iterator_next_ref(it, &ref);
+ if (err > 0) {
+ break;
+ }
+ if (err < 0) {
+ ..error handling..
+ }
+ ..found..
+ }
+ iterator_destroy(&it);
+ ref_record_clear(&ref);
+ */
+int reader_seek_ref(struct reader *r, struct iterator *it, const char *name);
+
+/* seek to logs for the given name, older than update_index. */
+int reader_seek_log_at(struct reader *r, struct iterator *it, const char *name,
+ uint64_t update_index);
+
+/* seek to newest log entry for given name. */
+int reader_seek_log(struct reader *r, struct iterator *it, const char *name);
+
+/* closes and deallocates a reader. */
+void reader_free(struct reader *);
+
+/* return an iterator for the refs pointing to oid */
+int reader_refs_for(struct reader *r, struct iterator *it, byte *oid,
+ int oid_len);
+
+/* return the max_update_index for a table */
+uint64_t reader_max_update_index(struct reader *r);
+
+/* return the min_update_index for a table */
+uint64_t reader_min_update_index(struct reader *r);
+
+/* a merged table is implements seeking/iterating over a stack of tables. */
+struct merged_table;
+
+/* new_merged_table creates a new merged table. It takes ownership of the stack
+ array.
+*/
+int new_merged_table(struct merged_table **dest, struct reader **stack, int n);
+
+/* returns an iterator positioned just before 'name' */
+int merged_table_seek_ref(struct merged_table *mt, struct iterator *it,
+ const char *name);
+
+/* returns an iterator for log entry, at given update_index */
+int merged_table_seek_log_at(struct merged_table *mt, struct iterator *it,
+ const char *name, uint64_t update_index);
+
+/* like merged_table_seek_log_at but look for the newest entry. */
+int merged_table_seek_log(struct merged_table *mt, struct iterator *it,
+ const char *name);
+
+/* returns the max update_index covered by this merged table. */
+uint64_t merged_max_update_index(struct merged_table *mt);
+
+/* returns the min update_index covered by this merged table. */
+uint64_t merged_min_update_index(struct merged_table *mt);
+
+/* closes readers for the merged tables */
+void merged_table_close(struct merged_table *mt);
+
+/* releases memory for the merged_table */
+void merged_table_free(struct merged_table *m);
+
+/* a stack is a stack of reftables, which can be mutated by pushing a table to
+ * the top of the stack */
+struct stack;
+
+/* open a new reftable stack. The tables will be stored in 'dir', while the list
+ of tables is in 'list_file'. Typically, this should be .git/reftables and
+ .git/refs respectively.
+*/
+int new_stack(struct stack **dest, const char *dir, const char *list_file,
+ struct write_options config);
+
+/* returns the update_index at which a next table should be written. */
+uint64_t stack_next_update_index(struct stack *st);
+
+/* add a new table to the stack. The write_table function must call
+ writer_set_limits, add refs and return an error value. */
+int stack_add(struct stack *st,
+ int (*write_table)(struct writer *wr, void *write_arg),
+ void *write_arg);
+
+/* returns the merged_table for seeking. This table is valid until the
+ next write or reload, and should not be closed or deleted.
+*/
+struct merged_table *stack_merged_table(struct stack *st);
+
+/* frees all resources associated with the stack. */
+void stack_destroy(struct stack *st);
+
+/* reloads the stack if necessary. */
+int stack_reload(struct stack *st);
+
+/* Policy for expiring reflog entries. */
+struct log_expiry_config {
+ /* Drop entries older than this timestamp */
+ uint64_t time;
+
+ /* Drop older entries */
+ uint64_t min_update_index;
+};
+
+/* compacts all reftables into a giant table. Expire reflog entries if config is
+ * non-NULL */
+int stack_compact_all(struct stack *st, struct log_expiry_config *config);
+
+/* heuristically compact unbalanced table stack. */
+int stack_auto_compact(struct stack *st);
+
+/* convenience function to read a single ref. Returns < 0 for error, 0
+ for success, and 1 if ref not found. */
+int stack_read_ref(struct stack *st, const char *refname,
+ struct ref_record *ref);
+
+/* convenience function to read a single log. Returns < 0 for error, 0
+ for success, and 1 if ref not found. */
+int stack_read_log(struct stack *st, const char *refname,
+ struct log_record *log);
+
+/* statistics on past compactions. */
+struct compaction_stats {
+ uint64_t bytes;
+ int attempts;
+ int failures;
+};
+
+struct compaction_stats *stack_compaction_stats(struct stack *st);
+
+#endif
new file mode 100644
@@ -0,0 +1,199 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "slice.h"
+
+#include "system.h"
+
+#include "reftable.h"
+
+void slice_set_string(struct slice *s, const char *str)
+{
+ if (str == NULL) {
+ s->len = 0;
+ return;
+ }
+
+ {
+ int l = strlen(str);
+ l++; /* \0 */
+ slice_resize(s, l);
+ memcpy(s->buf, str, l);
+ s->len = l - 1;
+ }
+}
+
+void slice_resize(struct slice *s, int l)
+{
+ if (s->cap < l) {
+ int c = s->cap * 2;
+ if (c < l) {
+ c = l;
+ }
+ s->cap = c;
+ s->buf = realloc(s->buf, s->cap);
+ }
+ s->len = l;
+}
+
+void slice_append_string(struct slice *d, const char *s)
+{
+ int l1 = d->len;
+ int l2 = strlen(s);
+
+ slice_resize(d, l2 + l1);
+ memcpy(d->buf + l1, s, l2);
+}
+
+void slice_append(struct slice *s, struct slice a)
+{
+ int end = s->len;
+ slice_resize(s, s->len + a.len);
+ memcpy(s->buf + end, a.buf, a.len);
+}
+
+byte *slice_yield(struct slice *s)
+{
+ byte *p = s->buf;
+ s->buf = NULL;
+ s->cap = 0;
+ s->len = 0;
+ return p;
+}
+
+void slice_copy(struct slice *dest, struct slice src)
+{
+ slice_resize(dest, src.len);
+ memcpy(dest->buf, src.buf, src.len);
+}
+
+/* return the underlying data as char*. len is left unchanged, but
+ a \0 is added at the end. */
+const char *slice_as_string(struct slice *s)
+{
+ if (s->cap == s->len) {
+ int l = s->len;
+ slice_resize(s, l + 1);
+ s->len = l;
+ }
+ s->buf[s->len] = 0;
+ return (const char *)s->buf;
+}
+
+/* return a newly malloced string for this slice */
+char *slice_to_string(struct slice in)
+{
+ struct slice s = {};
+ slice_resize(&s, in.len + 1);
+ s.buf[in.len] = 0;
+ memcpy(s.buf, in.buf, in.len);
+ return (char *)slice_yield(&s);
+}
+
+bool slice_equal(struct slice a, struct slice b)
+{
+ if (a.len != b.len) {
+ return 0;
+ }
+ return memcmp(a.buf, b.buf, a.len) == 0;
