From 1217c03e7b87b15f2c78af5b1e1915a675050454 Mon Sep 17 00:00:00 2001 From: Garima Singh Date: Mon, 6 Apr 2020 16:59:50 +0000 Subject: commit-graph: reuse existing Bloom filters during write Add logic to a) parse Bloom filter information from the commit graph file and, b) re-use existing Bloom filters. See Documentation/technical/commit-graph-format for the format in which the Bloom filter information is written to the commit graph file. To read Bloom filter for a given commit with lexicographic position 'i' we need to: 1. Read BIDX[i] which essentially gives us the starting index in BDAT for filter of commit i+1. It is essentially the index past the end of the filter of commit i. It is called end_index in the code. 2. For i>0, read BIDX[i-1] which will give us the starting index in BDAT for filter of commit i. It is called the start_index in the code. For the first commit, where i = 0, Bloom filter data starts at the beginning, just past the header in the BDAT chunk. Hence, start_index will be 0. 3. The length of the filter will be end_index - start_index, because BIDX[i] gives the cumulative 8-byte words including the ith commit's filter. We toggle whether Bloom filters should be recomputed based on the compute_if_not_present flag. Helped-by: Derrick Stolee Signed-off-by: Garima Singh Signed-off-by: Junio C Hamano --- bloom.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'bloom.h') diff --git a/bloom.h b/bloom.h index 85ab8e9423..760d712237 100644 --- a/bloom.h +++ b/bloom.h @@ -32,6 +32,7 @@ struct bloom_filter_settings { #define DEFAULT_BLOOM_FILTER_SETTINGS { 1, 7, 10 } #define BITS_PER_WORD 8 +#define BLOOMDATA_CHUNK_HEADER_SIZE 3 * sizeof(uint32_t) /* * A bloom_filter struct represents a data segment to @@ -79,6 +80,7 @@ void add_key_to_filter(const struct bloom_key *key, void init_bloom_filters(void); struct bloom_filter *get_bloom_filter(struct repository *r, - struct commit *c); + struct commit *c, + int compute_if_not_present); #endif \ No newline at end of file -- cgit v1.2.3