diff options
Diffstat (limited to 'read-cache.c')
| -rw-r--r-- | read-cache.c | 1132 |
1 files changed, 956 insertions, 176 deletions
diff --git a/read-cache.c b/read-cache.c index e865254bea..d57958233e 100644 --- a/read-cache.c +++ b/read-cache.c @@ -6,6 +6,8 @@ #define NO_THE_INDEX_COMPATIBILITY_MACROS #include "cache.h" #include "config.h" +#include "diff.h" +#include "diffcore.h" #include "tempfile.h" #include "lockfile.h" #include "cache-tree.h" @@ -21,6 +23,8 @@ #include "split-index.h" #include "utf8.h" #include "fsmonitor.h" +#include "thread-utils.h" +#include "progress.h" /* Mask for the name length in ce_flags in the on-disk index */ @@ -41,12 +45,56 @@ #define CACHE_EXT_LINK 0x6c696e6b /* "link" */ #define CACHE_EXT_UNTRACKED 0x554E5452 /* "UNTR" */ #define CACHE_EXT_FSMONITOR 0x46534D4E /* "FSMN" */ +#define CACHE_EXT_ENDOFINDEXENTRIES 0x454F4945 /* "EOIE" */ +#define CACHE_EXT_INDEXENTRYOFFSETTABLE 0x49454F54 /* "IEOT" */ /* changes that can be kept in $GIT_DIR/index (basically all extensions) */ #define EXTMASK (RESOLVE_UNDO_CHANGED | CACHE_TREE_CHANGED | \ CE_ENTRY_ADDED | CE_ENTRY_REMOVED | CE_ENTRY_CHANGED | \ SPLIT_INDEX_ORDERED | UNTRACKED_CHANGED | FSMONITOR_CHANGED) + +/* + * This is an estimate of the pathname length in the index. We use + * this for V4 index files to guess the un-deltafied size of the index + * in memory because of pathname deltafication. This is not required + * for V2/V3 index formats because their pathnames are not compressed. + * If the initial amount of memory set aside is not sufficient, the + * mem pool will allocate extra memory. + */ +#define CACHE_ENTRY_PATH_LENGTH 80 + +static inline struct cache_entry *mem_pool__ce_alloc(struct mem_pool *mem_pool, size_t len) +{ + struct cache_entry *ce; + ce = mem_pool_alloc(mem_pool, cache_entry_size(len)); + ce->mem_pool_allocated = 1; + return ce; +} + +static inline struct cache_entry *mem_pool__ce_calloc(struct mem_pool *mem_pool, size_t len) +{ + struct cache_entry * ce; + ce = mem_pool_calloc(mem_pool, 1, cache_entry_size(len)); + ce->mem_pool_allocated = 1; + return ce; +} + +static struct mem_pool *find_mem_pool(struct index_state *istate) +{ + struct mem_pool **pool_ptr; + + if (istate->split_index && istate->split_index->base) + pool_ptr = &istate->split_index->base->ce_mem_pool; + else + pool_ptr = &istate->ce_mem_pool; + + if (!*pool_ptr) + mem_pool_init(pool_ptr, 0); + + return *pool_ptr; +} + struct index_state the_index; static const char *alternate_index_output; @@ -62,7 +110,7 @@ static void replace_index_entry(struct index_state *istate, int nr, struct cache replace_index_entry_in_base(istate, old, ce); remove_name_hash(istate, old); - free(old); + discard_cache_entry(old); ce->ce_flags &= ~CE_HASHED; set_index_entry(istate, nr, ce); ce->ce_flags |= CE_UPDATE_IN_BASE; @@ -75,7 +123,7 @@ void rename_index_entry_at(struct index_state *istate, int nr, const char *new_n struct cache_entry *old_entry = istate->cache[nr], *new_entry; int namelen = strlen(new_name); - new_entry = xmalloc(cache_entry_size(namelen)); + new_entry = make_empty_cache_entry(istate, namelen); copy_cache_entry(new_entry, old_entry); new_entry->ce_flags &= ~CE_HASHED; new_entry->ce_namelen = namelen; @@ -161,15 +209,17 @@ void fill_stat_cache_info(struct cache_entry *ce, struct stat *st) } } -static int ce_compare_data(const struct cache_entry *ce, struct stat *st) +static int ce_compare_data(struct index_state *istate, + const struct cache_entry *ce, + struct stat *st) { int match = -1; int fd = git_open_cloexec(ce->name, O_RDONLY); if (fd >= 0) { struct object_id oid; - if (!index_fd(&oid, fd, st, OBJ_BLOB, ce->name, 0)) - match = oidcmp(&oid, &ce->oid); + if (!index_fd(istate, &oid, fd, st, OBJ_BLOB, ce->name, 0)) + match = !oideq(&oid, &ce->oid); /* index_fd() closed the file descriptor already */ } return match; @@ -210,14 +260,16 @@ static int ce_compare_gitlink(const struct cache_entry *ce) */ if (resolve_gitlink_ref(ce->name, "HEAD", &oid) < 0) return 0; - return oidcmp(&oid, &ce->oid); + return !oideq(&oid, &ce->oid); } -static int ce_modified_check_fs(const struct cache_entry *ce, struct stat *st) +static int ce_modified_check_fs(struct index_state *istate, + const struct cache_entry *ce, + struct stat *st) { switch (st->st_mode & S_IFMT) { case S_IFREG: - if (ce_compare_data(ce, st)) + if (ce_compare_data(istate, ce, st)) return DATA_CHANGED; break; case S_IFLNK: @@ -293,7 +345,7 @@ static int is_racy_stat(const struct index_state *istate, ); } -static int is_racy_timestamp(const struct index_state *istate, +int is_racy_timestamp(const struct index_state *istate, const struct cache_entry *ce) { return (!S_ISGITLINK(ce->ce_mode) && @@ -363,7 +415,7 @@ int ie_match_stat(struct index_state *istate, if (assume_racy_is_modified) changed |= DATA_CHANGED; else - changed |= ce_modified_check_fs(ce, st); + changed |= ce_modified_check_fs(istate, ce, st); } return changed; @@ -403,7 +455,7 @@ int ie_modified(struct index_state *istate, (S_ISGITLINK(ce->ce_mode) || ce->ce_stat_data.sd_size != 0)) return changed; - changed_fs = ce_modified_check_fs(ce, st); + changed_fs = ce_modified_check_fs(istate, ce, st); if (changed_fs) return changed | changed_fs; return 0; @@ -624,7 +676,7 @@ static struct cache_entry *create_alias_ce(struct index_state *istate, /* Ok, create the new entry using the name of the existing alias */ len = ce_namelen(alias); - new_entry = xcalloc(1, cache_entry_size(len)); + new_entry = make_empty_cache_entry(istate, len); memcpy(new_entry->name, alias->name, len); copy_cache_entry(new_entry, ce); save_or_free_index_entry(istate, ce); @@ -641,7 +693,7 @@ void set_object_name_for_intent_to_add_entry(struct cache_entry *ce) int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags) { - int size, namelen, was_same; + int namelen, was_same; mode_t st_mode = st->st_mode; struct cache_entry *ce, *alias = NULL; unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY; @@ -663,8 +715,7 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st, while (namelen && path[namelen-1] == '/') namelen--; } - size = cache_entry_size(namelen); - ce = xcalloc(1, size); + ce = make_empty_cache_entry(istate, namelen); memcpy(ce->name, path, namelen); ce->ce_namelen = namelen; if (!intent_only) @@ -705,13 +756,13 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st, ce_mark_uptodate(alias); alias->ce_flags |= CE_ADDED; - free(ce); + discard_cache_entry(ce); return 0; } } if (!intent_only) { - if (index_path(&ce->oid, path, st, newflags)) { - free(ce); + if (index_path(istate, &ce->oid, path, st, newflags)) { + discard_cache_entry(ce); return error("unable to index file %s", path); } } else @@ -724,13 +775,13 @@ int add_to_index(struct index_state *istate, const char *path, struct stat *st, /* It was suspected to be racily clean, but it turns out to be Ok */ was_same = (alias && !ce_stage(alias) && - !oidcmp(&alias->oid, &ce->oid) && + oideq(&alias->oid, &ce->oid) && ce->ce_mode == alias->ce_mode); if (pretend) - free(ce); + discard_cache_entry(ce); else if (add_index_entry(istate, ce, add_option)) { - free(ce); + discard_cache_entry(ce); return error("unable to add %s to index", path); } if (verbose && !was_same) @@ -746,12 +797,25 @@ int add_file_to_index(struct index_state *istate, const char *path, int flags) return add_to_index(istate, path, &st, flags); } -struct cache_entry *make_cache_entry(unsigned int mode, - const unsigned char *sha1, const char *path, int stage, - unsigned int refresh_options) +struct cache_entry *make_empty_cache_entry(struct index_state *istate, size_t len) +{ + return mem_pool__ce_calloc(find_mem_pool(istate), len); +} + +struct cache_entry *make_empty_transient_cache_entry(size_t len) +{ + return xcalloc(1, cache_entry_size(len)); +} + +struct cache_entry *make_cache_entry(struct index_state *istate, + unsigned int mode, + const struct object_id *oid, + const char *path, + int stage, + unsigned int refresh_options) { - int size, len; struct cache_entry *ce, *ret; + int len; if (!verify_path(path, mode)) { error("Invalid path '%s'", path); @@ -759,21 +823,43 @@ struct cache_entry *make_cache_entry(unsigned int mode, } len = strlen(path); - size = cache_entry_size(len); - ce = xcalloc(1, size); + ce = make_empty_cache_entry(istate, len); - hashcpy(ce->oid.hash, sha1); + oidcpy(&ce->oid, oid); memcpy(ce->name, path, len); ce->ce_flags = create_ce_flags(stage); ce->ce_namelen = len; ce->ce_mode = create_ce_mode(mode); - ret = refresh_cache_entry(ce, refresh_options); + ret = refresh_cache_entry(istate, ce, refresh_options); if (ret != ce) - free(ce); + discard_cache_entry(ce); return ret; } +struct cache_entry *make_transient_cache_entry(unsigned int mode, const struct object_id *oid, + const char *path, int stage) +{ + struct cache_entry *ce; + int len; + + if (!verify_path(path, mode)) { + error("Invalid path '%s'", path); + return NULL; + } + + len = strlen(path); + ce = make_empty_transient_cache_entry(len); + + oidcpy(&ce->oid, oid); + memcpy(ce->name, path, len); + ce->ce_flags = create_ce_flags(stage); + ce->ce_namelen = len; + ce->ce_mode = create_ce_mode(mode); + + return ce; +} + /* * Chmod an index entry with either +x or -x. * @@ -1269,7 +1355,7 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate, { struct stat st; struct cache_entry *updated; - int changed, size; + int changed; int refresh = options & CE_MATCH_REFRESH; int ignore_valid = options & CE_MATCH_IGNORE_VALID; int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE; @@ -1349,8 +1435,7 @@ static struct cache_entry *refresh_cache_ent(struct index_state *istate, return NULL; } - size = ce_size(ce); - updated = xmalloc(size); + updated = make_empty_cache_entry(istate, ce_namelen(ce)); copy_cache_entry(updated, ce); memcpy(updated->name, ce->name, ce->ce_namelen + 1); fill_stat_cache_info(updated, &st); @@ -1399,8 +1484,13 @@ int refresh_index(struct index_state *istate, unsigned int flags, const char *typechange_fmt; const char *added_fmt; const char *unmerged_fmt; - uint64_t start = getnanotime(); + struct progress *progress = NULL; + + if (flags & REFRESH_PROGRESS && isatty(2)) + progress = start_delayed_progress(_("Refresh index"), + istate->cache_nr); + trace_performance_enter(); modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n"); deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n"); typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n"); @@ -1416,7 +1506,7 @@ int refresh_index(struct index_state *istate, unsigned int flags, if (ignore_submodules && S_ISGITLINK(ce->ce_mode)) continue; - if (pathspec && !ce_path_match(ce, pathspec, seen)) + if (pathspec && !ce_path_match(istate, ce, pathspec, seen)) filtered = 1; if (ce_stage(ce)) { @@ -1439,6 +1529,8 @@ int refresh_index(struct index_state *istate, unsigned int flags, new_entry = refresh_cache_ent(istate, ce, options, &cache_errno, &changed); if (new_entry == ce) continue; + if (progress) + display_progress(progress, i); if (!new_entry) { const char *fmt; @@ -1470,14 +1562,19 @@ int refresh_index(struct index_state *istate, unsigned int flags, replace_index_entry(istate, i, new_entry); } - trace_performance_since(start, "refresh index"); + if (progress) { + display_progress(progress, istate->cache_nr); + stop_progress(&progress); + } + trace_performance_leave("refresh index"); return has_errors; } -struct cache_entry *refresh_cache_entry(struct cache_entry *ce, - unsigned int options) +struct cache_entry *refresh_cache_entry(struct index_state *istate, + struct cache_entry *ce, + unsigned int options) { - return refresh_cache_ent(&the_index, ce, options, NULL, NULL); + return refresh_cache_ent(istate, ce, options, NULL, NULL); } @@ -1572,7 +1669,7 @@ int verify_index_checksum; /* Allow fsck to force verification of the cache entry order. */ int verify_ce_order; -static int verify_hdr(struct cache_header *hdr, unsigned long size) +static int verify_hdr(const struct cache_header *hdr, unsigned long size) { git_hash_ctx c; unsigned char hash[GIT_MAX_RAWSZ]; @@ -1590,13 +1687,13 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size) the_hash_algo->init_fn(&c); the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz); the_hash_algo->final_fn(hash, &c); - if (hashcmp(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz)) + if (!hasheq(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz)) return error("bad index file sha1 signature"); return 0; } static int