+}
+
+int slice_compare(struct slice a, struct slice b)
+{
+ int min = a.len < b.len ? a.len : b.len;
+ int res = memcmp(a.buf, b.buf, min);
+ if (res != 0) {
+ return res;
+ }
+ if (a.len < b.len) {
+ return -1;
+ } else if (a.len > b.len) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+int slice_write(struct slice *b, byte *data, int sz)
+{
+ if (b->len + sz > b->cap) {
+ int newcap = 2 * b->cap + 1;
+ if (newcap < b->len + sz) {
+ newcap = (b->len + sz);
+ }
+ b->buf = realloc(b->buf, newcap);
+ b->cap = newcap;
+ }
+
+ memcpy(b->buf + b->len, data, sz);
+ b->len += sz;
+ return sz;
+}
+
+int slice_write_void(void *b, byte *data, int sz)
+{
+ return slice_write((struct slice *)b, data, sz);
+}
+
+static uint64_t slice_size(void *b)
+{
+ return ((struct slice *)b)->len;
+}
+
+static void slice_return_block(void *b, struct block *dest)
+{
+ memset(dest->data, 0xff, dest->len);
+ free(dest->data);
+}
+
+static void slice_close(void *b)
+{
+}
+
+static int slice_read_block(void *v, struct block *dest, uint64_t off,
+ uint32_t size)
+{
+ struct slice *b = (struct slice *)v;
+ assert(off + size <= b->len);
+ dest->data = calloc(size, 1);
+ memcpy(dest->data, b->buf + off, size);
+ dest->len = size;
+ return size;
+}
+
+struct block_source_vtable slice_vtable = {
+ .size = &slice_size,
+ .read_block = &slice_read_block,
+ .return_block = &slice_return_block,
+ .close = &slice_close,
+};
+
+void block_source_from_slice(struct block_source *bs, struct slice *buf)
+{
+ bs->ops = &slice_vtable;
+ bs->arg = buf;
+}
+
+static void malloc_return_block(void *b, struct block *dest)
+{
+ memset(dest->data, 0xff, dest->len);
+ free(dest->data);
+}
+
+struct block_source_vtable malloc_vtable = {
+ .return_block = &malloc_return_block,
+};
+
+struct block_source malloc_block_source_instance = {
+ .ops = &malloc_vtable,
+};
+
+struct block_source malloc_block_source(void)
+{
+ return malloc_block_source_instance;
+}
new file mode 100644
@@ -0,0 +1,39 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef SLICE_H
+#define SLICE_H
+
+#include "basics.h"
+#include "reftable.h"
+
+struct slice {
+ byte *buf;
+ int len;
+ int cap;
+};
+
+void slice_set_string(struct slice *dest, const char *);
+void slice_append_string(struct slice *dest, const char *);
+char *slice_to_string(struct slice src);
+const char *slice_as_string(struct slice *src);
+bool slice_equal(struct slice a, struct slice b);
+byte *slice_yield(struct slice *s);
+void slice_copy(struct slice *dest, struct slice src);
+void slice_resize(struct slice *s, int l);
+int slice_compare(struct slice a, struct slice b);
+int slice_write(struct slice *b, byte *data, int sz);
+int slice_write_void(void *b, byte *data, int sz);
+void slice_append(struct slice *dest, struct slice add);
+
+struct block_source;
+void block_source_from_slice(struct block_source *bs, struct slice *buf);
+
+struct block_source malloc_block_source(void);
+
+#endif
new file mode 100644
@@ -0,0 +1,983 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "stack.h"
+
+#include "system.h"
+#include "merged.h"
+#include "reader.h"
+#include "reftable.h"
+#include "writer.h"
+
+int new_stack(struct stack **dest, const char *dir, const char *list_file,
+ struct write_options config)
+{
+ struct stack *p = calloc(sizeof(struct stack), 1);
+ int err = 0;
+ *dest = NULL;
+ p->list_file = strdup(list_file);
+ p->reftable_dir = strdup(dir);
+ p->config = config;
+
+ err = stack_reload(p);
+ if (err < 0) {
+ stack_destroy(p);
+ } else {
+ *dest = p;
+ }
+ return err;
+}
+
+static int fread_lines(FILE *f, char ***namesp)
+{
+ long size = 0;
+ int err = fseek(f, 0, SEEK_END);
+ char *buf = NULL;
+ if (err < 0) {
+ err = IO_ERROR;
+ goto exit;
+ }
+ size = ftell(f);
+ if (size < 0) {
+ err = IO_ERROR;
+ goto exit;
+ }
+ err = fseek(f, 0, SEEK_SET);
+ if (err < 0) {
+ err = IO_ERROR;
+ goto exit;
+ }
+
+ buf = malloc(size + 1);
+ if (fread(buf, 1, size, f) != size) {
+ err = IO_ERROR;
+ goto exit;
+ }
+ buf[size] = 0;
+
+ parse_names(buf, size, namesp);
+exit:
+ free(buf);
+ return err;
+}
+
+int read_lines(const char *filename, char ***namesp)
+{
+ FILE *f = fopen(filename, "r");
+ int err = 0;
+ if (f == NULL) {
+ if (errno == ENOENT) {
+ *namesp = calloc(sizeof(char *), 1);
+ return 0;
+ }
+
+ return IO_ERROR;
+ }
+ err = fread_lines(f, namesp);
+ fclose(f);
+ return err;
+}
+
+struct merged_table *stack_merged_table(struct stack *st)
+{
+ return st->merged;
+}
+
+/* Close and free the stack */
+void stack_destroy(struct stack *st)
+{
+ if (st->merged == NULL) {
+ return;
+ }
+
+ merged_table_close(st->merged);
+ merged_table_free(st->merged);
+ st->merged = NULL;
+
+ FREE_AND_NULL(st->list_file);
+ FREE_AND_NULL(st->reftable_dir);
+ free(st);
+}
+
+static struct reader **stack_copy_readers(struct stack *st, int cur_len)
+{
+ struct reader **cur = calloc(sizeof(struct reader *), cur_len);
+ int i = 0;
+ for (i = 0; i < cur_len; i++) {
+ cur[i] = st->merged->stack[i];
+ }
+ return cur;
+}
+
+static int stack_reload_once(struct stack *st, char **names, bool reuse_open)
+{
+ int cur_len = st->merged == NULL ? 0 : st->merged->stack_len;
+ struct reader **cur = stack_copy_readers(st, cur_len);
+ int err = 0;
+ int names_len = names_length(names);
+ struct reader **new_tables =
+ malloc(sizeof(struct reader *) * names_len);
+ int new_tables_len = 0;
+ struct merged_table *new_merged = NULL;
+
+ struct slice table_path = {};
+
+ while (*names) {
+ struct reader *rd = NULL;
+ char *name = *names++;
+
+ /* this is linear; we assume compaction keeps the number of
+ tables under control so this is not quadratic. */
+ int j = 0;
+ for (j = 0; reuse_open && j < cur_len; j++) {
+ if (cur[j] != NULL && 0 == strcmp(cur[j]->name, name)) {
+ rd = cur[j];
+ cur[j] = NULL;
+ break;
+ }
+ }
+
+ if (rd == NULL) {
+ struct block_source src = {};
+ slice_set_string(&table_path, st->reftable_dir);
+ slice_append_string(&table_path, "/");
+ slice_append_string(&table_path, name);
+
+ err = block_source_from_file(
+ &src, slice_as_string(&table_path));
+ if (err < 0) {
+ goto exit;
+ }
+
+ err = new_reader(&rd, src, name);
+ if (err < 0) {
+ goto exit;
+ }
+ }
+
+ new_tables[new_tables_len++] = rd;
+ }
+
+ /* success! */
+ err = new_merged_table(&new_merged, new_tables, new_tables_len);
