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;
/*
* The number of times a path is hashed, i.e. the
- * number of bit positions tht cumulatively
+ * number of bit positions that cumulatively
* determine whether a path is present in the
* Bloom filter.
*/
struct bloom_filter {
unsigned char *data;
size_t len;
+ int version;
+
+ void *to_free;
};
/*
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.
* 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,
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,
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,