From: Han Xin <hanxin.hx@xxxxxxxxxxxxxxx> Changes since v4: * Refactor to "struct input_stream" implementations so that we can reduce the changes to "write_loose_object()" sugguest by Ævar Arnfjörð Bjarmason. * Add a new flag called "HASH_STREAM" to support this feature. * Add a new config "core.bigFileStreamingThreshold" instread of "core.bigFileThreshold" sugguest by Ævar Arnfjörð Bjarmason[1]. * Roll destination repository preparement into a function in "t5590-unpack-non-delta-objects.sh", so that we can run testcases with --run=setup,3,4. 1. https://lore.kernel.org/git/211203.86zgphsu5a.gmgdl@xxxxxxxxxxxxxxxxxxx/ Han Xin (6): object-file: refactor write_loose_object() to support read from stream object-file.c: handle undetermined oid in write_loose_object() object-file.c: read stream in a loop in write_loose_object() unpack-objects.c: add dry_run mode for get_data() object-file.c: make "write_object_file_flags()" to support "HASH_STREAM" unpack-objects: unpack_non_delta_entry() read data in a stream Documentation/config/core.txt | 11 ++++ builtin/unpack-objects.c | 86 +++++++++++++++++++++++++++-- cache.h | 2 + config.c | 5 ++ environment.c | 1 + object-file.c | 73 +++++++++++++++++++----- object-store.h | 5 ++ t/t5590-unpack-non-delta-objects.sh | 70 +++++++++++++++++++++++ 8 files changed, 234 insertions(+), 19 deletions(-) create mode 100755 t/t5590-unpack-non-delta-objects.sh Range-diff against v4: 1: af707ef304 < -: ---------- object-file: refactor write_loose_object() to read buffer from stream 2: 321ad90d8e < -: ---------- object-file.c: handle undetermined oid in write_loose_object() 3: 1992ac39af < -: ---------- object-file.c: read stream in a loop in write_loose_object() -: ---------- > 1: f3595e68cc object-file: refactor write_loose_object() to support read from stream -: ---------- > 2: c25fdd1fe5 object-file.c: handle undetermined oid in write_loose_object() -: ---------- > 3: ed226f2f9f object-file.c: read stream in a loop in write_loose_object() 4: c41eb06533 ! 4: 2f91e540f6 unpack-objects.c: add dry_run mode for get_data() @@ builtin/unpack-objects.c: static void use(int bytes) { git_zstream stream; - void *buf = xmallocz(size); -+ unsigned long bufsize = dry_run ? 4096 : size; ++ unsigned long bufsize = dry_run ? 8192 : size; + void *buf = xmallocz(bufsize); memset(&stream, 0, sizeof(stream)); -: ---------- > 5: 7698938eac object-file.c: make "write_object_file_flags()" to support "HASH_STREAM" 5: 9427775bdc ! 6: 103bb1db06 unpack-objects: unpack_non_delta_entry() read data in a stream @@ Commit message However, unpack non-delta objects from a stream instead of from an entrie buffer will have 10% performance penalty. Therefore, only unpack object - larger than the "big_file_threshold" in zstream. See the following + larger than the "core.BigFileStreamingThreshold" in zstream. See the following benchmarks: hyperfine \ --setup \ 'if ! test -d scalar.git; then git clone --bare https://github.com/microsoft/scalar.git; cp scalar.git/objects/pack/*.pack small.pack; fi' \ - --prepare 'rm -rf dest.git && git init --bare dest.git' \ - -n 'old' 'git -C dest.git unpack-objects <small.pack' \ - -n 'new' 'new/git -C dest.git unpack-objects <small.pack' \ - -n 'new (small threshold)' \ - 'new/git -c core.bigfilethreshold=16k -C dest.git unpack-objects <small.pack' - Benchmark 1: old - Time (mean ± σ): 6.075 s ± 0.069 s [User: 5.047 s, System: 0.991 s] - Range (min … max): 6.018 s … 6.189 s 10 runs - - Benchmark 2: new - Time (mean ± σ): 6.090 s ± 0.033 s [User: 5.075 s, System: 0.976 s] - Range (min … max): 6.030 s … 6.142 s 10 runs - - Benchmark 3: new (small threshold) - Time (mean ± σ): 6.755 s ± 0.029 s [User: 5.150 s, System: 1.560 s] - Range (min … max): 6.711 s … 6.809 s 10 runs + --prepare 'rm -rf dest.git && git init --bare dest.git' Summary - 'old' ran - 1.00 ± 0.01 times faster than 'new' - 1.11 ± 0.01 times faster than 'new (small threshold)' + './git -C dest.git -c core.bigfilethreshold=512m