| Message ID | 2b83989fbcd3d464a3172eeb7cfea2e06e4f3785.1614111270.git.gitgitgadget@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Sparse Index: Design, Format, Tests | expand |
On Tue, Feb 23, 2021 at 12:14 PM Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com> wrote: > > From: Derrick Stolee <dstolee@microsoft.com> > > We will mark an in-memory index_state as having sparse directory entries > with the sparse_index bit. These currently cannot exist, but we will add > a mechanism for collapsing a full index to a sparse one in a later > change. That will happen at write time, so we must first allow parsing > the format before writing it. > > Commands or methods that require a full index in order to operate can > call ensure_full_index() to expand that index in-memory. This requires > parsing trees using that index's repository. > > Sparse directory entries have a specific 'ce_mode' value. The macro > S_ISSPARSEDIR(ce->ce_mode) can check if a cache_entry 'ce' has this type. > This ce_mode is not possible with the existing index formats, so we don't > also verify all properties of a sparse-directory entry, which are: > > 1. ce->ce_mode == 0040000 > 2. ce->flags & CE_SKIP_WORKTREE is true > 3. ce->name[ce->namelen - 1] == '/' (ends in dir separator) > 4. ce->oid references a tree object. > > These are all semi-enforced in ensure_full_index() to some extent. Any > deviation will cause a warning at minimum or a failure in the worst > case. Thanks for spelling these all out; looks good. > > Signed-off-by: Derrick Stolee <dstolee@microsoft.com> > --- > cache.h | 7 +++- > read-cache.c | 9 +++++ > sparse-index.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++- > 3 files changed, 109 insertions(+), 2 deletions(-) > > diff --git a/cache.h b/cache.h > index d92814961405..1336c8d7435e 100644 > --- a/cache.h > +++ b/cache.h > @@ -204,6 +204,8 @@ struct cache_entry { > #error "CE_EXTENDED_FLAGS out of range" > #endif > > +#define S_ISSPARSEDIR(m) ((m) == S_IFDIR) Much nicer, thanks. :-) > + > /* Forward structure decls */ > struct pathspec; > struct child_process; > @@ -319,7 +321,8 @@ struct index_state { > drop_cache_tree : 1, > updated_workdir : 1, > updated_skipworktree : 1, > - fsmonitor_has_run_once : 1; > + fsmonitor_has_run_once : 1, > + sparse_index : 1; > struct hashmap name_hash; > struct hashmap dir_hash; > struct object_id oid; > @@ -722,6 +725,8 @@ int read_index_from(struct index_state *, const char *path, > const char *gitdir); > int is_index_unborn(struct index_state *); > > +void ensure_full_index(struct index_state *istate); > + > /* For use with `write_locked_index()`. */ > #define COMMIT_LOCK (1 << 0) > #define SKIP_IF_UNCHANGED (1 << 1) > diff --git a/read-cache.c b/read-cache.c > index 29144cf879e7..97dbf2434f30 100644 > --- a/read-cache.c > +++ b/read-cache.c > @@ -101,6 +101,9 @@ static const char *alternate_index_output; > > static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) > { > + if (S_ISSPARSEDIR(ce->ce_mode)) > + istate->sparse_index = 1; A very minor question -- someone who sees "sparse_index" could probably easily think either "index with missing entries, due to having a SKIP_WORKTREE directory instead" or perhaps "index when using the sparse-checkout feature, i.e. it has some SKIP_WORKTREE entries in it". From the code here, clearly the former is your intent. I wonder if it'd help to have a small comment near the declaration of sparse_index to mention its