+ if (err < 0) {
+ goto exit;
+ }
+
+ new_tables = NULL;
+ new_tables_len = 0;
+ if (st->merged != NULL) {
+ merged_table_clear(st->merged);
+ merged_table_free(st->merged);
+ }
+ st->merged = new_merged;
+
+ {
+ int i = 0;
+ for (i = 0; i < cur_len; i++) {
+ if (cur[i] != NULL) {
+ reader_close(cur[i]);
+ reader_free(cur[i]);
+ }
+ }
+ }
+exit:
+ free(slice_yield(&table_path));
+ {
+ int i = 0;
+ for (i = 0; i < new_tables_len; i++) {
+ reader_close(new_tables[i]);
+ }
+ }
+ free(new_tables);
+ free(cur);
+ return err;
+}
+
+/* return negative if a before b. */
+static int tv_cmp(struct timeval *a, struct timeval *b)
+{
+ time_t diff = a->tv_sec - b->tv_sec;
+ int udiff = a->tv_usec - b->tv_usec;
+
+ if (diff != 0) {
+ return diff;
+ }
+
+ return udiff;
+}
+
+static int stack_reload_maybe_reuse(struct stack *st, bool reuse_open)
+{
+ struct timeval deadline = {};
+ int err = gettimeofday(&deadline, NULL);
+ int64_t delay = 0;
+ int tries = 0;
+ if (err < 0) {
+ return err;
+ }
+
+ deadline.tv_sec += 3;
+ while (true) {
+ char **names = NULL;
+ char **names_after = NULL;
+ struct timeval now = {};
+ int err = gettimeofday(&now, NULL);
+ if (err < 0) {
+ return err;
+ }
+
+ /* Only look at deadlines after the first few times. This
+ simplifies debugging in GDB */
+ tries++;
+ if (tries > 3 && tv_cmp(&now, &deadline) >= 0) {
+ break;
+ }
+
+ err = read_lines(st->list_file, &names);
+ if (err < 0) {
+ free_names(names);
+ return err;
+ }
+ err = stack_reload_once(st, names, reuse_open);
+ if (err == 0) {
+ free_names(names);
+ break;
+ }
+ if (err != NOT_EXIST_ERROR) {
+ free_names(names);
+ return err;
+ }
+
+ err = read_lines(st->list_file, &names_after);
+ if (err < 0) {
+ free_names(names);
+ return err;
+ }
+
+ if (names_equal(names_after, names)) {
+ free_names(names);
+ free_names(names_after);
+ return -1;
+ }
+ free_names(names);
+ free_names(names_after);
+
+ delay = delay + (delay * rand()) / RAND_MAX + 100;
+ usleep(delay);
+ }
+
+ return 0;
+}
+
+int stack_reload(struct stack *st)
+{
+ return stack_reload_maybe_reuse(st, true);
+}
+
+/* -1 = error
+ 0 = up to date
+ 1 = changed. */
+static int stack_uptodate(struct stack *st)
+{
+ char **names = NULL;
+ int err = read_lines(st->list_file, &names);
+ int i = 0;
+ if (err < 0) {
+ return err;
+ }
+
+ for (i = 0; i < st->merged->stack_len; i++) {
+ if (names[i] == NULL) {
+ err = 1;
+ goto exit;
+ }
+
+ if (strcmp(st->merged->stack[i]->name, names[i])) {
+ err = 1;
+ goto exit;
+ }
+ }
+
+ if (names[st->merged->stack_len] != NULL) {
+ err = 1;
+ goto exit;
+ }
+
+exit:
+ free_names(names);
+ return err;
+}
+
+int stack_add(struct stack *st, int (*write)(struct writer *wr, void *arg),
+ void *arg)
+{
+ int err = stack_try_add(st, write, arg);
+ if (err < 0) {
+ if (err == LOCK_ERROR) {
+ err = stack_reload(st);
+ }
+ return err;
+ }
+
+ return stack_auto_compact(st);
+}
+
+static void format_name(struct slice *dest, uint64_t min, uint64_t max)
+{
+ char buf[100];
+ snprintf(buf, sizeof(buf), "%012" PRIx64 "-%012" PRIx64, min, max);
+ slice_set_string(dest, buf);
+}
+
+int stack_try_add(struct stack *st,
+ int (*write_table)(struct writer *wr, void *arg), void *arg)
+{
+ struct slice lock_name = {};
+ struct slice temp_tab_name = {};
+ struct slice tab_name = {};
+ struct slice next_name = {};
+ struct slice table_list = {};
+ struct writer *wr = NULL;
+ int err = 0;
+ int tab_fd = 0;
+ int lock_fd = 0;
+ uint64_t next_update_index = 0;
+
+ slice_set_string(&lock_name, st->list_file);
+ slice_append_string(&lock_name, ".lock");
+
+ lock_fd = open(slice_as_string(&lock_name), O_EXCL | O_CREAT | O_WRONLY,
+ 0644);
+ if (lock_fd < 0) {
+ if (errno == EEXIST) {
+ err = LOCK_ERROR;
+ goto exit;
+ }
+ err = IO_ERROR;
+ goto exit;
+ }
+
+ err = stack_uptodate(st);
+ if (err < 0) {
+ goto exit;
+ }
+
+ if (err > 1) {
+ err = LOCK_ERROR;
+ goto exit;
+ }
+
+ next_update_index = stack_next_update_index(st);
+
+ slice_resize(&next_name, 0);
+ format_name(&next_name, next_update_index, next_update_index);
+
+ slice_set_string(&temp_tab_name, st->reftable_dir);
+ slice_append_string(&temp_tab_name, "/");
+ slice_append(&temp_tab_name, next_name);
+ slice_append_string(&temp_tab_name, ".temp.XXXXXX");
+
+ tab_fd = mkstemp((char *)slice_as_string(&temp_tab_name));
+ if (tab_fd < 0) {
+ err = IO_ERROR;
+ goto exit;
+ }
+
+ wr = new_writer(fd_writer, &tab_fd, &st->config);
+ err = write_table(wr, arg);
+ if (err < 0) {
+ goto exit;
+ }
+
+ err = writer_close(wr);
+ if (err < 0) {
+ goto exit;
+ }
+
+ err = close(tab_fd);
+ tab_fd = 0;
+ if (err < 0) {
+ err = IO_ERROR;
+ goto exit;
+ }
+
+ if (wr->min_update_index < next_update_index) {
+ err = API_ERROR;
+ goto exit;
+ }
+
+ {
+ int i = 0;
+ for (i = 0; i < st->merged->stack_len; i++) {
+ slice_append_string(&table_list,
+ st->merged->stack[i]->name);
+ slice_append_string(&table_list, "\n");
+ }
+ }
+
+ format_name(&next_name, wr->min_update_index, wr->max_update_index);
+ slice_append_string(&next_name, ".ref");
+ slice_append(&table_list, next_name);
+ slice_append_string(&table_list, "\n");
+
+ slice_set_string(&tab_name, st->reftable_dir);
+ slice_append_string(&tab_name, "/");
+ slice_append(&tab_name, next_name);
+
+ err = rename(slice_as_string(&temp_tab_name),
+ slice_as_string(&tab_name));
+ if (err < 0) {
+ err = IO_ERROR;
+ goto exit;
+ }
+ free(slice_yield(&temp_tab_name));
+
+ err = write(lock_fd, table_list.buf, table_list.len);
+ if (err < 0) {
+ err = IO_ERROR;
+ goto exit;
+ }
+ err = close(lock_fd);
+ lock_fd = 0;
+ if (err < 0) {
+ unlink(slice_as_string(&tab_name));
+ err = IO_ERROR;
+ goto exit;
+ }
+
+ err = rename(slice_as_string(&lock_name), st->list_file);
+ if (err < 0) {
+ unlink(slice_as_string(&tab_name));
+ err = IO_ERROR;
+ goto exit;
+ }
+
+ err = stack_reload(st);
+exit:
+ if (tab_fd > 0) {
+ close(tab_fd);
+ tab_fd = 0;
+ }
+ if (temp_tab_name.len > 0) {
+ unlink(slice_as_string(&temp_tab_name));
+ }
+ unlink(slice_as_string(&lock_name));
+
+ if (lock_fd > 0) {
+ close(lock_fd);
+ lock_fd = 0;
+ }
+
+ free(slice_yield(&lock_name));
+ free(slice_yield(&temp_tab_name));
+ free(slice_yield(&tab_name));
+ free(slice_yield(&next_name));
+ free(slice_yield(&table_list));
+ writer_free(wr);
+ return err;