unpack-objects <small.pack' in 'origin/master' + 1.01 ± 0.04 times faster than './git -C dest.git -c core.bigfilethreshold=512m unpack-objects <small.pack' in 'HEAD~1' + 1.01 ± 0.04 times faster than './git -C dest.git -c core.bigfilethreshold=512m unpack-objects <small.pack' in 'HEAD~0' + 1.03 ± 0.10 times faster than './git -C dest.git -c core.bigfilethreshold=16k unpack-objects <small.pack' in 'origin/master' + 1.02 ± 0.07 times faster than './git -C dest.git -c core.bigfilethreshold=16k unpack-objects <small.pack' in 'HEAD~0' + 1.10 ± 0.04 times faster than './git -C dest.git -c core.bigfilethreshold=16k unpack-objects <small.pack' in 'HEAD~1' + Helped-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> Helped-by: Derrick Stolee <stolee@xxxxxxxxx> Helped-by: Jiang Xin <zhiyou.jx@xxxxxxxxxxxxxxx> Signed-off-by: Han Xin <hanxin.hx@xxxxxxxxxxxxxxx> + ## Documentation/config/core.txt ## +@@ Documentation/config/core.txt: be delta compressed, but larger binary media files won't be. + + + Common unit suffixes of 'k', 'm', or 'g' are supported. + ++core.bigFileStreamingThreshold:: ++ Files larger than this will be streamed out to a temporary ++ object file while being hashed, which will when be renamed ++ in-place to a loose object, particularly if the ++ `core.bigFileThreshold' setting dictates that they're always ++ written out as loose objects. +++ ++Default is 128 MiB on all platforms. +++ ++Common unit suffixes of 'k', 'm', or 'g' are supported. ++ + core.excludesFile:: + Specifies the pathname to the file that contains patterns to + describe paths that are not meant to be tracked, in addition + ## builtin/unpack-objects.c ## @@ builtin/unpack-objects.c: static void added_object(unsigned nr, enum object_type type, } @@ builtin/unpack-objects.c: static void added_object(unsigned nr, enum object_type + +static void write_stream_blob(unsigned nr, unsigned long size) +{ -+ char hdr[32]; -+ int hdrlen; + git_zstream zstream; + struct input_zstream_data data; + struct input_stream in_stream = { + .read = feed_input_zstream, + .data = &data, -+ .size = size, + }; -+ struct object_id *oid = &obj_list[nr].oid; + int ret; + + memset(&zstream, 0, sizeof(zstream)); @@ builtin/unpack-objects.c: static void added_object(unsigned nr, enum object_type + data.zstream = &zstream; + git_inflate_init(&zstream); + -+ /* Generate the header */ -+ hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX, type_name(OBJ_BLOB), (uintmax_t)size) + 1; -+ -+ if ((ret = write_loose_object(oid, hdr, hdrlen, &in_stream, 0, 0))) ++ if ((ret = write_object_file_flags(&in_stream, size, type_name(OBJ_BLOB) ,&obj_list[nr].oid, HASH_STREAM))) + die(_("failed to write object in stream %d"), ret); + + if (zstream.total_out != size || data.status != Z_STREAM_END) @@ builtin/unpack-objects.c: static void added_object(unsigned nr, enum object_type + git_inflate_end(&zstream); + + if (strict && !dry_run) { -+ struct blob *blob = lookup_blob(the_repository, oid); ++ struct blob *blob = lookup_blob(the_repository, &obj_list[nr].oid); + if (blob) + blob->object.flags |= FLAG_WRITTEN; + else @@ builtin/unpack-objects.c: static void added_object(unsigned nr, enum object_type + void *buf; + + /* Write large blob in stream without allocating full buffer. */ -+ if (!dry_run && type == OBJ_BLOB && size > big_file_threshold) { ++ if (!dry_run && type == OBJ_BLOB && size > big_file_streaming_threshold) { + write_stream_blob(nr, size); + return; + } @@ builtin/unpack-objects.c: static void added_object(unsigned nr, enum object_type write_object(nr, type, buf, size); else - ## object-file.c ## -@@ object-file.c: static const void *feed_simple_input_stream(struct input_stream *in_stream, unsi - return data->buf; - } + ## cache.h ## +@@ cache.h: extern size_t packed_git_window_size; + extern size_t packed_git_limit; + extern size_t delta_base_cache_limit; + extern unsigned long big_file_threshold; ++extern unsigned long big_file_streaming_threshold; + extern unsigned long