intent. > + > istate->cache[nr] = ce; > add_name_hash(istate, ce); > } > @@ -2255,6 +2258,12 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist) > trace2_data_intmax("index", the_repository, "read/cache_nr", > istate->cache_nr); > > + if (!istate->repo) > + istate->repo = the_repository; > + prepare_repo_settings(istate->repo); > + if (istate->repo->settings.command_requires_full_index) > + ensure_full_index(istate); > + > return istate->cache_nr; > > unmap: > diff --git a/sparse-index.c b/sparse-index.c > index 82183ead563b..316cb949b74b 100644 > --- a/sparse-index.c > +++ b/sparse-index.c > @@ -1,8 +1,101 @@ > #include "cache.h" > #include "repository.h" > #include "sparse-index.h" > +#include "tree.h" > +#include "pathspec.h" > +#include "trace2.h" > + > +static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) > +{ > + ALLOC_GROW(istate->cache, nr + 1, istate->cache_alloc); > + > + istate->cache[nr] = ce; > + add_name_hash(istate, ce); > +} > + > +static int add_path_to_index(const struct object_id *oid, > + struct strbuf *base, const char *path, > + unsigned int mode, int stage, void *context) > +{ > + struct index_state *istate = (struct index_state *)context; > + struct cache_entry *ce; > + size_t len = base->len; > + > + if (S_ISDIR(mode)) > + return READ_TREE_RECURSIVE; > + > + strbuf_addstr(base, path); > + > + ce = make_cache_entry(istate, mode, oid, base->buf, 0, 0); > + ce->ce_flags |= CE_SKIP_WORKTREE; > + set_index_entry(istate, istate->cache_nr++, ce); > + > + strbuf_setlen(base, len); > + return 0; > +} > > void ensure_full_index(struct index_state *istate) > { > - /* intentionally left blank */ > + int i; > + struct index_state *full; > + > + if (!istate || !istate->sparse_index) > + return; > + > + if (!istate->repo) > + istate->repo = the_repository; > + > + trace2_region_enter("index", "ensure_full_index", istate->repo); > + > + /* initialize basics of new index */ > + full = xcalloc(1, sizeof(struct index_state)); > + memcpy(full, istate, sizeof(struct index_state)); > + > + /* then change the necessary things */ > + full->sparse_index = 0; > + full->cache_alloc = (3 * istate->cache_alloc) / 2; > + full->cache_nr = 0; > + ALLOC_ARRAY(full->cache, full->cache_alloc); > + > + for (i = 0; i < istate->cache_nr; i++) { > + struct cache_entry *ce = istate->cache[i]; > + struct tree *tree; > + struct pathspec ps; > + > + if (!S_ISSPARSEDIR(ce->ce_mode)) { > + set_index_entry(full, full->cache_nr++, ce); > + continue; > + } > + if (!(ce->ce_flags & CE_SKIP_WORKTREE)) > + warning(_("index entry is a directory, but not sparse (%08x)"), > + ce->ce_flags); > + > + /* recursively walk into cd->name */ > + tree = lookup_tree(istate->repo, &ce->oid); > + > + memset(&ps, 0, sizeof(ps)); > + ps.recursive = 1; > + ps.has_wildcard = 1; > + ps.max_depth = -1; > + > + read_tree_recursive(istate->repo, tree, > + ce->name, strlen(ce->name), > + 0, &ps, > + add_path_to_index, full); > + > + /* free directory entries. full entries are re-used */ > + discard_cache_entry(ce); > + } > + > + /* Copy back into original index. */ > + memcpy(&istate->name_hash, &full->name_hash, sizeof(full->name_hash)); > + istate->sparse_index = 0; > + free(istate->cache); Thanks for fixing that leak that from the RFC series. > + istate->cache = full->cache; > + istate->cache_nr = full->cache_nr; > + istate->cache_alloc = full->cache_alloc; > + > + free(full); > + > + trace2_region_leave("index", "ensure_full_index", istate->repo); > } > -- > gitgitgadget Looks good to me.
