@@ -2442,6 +2442,7 @@ REFTABLE_OBJS += reftable/block.o
REFTABLE_OBJS += reftable/blocksource.o
REFTABLE_OBJS += reftable/iter.o
REFTABLE_OBJS += reftable/publicbasics.o
+REFTABLE_OBJS += reftable/merged.o
REFTABLE_OBJS += reftable/pq.o
REFTABLE_OBJS += reftable/reader.o
REFTABLE_OBJS += reftable/record.o
@@ -2453,6 +2454,7 @@ REFTABLE_OBJS += reftable/writer.o
REFTABLE_TEST_OBJS += reftable/basics_test.o
REFTABLE_TEST_OBJS += reftable/block_test.o
+REFTABLE_TEST_OBJS += reftable/merged_test.o
REFTABLE_TEST_OBJS += reftable/pq_test.o
REFTABLE_TEST_OBJS += reftable/record_test.o
REFTABLE_TEST_OBJS += reftable/readwrite_test.o
new file mode 100644
@@ -0,0 +1,362 @@
+/*
+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 "constants.h"
+#include "iter.h"
+#include "pq.h"
+#include "reader.h"
+#include "record.h"
+#include "generic.h"
+#include "reftable-merged.h"
+#include "reftable-error.h"
+#include "system.h"
+
+static int merged_iter_init(struct merged_iter *mi)
+{
+ int i = 0;
+ for (i = 0; i < mi->stack_len; i++) {
+ struct reftable_record rec = reftable_new_record(mi->typ);
+ int err = iterator_next(&mi->stack[i], &rec);
+ if (err < 0) {
+ return err;
+ }
+
+ if (err > 0) {
+ reftable_iterator_destroy(&mi->stack[i]);
+ reftable_record_destroy(&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 = p;
+ int i = 0;
+ merged_iter_pqueue_release(&mi->pq);
+ for (i = 0; i < mi->stack_len; i++) {
+ reftable_iterator_destroy(&mi->stack[i]);
+ }
+ reftable_free(mi->stack);
+}
+
+static int merged_iter_advance_nonnull_subiter(struct merged_iter *mi,
+ size_t idx)
+{
+ struct reftable_record rec = reftable_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) {
+ reftable_iterator_destroy(&mi->stack[idx]);
+ reftable_record_destroy(&rec);
+ return 0;
+ }
+
+ merged_iter_pqueue_add(&mi->pq, e);
+ return 0;
+}
+
+static int merged_iter_advance_subiter(struct merged_iter *mi, size_t idx)
+{
+ if (iterator_is_null(&mi->stack[idx]))
+ return 0;
+ return merged_iter_advance_nonnull_subiter(mi, idx);
+}
+
+static int merged_iter_next_entry(struct merged_iter *mi,
+ struct reftable_record *rec)
+{
+ struct strbuf entry_key = STRBUF_INIT;
+ struct pq_entry entry = { 0 };
+ int err = 0;
+
+ if (merged_iter_pqueue_is_empty(mi->pq))
+ return 1;
+
+ entry = merged_iter_pqueue_remove(&mi->pq);
+ err = merged_iter_advance_subiter(mi, entry.index);
+ if (err < 0)
+ return err;
+
+ /*
+ One can also use reftable as datacenter-local storage, where the ref
+ database is maintained in globally consistent database (eg.
+ CockroachDB or Spanner). In this scenario, replication delays together
+ with compaction may cause newer tables to contain older entries. In
+ such a deployment, the loop below must be changed to collect all
+ entries for the same key, and return new the newest one.