read_index_extension(struct index_state *istate, - const char *ext, void *data, unsigned long sz) + const char *ext, const char *data, unsigned long sz) { switch (CACHE_EXT(ext)) { case CACHE_EXT_TREE: @@ -1615,6 +1712,10 @@ static int read_index_extension(struct index_state *istate, case CACHE_EXT_FSMONITOR: read_fsmonitor_extension(istate, data, sz); break; + case CACHE_EXT_ENDOFINDEXENTRIES: + case CACHE_EXT_INDEXENTRYOFFSETTABLE: + /* already handled in do_read_index() */ + break; default: if (*ext < 'A' || 'Z' < *ext) return error("index uses %.4s extension, which we do not understand", @@ -1635,61 +1736,25 @@ int read_index(struct index_state *istate) return read_index_from(istate, get_index_file(), get_git_dir()); } -static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk, - unsigned int flags, - const char *name, - size_t len) -{ - struct cache_entry *ce = xmalloc(cache_entry_size(len)); - - ce->ce_stat_data.sd_ctime.sec = get_be32(&ondisk->ctime.sec); - ce->ce_stat_data.sd_mtime.sec = get_be32(&ondisk->mtime.sec); - ce->ce_stat_data.sd_ctime.nsec = get_be32(&ondisk->ctime.nsec); - ce->ce_stat_data.sd_mtime.nsec = get_be32(&ondisk->mtime.nsec); - ce->ce_stat_data.sd_dev = get_be32(&ondisk->dev); - ce->ce_stat_data.sd_ino = get_be32(&ondisk->ino); - ce->ce_mode = get_be32(&ondisk->mode); - ce->ce_stat_data.sd_uid = get_be32(&ondisk->uid); - ce->ce_stat_data.sd_gid = get_be32(&ondisk->gid); - ce->ce_stat_data.sd_size = get_be32(&ondisk->size); - ce->ce_flags = flags & ~CE_NAMEMASK; - ce->ce_namelen = len; - ce->index = 0; - hashcpy(ce->oid.hash, ondisk->sha1); - memcpy(ce->name, name, len); - ce->name[len] = '\0'; - return ce; -} - -/* - * Adjacent cache entries tend to share the leading paths, so it makes - * sense to only store the differences in later entries. In the v4 - * on-disk format of the index, each on-disk cache entry stores the - * number of bytes to be stripped from the end of the previous name, - * and the bytes to append to the result, to come up with its name. - */ -static unsigned long expand_name_field(struct strbuf *name, const char *cp_) -{ - const unsigned char *ep, *cp = (const unsigned char *)cp_; - size_t len = decode_varint(&cp); - - if (name->len < len) - die("malformed name field in the index"); - strbuf_remove(name, name->len - len, len); - for (ep = cp; *ep; ep++) - ; /* find the end */ - strbuf_add(name, cp, ep - cp); - return (const char *)ep + 1 - cp_; -} - -static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk, +static struct cache_entry *create_from_disk(struct mem_pool *ce_mem_pool, + unsigned int version, + struct ondisk_cache_entry *ondisk, unsigned long *ent_size, - struct strbuf *previous_name) + const struct cache_entry *previous_ce) { struct cache_entry *ce; size_t len; const char *name; unsigned int flags; + size_t copy_len; + /* + * Adjacent cache entries tend to share the leading paths, so it makes + * sense to only store the differences in later entries. In the v4 + * on-disk format of the index, each on-disk cache entry stores the + * number of bytes to be stripped from the end of the previous name, + * and the bytes to append to the result, to come up with its name. + */ + int expand_name_field = version == 4; /* On-disk flags are just 16 bits */ flags = get_be16(&ondisk->flags); @@ -1709,21 +1774,55 @@ static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk, else name = ondisk->name; - if (!previous_name) { - /* v3 and earlier */ - if (len == CE_NAMEMASK) - len = strlen(name); - ce = cache_entry_from_ondisk(ondisk, flags, name, len); + if (expand_name_field) { + const unsigned char *cp = (const unsigned char *)name; + size_t strip_len, previous_len; + + /* If we're at the begining of a block, ignore the previous name */ + strip_len = decode_varint(&cp); + if (previous_ce) { + previous_len = previous_ce->ce_namelen; + if (previous_len < strip_len) + die(_("malformed name field in the index, near path '%s'"), + previous_ce->name); + copy_len = previous_len - strip_len; + } else { + copy_len = 0; + } + name = (const char *)cp; + } - *ent_size = ondisk_ce_size(ce); - } else { - unsigned long consumed; - consumed = expand_name_field(previous_name, name); - ce = cache_entry_from_ondisk(ondisk, flags, - previous_name->buf, - previous_name->len); + if (len == CE_NAMEMASK) { + len = strlen(name); + if (expand_name_field) + len += copy_len; + } - *ent_size = (name - ((char *)ondisk)) + consumed; + ce = mem_pool__ce_alloc(ce_mem_pool, len); + + ce->ce_stat_data.sd_ctime.sec = get_be32(&ondisk->ctime.sec); + ce->ce_stat_data.sd_mtime.sec = get_be32(&ondisk->mtime.sec); + ce->ce_stat_data.sd_ctime.nsec = get_be32(&ondisk->ctime.nsec); + ce->ce_stat_data.sd_mtime.nsec = get_be32(&ondisk->mtime.nsec); + ce->ce_stat_data.sd_dev = get_be32(&ondisk->dev); + ce->ce_stat_data.sd_ino = get_be32(&ondisk->ino); + ce->ce_mode = get_be32(&ondisk->mode); + ce->ce_stat_data.sd_uid = get_be32(&ondisk->uid); + ce->ce_stat_data.sd_gid = get_be32(&ondisk->gid); + ce->ce_stat_data.sd_size = get_be32(&ondisk->size); + ce->ce_flags = flags & ~CE_NAMEMASK; + ce->ce_namelen = len; + ce->index = 0; + hashcpy(ce->oid.hash, ondisk->sha1); + + if (expand_name_field) { + if (copy_len) + memcpy(ce->name, previous_ce->name, copy_len); + memcpy(ce->name + copy_len, name, len + 1 - copy_len); + *ent_size = (name - ((char *)ondisk)) + len + 1 - copy_len; + } else { + memcpy(ce->name, name, len + 1); + *ent_size = ondisk_ce_size(ce); } return ce; } @@ -1793,16 +1892,253 @@ static void post_read_index_from(struct index_state *istate) tweak_fsmonitor(istate); } +static size_t estimate_cache_size_from_compressed(unsigned int entries) +{ + return entries * (sizeof(struct cache_entry) + CACHE_ENTRY_PATH_LENGTH); +} + +static size_t estimate_cache_size(size_t ondisk_size, unsigned int entries) +{ + long per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry); + + /* + * Account for potential alignment differences. + */ + per_entry += align_padding_size(sizeof(struct cache_entry), -sizeof(struct ondisk_cache_entry)); + return ondisk_size + entries * per_entry; +} + +struct index_entry_offset +{ + /* starting byte offset into index file, count of index entries in this block */ + int