diff --git a/cache.h b/cache.h index d92814961405..1336c8d7435e 100644 --- a/cache.h +++ b/cache.h @@ -204,6 +204,8 @@ struct cache_entry { #error "CE_EXTENDED_FLAGS out of range" #endif +#define S_ISSPARSEDIR(m) ((m) == S_IFDIR) + /* Forward structure decls */ struct pathspec; struct child_process; @@ -319,7 +321,8 @@ struct index_state { drop_cache_tree : 1, updated_workdir : 1, updated_skipworktree : 1, - fsmonitor_has_run_once : 1; + fsmonitor_has_run_once : 1, + sparse_index : 1; struct hashmap name_hash; struct hashmap dir_hash; struct object_id oid; @@ -722,6 +725,8 @@ int read_index_from(struct index_state *, const char *path, const char *gitdir); int is_index_unborn(struct index_state *); +void ensure_full_index(struct index_state *istate); + /* For use with `write_locked_index()`. */ #define COMMIT_LOCK (1 << 0) #define SKIP_IF_UNCHANGED (1 << 1) diff --git a/read-cache.c b/read-cache.c index 29144cf879e7..97dbf2434f30 100644 --- a/read-cache.c +++ b/read-cache.c @@ -101,6 +101,9 @@ static const char *alternate_index_output; static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) { + if (S_ISSPARSEDIR(ce->ce_mode)) + istate->sparse_index = 1; + istate->cache[nr] = ce; add_name_hash(istate, ce); } @@ -2255,6 +2258,12 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist) trace2_data_intmax("index", the_repository, "read/cache_nr", istate->cache_nr); + if (!istate->repo) + istate->repo = the_repository; + prepare_repo_settings(istate->repo); + if (istate->repo->settings.command_requires_full_index) + ensure_full_index(istate); + return istate->cache_nr; unmap: diff --git a/sparse-index.c b/sparse-index.c index 82183ead563b..316cb949b74b 100644 --- a/sparse-index.c +++ b/sparse-index.c @@ -1,8 +1,101 @@ #include "cache.h" #include "repository.h" #include "sparse-index.h" +#include "tree.h" +#include "pathspec.h" +#include "trace2.h" + +static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce) +{ + ALLOC_GROW(istate->cache, nr + 1, istate->cache_alloc); + + istate->cache[nr] = ce; + add_name_hash(istate, ce); +} + +static int add_path_to_index(const struct object_id *oid, + struct strbuf *base, const char *path, + unsigned int mode, int stage, void *context) +{ + struct index_state *istate = (struct index_state *)context; + struct cache_entry *ce; + size_t len = base->len; + + if (S_ISDIR(mode)) + return READ_TREE_RECURSIVE; + + strbuf_addstr(base, path); + + ce = make_cache_entry(istate, mode, oid, base->buf, 0, 0); + ce->ce_flags |= CE_SKIP_WORKTREE; + set_index_entry(istate, istate->cache_nr++, ce); + + strbuf_setlen(base, len); + return 0; +} void ensure_full_index(struct index_state *istate) { - /* intentionally left blank */ + int i; + struct index_state *full; + + if (!istate || !istate->sparse_index) + return; + + if (!istate->repo) + istate->repo = the_repository; + + trace2_region_enter("index", "ensure_full_index", istate->repo); + + /* initialize basics of new index */ + full = xcalloc(1, sizeof(struct index_state)); + memcpy(full, istate, sizeof(struct index_state)); + + /* then change the necessary things */ + full->sparse_index = 0; + full->cache_alloc = (3 * istate->cache_alloc) / 2; + full->cache_nr = 0; + ALLOC_ARRAY(full->cache, full->cache_alloc); + + for (i = 0; i < istate->cache_nr; i++) { + struct cache_entry *ce = istate->cache[i]; + struct tree *tree; + struct pathspec ps; + + if (!S_ISSPARSEDIR(ce->ce_mode)) { + set_index_entry(full, full->cache_nr++, ce); + continue; + } + if (!(ce->ce_flags & CE_SKIP_WORKTREE)) + warning(_("index entry is a directory, but not sparse (%08x)"), + ce->ce_flags); + + /* recursively walk into cd->name */ + tree = lookup_tree(istate->repo, &ce->oid); + + memset(&ps, 0, sizeof(ps)); + ps.recursive = 1; + ps.has_wildcard = 1; + ps.max_depth = -1; + + read_tree_recursive(istate->repo, tree, + ce->name, strlen(ce->name), + 0, &ps, + add_path_to_index, full); + + /* free directory entries. full entries are re-used */ + discard_cache_entry(ce); + } + + /* Copy back into original index. */ + memcpy(&istate->name_hash, &full->name_hash, sizeof(full->name_hash)); + istate->sparse_index = 0; + free(istate->cache); + istate->cache = full->cache; + istate->cache_nr = full->cache_nr; + istate->cache_alloc = full->cache_alloc; + + free(full); + + trace2_region_leave("index", "ensure_full_index", istate->repo); }