+}
+
+uint64_t stack_next_update_index(struct stack *st)
+{
+ int sz = st->merged->stack_len;
+ if (sz > 0) {
+ return reader_max_update_index(st->merged->stack[sz - 1]) + 1;
+ }
+ return 1;
+}
+
+static int stack_compact_locked(struct stack *st, int first, int last,
+ struct slice *temp_tab,
+ struct log_expiry_config *config)
+{
+ struct slice next_name = {};
+ int tab_fd = -1;
+ struct writer *wr = NULL;
+ int err = 0;
+
+ format_name(&next_name,
+ reader_min_update_index(st->merged->stack[first]),
+ reader_max_update_index(st->merged->stack[first]));
+
+ slice_set_string(temp_tab, st->reftable_dir);
+ slice_append_string(temp_tab, "/");
+ slice_append(temp_tab, next_name);
+ slice_append_string(temp_tab, ".temp.XXXXXX");
+
+ tab_fd = mkstemp((char *)slice_as_string(temp_tab));
+ wr = new_writer(fd_writer, &tab_fd, &st->config);
+
+ err = stack_write_compact(st, wr, first, last, config);
+ if (err < 0) {
+ goto exit;
+ }
+ err = writer_close(wr);
+ if (err < 0) {
+ goto exit;
+ }
+ writer_free(wr);
+
+ err = close(tab_fd);
+ tab_fd = 0;
+
+exit:
+ if (tab_fd > 0) {
+ close(tab_fd);
+ tab_fd = 0;
+ }
+ if (err != 0 && temp_tab->len > 0) {
+ unlink(slice_as_string(temp_tab));
+ free(slice_yield(temp_tab));
+ }
+ free(slice_yield(&next_name));
+ return err;
+}
+
+int stack_write_compact(struct stack *st, struct writer *wr, int first,
+ int last, struct log_expiry_config *config)
+{
+ int subtabs_len = last - first + 1;
+ struct reader **subtabs =
+ calloc(sizeof(struct reader *), last - first + 1);
+ struct merged_table *mt = NULL;
+ int err = 0;
+ struct iterator it = {};
+ struct ref_record ref = {};
+ struct log_record log = {};
+
+ int i = 0, j = 0;
+ for (i = first, j = 0; i <= last; i++) {
+ struct reader *t = st->merged->stack[i];
+ subtabs[j++] = t;
+ st->stats.bytes += t->size;
+ }
+ writer_set_limits(wr, st->merged->stack[first]->min_update_index,
+ st->merged->stack[last]->max_update_index);
+
+ err = new_merged_table(&mt, subtabs, subtabs_len);
+ if (err < 0) {
+ free(subtabs);
+ goto exit;
+ }
+
+ err = merged_table_seek_ref(mt, &it, "");
+ if (err < 0) {
+ goto exit;
+ }
+
+ while (true) {
+ err = iterator_next_ref(it, &ref);
+ if (err > 0) {
+ err = 0;
+ break;
+ }
+ if (err < 0) {
+ break;
+ }
+ if (first == 0 && ref_record_is_deletion(&ref)) {
+ continue;
+ }
+
+ err = writer_add_ref(wr, &ref);
+ if (err < 0) {
+ break;
+ }
+ }
+
+ err = merged_table_seek_log(mt, &it, "");
+ if (err < 0) {
+ goto exit;
+ }
+
+ while (true) {
+ err = iterator_next_log(it, &log);
+ if (err > 0) {
+ err = 0;
+ break;
+ }
+ if (err < 0) {
+ break;
+ }
+ if (first == 0 && log_record_is_deletion(&log)) {
+ continue;
+ }
+
+ /* XXX collect stats? */
+
+ if (config != NULL && config->time > 0 &&
+ log.time < config->time) {
+ continue;
+ }
+
+ if (config != NULL && config->min_update_index > 0 &&
+ log.update_index < config->min_update_index) {
+ continue;
+ }
+
+ err = writer_add_log(wr, &log);
+ if (err < 0) {
+ break;
+ }
+ }
+
+exit:
+ iterator_destroy(&it);
+ if (mt != NULL) {
+ merged_table_clear(mt);
+ merged_table_free(mt);
+ }
+ ref_record_clear(&ref);
+
+ return err;
+}
+
+/* < 0: error. 0 == OK, > 0 attempt failed; could retry. */
+static int stack_compact_range(struct stack *st, int first, int last,
+ struct log_expiry_config *expiry)
+{
+ struct slice temp_tab_name = {};
+ struct slice new_table_name = {};
+ struct slice lock_file_name = {};
+ struct slice ref_list_contents = {};
+ struct slice new_table_path = {};
+ int err = 0;
+ bool have_lock = false;
+ int lock_file_fd = 0;
+ int compact_count = last - first + 1;
+ char **delete_on_success = calloc(sizeof(char *), compact_count + 1);
+ char **subtable_locks = calloc(sizeof(char *), compact_count + 1);
+ int i = 0;
+ int j = 0;
+
+ if (first > last || (expiry == NULL && first == last)) {
+ err = 0;
+ goto exit;
+ }
+
+ st->stats.attempts++;
+
+ slice_set_string(&lock_file_name, st->list_file);
+ slice_append_string(&lock_file_name, ".lock");
+
+ lock_file_fd = open(slice_as_string(&lock_file_name),
+ O_EXCL | O_CREAT | O_WRONLY, 0644);
+ if (lock_file_fd < 0) {
+ if (errno == EEXIST) {
+ err = 1;
+ } else {
+ err = IO_ERROR;
+ }
+ goto exit;
+ }
+ have_lock = true;
+ err = stack_uptodate(st);
+ if (err != 0) {
+ goto exit;
+ }
+
+ for (i = first, j = 0; i <= last; i++) {
+ struct slice subtab_name = {};
+ struct slice subtab_lock = {};
+ slice_set_string(&subtab_name, st->reftable_dir);
+ slice_append_string(&subtab_name, "/");
+ slice_append_string(&subtab_name,
+ reader_name(st->merged->stack[i]));
+
+ slice_copy(&subtab_lock, subtab_name);
+ slice_append_string(&subtab_lock, ".lock");
+
+ {
+ int sublock_file_fd =
+ open(slice_as_string(&subtab_lock),
+ O_EXCL | O_CREAT | O_WRONLY, 0644);
+ if (sublock_file_fd > 0) {
+ close(sublock_file_fd);
+ } else if (sublock_file_fd < 0) {
+ if (errno == EEXIST) {
+ err = 1;
+ }
+ err = IO_ERROR;
+ }
+ }
+
+ subtable_locks[j] = (char *)slice_as_string(&subtab_lock);
+ delete_on_success[j] = (char *)slice_as_string(&subtab_name);
+ j++;
+
+ if (err != 0) {
+ goto exit;
+ }
+ }
+
+ err = unlink(slice_as_string(&lock_file_name));
+ if (err < 0) {
+ goto exit;
+ }
+ have_lock = false;
+
+ err = stack_compact_locked(st, first, last, &temp_tab_name, expiry);
+ if (err < 0) {
+ goto exit;
+ }
+
+ lock_file_fd = open(slice_as_string(&lock_file_name),
+ O_EXCL | O_CREAT | O_WRONLY, 0644);
+ if (lock_file_fd < 0) {
+ if (errno == EEXIST) {
+ err = 1;
+ } else {
+ err = IO_ERROR;
+ }
+ goto exit;
+ }
+ have_lock = true;
+
+ format_name(&new_table_name, st->merged->stack[first]->min_update_index,
+ st->merged->stack[last]->max_update_index);
+ slice_append_string(&new_table_name, ".ref");
+
+ slice_set_string(&new_table_path, st->reftable_dir);
+ slice_append_string(&new_table_path, "/");
+
+ slice_append(&new_table_path, new_table_name);
+
+ err = rename(slice_as_string(&temp_tab_name),
+ slice_as_string(&new_table_path));
+ if (err < 0) {
+ goto exit;
+ }
+
+ for (i = 0; i < first; i++) {
+ slice_append_string(&ref_list_contents,
+ st->merged->stack[i]->name);
+ slice_append_string(&ref_list_contents, "\n");
+ }
+ slice_append(&ref_list_contents, new_table_name);
+ slice_append_string(&ref_list_contents, "\n");
+ for (i = last + 1; i < st->merged->stack_len; i++) {