offset, nr; +}; + +struct index_entry_offset_table +{ + int nr; + struct index_entry_offset entries[FLEX_ARRAY]; +}; + +#ifndef NO_PTHREADS +static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset); +static void write_ieot_extension(struct strbuf *sb, struct index_entry_offset_table *ieot); +#endif + +static size_t read_eoie_extension(const char *mmap, size_t mmap_size); +static void write_eoie_extension(struct strbuf *sb, git_hash_ctx *eoie_context, size_t offset); + +struct load_index_extensions +{ +#ifndef NO_PTHREADS + pthread_t pthread; +#endif + struct index_state *istate; + const char *mmap; + size_t mmap_size; + unsigned long src_offset; +}; + +static void *load_index_extensions(void *_data) +{ + struct load_index_extensions *p = _data; + unsigned long src_offset = p->src_offset; + + while (src_offset <= p->mmap_size - the_hash_algo->rawsz - 8) { + /* After an array of active_nr index entries, + * there can be arbitrary number of extended + * sections, each of which is prefixed with + * extension name (4-byte) and section length + * in 4-byte network byte order. + */ + uint32_t extsize = get_be32(p->mmap + src_offset + 4); + if (read_index_extension(p->istate, + p->mmap + src_offset, + p->mmap + src_offset + 8, + extsize) < 0) { + munmap((void *)p->mmap, p->mmap_size); + die(_("index file corrupt")); + } + src_offset += 8; + src_offset += extsize; + } + + return NULL; +} + +/* + * A helper function that will load the specified range of cache entries + * from the memory mapped file and add them to the given index. + */ +static unsigned long load_cache_entry_block(struct index_state *istate, + struct mem_pool *ce_mem_pool, int offset, int nr, const char *mmap, + unsigned long start_offset, const struct cache_entry *previous_ce) +{ + int i; + unsigned long src_offset = start_offset; + + for (i = offset; i < offset + nr; i++) { + struct ondisk_cache_entry *disk_ce; + struct cache_entry *ce; + unsigned long consumed; + + disk_ce = (struct ondisk_cache_entry *)(mmap + src_offset); + ce = create_from_disk(ce_mem_pool, istate->version, disk_ce, &consumed, previous_ce); + set_index_entry(istate, i, ce); + + src_offset += consumed; + previous_ce = ce; + } + return src_offset - start_offset; +} + +static unsigned long load_all_cache_entries(struct index_state *istate, + const char *mmap, size_t mmap_size, unsigned long src_offset) +{ + unsigned long consumed; + + if (istate->version == 4) { + mem_pool_init(&istate->ce_mem_pool, + estimate_cache_size_from_compressed(istate->cache_nr)); + } else { + mem_pool_init(&istate->ce_mem_pool, + estimate_cache_size(mmap_size, istate->cache_nr)); + } + + consumed = load_cache_entry_block(istate, istate->ce_mem_pool, + 0, istate->cache_nr, mmap, src_offset, NULL); + return consumed; +} + +#ifndef NO_PTHREADS + +/* + * Mostly randomly chosen maximum thread counts: we + * cap the parallelism to online_cpus() threads, and we want + * to have at least 10000 cache entries per thread for it to + * be worth starting a thread. + */ + +#define THREAD_COST (10000) + +struct load_cache_entries_thread_data +{ + pthread_t pthread; + struct index_state *istate; + struct mem_pool *ce_mem_pool; + int offset; + const char *mmap; + struct index_entry_offset_table *ieot; + int ieot_start; /* starting index into the ieot array */ + int ieot_blocks; /* count of ieot entries to process */ + unsigned long consumed; /* return # of bytes in index file processed */ +}; + +/* + * A thread proc to run the load_cache_entries() computation + * across multiple background threads. + */ +static void *load_cache_entries_thread(void *_data) +{ + struct load_cache_entries_thread_data *p = _data; + int i; + + /* iterate across all ieot blocks assigned to this thread */ + for (i = p->ieot_start; i < p->ieot_start + p->ieot_blocks; i++) { + p->consumed += load_cache_entry_block(p->istate, p->ce_mem_pool, + p->offset, p->ieot->entries[i].nr, p->mmap, p->ieot->entries[i].offset, NULL); + p->offset += p->ieot->entries[i].nr; + } + return NULL; +} + +static unsigned long load_cache_entries_threaded(struct index_state *istate, const char *mmap, size_t mmap_size, + unsigned long src_offset, int nr_threads, struct index_entry_offset_table *ieot) +{ + int i, offset, ieot_blocks, ieot_start, err; + struct load_cache_entries_thread_data *data; + unsigned long consumed = 0; + + /* a little sanity checking */ + if (istate->name_hash_initialized) + BUG("the name hash isn't thread safe"); + + mem_pool_init(&istate->ce_mem_pool, 0); + + /* ensure we have no more threads than we have blocks to process */ + if (nr_threads > ieot->nr) + nr_threads = ieot->nr; + data = xcalloc(nr_threads, sizeof(*data)); + + offset = ieot_start = 0; + ieot_blocks = DIV_ROUND_UP(ieot->nr, nr_threads); + for (i = 0; i < nr_threads; i++) { + struct load_cache_entries_thread_data *p = &data[i]; + int nr, j; + + if (ieot_start + ieot_blocks > ieot->nr) + ieot_blocks = ieot->nr - ieot_start; + + p->istate = istate; + p->offset = offset; + p->mmap = mmap; + p->ieot = ieot; + p->ieot_start = ieot_start; + p->ieot_blocks = ieot_blocks; + + /* create a mem_pool for each thread */ + nr = 0; + for (j = p->ieot_start; j < p->ieot_start + p->ieot_blocks; j++) + nr += p->ieot->entries[j].nr; + if (istate->version == 4) { + mem_pool_init(&p->ce_mem_pool, + estimate_cache_size_from_compressed(nr)); + } else { + mem_pool_init(&p->ce_mem_pool, + estimate_cache_size(mmap_size, nr)); + } + + err = pthread_create(&p->pthread, NULL, load_cache_entries_thread, p); + if (err) + die(_("unable to create load_cache_entries thread: %s"), strerror(err)); + + /* increment by the number of cache entries in the ieot block being processed */ + for (j = 0; j < ieot_blocks; j++) + offset += ieot->entries[ieot_start + j].nr; + ieot_start += ieot_blocks; + } + + for (i = 0; i < nr_threads; i++) { + struct load_cache_entries_thread_data *p = &data[i]; + + err = pthread_join(p->pthread, NULL); + if (err) + die(_("unable to join load_cache_entries thread: %s"), strerror(err)); + mem_pool_combine(istate->ce_mem_pool, p->ce_mem_pool); + consumed += p->consumed; + } + + free(data); + + return consumed; +} +#endif + /* remember to discard_cache() before reading a different cache! */ int do_read_index(struct