diff options
Diffstat (limited to 'bloom.c')
| -rw-r--r-- | bloom.c | 252 |
1 files changed, 232 insertions, 20 deletions
@@ -2,11 +2,14 @@ #include "bloom.h" #include "diff.h" #include "diffcore.h" -#include "revision.h" #include "hashmap.h" #include "commit-graph.h" #include "commit.h" #include "commit-slab.h" +#include "tree.h" +#include "tree-walk.h" +#include "config.h" +#include "repository.h" define_commit_slab(bloom_filter_slab, struct bloom_filter); @@ -29,9 +32,29 @@ static inline unsigned char get_bitmask(uint32_t pos) return ((unsigned char)1) << (pos & (BITS_PER_WORD - 1)); } -static int load_bloom_filter_from_graph(struct commit_graph *g, - struct bloom_filter *filter, - uint32_t graph_pos) +static int check_bloom_offset(struct commit_graph *g, uint32_t pos, + uint32_t offset) +{ + /* + * Note that we allow offsets equal to the data size, which would set + * our pointers at one past the end of the chunk memory. This is + * necessary because the on-disk index points to the end of the + * entries (so we can compute size by comparing adjacent ones). And + * naturally the final entry's end is one-past-the-end of the chunk. + */ + if (offset <= g->chunk_bloom_data_size - BLOOMDATA_CHUNK_HEADER_SIZE) + return 0; + + warning("ignoring out-of-range offset (%"PRIuMAX") for changed-path" + " filter at pos %"PRIuMAX" of %s (chunk size: %"PRIuMAX")", + (uintmax_t)offset, (uintmax_t)pos, + g->filename, (uintmax_t)g->chunk_bloom_data_size); + return -1; +} + +int load_bloom_filter_from_graph(struct commit_graph *g, + struct bloom_filter *filter, + uint32_t graph_pos) { uint32_t lex_pos, start_index, end_index; @@ -51,10 +74,26 @@ static int load_bloom_filter_from_graph(struct commit_graph *g, else start_index = 0; + if (check_bloom_offset(g, lex_pos, end_index) < 0 || + check_bloom_offset(g, lex_pos - 1, start_index) < 0) + return 0; + + if (end_index < start_index) { + warning("ignoring decreasing changed-path index offsets" + " (%"PRIuMAX" > %"PRIuMAX") for positions" + " %"PRIuMAX" and %"PRIuMAX" of %s", + (uintmax_t)start_index, (uintmax_t)end_index, + (uintmax_t)(lex_pos-1), (uintmax_t)lex_pos, + g->filename); + return 0; + } + filter->len = end_index - start_index; filter->data = (unsigned char *)(g->chunk_bloom_data + sizeof(unsigned char) * start_index + BLOOMDATA_CHUNK_HEADER_SIZE); + filter->version = g->bloom_filter_settings->hash_version; + filter->to_free = NULL; return 1; } @@ -66,7 +105,64 @@ static int load_bloom_filter_from_graph(struct commit_graph *g, * Not considered to be cryptographically secure. * Implemented as described in https://en.wikipedia.org/wiki/MurmurHash#Algorithm */ -uint32_t murmur3_seeded(uint32_t seed, const char *data, size_t len) +uint32_t murmur3_seeded_v2(uint32_t seed, const char *data, size_t len) +{ + const uint32_t c1 = 0xcc9e2d51; + const uint32_t c2 = 0x1b873593; + const uint32_t r1 = 15; + const uint32_t r2 = 13; + const uint32_t m = 5; + const uint32_t n = 0xe6546b64; + int i; + uint32_t k1 = 0; + const char *tail; + + int len4 = len / sizeof(uint32_t); + + uint32_t k; + for (i = 0; i < len4; i++) { + uint32_t byte1 = (uint32_t)(unsigned char)data[4*i]; + uint32_t byte2 = ((uint32_t)(unsigned char)data[4*i + 1]) << 8; + uint32_t byte3 = ((uint32_t)(unsigned