pack_size_limit_cfg; --static int write_loose_object(const struct object_id *oid, char *hdr, -- int hdrlen, struct input_stream *in_stream, -- time_t mtime, unsigned flags) -+int write_loose_object(const struct object_id *oid, char *hdr, -+ int hdrlen, struct input_stream *in_stream, -+ time_t mtime, unsigned flags) - { - int fd, ret; - unsigned char compressed[4096]; + /* - ## object-store.h ## -@@ object-store.h: int hash_object_file(const struct git_hash_algo *algo, const void *buf, - unsigned long len, const char *type, - struct object_id *oid); + ## config.c ## +@@ config.c: static int git_default_core_config(const char *var, const char *value, void *cb) + return 0; + } -+int write_loose_object(const struct object_id *oid, char *hdr, -+ int hdrlen, struct input_stream *in_stream, -+ time_t mtime, unsigned flags); ++ if (!strcmp(var, "core.bigfilestreamingthreshold")) { ++ big_file_streaming_threshold = git_config_ulong(var, value); ++ return 0; ++ } + - int write_object_file_flags(const void *buf, unsigned long len, - const char *type, struct object_id *oid, - unsigned flags); + if (!strcmp(var, "core.packedgitlimit")) { + packed_git_limit = git_config_ulong(var, value); + return 0; + + ## environment.c ## +@@ environment.c: size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE; + size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT; + size_t delta_base_cache_limit = 96 * 1024 * 1024; + unsigned long big_file_threshold = 512 * 1024 * 1024; ++unsigned long big_file_streaming_threshold = 128 * 1024 * 1024; + int pager_use_color = 1; + const char *editor_program; + const char *askpass_program; ## t/t5590-unpack-non-delta-objects.sh (new) ## @@ @@ t/t5590-unpack-non-delta-objects.sh (new) + +. ./test-lib.sh + -+test_expect_success "create commit with big blobs (1.5 MB)" ' ++prepare_dest () { ++ test_when_finished "rm -rf dest.git" && ++ git init --bare dest.git && ++ git -C dest.git config core.bigFileStreamingThreshold $1 ++ git -C dest.git config core.bigFileThreshold $1 ++} ++ ++test_expect_success "setup repo with big blobs (1.5 MB)" ' + test-tool genrandom foo 1500000 >big-blob && + test_commit --append foo big-blob && + test-tool genrandom bar 1500000 >big-blob && @@ t/t5590-unpack-non-delta-objects.sh (new) + cd .git && + find objects/?? -type f | sort + ) >expect && -+ PACK=$(echo main | git pack-objects --progress --revs test) ++ PACK=$(echo main | git pack-objects --revs test) +' + -+test_expect_success 'setup GIT_ALLOC_LIMIT to 1MB' ' ++test_expect_success 'setup env: GIT_ALLOC_LIMIT to 1MB' ' + GIT_ALLOC_LIMIT=1m && + export GIT_ALLOC_LIMIT +' + -+test_expect_success 'prepare dest repository' ' -+ git init --bare dest.git && -+ git -C dest.git config core.bigFileThreshold 2m && -+ git -C dest.git config receive.unpacklimit 100 -+' -+ +test_expect_success 'fail to unpack-objects: cannot allocate' ' ++ prepare_dest 2m && + test_must_fail git -C dest.git unpack-objects <test-$PACK.pack 2>err && -+ test_i18ngrep "fatal: attempting to allocate" err && ++ grep "fatal: attempting to allocate" err && + ( + cd dest.git && + find objects/?? -type f | sort + ) >actual && ++ test_file_not_empty actual && + ! test_cmp expect actual +' + -+test_expect_success 'set a lower bigfile threshold' ' -+ git -C dest.git config core.bigFileThreshold 1m -+' -+ +test_expect_success 'unpack big object in stream' ' ++ prepare_dest 1m && + git -C dest.git unpack-objects <test-$PACK.pack && + git -C dest.git fsck && + ( @@ t/t5590-unpack-non-delta-objects.sh (new) + test_cmp expect actual +' + -+test_expect_success 'setup for unpack-objects dry-run test' ' -+ git init --bare unpack-test.git -+' -+ +test_expect_success 'unpack-objects dry-run' ' ++ prepare_dest 1m && ++ git -C dest.git unpack-objects -n <test-$PACK.pack && + ( -+ cd unpack-test.git && -+ git unpack-objects -n <../test-$PACK.pack -+ ) && -+ ( -+ cd unpack-test.git && ++ cd dest.git && + find objects/ -type f + ) >actual && + test_must_be_empty actual -- 2.34.0