+ slice_append_string(&ref_list_contents,
+ st->merged->stack[i]->name);
+ slice_append_string(&ref_list_contents, "\n");
+ }
+
+ err = write(lock_file_fd, ref_list_contents.buf, ref_list_contents.len);
+ if (err < 0) {
+ unlink(slice_as_string(&new_table_path));
+ goto exit;
+ }
+ err = close(lock_file_fd);
+ lock_file_fd = 0;
+ if (err < 0) {
+ unlink(slice_as_string(&new_table_path));
+ goto exit;
+ }
+
+ err = rename(slice_as_string(&lock_file_name), st->list_file);
+ if (err < 0) {
+ unlink(slice_as_string(&new_table_path));
+ goto exit;
+ }
+ have_lock = false;
+
+ for (char **p = delete_on_success; *p; p++) {
+ if (strcmp(*p, slice_as_string(&new_table_path))) {
+ unlink(*p);
+ }
+ }
+
+ err = stack_reload_maybe_reuse(st, first < last);
+exit:
+ for (char **p = subtable_locks; *p; p++) {
+ unlink(*p);
+ }
+ free_names(delete_on_success);
+ free_names(subtable_locks);
+ if (lock_file_fd > 0) {
+ close(lock_file_fd);
+ lock_file_fd = 0;
+ }
+ if (have_lock) {
+ unlink(slice_as_string(&lock_file_name));
+ }
+ free(slice_yield(&new_table_name));
+ free(slice_yield(&new_table_path));
+ free(slice_yield(&ref_list_contents));
+ free(slice_yield(&temp_tab_name));
+ free(slice_yield(&lock_file_name));
+ return err;
+}
+
+int stack_compact_all(struct stack *st, struct log_expiry_config *config)
+{
+ return stack_compact_range(st, 0, st->merged->stack_len - 1, config);
+}
+
+static int stack_compact_range_stats(struct stack *st, int first, int last,
+ struct log_expiry_config *config)
+{
+ int err = stack_compact_range(st, first, last, config);
+ if (err > 0) {
+ st->stats.failures++;
+ }
+ return err;
+}
+
+static int segment_size(struct segment *s)
+{
+ return s->end - s->start;
+}
+
+int fastlog2(uint64_t sz)
+{
+ int l = 0;
+ assert(sz > 0);
+ for (; sz; sz /= 2) {
+ l++;
+ }
+ return l - 1;
+}
+
+struct segment *sizes_to_segments(int *seglen, uint64_t *sizes, int n)
+{
+ struct segment *segs = calloc(sizeof(struct segment), n);
+ int next = 0;
+ struct segment cur = {};
+ int i = 0;
+ for (i = 0; i < n; i++) {
+ int log = fastlog2(sizes[i]);
+ if (cur.log != log && cur.bytes > 0) {
+ struct segment fresh = {
+ .start = i,
+ };
+
+ segs[next++] = cur;
+ cur = fresh;
+ }
+
+ cur.log = log;
+ cur.end = i + 1;
+ cur.bytes += sizes[i];
+ }
+
+ segs[next++] = cur;
+ *seglen = next;
+ return segs;
+}
+
+struct segment suggest_compaction_segment(uint64_t *sizes, int n)
+{
+ int seglen = 0;
+ struct segment *segs = sizes_to_segments(&seglen, sizes, n);
+ struct segment min_seg = {
+ .log = 64,
+ };
+ int i = 0;
+ for (i = 0; i < seglen; i++) {
+ if (segment_size(&segs[i]) == 1) {
+ continue;
+ }
+
+ if (segs[i].log < min_seg.log) {
+ min_seg = segs[i];
+ }
+ }
+
+ while (min_seg.start > 0) {
+ int prev = min_seg.start - 1;
+ if (fastlog2(min_seg.bytes) < fastlog2(sizes[prev])) {
+ break;
+ }
+
+ min_seg.start = prev;
+ min_seg.bytes += sizes[prev];
+ }
+
+ free(segs);
+ return min_seg;
+}
+
+static uint64_t *stack_table_sizes_for_compaction(struct stack *st)
+{
+ uint64_t *sizes = calloc(sizeof(uint64_t), st->merged->stack_len);
+ int i = 0;
+ for (i = 0; i < st->merged->stack_len; i++) {
+ /* overhead is 24 + 68 = 92. */
+ sizes[i] = st->merged->stack[i]->size - 91;
+ }
+ return sizes;
+}
+
+int stack_auto_compact(struct stack *st)
+{
+ uint64_t *sizes = stack_table_sizes_for_compaction(st);
+ struct segment seg =
+ suggest_compaction_segment(sizes, st->merged->stack_len);
+ free(sizes);
+ if (segment_size(&seg) > 0) {
+ return stack_compact_range_stats(st, seg.start, seg.end - 1,
+ NULL);
+ }
+
+ return 0;
+}
+
+struct compaction_stats *stack_compaction_stats(struct stack *st)
+{
+ return &st->stats;
+}
+
+int stack_read_ref(struct stack *st, const char *refname,
+ struct ref_record *ref)
+{
+ struct iterator it = {};
+ struct merged_table *mt = stack_merged_table(st);
+ int err = merged_table_seek_ref(mt, &it, refname);
+ if (err) {
+ goto exit;
+ }
+
+ err = iterator_next_ref(it, ref);
+ if (err) {
+ goto exit;
+ }
+
+ if (strcmp(ref->ref_name, refname) || ref_record_is_deletion(ref)) {
+ err = 1;
+ goto exit;
+ }
+
+exit:
+ iterator_destroy(&it);
+ return err;
+}
+
+int stack_read_log(struct stack *st, const char *refname,
+ struct log_record *log)
+{
+ struct iterator it = {};
+ struct merged_table *mt = stack_merged_table(st);
+ int err = merged_table_seek_log(mt, &it, refname);
+ if (err) {
+ goto exit;
+ }
+
+ err = iterator_next_log(it, log);
+ if (err) {
+ goto exit;
+ }
+
+ if (strcmp(log->ref_name, refname) || log_record_is_deletion(log)) {
+ err = 1;
+ goto exit;
+ }
+
+exit:
+ iterator_destroy(&it);
+ return err;
+}
new file mode 100644
@@ -0,0 +1,40 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef STACK_H
+#define STACK_H
+
+#include "reftable.h"
+
+struct stack {
+ char *list_file;
+ char *reftable_dir;
+
+ struct write_options config;
+
+ struct merged_table *merged;
+ struct compaction_stats stats;
+};
+
+int read_lines(const char *filename, char ***lines);
+int stack_try_add(struct stack *st,
+ int (*write_table)(struct writer *wr, void *arg), void *arg);
+int stack_write_compact(struct stack *st, struct writer *wr, int first,
+ int last, struct log_expiry_config *config);
+int fastlog2(uint64_t sz);
+
+struct segment {
+ int start, end;
+ int log;
+ uint64_t bytes;
+};
+
+struct segment *sizes_to_segments(int *seglen, uint64_t *sizes, int n);
+struct segment suggest_compaction_segment(uint64_t *sizes, int n);
+
+#endif
new file mode 100644
@@ -0,0 +1,55 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef SYSTEM_H
+#define SYSTEM_H
+
+#include "config.h"
+
+#ifndef REFTABLE_STANDALONE
+
+#include "git-compat-util.h"
+#include <zlib.h>
+
+#else
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <zlib.h>
+
+#define ARRAY_SIZE(a) sizeof((a)) / sizeof((a)[0])
+#define FREE_AND_NULL(x) \
+ do { \
+ free(x); \
+ (x) = NULL; \
+ } while (0)
+#define QSORT(arr, n, cmp) qsort(arr, n, sizeof(arr[0]), cmp)
+#define SWAP(a, b) \
+ { \
+ char tmp[sizeof(a)]; \
+ assert(sizeof(a) == sizeof(b)); \
+ memcpy(&tmp[0], &a, sizeof(a)); \
+ memcpy(&a, &b, sizeof(a)); \
+ memcpy(&b, &tmp[0], sizeof(a)); \
+ }
+#endif
+
+int uncompress_return_consumed(Bytef *dest, uLongf *destLen,
+ const Bytef *source, uLong *sourceLen);
+
+#endif
