diff options
Diffstat (limited to 'bloom.h')
| -rw-r--r-- | bloom.h | 38 |
1 files changed, 33 insertions, 5 deletions
@@ -3,13 +3,16 @@ struct commit; struct repository; +struct commit_graph; struct bloom_filter_settings { /* * The version of the hashing technique being used. - * We currently only support version = 1 which is + * The newest version is 2, which is * the seeded murmur3 hashing technique implemented - * in bloom.c. + * in bloom.c. Bloom filters of version 1 were created + * with prior versions of Git, which had a bug in the + * implementation of the hash function. */ uint32_t hash_version; @@ -52,6 +55,9 @@ struct bloom_filter_settings { struct bloom_filter { unsigned char *data; size_t len; + int version; + + void *to_free; }; /* @@ -68,6 +74,10 @@ struct bloom_key { uint32_t *hashes; }; +int load_bloom_filter_from_graph(struct commit_graph *g, + struct bloom_filter *filter, + uint32_t graph_pos); + /* * Calculate the murmur3 32-bit hash value for the given data * using the given seed. @@ -75,7 +85,7 @@ struct bloom_key { * 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); void fill_bloom_key(const char *data, size_t len, @@ -88,12 +98,14 @@ void add_key_to_filter(const struct bloom_key *key, const struct bloom_filter_settings *settings); void init_bloom_filters(void); +void deinit_bloom_filters(void); enum bloom_filter_computed { BLOOM_NOT_COMPUTED = (1 << 0), BLOOM_COMPUTED = (1 << 1), BLOOM_TRUNC_LARGE = (1 << 2), BLOOM_TRUNC_EMPTY = (1 << 3), + BLOOM_UPGRADED = (1 << 4), }; struct bloom_filter *get_or_compute_bloom_filter(struct repository *r, @@ -102,8 +114,24 @@ struct bloom_filter *get_or_compute_bloom_filter(struct repository *r, const struct bloom_filter_settings *settings, enum bloom_filter_computed *computed); -#define get_bloom_filter(r, c) get_or_compute_bloom_filter( \ - (r), (c), 0, NULL, NULL) +/* + * Find the Bloom filter associated with the given commit "c". + * + * If any of the following are true + * + * - the repository does not have a commit-graph, or + * - the repository disables reading from the commit-graph, or + * - the given commit does not have a Bloom filter computed, or + * - there is a Bloom filter for commit "c", but it cannot be read + * because the filter uses an incompatible version of murmur3 + * + * , then `get_bloom_filter()` will return NULL. Otherwise, the corresponding + * Bloom filter will be returned. + * + * For callers who wish to inspect Bloom filters with incompatible hash + * versions, use get_or_compute_bloom_filter(). + */ +struct bloom_filter *get_bloom_filter(struct repository *r, struct commit *c); int bloom_filter_contains(const struct bloom_filter *filter, const struct bloom_key *key, |