+ */
+ reftable_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 strbuf k = STRBUF_INIT;
+ int err = 0, cmp = 0;
+
+ reftable_record_key(&top.rec, &k);
+
+ cmp = strbuf_cmp(&k, &entry_key);
+ strbuf_release(&k);
+
+ if (cmp > 0) {
+ break;
+ }
+
+ merged_iter_pqueue_remove(&mi->pq);
+ err = merged_iter_advance_subiter(mi, top.index);
+ if (err < 0) {
+ return err;
+ }
+ reftable_record_destroy(&top.rec);
+ }
+
+ reftable_record_copy_from(rec, &entry.rec, hash_size(mi->hash_id));
+ reftable_record_destroy(&entry.rec);
+ strbuf_release(&entry_key);
+ return 0;
+}
+
+static int merged_iter_next(struct merged_iter *mi, struct reftable_record *rec)
+{
+ while (1) {
+ int err = merged_iter_next_entry(mi, rec);
+ if (err == 0 && mi->suppress_deletions &&
+ reftable_record_is_deletion(rec)) {
+ continue;
+ }
+
+ return err;
+ }
+}
+
+static int merged_iter_next_void(void *p, struct reftable_record *rec)
+{
+ struct merged_iter *mi = p;
+ if (merged_iter_pqueue_is_empty(mi->pq))
+ return 1;
+
+ return merged_iter_next(mi, rec);
+}
+
+static struct reftable_iterator_vtable merged_iter_vtable = {
+ .next = &merged_iter_next_void,
+ .close = &merged_iter_close,
+};
+
+static void iterator_from_merged_iter(struct reftable_iterator *it,
+ struct merged_iter *mi)
+{
+ assert(!it->ops);
+ it->iter_arg = mi;
+ it->ops = &merged_iter_vtable;
+}
+
+int reftable_new_merged_table(struct reftable_merged_table **dest,
+ struct reftable_table *stack, int n,
+ uint32_t hash_id)
+{
+ struct reftable_merged_table *m = NULL;
+ uint64_t last_max = 0;
+ uint64_t first_min = 0;
+ int i = 0;
+ for (i = 0; i < n; i++) {
+ uint64_t min = reftable_table_min_update_index(&stack[i]);
+ uint64_t max = reftable_table_max_update_index(&stack[i]);
+
+ if (reftable_table_hash_id(&stack[i]) != hash_id) {
+ return REFTABLE_FORMAT_ERROR;
+ }
+ if (i == 0 || min < first_min) {
+ first_min = min;
+ }
+ if (i == 0 || max > last_max) {
+ last_max = max;
+ }
+ }
+
+ m = reftable_calloc(sizeof(struct reftable_merged_table));
+ m->stack = stack;
+ m->stack_len = n;
+ m->min = first_min;
+ m->max = last_max;
+ m->hash_id = hash_id;
+ *dest = m;
+ return 0;
+}
+
+/* clears the list of subtable, without affecting the readers themselves. */
+void merged_table_release(struct reftable_merged_table *mt)
+{
+ FREE_AND_NULL(mt->stack);
+ mt->stack_len = 0;
+}
+
+void reftable_merged_table_free(struct reftable_merged_table *mt)
+{
+ if (!mt) {
+ return;
+ }
+ merged_table_release(mt);
+ reftable_free(mt);
+}
+
+uint64_t
+reftable_merged_table_max_update_index(struct reftable_merged_table *mt)
+{
+ return mt->max;
+}
+
+uint64_t
+reftable_merged_table_min_update_index(struct reftable_merged_table *mt)
+{
+ return mt->min;
+}
+
+static int reftable_table_seek_record(struct reftable_table *tab,
+ struct reftable_iterator *it,
+ struct reftable_record *rec)
+{
+ return tab->ops->seek_record(tab->table_arg, it, rec);
+}
+
+static int merged_table_seek_record(struct reftable_merged_table *mt,
+ struct reftable_iterator *it,
+ struct reftable_record *rec)
+{
+ struct reftable_iterator *iters = reftable_calloc(
+ sizeof(struct reftable_iterator) * mt->stack_len);
+ struct merged_iter merged = {
+ .stack = iters,
+ .typ = reftable_record_type(rec),
+ .hash_id = mt->hash_id,
+ .suppress_deletions = mt->suppress_deletions,
+ };
+ int n = 0;
+ int err = 0;
+ int i = 0;
+ for (i = 0; i < mt->stack_len && err == 0; i++) {
