This builds on sg/commit-graph-cleanups, which took several patches from Szeder's series [1] and applied them almost directly to a more-recent version of Git [2]. [1] https://lore.kernel.org/git/20200529085038.26008-1-szeder.dev@xxxxxxxxx/ [2] https://lore.kernel.org/git/pull.650.git.1591362032.gitgitgadget@xxxxxxxxx/ This series adds a few extra improvements, several of which are rooted in Szeder's original series. I maintained his authorship and sign-off, even though the patches did not apply or cherry-pick at all. (In v2, I have removed the range-diff comparison to Szeder's series, so look at the v1 cover letter for that.) The patches have been significantly reordered. René pointed out (and Szeder discovered in the old thread) that we are not re-using the bloom_filter_settings from the existing commit-graph when writing a new one. 1. commit-graph: place bloom_settings in context 2. commit-graph: change test to die on parse, not load These are mostly the same, except we now use a pointer to the settings in the commit-graph write context. 3. bloom: get_bloom_filter() cleanups This new patch is a subtle change in behavior that will become relevant in the very next patch. In fact, if we swap patch 3 and 4, then t4216-log-bloom.sh fails with a segfault due to a NULL filter. 4. commit-graph: persist existence of changed-paths This patch is now updated to use the existing changed-path filter settings. 5. commit-graph: unify the signatures of all write_graph_chunk_*() functions 6. commit-graph: simplify chunk writes into loop 7. commit-graph: check chunk sizes after writing These are all the same as before. 8. revision.c: fix whitespace This patch is the cleanup part of Taylor's patch. 9. revision: empty pathspecs should not use Bloom filters Here is Taylor's fix for empty pathspecs. 10. commit-graph: check all leading directories in changed path Bloom filters 11. bloom: enforce a minimum size of 8 bytes Finally, we get these performance patches. Patch 10 is updated to have the better logic around directory separators and empty paths. Also, the list of Bloom keys is ordered with the deepest path first. That has some tiny performance benefits for deep paths since we can short-circuit the multi-key checks more often. That code path is much faster than the tree parsing, so it is hard to measure any change. Thanks, -Stolee Derrick Stolee (6): commit-graph: place bloom_settings in context commit-graph: change test to die on parse, not load bloom: get_bloom_filter() cleanups commit-graph: persist existence of changed-paths revision.c: fix whitespace bloom: enforce a minimum size of 8 bytes SZEDER Gábor (4): commit-graph: unify the signatures of all write_graph_chunk_*() functions commit-graph: simplify chunk writes into loop commit-graph: check chunk sizes after writing commit-graph: check all leading directories in changed path Bloom filters Taylor Blau (1): revision: empty pathspecs should not use Bloom filters Documentation/git-commit-graph.txt | 5 +- bloom.c | 19 ++-- builtin/commit-graph.c | 5 +- commit-graph.c | 136 +++++++++++++++++++++-------- commit-graph.h | 3 +- revision.c | 53 ++++++++--- revision.h | 6 +- t/t4216-log-bloom.sh | 35 +++++++- t/t5318-commit-graph.sh | 2 +- 9 files changed, 200 insertions(+), 64 deletions(-) base-commit: 7fbfe07ab4d4e58c0971dac73001b89f180a0af3 Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-659%2Fderrickstolee%2Fbloom-2-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-659/derrickstolee/bloom-2-v2 Pull-Request: https://github.com/gitgitgadget/git/pull/659 Range-diff vs v1: 1: c966969071 ! 1: 57002040bc commit-graph: place bloom_settings in context @@ Commit message to combine the function prototypes and use function pointers to simplify write_commit_graph_file(). + By using a pointer, we can later replace the settings to match those + that exist in the current commit-graph, in case a future Git version + allows customization of these parameters. + Reported-by: SZEDER Gábor <szeder.dev@xxxxxxxxx> Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx> @@ commit-graph.c: struct write_commit_graph_context { const struct split_commit_graph_opts *split_opts; size_t total_bloom_filter_data_size; -+ struct bloom_filter_settings bloom_settings; ++ const struct bloom_filter_settings *bloom_settings; }; static void write_graph_chunk_fanout(struct hashfile *f, @@ commit-graph.c: static void write_graph_chunk_bloom_data(struct hashfile *f, - hashwrite_be32(f, settings->hash_version); - hashwrite_be32(f, settings->num_hashes); - hashwrite_be32(f, settings->bits_per_entry); -+ hashwrite_be32(f, ctx->bloom_settings.hash_version); -+ hashwrite_be32(f, ctx->bloom_settings.num_hashes); -+ hashwrite_be32(f, ctx->bloom_settings.bits_per_entry); ++ hashwrite_be32(f, ctx->bloom_settings->hash_version); ++ hashwrite_be32(f, ctx->bloom_settings->num_hashes); ++ hashwrite_be32(f, ctx->bloom_settings->bits_per_entry); while (list < last) { struct bloom_filter *filter = get_bloom_filter(ctx->r, *list, 0); @@ commit-graph.c: static int write_commit_graph_file(struct write_commit_graph_con struct object_id file_hash; const struct bloom_filter_settings bloom_settings = DEFAULT_BLOOM_FILTER_SETTINGS; -+ ctx->bloom_settings = bloom_settings; ++ ctx->bloom_settings = &bloom_settings; + if (ctx->split) { struct strbuf tmp_file = STRBUF_INIT; 7: 60bbc15d24 = 2: 6b63f9bd8a commit-graph: change test to die on parse, not load -: ---------- > 3: 492deaf916 bloom: get_bloom_filter() cleanups 8: db5b8fe843 ! 4: 8727b25468 commit-graph: persist existence of changed-paths @@ Commit message property of "my commit-graph has changed-path filters" automatically. A user can drop filters using the --no-changed-paths option. + In the process, we need to be extremely careful to match the Bloom + filter settings as specified by the commit-graph. This will allow future + versions of Git to customize these settings, and the version with this + change will persist those settings as commit-graphs are rewritten on + top. + + Use the trace2 API to signal the settings used during the write, and + check that output in a test after manually adjusting the correct bytes + in the commit-graph file. + Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx> ## Documentation/git-commit-graph.txt ## @@ builtin/commit-graph.c: static int graph_write(int argc, const char **argv) ## commit-graph.c ## +@@ + #include "progress.h" + #include "bloom.h" + #include "commit-slab.h" ++#include "json-writer.h" ++#include "trace2.h" + + void git_test_write_commit_graph_or_die(void) + { +@@ commit-graph.c: static void write_graph_chunk_bloom_indexes(struct hashfile *f, + stop_progress(&progress); + } + ++static void trace2_bloom_filter_settings(struct write_commit_graph_context *ctx) ++{ ++ struct json_writer jw = JSON_WRITER_INIT; ++ ++ jw_object_begin(&jw, 0); ++ jw_object_intmax(&jw, "hash_version", ctx->bloom_settings->hash_version); ++ jw_object_intmax(&jw, "num_hashes", ctx->bloom_settings->num_hashes); ++ jw_object_intmax(&jw, "bits_per_entry", ctx->bloom_settings->bits_per_entry); ++ jw_end(&jw); ++ ++ trace2_data_json("bloom", ctx->r, "settings", &jw); ++ ++ jw_release(&jw); ++} ++ + static void write_graph_chunk_bloom_data(struct hashfile *f, + struct write_commit_graph_context *ctx) + { +@@ commit-graph.c: static void write_graph_chunk_bloom_data(struct hashfile *f, + struct progress *progress = NULL; + int i = 0; + ++ trace2_bloom_filter_settings(ctx); ++ + if (ctx->report_progress) + progress = start_delayed_progress( + _("Writing changed paths Bloom filters data"), +@@ commit-graph.c: static int write_commit_graph_file(struct write_commit_graph_context *ctx) + struct object_id file_hash; + const struct bloom_filter_settings bloom_settings = DEFAULT_BLOOM_FILTER_SETTINGS; + +- ctx->bloom_settings = &bloom_settings; ++ if (!ctx->bloom_settings) ++ ctx->bloom_settings = &bloom_settings; + + if (ctx->split) { + struct strbuf tmp_file = STRBUF_INIT; @@ commit-graph.c: int write_commit_graph(struct object_directory *odb, ctx->split = flags & COMMIT_GRAPH_WRITE_SPLIT ? 1 : 0; ctx->check_oids = flags & COMMIT_GRAPH_WRITE_CHECK_OIDS ? 1 : 0; @@ commit-graph.c: int write_commit_graph(struct object_directory *odb, + if (flags & COMMIT_GRAPH_WRITE_BLOOM_FILTERS) + ctx->changed_paths = 1; -+ else if (!(flags & COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS)) { ++ if (!