new file mode 100644
@@ -0,0 +1,66 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "tree.h"
+
+#include "system.h"
+
+struct tree_node *tree_search(void *key, struct tree_node **rootp,
+ int (*compare)(const void *, const void *),
+ int insert)
+{
+ if (*rootp == NULL) {
+ if (!insert) {
+ return NULL;
+ } else {
+ struct tree_node *n =
+ calloc(sizeof(struct tree_node), 1);
+ n->key = key;
+ *rootp = n;
+ return *rootp;
+ }
+ }
+
+ {
+ int res = compare(key, (*rootp)->key);
+ if (res < 0) {
+ return tree_search(key, &(*rootp)->left, compare,
+ insert);
+ } else if (res > 0) {
+ return tree_search(key, &(*rootp)->right, compare,
+ insert);
+ }
+ }
+ return *rootp;
+}
+
+void infix_walk(struct tree_node *t, void (*action)(void *arg, void *key),
+ void *arg)
+{
+ if (t->left != NULL) {
+ infix_walk(t->left, action, arg);
+ }
+ action(arg, t->key);
+ if (t->right != NULL) {
+ infix_walk(t->right, action, arg);
+ }
+}
+
+void tree_free(struct tree_node *t)
+{
+ if (t == NULL) {
+ return;
+ }
+ if (t->left != NULL) {
+ tree_free(t->left);
+ }
+ if (t->right != NULL) {
+ tree_free(t->right);
+ }
+ free(t);
+}
new file mode 100644
@@ -0,0 +1,24 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef TREE_H
+#define TREE_H
+
+struct tree_node {
+ void *key;
+ struct tree_node *left, *right;
+};
+
+struct tree_node *tree_search(void *key, struct tree_node **rootp,
+ int (*compare)(const void *, const void *),
+ int insert);
+void infix_walk(struct tree_node *t, void (*action)(void *arg, void *key),
+ void *arg);
+void tree_free(struct tree_node *t);
+
+#endif
new file mode 100644
@@ -0,0 +1,623 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#include "writer.h"
+
+#include "system.h"
+
+#include "block.h"
+#include "constants.h"
+#include "record.h"
+#include "reftable.h"
+#include "tree.h"
+
+static struct block_stats *writer_block_stats(struct writer *w, byte typ)
+{
+ switch (typ) {
+ case 'r':
+ return &w->stats.ref_stats;
+ case 'o':
+ return &w->stats.obj_stats;
+ case 'i':
+ return &w->stats.idx_stats;
+ case 'g':
+ return &w->stats.log_stats;
+ }
+ assert(false);
+ return NULL;
+}
+
+/* write data, queuing the padding for the next write. Returns negative for
+ * error. */
+static int padded_write(struct writer *w, byte *data, size_t len, int padding)
+{
+ int n = 0;
+ if (w->pending_padding > 0) {
+ byte *zeroed = calloc(w->pending_padding, 1);
+ int n = w->write(w->write_arg, zeroed, w->pending_padding);
+ if (n < 0) {
+ return n;
+ }
+
+ w->pending_padding = 0;
+ free(zeroed);
+ }
+
+ w->pending_padding = padding;
+ n = w->write(w->write_arg, data, len);
+ if (n < 0) {
+ return n;
+ }
+ n += padding;
+ return 0;
+}
+
+static void options_set_defaults(struct write_options *opts)
+{
+ if (opts->restart_interval == 0) {
+ opts->restart_interval = 16;
+ }
+
+ if (opts->block_size == 0) {
+ opts->block_size = DEFAULT_BLOCK_SIZE;
+ }
+}
+
+static int writer_write_header(struct writer *w, byte *dest)
+{
+ memcpy((char *)dest, "REFT", 4);
+ dest[4] = 1; /* version */
+ put_u24(dest + 5, w->opts.block_size);
+ put_u64(dest + 8, w->min_update_index);
+ put_u64(dest + 16, w->max_update_index);
+ return 24;
+}
+
+static void writer_reinit_block_writer(struct writer *w, byte typ)
+{
+ int block_start = 0;
+ if (w->next == 0) {
+ block_start = HEADER_SIZE;
+ }
+
+ block_writer_init(&w->block_writer_data, typ, w->block,
+ w->opts.block_size, block_start, w->hash_size);
+ w->block_writer = &w->block_writer_data;
+ w->block_writer->restart_interval = w->opts.restart_interval;
+}
+
+struct writer *new_writer(int (*writer_func)(void *, byte *, int),
+ void *writer_arg, struct write_options *opts)
+{
+ struct writer *wp = calloc(sizeof(struct writer), 1);
+ options_set_defaults(opts);
+ if (opts->block_size >= (1 << 24)) {
+ /* TODO - error return? */
+ abort();
+ }
+ wp->hash_size = SHA1_SIZE;
+ wp->block = calloc(opts->block_size, 1);
+ wp->write = writer_func;
+ wp->write_arg = writer_arg;
+ wp->opts = *opts;
+ writer_reinit_block_writer(wp, BLOCK_TYPE_REF);
+
+ return wp;
+}
+
+void writer_set_limits(struct writer *w, uint64_t min, uint64_t max)
+{
+ w->min_update_index = min;
+ w->max_update_index = max;
+}
+
+void writer_free(struct writer *w)
+{
+ free(w->block);
+ free(w);
+}
+
+struct obj_index_tree_node {
+ struct slice hash;
+ uint64_t *offsets;
+ int offset_len;
+ int offset_cap;
+};
+
+static int obj_index_tree_node_compare(const void *a, const void *b)
+{
+ return slice_compare(((const struct obj_index_tree_node *)a)->hash,
+ ((const struct obj_index_tree_node *)b)->hash);
+}
+
+static void writer_index_hash(struct writer *w, struct slice hash)
+{
+ uint64_t off = w->next;
+
+ struct obj_index_tree_node want = { .hash = hash };
+
+ struct tree_node *node = tree_search(&want, &w->obj_index_tree,
+ &obj_index_tree_node_compare, 0);
+ struct obj_index_tree_node *key = NULL;
+ if (node == NULL) {
+ key = calloc(sizeof(struct obj_index_tree_node), 1);
+ slice_copy(&key->hash, hash);
+ tree_search((void *)key, &w->obj_index_tree,
+ &obj_index_tree_node_compare, 1);
+ } else {
+ key = node->key;
+ }
+
+ if (key->offset_len > 0 && key->offsets[key->offset_len - 1] == off) {
+ return;
+ }
+
+ if (key->offset_len == key->offset_cap) {
+ key->offset_cap = 2 * key->offset_cap + 1;
+ key->offsets = realloc(key->offsets,
+ sizeof(uint64_t) * key->offset_cap);
+ }
+
+ key->offsets[key->offset_len++] = off;
+}
+
+static int writer_add_record(struct writer *w, struct record rec)
+{
+ int result = -1;
+ struct slice key = {};
+ int err = 0;
+ record_key(rec, &key);
+ if (slice_compare(w->last_key, key) >= 0) {
+ goto exit;
+ }
+
+ slice_copy(&w->last_key, key);
+ if (w->block_writer == NULL) {
+ writer_reinit_block_writer(w, record_type(rec));
+ }
+
+ assert(block_writer_type(w->block_writer) == record_type(rec));
+
+ if (block_writer_add(w->block_writer, rec) == 0) {
+ result = 0;
+ goto exit;
+ }
+
+ err = writer_flush_block(w);
+ if (err < 0) {
+ result = err;
+ goto exit;
+ }
+
+ writer_reinit_block_writer(w, record_type(rec));
+ err = block_writer_add(w->block_writer, rec);
+ if (err < 0) {
+ result = err;
+ goto exit;
+ }
+
+ result = 0;
+exit:
+ free(slice_yield(&key));
+ return result;
+}
+
+int writer_add_ref(struct writer *w, struct ref_record *ref)