+ int e = reftable_table_seek_record(&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++) {
+ reftable_iterator_destroy(&iters[i]);
+ }
+ reftable_free(iters);
+ return err;
+ }
+
+ merged.stack_len = n;
+ err = merged_iter_init(&merged);
+ if (err < 0) {
+ merged_iter_close(&merged);
+ return err;
+ } else {
+ struct merged_iter *p =
+ reftable_malloc(sizeof(struct merged_iter));
+ *p = merged;
+ iterator_from_merged_iter(it, p);
+ }
+ return 0;
+}
+
+int reftable_merged_table_seek_ref(struct reftable_merged_table *mt,
+ struct reftable_iterator *it,
+ const char *name)
+{
+ struct reftable_ref_record ref = {
+ .refname = (char *)name,
+ };
+ struct reftable_record rec = { NULL };
+ reftable_record_from_ref(&rec, &ref);
+ return merged_table_seek_record(mt, it, &rec);
+}
+
+int reftable_merged_table_seek_log_at(struct reftable_merged_table *mt,
+ struct reftable_iterator *it,
+ const char *name, uint64_t update_index)
+{
+ struct reftable_log_record log = {
+ .refname = (char *)name,
+ .update_index = update_index,
+ };
+ struct reftable_record rec = { NULL };
+ reftable_record_from_log(&rec, &log);
+ return merged_table_seek_record(mt, it, &rec);
+}
+
+int reftable_merged_table_seek_log(struct reftable_merged_table *mt,
+ struct reftable_iterator *it,
+ const char *name)
+{
+ uint64_t max = ~((uint64_t)0);
+ return reftable_merged_table_seek_log_at(mt, it, name, max);
+}
+
+uint32_t reftable_merged_table_hash_id(struct reftable_merged_table *mt)
+{
+ return mt->hash_id;
+}
+
+static int reftable_merged_table_seek_void(void *tab,
+ struct reftable_iterator *it,
+ struct reftable_record *rec)
+{
+ return merged_table_seek_record(tab, it, rec);
+}
+
+static uint32_t reftable_merged_table_hash_id_void(void *tab)
+{
+ return reftable_merged_table_hash_id(tab);
+}
+
+static uint64_t reftable_merged_table_min_update_index_void(void *tab)
+{
+ return reftable_merged_table_min_update_index(tab);
+}
+
+static uint64_t reftable_merged_table_max_update_index_void(void *tab)
+{
+ return reftable_merged_table_max_update_index(tab);
+}
+
+static struct reftable_table_vtable merged_table_vtable = {
+ .seek_record = reftable_merged_table_seek_void,
+ .hash_id = reftable_merged_table_hash_id_void,
+ .min_update_index = reftable_merged_table_min_update_index_void,
+ .max_update_index = reftable_merged_table_max_update_index_void,
+};
+
+void reftable_table_from_merged_table(struct reftable_table *tab,
+ struct reftable_merged_table *merged)
+{
+ assert(!tab->ops);
+ tab->ops = &merged_table_vtable;
+ tab->table_arg = merged;
+}
new file mode 100644
@@ -0,0 +1,38 @@
+/*
+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"
+
+struct reftable_merged_table {
+ struct reftable_table *stack;
+ size_t stack_len;
+ uint32_t hash_id;
+
+ /* If unset, produce deletions. This is useful for compaction. For the
+ * full stack, deletions should be produced. */
+ int suppress_deletions;
+
+ uint64_t min;
+ uint64_t max;
+};
+
+struct merged_iter {
+ struct reftable_iterator *stack;
+ uint32_t hash_id;
+ size_t stack_len;
+ uint8_t typ;
+ int suppress_deletions;
+ struct merged_iter_pqueue pq;
+};
+
+void merged_table_release(struct reftable_merged_table *mt);
+
+#endif
new file mode 100644
@@ -0,0 +1,468 @@
+/*
+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 "basics.h"
+#include "blocksource.h"
+#include "constants.h"
+#include "reader.h"
+#include "record.h"
+#include "test_framework.h"
+#include "reftable-merged.h"
+#include "reftable-tests.h"