index_state *istate, const char *path, int must_exist) { - int fd, i; + int fd; struct stat st; unsigned long src_offset; - struct cache_header *hdr; - void *mmap; + const struct cache_header *hdr; + const char *mmap; size_t mmap_size; - struct strbuf previous_name_buf = STRBUF_INIT, *previous_name; + struct load_index_extensions p; + size_t extension_offset = 0; +#ifndef NO_PTHREADS + int nr_threads, cpus; + struct index_entry_offset_table *ieot = NULL; +#endif if (istate->initialized) return istate->cache_nr; @@ -1828,7 +2164,7 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist) die_errno("unable to map index file"); close(fd); - hdr = mmap; + hdr = (const struct cache_header *)mmap; if (verify_hdr(hdr, mmap_size) < 0) goto unmap; @@ -1839,50 +2175,74 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist) istate->cache = xcalloc(istate->cache_alloc, sizeof(*istate->cache)); istate->initialized = 1; - if (istate->version == 4) - previous_name = &previous_name_buf; - else - previous_name = NULL; + p.istate = istate; + p.mmap = mmap; + p.mmap_size = mmap_size; src_offset = sizeof(*hdr); - for (i = 0; i < istate->cache_nr; i++) { - struct ondisk_cache_entry *disk_ce; - struct cache_entry *ce; - unsigned long consumed; - disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset); - ce = create_from_disk(disk_ce, &consumed, previous_name); - set_index_entry(istate, i, ce); +#ifndef NO_PTHREADS + nr_threads = git_config_get_index_threads(); - src_offset += consumed; + /* TODO: does creating more threads than cores help? */ + if (!nr_threads) { + nr_threads = istate->cache_nr / THREAD_COST; + cpus = online_cpus(); + if (nr_threads > cpus) + nr_threads = cpus; } - strbuf_release(&previous_name_buf); + + if (nr_threads > 1) { + extension_offset = read_eoie_extension(mmap, mmap_size); + if (extension_offset) { + int err; + + p.src_offset = extension_offset; + err = pthread_create(&p.pthread, NULL, load_index_extensions, &p); + if (err) + die(_("unable to create load_index_extensions thread: %s"), strerror(err)); + + nr_threads--; + } + } + + /* + * Locate and read the index entry offset table so that we can use it + * to multi-thread the reading of the cache entries. + */ + if (extension_offset && nr_threads > 1) + ieot = read_ieot_extension(mmap, mmap_size, extension_offset); + + if (ieot) { + src_offset += load_cache_entries_threaded(istate, mmap, mmap_size, src_offset, nr_threads, ieot); + free(ieot); + } else { + src_offset += load_all_cache_entries(istate, mmap, mmap_size, src_offset); + } +#else + src_offset += load_all_cache_entries(istate, mmap, mmap_size, src_offset); +#endif + istate->timestamp.sec = st.st_mtime; istate->timestamp.nsec = ST_MTIME_NSEC(st); - while (src_offset <= mmap_size - the_hash_algo->rawsz - 8) { - /* After an array of active_nr index entries, - * there can be arbitrary number of extended - * sections, each of which is prefixed with - * extension name (4-byte) and section length - * in 4-byte network byte order. - */ - uint32_t extsize; - memcpy(&extsize, (char *)mmap + src_offset + 4, 4); - extsize = ntohl(extsize); - if (read_index_extension(istate, - (const char *) mmap + src_offset, - (char *) mmap + src_offset + 8, - extsize) < 0) - goto unmap; - src_offset += 8; - src_offset += extsize; + /* if we created a thread, join it otherwise load the extensions on the primary thread */ +#ifndef NO_PTHREADS + if (extension_offset) { + int ret = pthread_join(p.pthread, NULL); + if (ret) + die(_("unable to join load_index_extensions thread: %s"), strerror(ret)); + } +#endif + if (!extension_offset) { + p.src_offset = src_offset; + load_index_extensions(&p); } - munmap(mmap, mmap_size); + munmap((void *)mmap, mmap_size); return istate->cache_nr; unmap: - munmap(mmap, mmap_size); + munmap((void *)mmap, mmap_size); die("index file corrupt"); } @@ -1901,7 +2261,6 @@ static void freshen_shared_index(const char *shared_index, int warn) int read_index_from(struct index_state *istate, const char *path, const char *gitdir) { - uint64_t start = getnanotime(); struct split_index *split_index; int ret; char *base_oid_hex; @@ -1911,8 +2270,9 @@ int read_index_from(struct index_state *istate, const char *path, if (istate->initialized) return istate->cache_nr; + trace_performance_enter(); ret = do_read_index(istate, path, 0); - trace_performance_since(start, "read cache %s", path); + trace_performance_leave("read cache %s", path); split_index = istate->split_index; if (!split_index || is_null_oid(&split_index->base_oid)) { @@ -1920,6 +2280,7 @@ int read_index_from(struct index_state *istate, const char *path, return ret; } + trace_performance_enter(); if (split_index->base) discard_index(split_index->base); else @@ -1928,7 +2289,7 @@ int read_index_from(struct index_state *istate, const char *path, base_oid_hex = oid_to_hex(&split_index->base_oid); base_path = xstrfmt("%s/sharedindex.%s", gitdir, base_oid_hex); ret = do_read_index(split_index->base, base_path, 1); - if (oidcmp(&split_index->base_oid, &split_index->base->oid)) + if (!oideq(&split_index->base_oid, &split_index->base->oid)) die("broken index, expect %s in %s, got %s", base_oid_hex, base_path, oid_to_hex(&split_index->base->oid)); @@ -1936,8 +2297,8 @@ int read_index_from(struct index_state *istate, const char *path, freshen_shared_index(base_path, 0); merge_base_index(istate); post_read_index_from(istate); - trace_performance_since(start, "read cache %s", base_path); free(base_path); + trace_performance_leave("read cache %s", base_path); return ret; } @@ -1948,17 +2309,15 @@ int is_index_unborn(struct index_state *istate) int discard_index(struct index_state *istate) { - int i; + /* + * Cache entries in istate->cache[] should have been allocated + * from the memory pool associated with this index, or from an + * associated split_index. There is no need to free individual + * cache entries. validate_cache_entries can detect when this + * assertion does not hold. + */ + validate_cache_entries(istate); - for (i = 0; i < istate->cache_nr; i++) { - if (istate->cache[i]->index && - istate->split_index && - istate->split_index->base && - istate->cache[i]->index <= istate->split_index->base->cache_nr && - istate->cache[i] == istate->split_index->base->cache[istate->cache[i]->index - 1]) - continue; - free(istate->cache[i]); - } resolve_undo_clear_index(istate); istate->cache_nr = 0; istate->cache_changed = 0; @@ -1972,9 +2331,47 @@ int discard_index(struct index_state *istate) discard_split_index(istate); free_untracked_cache(istate->untracked); istate->untracked = NULL; + + if (istate->ce_mem_pool) { + mem_pool_discard(istate->ce_mem_pool, should_validate_cache_entries()); + istate->ce_mem_pool = NULL; + } + return 0; } +/* + * Validate the cache entries of this index. + * All cache entries associated with this index + * should have been allocated by the memory pool + * associated with this index, or by a referenced + * split index. + */ +void validate_cache_entries(const struct index_state *istate) +{ + int i; + + if (!should_validate_cache_entries() ||!istate || !istate->initialized) + return; + + for (i = 0; i < istate->cache_nr; i++) { + if (!istate) { + die("internal error: cache entry is not allocated from expected memory pool"); + } else if (!istate->ce_mem_pool || + !mem_pool_contains(istate->ce_mem_pool, istate->cache[i])) { + if (!istate->split_index || + !istate->split_index->base || + !istate->split_index->base->ce_mem_pool || + !mem_pool_contains(istate->split_index->base->ce_mem_pool, istate->cache[i])) { + die("internal error: cache entry is not allocated from expected memory pool"); + } + } + } + + if (istate->split_index) + validate_cache_entries(istate->split_index->base); +} + int unmerged_index(const struct index_state *istate) { int i; @@ -1985,6 +2382,44 @@ int unmerged_index(const struct index_state *istate) return 0; } +int index_has_changes(struct index_state *istate, + struct tree *tree, + struct strbuf *sb) +{ + struct object_id cmp; + int i; + + if (istate != &the_index) { + BUG("index_has_changes cannot yet accept istate != &the_index; do_diff_cache needs updating first."); + } + if (tree) + cmp = tree->object.oid; + if (tree || !get_oid_tree("HEAD", &cmp)) { + struct diff_options opt; + + repo_diff_setup(the_repository, &opt); + opt.flags.exit_with_status = 1; + if (!sb) + opt.flags.quick = 1; + do_diff_cache(&cmp, &opt); + diffcore_std(&opt); + for (i = 0; sb && i < diff_queued_diff.nr; i++) { + if (i) + strbuf_addch(sb, ' '); + strbuf_addstr(sb, diff_queued_diff.queue[i]->two->path); + } + diff_flush(&opt); + return opt.flags.has_changes != 0; + } else { + for (i = 0; sb && i < istate->cache_nr; i++) { + if (i) + strbuf_addch(sb, ' '); + strbuf_addstr(sb, istate->cache[i]->name); + } + return !!istate->cache_nr; + } +} + #define WRITE_BUFFER_SIZE 8192 static unsigned char write_buffer[WRITE_BUFFER_SIZE]; static unsigned long write_buffer_len; @@ -2023,11 +2458,15 @@ static int ce_write(git_hash_ctx *context, int fd, void *data, unsigned int len) return 0; } -static int write_index_ext_header(git_hash_ctx *context, int fd, - unsigned int ext, unsigned int sz) +static int write_index_ext_header(git_hash_ctx *context, git_hash_ctx *eoie_context, + int fd, unsigned int ext, unsigned int sz) { ext = htonl(ext); sz = htonl(sz); + if (eoie_context) { + the_hash_algo->update_fn(eoie_context, &ext, 4); + the_hash_algo->update_fn(eoie_context, &sz, 4); + } return ((ce_write(context, fd, &ext, 4) < 0) || (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0; } @@ -2055,7 +2494,8 @@ static int ce_flush(git_hash_ctx *context, int fd, unsigned char *hash) return (write_in_full(fd, write_buffer, left) < 0) ? -1 : 0; } -static void ce_smudge_racily_clean_entry(struct cache_entry *ce) +static void ce_smudge_racily_clean_entry(struct index_state *istate, + struct cache_entry *ce) { /* * The only thing we care about in this function is to smudge the @@ -2074,7 +2514,7 @@ static void ce_smudge_racily_clean_entry(struct cache_entry *ce) return; if (ce_match_stat_basic(ce, &st)) return; - if (ce_modified_check_fs(ce, &st)) { + if (ce_modified_check_fs(istate, ce, &st)) { /* This is "racily clean"; smudge it. Note that this * is a tricky code. At first glance, it may appear * that it can break with this sequence: @@ -2220,7 +2660,7 @@ static int verify_index_from(const struct index_state *istate, const char *path) if (n != the_hash_algo->rawsz) goto out; - if (hashcmp(istate->oid.hash, hash)) + if (!hasheq(istate->oid.hash, hash)) goto out; close(fd); @@ -2270,7 +2710,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, { uint64_t start = getnanotime(); int newfd = tempfile->fd; - git_hash_ctx c; + git_hash_ctx c, eoie_c; struct cache_header hdr; int i, err = 0, removed, extended, hdr_version; struct cache_entry **cache = istate->cache; @@ -2279,6 +2719,10 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, struct ondisk_cache_entry_extended ondisk; struct strbuf previous_name_buf = STRBUF_INIT, *previous_name; int drop_cache_tree = istate->drop_cache_tree; + off_t offset; + int ieot_entries = 1; + struct index_entry_offset_table *ieot = NULL; + int nr, nr_threads; for (i = removed = extended = 0; i < entries; i++) { if (cache[i]->ce_flags & CE_REMOVE) @@ -2312,6 +2756,46 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0) return -1; +#ifndef NO_PTHREADS + nr_threads = git_config_get_index_threads(); + if (nr_threads != 1) { + int ieot_blocks, cpus; + + /* + * ensure default number of ieot blocks maps evenly to the + * default number of threads that will process them leaving + * room for the thread to load the index extensions. + */ + if (!nr_threads) { + ieot_blocks = istate->cache_nr / THREAD_COST; + cpus = online_cpus(); + if (ieot_blocks > cpus - 1) + ieot_blocks = cpus - 1; + } else { + ieot_blocks = nr_threads; + if (ieot_blocks > istate->cache_nr) + ieot_blocks = istate->cache_nr; + } + + /* + * no reason to write out the IEOT extension if we don't + * have enough blocks to utilize multi-threading + */ + if (ieot_blocks > 1) { + ieot = xcalloc(1, sizeof(struct index_entry_offset_table) + + (ieot_blocks * sizeof(struct index_entry_offset))); + ieot_entries = DIV_ROUND_UP(entries, ieot_blocks); + } + } +#endif + + offset = lseek(newfd, 0, SEEK_CUR); + if (offset < 0) { + free(ieot); + return -1; + } + offset += write_buffer_len; + nr = 0; previous_name = (hdr_version == 4) ? &previous_name_buf : NULL; for (i = 