+{
+ struct record rec = {};
+ struct ref_record copy = *ref;
+ int err = 0;
+
+ if (ref->ref_name == NULL) {
+ return API_ERROR;
+ }
+ if (ref->update_index < w->min_update_index ||
+ ref->update_index > w->max_update_index) {
+ return API_ERROR;
+ }
+
+ record_from_ref(&rec, ©);
+ copy.update_index -= w->min_update_index;
+ err = writer_add_record(w, rec);
+ if (err < 0) {
+ return err;
+ }
+
+ if (!w->opts.skip_index_objects && ref->value != NULL) {
+ struct slice h = {
+ .buf = ref->value,
+ .len = w->hash_size,
+ };
+
+ writer_index_hash(w, h);
+ }
+ if (!w->opts.skip_index_objects && ref->target_value != NULL) {
+ struct slice h = {
+ .buf = ref->target_value,
+ .len = w->hash_size,
+ };
+ writer_index_hash(w, h);
+ }
+ return 0;
+}
+
+int writer_add_refs(struct writer *w, struct ref_record *refs, int n)
+{
+ int err = 0;
+ int i = 0;
+ QSORT(refs, n, ref_record_compare_name);
+ for (i = 0; err == 0 && i < n; i++) {
+ err = writer_add_ref(w, &refs[i]);
+ }
+ return err;
+}
+
+int writer_add_log(struct writer *w, struct log_record *log)
+{
+ if (log->ref_name == NULL) {
+ return API_ERROR;
+ }
+
+ if (w->block_writer != NULL &&
+ block_writer_type(w->block_writer) == BLOCK_TYPE_REF) {
+ int err = writer_finish_public_section(w);
+ if (err < 0) {
+ return err;
+ }
+ }
+
+ w->next -= w->pending_padding;
+ w->pending_padding = 0;
+
+ {
+ struct record rec = {};
+ int err;
+ record_from_log(&rec, log);
+ err = writer_add_record(w, rec);
+ return err;
+ }
+}
+
+int writer_add_logs(struct writer *w, struct log_record *logs, int n)
+{
+ int err = 0;
+ int i = 0;
+ QSORT(logs, n, log_record_compare_key);
+ for (i = 0; err == 0 && i < n; i++) {
+ err = writer_add_log(w, &logs[i]);
+ }
+ return err;
+}
+
+static int writer_finish_section(struct writer *w)
+{
+ byte typ = block_writer_type(w->block_writer);
+ uint64_t index_start = 0;
+ int max_level = 0;
+ int threshold = w->opts.unpadded ? 1 : 3;
+ int before_blocks = w->stats.idx_stats.blocks;
+ int err = writer_flush_block(w);
+ int i = 0;
+ if (err < 0) {
+ return err;
+ }
+
+ while (w->index_len > threshold) {
+ struct index_record *idx = NULL;
+ int idx_len = 0;
+
+ max_level++;
+ index_start = w->next;
+ writer_reinit_block_writer(w, BLOCK_TYPE_INDEX);
+
+ idx = w->index;
+ idx_len = w->index_len;
+
+ w->index = NULL;
+ w->index_len = 0;
+ w->index_cap = 0;
+ for (i = 0; i < idx_len; i++) {
+ struct record rec = {};
+ record_from_index(&rec, idx + i);
+ if (block_writer_add(w->block_writer, rec) == 0) {
+ continue;
+ }
+
+ {
+ int err = writer_flush_block(w);
+ if (err < 0) {
+ return err;
+ }
+ }
+
+ writer_reinit_block_writer(w, BLOCK_TYPE_INDEX);
+
+ err = block_writer_add(w->block_writer, rec);
+ assert(err == 0);
+ }
+ for (i = 0; i < idx_len; i++) {
+ free(slice_yield(&idx[i].last_key));
+ }
+ free(idx);
+ }
+
+ writer_clear_index(w);
+
+ err = writer_flush_block(w);
+ if (err < 0) {
+ return err;
+ }
+
+ {
+ struct block_stats *bstats = writer_block_stats(w, typ);
+ bstats->index_blocks =
+ w->stats.idx_stats.blocks - before_blocks;
+ bstats->index_offset = index_start;
+ bstats->max_index_level = max_level;
+ }
+
+ /* Reinit lastKey, as the next section can start with any key. */
+ w->last_key.len = 0;
+
+ return 0;
+}
+
+struct common_prefix_arg {
+ struct slice *last;
+ int max;
+};
+
+static void update_common(void *void_arg, void *key)
+{
+ struct common_prefix_arg *arg = (struct common_prefix_arg *)void_arg;
+ struct obj_index_tree_node *entry = (struct obj_index_tree_node *)key;
+ if (arg->last != NULL) {
+ int n = common_prefix_size(entry->hash, *arg->last);
+ if (n > arg->max) {
+ arg->max = n;
+ }
+ }
+ arg->last = &entry->hash;
+}
+
+struct write_record_arg {
+ struct writer *w;
+ int err;
+};
+
+static void write_object_record(void *void_arg, void *key)
+{
+ struct write_record_arg *arg = (struct write_record_arg *)void_arg;
+ struct obj_index_tree_node *entry = (struct obj_index_tree_node *)key;
+ struct obj_record obj_rec = {
+ .hash_prefix = entry->hash.buf,
+ .hash_prefix_len = arg->w->stats.object_id_len,
+ .offsets = entry->offsets,
+ .offset_len = entry->offset_len,
+ };
+ struct record rec = {};
+ if (arg->err < 0) {
+ goto exit;
+ }
+
+ record_from_obj(&rec, &obj_rec);
+ arg->err = block_writer_add(arg->w->block_writer, rec);
+ if (arg->err == 0) {
+ goto exit;
+ }
+
+ arg->err = writer_flush_block(arg->w);
+ if (arg->err < 0) {
+ goto exit;
+ }
+
+ writer_reinit_block_writer(arg->w, BLOCK_TYPE_OBJ);
+ arg->err = block_writer_add(arg->w->block_writer, rec);
+ if (arg->err == 0) {
+ goto exit;
+ }
+ obj_rec.offset_len = 0;
+ arg->err = block_writer_add(arg->w->block_writer, rec);
+
+ /* Should be able to write into a fresh block. */
+ assert(arg->err == 0);
+
+exit:;
+}
+
+static void object_record_free(void *void_arg, void *key)
+{
+ struct obj_index_tree_node *entry = (struct obj_index_tree_node *)key;
+
+ FREE_AND_NULL(entry->offsets);
+ free(slice_yield(&entry->hash));
+ free(entry);
+}
+
+static int writer_dump_object_index(struct writer *w)
+{
+ struct write_record_arg closure = { .w = w };
+ struct common_prefix_arg common = {};
+ if (w->obj_index_tree != NULL) {
+ infix_walk(w->obj_index_tree, &update_common, &common);
+ }
+ w->stats.object_id_len = common.max + 1;
+
+ writer_reinit_block_writer(w, BLOCK_TYPE_OBJ);
+
+ if (w->obj_index_tree != NULL) {
+ infix_walk(w->obj_index_tree, &write_object_record, &closure);
+ }
+
+ if (closure.err < 0) {
+ return closure.err;
+ }
+ return writer_finish_section(w);
+}
+
+int writer_finish_public_section(struct writer *w)
+{
+ byte typ = 0;
+ int err = 0;
+
+ if (w->block_writer == NULL) {
+ return 0;
+ }
+
+ typ = block_writer_type(w->block_writer);
+ err = writer_finish_section(w);
+ if (err < 0) {
+ return err;
+ }
+ if (typ == BLOCK_TYPE_REF && !w->opts.skip_index_objects &&
+ w->stats.ref_stats.index_blocks > 0) {
+ err = writer_dump_object_index(w);
+ if (err < 0) {
+ return err;
+ }
+ }
+
+ if (w->obj_index_tree != NULL) {
+ infix_walk(w->obj_index_tree, &object_record_free, NULL);
+ tree_free(w->obj_index_tree);
+ w->obj_index_tree = NULL;
+ }
+
+ w->block_writer = NULL;
+ return 0;
+}
+
+int writer_close(struct writer *w)
+{
+ byte footer[68];
+ byte *p = footer;
+
+ writer_finish_public_section(w);
+