(flags & COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS)) { ++ struct commit_graph *g; + prepare_commit_graph_one(ctx->r, ctx->odb); + ++ g = ctx->r->objects->commit_graph; ++ + /* We have changed-paths already. Keep them in the next graph */ -+ if (ctx->r->objects->commit_graph && -+ ctx->r->objects->commit_graph->chunk_bloom_data) ++ if (g && g->chunk_bloom_data) { + ctx->changed_paths = 1; ++ ctx->bloom_settings = g->bloom_filter_settings; ++ } + } + if (ctx->split) { @@ t/t4216-log-bloom.sh: test_expect_success 'setup - add commit-graph to the chain test_line_count = 2 .git/objects/info/commit-graphs/commit-graph-chain ' +@@ t/t4216-log-bloom.sh: test_expect_success 'Use Bloom filters if they exist in the latest but not all c + test_bloom_filters_used_when_some_filters_are_missing "-- A/B" + ' + ++BASE_BDAT_OFFSET=2240 ++BASE_K_BYTE_OFFSET=$((BASE_BDAT_OFFSET + 10)) ++BASE_LEN_BYTE_OFFSET=$((BASE_BDAT_OFFSET + 14)) ++ ++corrupt_graph() { ++ pos=$1 ++ data="${2:-\0}" ++ grepstr=$3 ++ orig_size=$(wc -c < .git/objects/info/commit-graph) && ++ zero_pos=${4:-${orig_size}} && ++ printf "$data" | dd of=".git/objects/info/commit-graph" bs=1 seek="$pos" conv=notrunc && ++ dd of=".git/objects/info/commit-graph" bs=1 seek="$zero_pos" if=/dev/null ++} ++ ++test_expect_success 'persist filter settings' ' ++ test_when_finished rm -rf .git/objects/info/commit-graph* && ++ GIT_TRACE2_EVENT="$(pwd)/trace2.txt" git commit-graph write --reachable --changed-paths && ++ grep "{\"hash_version\":1,\"num_hashes\":7,\"bits_per_entry\":10}" trace2.txt && ++ cp .git/objects/info/commit-graph commit-graph-before && ++ corrupt_graph $BASE_K_BYTE_OFFSET "\09" && ++ corrupt_graph $BASE_LEN_BYTE_OFFSET "\0F" && ++ cp .git/objects/info/commit-graph commit-graph-after && ++ test_commit c18 A/corrupt && ++ GIT_TRACE2_EVENT="$(pwd)/trace2.txt" git commit-graph write --reachable --changed-paths && ++ grep "{\"hash_version\":1,\"num_hashes\":57,\"bits_per_entry\":70}" trace2.txt ++' ++ + test_done + \ No newline at end of file 2: 65eb15221c ! 5: 244668fec4 commit-graph: unify the signatures of all write_graph_chunk_*() functions @@ Commit message ## commit-graph.c ## @@ commit-graph.c: struct write_commit_graph_context { - struct bloom_filter_settings bloom_settings; + const struct bloom_filter_settings *bloom_settings; }; -static void write_graph_chunk_fanout(struct hashfile *f, @@ commit-graph.c: static void write_graph_chunk_bloom_indexes(struct hashfile *f, + return 0; } + static void trace2_bloom_filter_settings(struct write_commit_graph_context *ctx) +@@ commit-graph.c: static void trace2_bloom_filter_settings(struct write_commit_graph_context *ctx) + jw_release(&jw); + } + -static void write_graph_chunk_bloom_data(struct hashfile *f, - struct write_commit_graph_context *ctx) +static int write_graph_chunk_bloom_data(struct hashfile *f, 3: 3d24b9802d = 6: 8b959f2f37 commit-graph: simplify chunk writes into loop 4: bdca834e6d = 7: 3eb10933dc commit-graph: check chunk sizes after writing -: ---------- > 8: 0bcfc1f051 revision.c: fix whitespace -: ---------- > 9: 719c7091a7 revision: empty pathspecs should not use Bloom filters 5: 9975fc96f1 ! 10: 9c2076b4ce commit-graph: check all leading directories in changed path Bloom filters @@ Commit message This adjusts the tracing values in t4216-log-bloom.sh, which provides a concrete way to notice the improvement. + Helped-by: Taylor Blau <me@xxxxxxxxxxxx> + Helped-by: René Scharfe <l.s.r@xxxxxx> Signed-off-by: SZEDER Gábor <szeder.dev@xxxxxxxxx> Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx> @@ revision.c: static void prepare_to_use_bloom_filter(struct rev_info *revs) int last_index; - int len; + size_t len; -+ int path_component_nr = 0, j; ++ int path_component_nr = 1; if (!revs->commits) return; @@ revision.c: static void prepare_to_use_bloom_filter(struct rev_info *revs) - - len = strlen(path); + return; + } - revs->bloom_key = xmalloc(sizeof(struct bloom_key)); - fill_bloom_key(path, len, revs->bloom_key, revs->bloom_filter_settings); + p = path; -+ do { -+ p = strchrnul(p + 1, '/'); -+ path_component_nr++; -+ } while (p - path < len); ++ while (*p) { ++ if (is_dir_sep(*p)) ++ path_component_nr++; ++ p++; ++ } + + revs->bloom_keys_nr = path_component_nr; + ALLOC_ARRAY(revs->bloom_keys, revs->bloom_keys_nr); + -+ p = path; -+ for (j = 0; j < revs->bloom_keys_nr; j++) { -+ p = strchrnul(p + 1, '/'); ++ fill_bloom_key(path, len, &revs->bloom_keys[0], ++ revs->bloom_filter_settings); ++ path_component_nr = 1; + -+ fill_bloom_key(path, p - path, &revs->bloom_keys[j], -+ revs->bloom_filter_settings); ++ p = path + len - 1; ++ while (p > path) { ++ if (is_dir_sep(*p)) ++ fill_bloom_key(path, p - path, ++ &revs->bloom_keys[path_component_nr++], ++ revs->bloom_filter_settings); ++ p--; + } if (trace2_is_enabled() && !bloom_filter_atexit_registered) { 6: 2a5f1e1752 = 11: 1022c0ad21 bloom: enforce a minimum size of 8 bytes -- gitgitgadget
