From: John Cai <johncai86@xxxxxxxxx> When format is passed into --batch, --batch-check, --batch-command, the format gets expanded. When nothing is passed in, the default format is set and the expand_format() gets called. We can save on these cycles by hardcoding how to print the information when nothing is passed as the format, or when the default format is passed. There is no need for the fully expanded format with the default. Since batch_object_write() happens on every object provided in batch mode, we get a nice performance improvement. git rev-list --all > /tmp/all-obj.txt git cat-file --batch-check </tmp/all-obj.txt with HEAD^: Time (mean ± σ): 57.6 ms ± 1.7 ms [User: 51.5 ms, System: 6.2 ms] Range (min … max): 54.6 ms … 64.7 ms 50 runs with HEAD: Time (mean ± σ): 49.8 ms ± 1.7 ms [User: 42.6 ms, System: 7.3 ms] Range (min … max): 46.9 ms … 55.9 ms 56 runs If nothing is provided as a format argument, or if the default format is passed, skip expanding of the format and print the object info with a default format. Based-on-patch-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> Signed-off-by: John Cai <johncai86@xxxxxxxxx> See https://lore.kernel.org/git/87eecf8ork.fsf@xxxxxxxxxxxxxxxxxxx/ --- optimize cat file batch info writing When cat-file --batch or --batch-check is used, we can skip having to expand the format if no format is specified or if the default format is specified. In this case we know exactly how to print the objects without the full expanded format. This was first discussed in [1]. We get a little performance boost from this optimization because this happens for each objects provided to --batch, --batch-check, or --batch-command. Because batch_object_write() is called on every oid provided in batch mode, this optimization adds up when a large number of oid info is printed. git rev-list --all >/tmp/all-objs.txt git cat-file --batch-check </tmp/all-obj.txt (with hyperfine) run on origin/master: Time (mean ± σ): 57.6 ms ± 1.7 ms [User: 51.5 ms, System: 6.2 ms] Range (min … max): 54.6 ms … 64.7 ms 50 runs run on jc/optimize-cat-file-batch-default-format: Time (mean ± σ): 49.8 ms ± 1.7 ms [User: 42.6 ms, System: 7.3 ms] Range (min … max): 46.9 ms … 55.9 ms 56 runs 1. https://lore.kernel.org/git/87eecf8ork.fsf@xxxxxxxxxxxxxxxxxxx/ Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1221%2Fjohn-cai%2Fjc%2Foptimize-cat-file-batch-default-format-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1221/john-cai/jc/optimize-cat-file-batch-default-format-v1 Pull-Request: https://github.com/git/git/pull/1221 builtin/cat-file.c | 39 +++++++++++++++++++++++++++++++++------ t/perf/p1006-cat-file.sh | 16 ++++++++++++++++ 2 files changed, 49 insertions(+), 6 deletions(-) create mode 100755 t/perf/p1006-cat-file.sh diff --git a/builtin/cat-file.c b/builtin/cat-file.c index 7b3f42950ec..6a337941638 100644 --- a/builtin/cat-file.c +++ b/builtin/cat-file.c @@ -17,6 +17,7 @@ #include "object-store.h" #include "promisor-remote.h" +static const char *default_format = "%(objectname) %(objecttype) %(objectsize)"; struct batch_options { int enabled; int follow_symlinks; @@ -351,6 +352,14 @@ static void print_object_or_die(struct batch_options *opt, struct expand_data *d } } +static void print_default_format(char *buf, int len, struct expand_data *data) +{ + snprintf(buf, len, "%s %s %"PRIuMAX"\n", oid_to_hex(&data->oid), + data->info.type_name->buf, + (uintmax_t)*data->info.sizep); + +} + /* * If "pack" is non-NULL, then "offset" is the byte offset within the pack from * which the object may be accessed (though note that we may also rely on @@ -363,6 +372,12 @@ static void batch_object_write(const char *obj_name, struct packed_git *pack, off_t offset) { + const char *fmt; + + struct strbuf type_name = STRBUF_INIT; + if (!opt->format) + data->info.type_name = &type_name; + if (!data->skip_object_info) { int ret; @@ -377,12 +392,21 @@ static void batch_object_write(const char *obj_name, printf("%s missing\n", obj_name ? obj_name : oid_to_hex(&data->oid)); fflush(stdout); - return; + goto cleanup; } } + if (!opt->format && !opt->print_contents) { + char buf[1024]; + + print_default_format(buf, 1024, data); + batch_write(opt, buf, strlen(buf)); + goto cleanup; + } + + fmt = opt->format ? opt->format : default_format; strbuf_reset(scratch); - strbuf_expand(scratch, opt->format, expand_format, data); + strbuf_expand(scratch, fmt, expand_format, data); strbuf_addch(scratch, '\n'); batch_write(opt, scratch->buf, scratch->len); @@ -390,8 +414,12 @@ static void batch_object_write(const char *obj_name, print_object_or_die(opt, data); batch_write(opt, "\n", 1); } + +cleanup: + strbuf_release(&type_name); } + static void batch_one_object(const char *obj_name, struct strbuf *scratch, struct batch_options *opt, @@ -515,9 +543,7 @@ static int batch_objects(struct batch_options *opt) struct expand_data data; int save_warning; int retval = 0; - - if (!opt->format) - opt->format = "%(objectname) %(objecttype) %(objectsize)"; + const char *fmt; /* * Expand once with our special mark_query flag, which will prime the @@ -526,7 +552,8 @@ static int batch_objects(struct batch_options *opt) */ memset(&data, 0, sizeof(data)); data.mark_query = 1; - strbuf_expand(&output, opt->format, expand_format, &data); + fmt = opt->format ? opt->format : default_format; + strbuf_expand(&output, fmt, expand_format, &data); data.mark_query = 0; strbuf_release(&output); if (opt->cmdmode) diff --git a/t/perf/p1006-cat-file.sh b/t/perf/p1006-cat-file.sh new file mode 100755 index 00000000000..e463623f5a3 --- /dev/null +++ b/t/perf/p1006-cat-file.sh @@ -0,0 +1,16 @@ +#!/bin/sh + +test_description='Basic sort performance tests' +. ./perf-lib.sh + +test_perf_large_repo + +test_expect_success 'setup' ' + git rev-list --all >rla +' + +test_perf 'cat-file --batch-check' ' + git cat-file --batch-check <rla +' + +test_done base-commit: 715d08a9e51251ad8290b181b6ac3b9e1f9719d7 -- gitgitgadget