+#include "reftable-generic.h"
+#include "reftable-writer.h"
+
+static void write_test_table(struct strbuf *buf,
+ struct reftable_ref_record refs[], int n)
+{
+ int min = 0xffffffff;
+ int max = 0;
+ int i = 0;
+ int err;
+
+ struct reftable_write_options opts = {
+ .block_size = 256,
+ };
+ struct reftable_writer *w = NULL;
+ for (i = 0; i < n; i++) {
+ uint64_t ui = refs[i].update_index;
+ if (ui > max) {
+ max = ui;
+ }
+ if (ui < min) {
+ min = ui;
+ }
+ }
+
+ w = reftable_new_writer(&strbuf_add_void, buf, &opts);
+ reftable_writer_set_limits(w, min, max);
+
+ for (i = 0; i < n; i++) {
+ uint64_t before = refs[i].update_index;
+ int n = reftable_writer_add_ref(w, &refs[i]);
+ EXPECT(n == 0);
+ EXPECT(before == refs[i].update_index);
+ }
+
+ err = reftable_writer_close(w);
+ EXPECT_ERR(err);
+
+ reftable_writer_free(w);
+}
+
+static void write_test_log_table(struct strbuf *buf,
+ struct reftable_log_record logs[], int n,
+ uint64_t update_index)
+{
+ int i = 0;
+ int err;
+
+ struct reftable_write_options opts = {
+ .block_size = 256,
+ .exact_log_message = 1,
+ };
+ struct reftable_writer *w = NULL;
+ w = reftable_new_writer(&strbuf_add_void, buf, &opts);
+ reftable_writer_set_limits(w, update_index, update_index);
+
+ for (i = 0; i < n; i++) {
+ int err = reftable_writer_add_log(w, &logs[i]);
+ EXPECT_ERR(err);
+ }
+
+ err = reftable_writer_close(w);
+ EXPECT_ERR(err);
+
+ reftable_writer_free(w);
+}
+
+static struct reftable_merged_table *
+merged_table_from_records(struct reftable_ref_record **refs,
+ struct reftable_block_source **source,
+ struct reftable_reader ***readers, int *sizes,
+ struct strbuf *buf, int n)
+{
+ int i = 0;
+ struct reftable_merged_table *mt = NULL;
+ int err;
+ struct reftable_table *tabs =
+ reftable_calloc(n * sizeof(struct reftable_table));
+ *readers = reftable_calloc(n * sizeof(struct reftable_reader *));
+ *source = reftable_calloc(n * sizeof(**source));
+ for (i = 0; i < n; i++) {
+ write_test_table(&buf[i], refs[i], sizes[i]);
+ block_source_from_strbuf(&(*source)[i], &buf[i]);
+
+ err = reftable_new_reader(&(*readers)[i], &(*source)[i],
+ "name");
+ EXPECT_ERR(err);
+ reftable_table_from_reader(&tabs[i], (*readers)[i]);
+ }
+
+ err = reftable_new_merged_table(&mt, tabs, n, GIT_SHA1_FORMAT_ID);
+ EXPECT_ERR(err);
+ return mt;
+}
+
+static void readers_destroy(struct reftable_reader **readers, size_t n)
+{
+ int i = 0;
+ for (; i < n; i++)
+ reftable_reader_free(readers[i]);
+ reftable_free(readers);
+}
+
+static void test_merged_between(void)
+{
+ uint8_t hash1[GIT_SHA1_RAWSZ] = { 1, 2, 3, 0 };
+
+ struct reftable_ref_record r1[] = { {
+ .refname = "b",
+ .update_index = 1,
+ .value_type = REFTABLE_REF_VAL1,
+ .value.val1 = hash1,
+ } };
+ struct reftable_ref_record r2[] = { {
+ .refname = "a",
+ .update_index = 2,
+ .value_type = REFTABLE_REF_DELETION,
+ } };
+
+ struct reftable_ref_record *refs[] = { r1, r2 };
+ int sizes[] = { 1, 1 };
+ struct strbuf bufs[2] = { STRBUF_INIT, STRBUF_INIT };
+ struct reftable_block_source *bs = NULL;
+ struct reftable_reader **readers = NULL;
+ struct reftable_merged_table *mt =
+ merged_table_from_records(refs, &bs, &readers, sizes, bufs, 2);
+ int i;
+ struct reftable_ref_record ref = { NULL };
+ struct reftable_iterator it = { NULL };
+ int err = reftable_merged_table_seek_ref(mt, &it, "a");
+ EXPECT_ERR(err);
+
+ err = reftable_iterator_next_ref(&it, &ref);
+ EXPECT_ERR(err);
+ EXPECT(ref.update_index == 2);