char)data[4*i + 2]) << 16; + uint32_t byte4 = ((uint32_t)(unsigned char)data[4*i + 3]) << 24; + k = byte1 | byte2 | byte3 | byte4; + k *= c1; + k = rotate_left(k, r1); + k *= c2; + + seed ^= k; + seed = rotate_left(seed, r2) * m + n; + } + + tail = (data + len4 * sizeof(uint32_t)); + + switch (len & (sizeof(uint32_t) - 1)) { + case 3: + k1 ^= ((uint32_t)(unsigned char)tail[2]) << 16; + /*-fallthrough*/ + case 2: + k1 ^= ((uint32_t)(unsigned char)tail[1]) << 8; + /*-fallthrough*/ + case 1: + k1 ^= ((uint32_t)(unsigned char)tail[0]) << 0; + k1 *= c1; + k1 = rotate_left(k1, r1); + k1 *= c2; + seed ^= k1; + break; + } + + seed ^= (uint32_t)len; + seed ^= (seed >> 16); + seed *= 0x85ebca6b; + seed ^= (seed >> 13); + seed *= 0xc2b2ae35; + seed ^= (seed >> 16); + + return seed; +} + +static uint32_t murmur3_seeded_v1(uint32_t seed, const char *data, size_t len) { const uint32_t c1 = 0xcc9e2d51; const uint32_t c2 = 0x1b873593; @@ -131,8 +227,14 @@ void fill_bloom_key(const char *data, int i; const uint32_t seed0 = 0x293ae76f; const uint32_t seed1 = 0x7e646e2c; - const uint32_t hash0 = murmur3_seeded(seed0, data, len); - const uint32_t hash1 = murmur3_seeded(seed1, data, len); + uint32_t hash0, hash1; + if (settings->hash_version == 2) { + hash0 = murmur3_seeded_v2(seed0, data, len); + hash1 = murmur3_seeded_v2(seed1, data, len); + } else { + hash0 = murmur3_seeded_v1(seed0, data, len); + hash1 = murmur3_seeded_v1(seed1, data, len); + } key->hashes = (uint32_t *)xcalloc(settings->num_hashes, sizeof(uint32_t)); for (i = 0; i < settings->num_hashes; i++) @@ -164,6 +266,18 @@ void init_bloom_filters(void) init_bloom_filter_slab(&bloom_filters); } +static void free_one_bloom_filter(struct bloom_filter *filter) +{ + if (!filter) + return; + free(filter->to_free); +} + +void deinit_bloom_filters(void) +{ + deep_clear_bloom_filter_slab(&bloom_filters, free_one_bloom_filter); +} + static int pathmap_cmp(const void *hashmap_cmp_fn_data UNUSED, const struct hashmap_entry *eptr, const struct hashmap_entry *entry_or_key, @@ -177,11 +291,97 @@ static int pathmap_cmp(const void *hashmap_cmp_fn_data UNUSED, return strcmp(e1->path, e2->path); } -static void init_truncated_large_filter(struct bloom_filter *filter) +static void init_truncated_large_filter(struct bloom_filter *filter, + int version) { - filter->data = xmalloc(1); + filter->data = filter->to_free = xmalloc(1); filter->data[0] = 0xFF; filter->len = 1; + filter->version = version; +} + +#define VISITED (1u<<21) +#define HIGH_BITS (1u<<22) + +static int has_entries_with_high_bit(struct repository *r, struct tree *t) +{ + if (parse_tree(t)) + return 1; + + if (!(t->object.flags & VISITED)) { + struct tree_desc desc; + struct name_entry entry; + + init_tree_desc(&desc, &t->object.oid, t->buffer, t->size); + while (tree_entry(&desc, &entry)) { + size_t i; + for (i = 0; i < entry.pathlen; i++) { + if (entry.path[i] & 0x80) { + t->object.flags |= HIGH_BITS; + goto done; + } + } + + if (S_ISDIR(entry.mode)) { + struct tree *sub = lookup_tree(r, &entry.oid); + if (sub && has_entries_with_high_bit(r, sub)) { + t->object.flags |= HIGH_BITS; + goto done; + } + } + + } + +done: + t->object.flags |= VISITED; + } + + return !!