0; i < entries; i++) { @@ -2319,7 +2803,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, if (ce->ce_flags & CE_REMOVE) continue; if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce)) - ce_smudge_racily_clean_entry(ce); + ce_smudge_racily_clean_entry(istate, ce); if (is_null_oid(&ce->oid)) { static const char msg[] = "cache entry has null sha1: %s"; static int allow = -1; @@ -2333,23 +2817,79 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, drop_cache_tree = 1; } + if (ieot && i && (i % ieot_entries == 0)) { + ieot->entries[ieot->nr].nr = nr; + ieot->entries[ieot->nr].offset = offset; + ieot->nr++; + /* + * If we have a V4 index, set the first byte to an invalid + * character to ensure there is nothing common with the previous + * entry + */ + if (previous_name) + previous_name->buf[0] = 0; + nr = 0; + offset = lseek(newfd, 0, SEEK_CUR); + if (offset < 0) { + free(ieot); + return -1; + } + offset += write_buffer_len; + } if (ce_write_entry(&c, newfd, ce, previous_name, (struct ondisk_cache_entry *)&ondisk) < 0) err = -1; if (err) break; + nr++; + } + if (ieot && nr) { + ieot->entries[ieot->nr].nr = nr; + ieot->entries[ieot->nr].offset = offset; + ieot->nr++; } strbuf_release(&previous_name_buf); - if (err) + if (err) { + free(ieot); return err; + } /* Write extension data here */ + offset = lseek(newfd, 0, SEEK_CUR); + if (offset < 0) { + free(ieot); + return -1; + } + offset += write_buffer_len; + the_hash_algo->init_fn(&eoie_c); + + /* + * Lets write out CACHE_EXT_INDEXENTRYOFFSETTABLE first so that we + * can minimize the number of extensions we have to scan through to + * find it during load. Write it out regardless of the + * strip_extensions parameter as we need it when loading the shared + * index. + */ +#ifndef NO_PTHREADS + if (ieot) { + struct strbuf sb = STRBUF_INIT; + + write_ieot_extension(&sb, ieot); + err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_INDEXENTRYOFFSETTABLE, sb.len) < 0 + || ce_write(&c, newfd, sb.buf, sb.len) < 0; + strbuf_release(&sb); + free(ieot); + if (err) + return -1; + } +#endif + if (!strip_extensions && istate->split_index) { struct strbuf sb = STRBUF_INIT; err = write_link_extension(&sb, istate) < 0 || - write_index_ext_header(&c, newfd, CACHE_EXT_LINK, + write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_LINK, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); @@ -2360,7 +2900,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, struct strbuf sb = STRBUF_INIT; cache_tree_write(&sb, istate->cache_tree); - err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0 + err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_TREE, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); if (err) @@ -2370,7 +2910,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, struct strbuf sb = STRBUF_INIT; resolve_undo_write(&sb, istate->resolve_undo); - err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO, + err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_RESOLVE_UNDO, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); @@ -2381,7 +2921,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, struct strbuf sb = STRBUF_INIT; write_untracked_extension(&sb, istate->untracked); - err = write_index_ext_header(&c, newfd, CACHE_EXT_UNTRACKED, + err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_UNTRACKED, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); @@ -2392,7 +2932,24 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile, struct strbuf sb = STRBUF_INIT; write_fsmonitor_extension(&sb, istate); - err = write_index_ext_header(&c, newfd, CACHE_EXT_FSMONITOR, sb.len) < 0 + err = write_index_ext_header(&c, &eoie_c, newfd, CACHE_EXT_FSMONITOR, sb.len) < 0 + || ce_write(&c, newfd, sb.buf, sb.len) < 0; + strbuf_release(&sb); + if (err) + return -1; + } + + /* + * CACHE_EXT_ENDOFINDEXENTRIES must be written as the last entry before the SHA1 + * so that it can be found and processed before all the index entries are + * read. Write it out regardless of the strip_extensions parameter as we need it + * when loading the shared index. + */ + if (offset) { + struct strbuf sb = STRBUF_INIT; + + write_eoie_extension(&sb, &eoie_c, offset); + err = write_index_ext_header(&c, NULL, newfd, CACHE_EXT_ENDOFINDEXENTRIES, sb.len) < 0 || ce_write(&c, newfd, sb.buf, sb.len) < 0; strbuf_release(&sb); if (err) @@ -2568,6 +3125,9 @@ int write_locked_index(struct index_state *istate, struct lock_file *lock, int new_shared_index, ret; struct split_index *si = istate->split_index; + if (git_env_bool("GIT_TEST_CHECK_CACHE_TREE", 0)) + cache_tree_verify(istate); + if ((flags & SKIP_IF_UNCHANGED) && !istate->cache_changed) { if (flags & COMMIT_LOCK) rollback_lock_file(lock); @@ -2633,10 +3193,13 @@ out: /* * Read the index file that is potentially unmerged into given - * index_state, dropping any unmerged entries. Returns true if - * the index is unmerged. Callers who want to refuse to work - * from an unmerged state can call this and check its return value, - * instead of calling read_cache(). + * index_state, dropping any unmerged entries to stage #0 (potentially + * resulting in a path appearing as both a file and a directory in the + * index; the caller is responsible to clear out the extra entries + * before writing the index to a tree). Returns true if the index is + * unmerged. Callers who want to refuse to work from an unmerged + * state can call this and check its return value, instead of calling + * read_cache(). */ int read_index_unmerged(struct index_state *istate) { @@ -2647,19 +3210,18 @@ int read_index_unmerged(struct index_state *istate) for (i = 0; i < istate->cache_nr; i++) { struct cache_entry *ce = istate->cache[i]; struct cache_entry *new_ce; - int size, len; + int len; if (!ce_stage(ce)) continue; unmerged = 1; len = ce_namelen(ce); - size = cache_entry_size(len); - new_ce = xcalloc(1, size); + new_ce = make_empty_cache_entry(istate, len); memcpy(new_ce->name, ce->name, len); new_ce->ce_flags = create_ce_flags(0) | CE_CONFLICTED; new_ce->ce_namelen = len; new_ce->ce_mode = ce->ce_mode; - if (add_index_entry(istate, new_ce, 0)) + if (add_index_entry(istate, new_ce, ADD_CACHE_SKIP_DFCHECK)) return error("%s: cannot drop to stage #0", new_ce->name); } @@ -2762,4 +3324,222 @@ void move_index_extensions(struct index_state *dst, struct index_state *src) { dst->untracked = src->untracked; src->untracked = NULL; + dst->cache_tree = src->cache_tree; + src->cache_tree = NULL; +} + +struct cache_entry *dup_cache_entry(const struct cache_entry *ce, + struct index_state *istate) +{ + unsigned int size = ce_size(ce); + int mem_pool_allocated; + struct cache_entry *new_entry = make_empty_cache_entry(istate, ce_namelen(ce)); + mem_pool_allocated = new_entry->mem_pool_allocated; + + memcpy(new_entry, ce, size); + new_entry->mem_pool_allocated = mem_pool_allocated; + return new_entry; +} + +void discard_cache_entry(struct cache_entry *ce) +{ + if (ce && should_validate_cache_entries()) + memset(ce, 0xCD, cache_entry_size(ce->ce_namelen)); + + if (ce && ce->mem_pool_allocated) + return; + + free(ce); +} + +int should_validate_cache_entries(void) +{ + static int validate_index_cache_entries = -1; + + if (validate_index_cache_entries < 0) { + if (getenv("GIT_TEST_VALIDATE_INDEX_CACHE_ENTRIES")) + validate_index_cache_entries = 1; + else + validate_index_cache_entries = 0; + } + + return validate_index_cache_entries; +} + +#define EOIE_SIZE (4 + GIT_SHA1_RAWSZ) /* <4-byte offset> + <20-byte hash> */ +#define EOIE_SIZE_WITH_HEADER (4 + 4 + EOIE_SIZE) /* <4-byte signature> + <4-byte length> + EOIE_SIZE */ + +static size_t read_eoie_extension(const char *mmap, size_t mmap_size) +{ + /* + * The end of index entries (EOIE) extension is guaranteed to be last + * so that it can be found by scanning backwards from the EOF. + * + * "EOIE" + * <4-byte length> + * <4-byte offset> + * <20-byte hash> + */ + const char *index, *eoie; + uint32_t extsize; + size_t offset, src_offset; + unsigned char hash[GIT_MAX_RAWSZ]; + git_hash_ctx c; + + /* ensure we have an index big enough to contain an EOIE extension */ + if (mmap_size < sizeof(struct cache_header) + EOIE_SIZE_WITH_HEADER + the_hash_algo->rawsz) + return 0; + + /* validate the extension signature */ + index = eoie = mmap + mmap_size - EOIE_SIZE_WITH_HEADER - the_hash_algo->rawsz; + if (CACHE_EXT(index) != CACHE_EXT_ENDOFINDEXENTRIES) + return 0; + index += sizeof(uint32_t); + + /* validate the extension size */ + extsize = get_be32(index); + if (extsize != EOIE_SIZE) + return 0; + index += sizeof(uint32_t); + + /* + * Validate the offset we're going to look for the first extension + * signature is after the index header and before the eoie extension. + */ + offset = get_be32(index); + if (mmap + offset < mmap + sizeof(struct cache_header)) + return 0; + if (mmap + offset >= eoie) + return 0; + index += sizeof(uint32_t); + + /* + * The hash is computed over extension types and their sizes (but not + * their contents). E.g. if we have "TREE" extension that is N-bytes + * long, "REUC" extension that is M-bytes long, followed by "EOIE", + * then the hash would be: + * + * SHA-1("TREE" + <binary representation of N> + + * "REUC" + <binary representation of M>) + */ + src_offset = offset; + the_hash_algo->init_fn(&c); + while (src_offset < mmap_size - the_hash_algo->rawsz - EOIE_SIZE_WITH_HEADER) { + /* After an array of active_nr index entries, + * there can be arbitrary number of extended + * sections, each of which is prefixed with + * extension name (4-byte) and section length + * in 4-byte network byte order. + */ + uint32_t extsize; + memcpy(&extsize, mmap + src_offset + 4, 4); + extsize = ntohl(extsize); + + /* verify the extension size isn't so large it will wrap around */ + if (src_offset + 8 + extsize < src_offset) + return 0; + + the_hash_algo->update_fn(&c, mmap + src_offset, 8); + + src_offset += 8; + src_offset += extsize; + } + the_hash_algo->final_fn(hash, &c); + if (!hasheq(hash, (const unsigned char *)index)) + return 0; + + /* Validate that the extension offsets returned us back to the eoie extension. */ + if (src_offset != mmap_size - the_hash_algo->rawsz - EOIE_SIZE_WITH_HEADER) + return 0; + + return offset; } + +static void write_eoie_extension(struct strbuf *sb, git_hash_ctx *eoie_context, size_t offset) +{ + uint32_t buffer; + unsigned char hash[GIT_MAX_RAWSZ]; + + /* offset */ + put_be32(&buffer, offset); + strbuf_add(sb, &buffer, sizeof(uint32_t)); + + /* hash */ + the_hash_algo->final_fn(hash, eoie_context); + strbuf_add(sb, hash, the_hash_algo->rawsz); +} + +#ifndef NO_PTHREADS +#define IEOT_VERSION (1) + +static struct index_entry_offset_table *read_ieot_extension(const char *mmap, size_t mmap_size, size_t offset) +{ + const char *index = NULL; + uint32_t extsize, ext_version; + struct index_entry_offset_table *ieot; + int i, nr; + + /* find the IEOT extension */ + if (!offset) + return NULL; + while (offset <= mmap_size - the_hash_algo->rawsz - 8) { + extsize = get_be32(mmap + offset + 4); + if (CACHE_EXT((mmap + offset)) == CACHE_EXT_INDEXENTRYOFFSETTABLE) { + index = mmap + offset + 4 + 4; + break; + } + offset += 8; + offset += extsize; + } + if (!index) + return NULL; + + /* validate the version is IEOT_VERSION */ + ext_version = get_be32(index); + if (ext_version != IEOT_VERSION) { + error("invalid IEOT version %d", ext_version); + return NULL; + } + index += sizeof(uint32_t); + + /* extension size - version bytes / bytes per entry */ + nr = (extsize - sizeof(uint32_t)) / (sizeof(uint32_t) + sizeof(uint32_t)); + if (!nr) { + error("invalid number of IEOT entries %d", nr); + return NULL; + } + ieot = xmalloc(sizeof(struct index_entry_offset_table) + + (nr * sizeof(struct index_entry_offset))); + ieot->nr = nr; + for (i = 0; i < nr; i++) { + ieot->entries[i].offset = get_be32(index); + index += sizeof(uint32_t); + ieot->entries[i].nr = get_be32(index); + index += sizeof(uint32_t); + } + + return ieot; +} + +static void write_ieot_extension(struct strbuf *sb, struct index_entry_offset_table *ieot) +{ + uint32_t buffer; + int i; + + /* version */ + put_be32(&buffer, IEOT_VERSION); + strbuf_add(sb, &buffer, sizeof(uint32_t)); + + /* ieot */ + for (i = 0; i < ieot->nr; i++) { + + /* offset */ + put_be32(&buffer, ieot->entries[i].offset); + strbuf_add(sb, &buffer, sizeof(uint32_t)); + + /* count */ + put_be32(&buffer, ieot->entries[i].nr); + strbuf_add(sb, &buffer, sizeof(uint32_t)); + } +} +#endif |