+ reftable_ref_record_release(&ref);
+ reftable_iterator_destroy(&it);
+ readers_destroy(readers, 2);
+ reftable_merged_table_free(mt);
+ for (i = 0; i < ARRAY_SIZE(bufs); i++) {
+ strbuf_release(&bufs[i]);
+ }
+ reftable_free(bs);
+}
+
+static void test_merged(void)
+{
+ uint8_t hash1[GIT_SHA1_RAWSZ] = { 1 };
+ uint8_t hash2[GIT_SHA1_RAWSZ] = { 2 };
+ struct reftable_ref_record r1[] = {
+ {
+ .refname = "a",
+ .update_index = 1,
+ .value_type = REFTABLE_REF_VAL1,
+ .value.val1 = hash1,
+ },
+ {
+ .refname = "b",
+ .update_index = 1,
+ .value_type = REFTABLE_REF_VAL1,
+ .value.val1 = hash1,
+ },
+ {
+ .refname = "c",
+ .update_index = 1,
+ .value_type = REFTABLE_REF_VAL1,
+ .value.val1 = hash1,
+ }
+ };
+ struct reftable_ref_record r2[] = { {
+ .refname = "a",
+ .update_index = 2,
+ .value_type = REFTABLE_REF_DELETION,
+ } };
+ struct reftable_ref_record r3[] = {
+ {
+ .refname = "c",
+ .update_index = 3,
+ .value_type = REFTABLE_REF_VAL1,
+ .value.val1 = hash2,
+ },
+ {
+ .refname = "d",
+ .update_index = 3,
+ .value_type = REFTABLE_REF_VAL1,
+ .value.val1 = hash1,
+ },
+ };
+
+ struct reftable_ref_record want[] = {
+ r2[0],
+ r1[1],
+ r3[0],
+ r3[1],
+ };
+
+ struct reftable_ref_record *refs[] = { r1, r2, r3 };
+ int sizes[3] = { 3, 1, 2 };
+ struct strbuf bufs[3] = { STRBUF_INIT, STRBUF_INIT, STRBUF_INIT };
+ struct reftable_block_source *bs = NULL;
+ struct reftable_reader **readers = NULL;
+ struct reftable_merged_table *mt =
+ merged_table_from_records(refs, &bs, &readers, sizes, bufs, 3);
+
+ struct reftable_iterator it = { NULL };
+ int err = reftable_merged_table_seek_ref(mt, &it, "a");
+ struct reftable_ref_record *out = NULL;
+ size_t len = 0;
+ size_t cap = 0;
+ int i = 0;
+
+ EXPECT_ERR(err);
+ EXPECT(reftable_merged_table_hash_id(mt) == GIT_SHA1_FORMAT_ID);
+ EXPECT(reftable_merged_table_min_update_index(mt) == 1);
+
+ while (len < 100) { /* cap loops/recursion. */
+ struct reftable_ref_record ref = { NULL };
+ int err = reftable_iterator_next_ref(&it, &ref);
+ if (err > 0) {
+ break;
+ }
+ if (len == cap) {
+ cap = 2 * cap + 1;
+ out = reftable_realloc(
+ out, sizeof(struct reftable_ref_record) * cap);
+ }
+ out[len++] = ref;
+ }
+ reftable_iterator_destroy(&it);
+
+ EXPECT(ARRAY_SIZE(want) == len);
+ for (i = 0; i < len; i++) {
+ EXPECT(reftable_ref_record_equal(&want[i], &out[i],
+ GIT_SHA1_RAWSZ));
+ }
+ for (i = 0; i < len; i++) {
+ reftable_ref_record_release(&out[i]);
+ }
+ reftable_free(out);
+
+ for (i = 0; i < 3; i++) {
+ strbuf_release(&bufs[i]);
+ }
+ readers_destroy(readers, 3);
+ reftable_merged_table_free(mt);
+ reftable_free(bs);
+}
+
+static struct reftable_merged_table *
+merged_table_from_log_records(struct reftable_log_record **logs,
+ struct reftable_block_source **source,
+ struct reftable_reader ***readers, int *sizes,
+ struct strbuf *buf, int n)
+{
+ int i = 0;
+ struct reftable_merged_table *mt = NULL;
+ int err;
+ struct reftable_table *tabs =
+ reftable_calloc(n * sizeof(struct reftable_table));
+ *readers = reftable_calloc(n * sizeof(struct reftable_reader *));
+ *source = reftable_calloc(n * sizeof(**source));
+ for (i = 0; i < n; i++) {
+ write_test_log_table(&buf[i], logs[i], sizes[i], i + 1);
+ block_source_from_strbuf(&(*source)[i], &buf[i]);
+
+ err = reftable_new_reader(&(*readers)[i], &(*source)[i],
+ "name");
+ EXPECT_ERR(err);
+ reftable_table_from_reader(&tabs[i], (*readers)[i]);
+ }
+
+ err = reftable_new_merged_table(&mt, tabs, n, GIT_SHA1_FORMAT_ID);