(t->object.flags & HIGH_BITS); +} + +static int commit_tree_has_high_bit_paths(struct repository *r, + struct commit *c) +{ + struct tree *t; + if (repo_parse_commit(r, c)) + return 1; + t = repo_get_commit_tree(r, c); + if (!t) + return 1; + return has_entries_with_high_bit(r, t); +} + +static struct bloom_filter *upgrade_filter(struct repository *r, struct commit *c, + struct bloom_filter *filter, + int hash_version) +{ + struct commit_list *p = c->parents; + if (commit_tree_has_high_bit_paths(r, c)) + return NULL; + + if (p && commit_tree_has_high_bit_paths(r, p->item)) + return NULL; + + filter->version = hash_version; + + return filter; +} + +struct bloom_filter *get_bloom_filter(struct repository *r, struct commit *c) +{ + struct bloom_filter *filter; + int hash_version; + + filter = get_or_compute_bloom_filter(r, c, 0, NULL, NULL); + if (!filter) + return NULL; + + prepare_repo_settings(r); + hash_version = r->settings.commit_graph_changed_paths_version; + + if (!(hash_version == -1 || hash_version == filter->version)) + return NULL; /* unusable filter */ + return filter; } struct bloom_filter *get_or_compute_bloom_filter(struct repository *r, @@ -209,8 +409,23 @@ struct bloom_filter *get_or_compute_bloom_filter(struct repository *r, filter, graph_pos); } - if (filter->data && filter->len) - return filter; + if (filter->data && filter->len) { + struct bloom_filter *upgrade; + if (!settings || settings->hash_version == filter->version) + return filter; + + /* version mismatch, see if we can upgrade */ + if (compute_if_not_present && + git_env_bool("GIT_TEST_UPGRADE_BLOOM_FILTERS", 1)) { + upgrade = upgrade_filter(r, c, filter, + settings->hash_version); + if (upgrade) { + if (computed) + *computed |= BLOOM_UPGRADED; + return upgrade; + } + } + } if (!compute_if_not_present) return NULL; @@ -261,24 +476,25 @@ struct bloom_filter *get_or_compute_bloom_filter(struct repository *r, *last_slash = '\0'; } while (*path); - - diff_free_filepair(diff_queued_diff.queue[i]); } if (hashmap_get_size(&pathmap) > settings->max_changed_paths) { - init_truncated_large_filter(filter); + init_truncated_large_filter(filter, + settings->hash_version); if (computed) *computed |= BLOOM_TRUNC_LARGE; goto cleanup; } filter->len = (hashmap_get_size(&pathmap) * settings->bits_per_entry + BITS_PER_WORD - 1) / BITS_PER_WORD; + filter->version = settings->hash_version; if (!filter->len) { if (computed) *computed |= BLOOM_TRUNC_EMPTY; filter->len = 1; } CALLOC_ARRAY(filter->data, filter->len); + filter->to_free = filter->data; hashmap_for_each_entry(&pathmap, &iter, e, entry) { struct bloom_key key; @@ -290,9 +506,7 @@ struct bloom_filter *get_or_compute_bloom_filter(struct repository *r, cleanup: hashmap_clear_and_free(&pathmap, struct pathmap_hash_entry, entry); } else { - for (i = 0; i < diff_queued_diff.nr; i++) - diff_free_filepair(diff_queued_diff.queue[i]); - init_truncated_large_filter(filter); + init_truncated_large_filter(filter, settings->hash_version); if (computed) *computed |= BLOOM_TRUNC_LARGE; @@ -301,9 +515,7 @@ struct bloom_filter *get_or_compute_bloom_filter(struct repository *r, if (computed) *computed |= BLOOM_COMPUTED; - free(diff_queued_diff.queue); - DIFF_QUEUE_CLEAR(&diff_queued_diff); - + diff_queue_clear(&diff_queued_diff); return filter; } |