+ writer_write_header(w, footer);
+ p += 24;
+ put_u64(p, w->stats.ref_stats.index_offset);
+ p += 8;
+ put_u64(p, (w->stats.obj_stats.offset) << 5 | w->stats.object_id_len);
+ p += 8;
+ put_u64(p, w->stats.obj_stats.index_offset);
+ p += 8;
+
+ put_u64(p, w->stats.log_stats.offset);
+ p += 8;
+ put_u64(p, w->stats.log_stats.index_offset);
+ p += 8;
+
+ put_u32(p, crc32(0, footer, p - footer));
+ p += 4;
+ w->pending_padding = 0;
+
+ {
+ int n = padded_write(w, footer, sizeof(footer), 0);
+ if (n < 0) {
+ return n;
+ }
+ }
+
+ /* free up memory. */
+ block_writer_clear(&w->block_writer_data);
+ writer_clear_index(w);
+ free(slice_yield(&w->last_key));
+ return 0;
+}
+
+void writer_clear_index(struct writer *w)
+{
+ int i = 0;
+ for (i = 0; i < w->index_len; i++) {
+ free(slice_yield(&w->index[i].last_key));
+ }
+
+ FREE_AND_NULL(w->index);
+ w->index_len = 0;
+ w->index_cap = 0;
+}
+
+const int debug = 0;
+
+static int writer_flush_nonempty_block(struct writer *w)
+{
+ byte typ = block_writer_type(w->block_writer);
+ struct block_stats *bstats = writer_block_stats(w, typ);
+ uint64_t block_typ_off = (bstats->blocks == 0) ? w->next : 0;
+ int raw_bytes = block_writer_finish(w->block_writer);
+ int padding = 0;
+ int err = 0;
+ if (raw_bytes < 0) {
+ return raw_bytes;
+ }
+
+ if (!w->opts.unpadded && typ != BLOCK_TYPE_LOG) {
+ padding = w->opts.block_size - raw_bytes;
+ }
+
+ if (block_typ_off > 0) {
+ bstats->offset = block_typ_off;
+ }
+
+ bstats->entries += w->block_writer->entries;
+ bstats->restarts += w->block_writer->restart_len;
+ bstats->blocks++;
+ w->stats.blocks++;
+
+ if (debug) {
+ fprintf(stderr, "block %c off %" PRIu64 " sz %d (%d)\n", typ,
+ w->next, raw_bytes,
+ get_u24(w->block + w->block_writer->header_off + 1));
+ }
+
+ if (w->next == 0) {
+ writer_write_header(w, w->block);
+ }
+
+ err = padded_write(w, w->block, raw_bytes, padding);
+ if (err < 0) {
+ return err;
+ }
+
+ if (w->index_cap == w->index_len) {
+ w->index_cap = 2 * w->index_cap + 1;
+ w->index = realloc(w->index,
+ sizeof(struct index_record) * w->index_cap);
+ }
+
+ {
+ struct index_record ir = {
+ .offset = w->next,
+ };
+ slice_copy(&ir.last_key, w->block_writer->last_key);
+ w->index[w->index_len] = ir;
+ }
+
+ w->index_len++;
+ w->next += padding + raw_bytes;
+ block_writer_reset(&w->block_writer_data);
+ w->block_writer = NULL;
+ return 0;
+}
+
+int writer_flush_block(struct writer *w)
+{
+ if (w->block_writer == NULL) {
+ return 0;
+ }
+ if (w->block_writer->entries == 0) {
+ return 0;
+ }
+ return writer_flush_nonempty_block(w);
+}
+
+struct stats *writer_stats(struct writer *w)
+{
+ return &w->stats;
+}
new file mode 100644
@@ -0,0 +1,46 @@
+/*
+Copyright 2020 Google LLC
+
+Use of this source code is governed by a BSD-style
+license that can be found in the LICENSE file or at
+https://developers.google.com/open-source/licenses/bsd
+*/
+
+#ifndef WRITER_H
+#define WRITER_H
+
+#include "basics.h"
+#include "block.h"
+#include "reftable.h"
+#include "slice.h"
+#include "tree.h"
+
+struct writer {
+ int (*write)(void *, byte *, int);
+ void *write_arg;
+ int pending_padding;
+ int hash_size;
+ struct slice last_key;
+
+ uint64_t next;
+ uint64_t min_update_index, max_update_index;
+ struct write_options opts;
+
+ byte *block;
+ struct block_writer *block_writer;
+ struct block_writer block_writer_data;
+ struct index_record *index;
+ int index_len;
+ int index_cap;
+
+ /* tree for use with tsearch */
+ struct tree_node *obj_index_tree;
+
+ struct stats stats;
+};
+
+int writer_flush_block(struct writer *w);
+void writer_clear_index(struct writer *w);
+int writer_finish_public_section(struct writer *w);
+
+#endif
new file mode 100644
@@ -0,0 +1,92 @@
+/* taken from zlib's uncompr.c
+
+ commit cacf7f1d4e3d44d871b605da3b647f07d718623f
+ Author: Mark Adler <madler@alumni.caltech.edu>
+ Date: Sun Jan 15 09:18:46 2017 -0800
+
+ zlib 1.2.11
+
+*/
+
+/*
+ * Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "system.h"
+
+/* clang-format off */
+
+/* ===========================================================================
+ Decompresses the source buffer into the destination buffer. *sourceLen is
+ the byte length of the source buffer. Upon entry, *destLen is the total size
+ of the destination buffer, which must be large enough to hold the entire
+ uncompressed data. (The size of the uncompressed data must have been saved
+ previously by the compressor and transmitted to the decompressor by some
+ mechanism outside the scope of this compression library.) Upon exit,
+ *destLen is the size of the decompressed data and *sourceLen is the number
+ of source bytes consumed. Upon return, source + *sourceLen points to the
+ first unused input byte.
+
+ uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough
+ memory, Z_BUF_ERROR if there was not enough room in the output buffer, or
+ Z_DATA_ERROR if the input data was corrupted, including if the input data is
+ an incomplete zlib stream.
+*/
+int ZEXPORT uncompress_return_consumed (
+ Bytef *dest,
+ uLongf *destLen,
+ const Bytef *source,
+ uLong *sourceLen) {
+ z_stream stream;
+ int err;
+ const uInt max = (uInt)-1;
+ uLong len, left;
+ Byte buf[1]; /* for detection of incomplete stream when *destLen == 0 */
+
+ len = *sourceLen;
+ if (*destLen) {
+ left = *destLen;
+ *destLen = 0;
+ }
+ else {
+ left = 1;
+ dest = buf;
+ }
+
+ stream.next_in = (z_const Bytef *)source;
+ stream.avail_in = 0;
+ stream.zalloc = (alloc_func)0;
+ stream.zfree = (free_func)0;
+ stream.opaque = (voidpf)0;
+
+ err = inflateInit(&stream);
+ if (err != Z_OK) return err;
+
+ stream.next_out = dest;
+ stream.avail_out = 0;
+
+ do {
+ if (stream.avail_out == 0) {
+ stream.avail_out = left > (uLong)max ? max : (uInt)left;
+ left -= stream.avail_out;
+ }
+ if (stream.avail_in == 0) {
+ stream.avail_in = len > (uLong)max ? max : (uInt)len;
+ len -= stream.avail_in;
+ }
+ err = inflate(&stream, Z_NO_FLUSH);
+ } while (err == Z_OK);
+
+ *sourceLen -= len + stream.avail_in;
+ if (dest != buf)
+ *destLen = stream.total_out;
+ else if (stream.total_out && err == Z_BUF_ERROR)
+ left = 1;
+
+ inflateEnd(&stream);
+ return err == Z_STREAM_END ? Z_OK :
+ err == Z_NEED_DICT ? Z_DATA_ERROR :
+ err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
+ err;
+}