+ EXPECT_ERR(err);
+ return mt;
+}
+
+static void test_merged_logs(void)
+{
+ uint8_t hash1[GIT_SHA1_RAWSZ] = { 1 };
+ uint8_t hash2[GIT_SHA1_RAWSZ] = { 2 };
+ uint8_t hash3[GIT_SHA1_RAWSZ] = { 3 };
+ struct reftable_log_record r1[] = {
+ {
+ .refname = "a",
+ .update_index = 2,
+ .value_type = REFTABLE_LOG_UPDATE,
+ .value.update = {
+ .old_hash = hash2,
+ /* deletion */
+ .name = "jane doe",
+ .email = "jane@invalid",
+ .message = "message2",
+ }
+ },
+ {
+ .refname = "a",
+ .update_index = 1,
+ .value_type = REFTABLE_LOG_UPDATE,
+ .value.update = {
+ .old_hash = hash1,
+ .new_hash = hash2,
+ .name = "jane doe",
+ .email = "jane@invalid",
+ .message = "message1",
+ }
+ },
+ };
+ struct reftable_log_record r2[] = {
+ {
+ .refname = "a",
+ .update_index = 3,
+ .value_type = REFTABLE_LOG_UPDATE,
+ .value.update = {
+ .new_hash = hash3,
+ .name = "jane doe",
+ .email = "jane@invalid",
+ .message = "message3",
+ }
+ },
+ };
+ struct reftable_log_record r3[] = {
+ {
+ .refname = "a",
+ .update_index = 2,
+ .value_type = REFTABLE_LOG_DELETION,
+ },
+ };
+ struct reftable_log_record want[] = {
+ r2[0],
+ r3[0],
+ r1[1],
+ };
+
+ struct reftable_log_record *logs[] = { r1, r2, r3 };
+ int sizes[3] = { 2, 1, 1 };
+ struct strbuf bufs[3] = { STRBUF_INIT, STRBUF_INIT, STRBUF_INIT };
+ struct reftable_block_source *bs = NULL;
+ struct reftable_reader **readers = NULL;
+ struct reftable_merged_table *mt = merged_table_from_log_records(
+ logs, &bs, &readers, sizes, bufs, 3);
+
+ struct reftable_iterator it = { NULL };
+ int err = reftable_merged_table_seek_log(mt, &it, "a");
+ struct reftable_log_record *out = NULL;
+ size_t len = 0;
+ size_t cap = 0;
+ int i = 0;
+
+ EXPECT_ERR(err);
+ EXPECT(reftable_merged_table_hash_id(mt) == GIT_SHA1_FORMAT_ID);
+ EXPECT(reftable_merged_table_min_update_index(mt) == 1);
+
+ while (len < 100) { /* cap loops/recursion. */
+ struct reftable_log_record log = { NULL };
+ int err = reftable_iterator_next_log(&it, &log);
+ if (err > 0) {
+ break;
+ }
+ if (len == cap) {
+ cap = 2 * cap + 1;
+ out = reftable_realloc(
+ out, sizeof(struct reftable_log_record) * cap);
+ }
+ out[len++] = log;
+ }
+ reftable_iterator_destroy(&it);
+
+ EXPECT(ARRAY_SIZE(want) == len);
+ for (i = 0; i < len; i++) {
+ EXPECT(reftable_log_record_equal(&want[i], &out[i],
+ GIT_SHA1_RAWSZ));
+ }
+
+ err = reftable_merged_table_seek_log_at(mt, &it, "a", 2);
+ EXPECT_ERR(err);
+ reftable_log_record_release(&out[0]);
+ err = reftable_iterator_next_log(&it, &out[0]);
+ EXPECT_ERR(err);
+ EXPECT(reftable_log_record_equal(&out[0], &r3[0], GIT_SHA1_RAWSZ));
+ reftable_iterator_destroy(&it);
+
+ for (i = 0; i < len; i++) {
+ reftable_log_record_release(&out[i]);
+ }
+ reftable_free(out);
+
+ for (i = 0; i < 3; i++) {
+ strbuf_release(&bufs[i]);
+ }
+ readers_destroy(readers, 3);
+ reftable_merged_table_free(mt);
+ reftable_free(bs);
+}
+
+static void test_default_write_opts(void)
+{
+ struct reftable_write_options opts = { 0 };
+ struct strbuf buf = STRBUF_INIT;
+ struct reftable_writer *w =
+ reftable_new_writer(&strbuf_add_void, &buf, &opts);
+
+ struct reftable_ref_record rec = {
+ .refname = "master",
+ .update_index = 1,
+ };
+ int err;
+ struct reftable_block_source source = { NULL };
+ struct reftable_table *tab = reftable_calloc(sizeof(*tab) * 1);
+ uint32_t hash_id;
+ struct reftable_reader *rd = NULL;
+ struct reftable_merged_table *merged = NULL;
+
+ reftable_writer_set_limits(w, 1, 1);
+
+ err = reftable_writer_add_ref(w, &rec);
+ EXPECT_ERR(err);
+
+ err = reftable_writer_close(w);
+ EXPECT_ERR(err);
+ reftable_writer_free(w);
+
+ block_source_from_strbuf(&source, &buf);
+
+ err = reftable_new_reader(&rd, &source, "filename");
+ EXPECT_ERR(err);
+
+ hash_id = reftable_reader_hash_id(rd);
+ EXPECT(hash_id == GIT_SHA1_FORMAT_ID);
+
+ reftable_table_from_reader(&tab[0], rd);
+ err = reftable_new_merged_table(&merged, tab, 1, GIT_SHA1_FORMAT_ID);
+ EXPECT_ERR(err);
+
+ reftable_reader_free(rd);
+ reftable_merged_table_free(merged);
+ strbuf_release(&buf);
+}
+
+/* XXX test refs_for(oid) */
+
+int merged_test_main(int argc, const char *argv[])
+{
+ RUN_TEST(test_merged_logs);
+ RUN_TEST(test_merged_between);
+ RUN_TEST(test_merged);
+ RUN_TEST(test_default_write_opts);
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,72 @@
+/*
+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_MERGED_H
+#define REFTABLE_MERGED_H
+
+#include "reftable-iterator.h"
+
+/*
+ * Merged tables
+ *
+ * A ref database kept in a sequence of table files. The merged_table presents a
+ * unified view to reading (seeking, iterating) a sequence of immutable tables.
+ *
+ * The merged tables are on purpose kept disconnected from their actual storage
+ * (eg. files on disk), because it is useful to merge tables aren't files. For
+ * example, the per-workspace and global ref namespace can be implemented as a
+ * merged table of two stacks of file-backed reftables.
+ */
+
+/* A merged table is implements seeking/iterating over a stack of tables. */
+struct reftable_merged_table;
+
+/* A generic reftable; see below. */
+struct reftable_table;
+
+/* reftable_new_merged_table creates a new merged table. It takes ownership of
+ the stack array.
+*/
+int reftable_new_merged_table(struct reftable_merged_table **dest,
+ struct reftable_table *stack, int n,
+ uint32_t hash_id);
+
+/* returns an iterator positioned just before 'name' */
+int reftable_merged_table_seek_ref(struct reftable_merged_table *mt,
+ struct reftable_iterator *it,
+ const char *name);
+
+/* returns an iterator for log entry, at given update_index */
+int reftable_merged_table_seek_log_at(struct reftable_merged_table *mt,
+ struct reftable_iterator *it,
+ const char *name, uint64_t update_index);
+
+/* like reftable_merged_table_seek_log_at but look for the newest entry. */
+int reftable_merged_table_seek_log(struct reftable_merged_table *mt,
+ struct reftable_iterator *it,
+ const char *name);
+
+/* returns the max update_index covered by this merged table. */
+uint64_t
+reftable_merged_table_max_update_index(struct reftable_merged_table *mt);
+
+/* returns the min update_index covered by this merged table. */
+uint64_t
+reftable_merged_table_min_update_index(struct reftable_merged_table *mt);
+
+/* releases memory for the merged_table */
+void reftable_merged_table_free(struct reftable_merged_table *m);
+
+/* return the hash ID of the merged table. */
+uint32_t reftable_merged_table_hash_id(struct reftable_merged_table *m);
+
+/* create a generic table from reftable_merged_table */
+void reftable_table_from_merged_table(struct reftable_table *tab,
+ struct reftable_merged_table *table);
+
+#endif
@@ -5,6 +5,7 @@ int cmd__reftable(int argc, const char **argv)
{
basics_test_main(argc, argv);
block_test_main(argc, argv);
+ merged_test_main(argc, argv);
pq_test_main(argc, argv);
record_test_main(argc, argv);
readwrite_test_main(argc, argv);