From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-3.5 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id EA6DF1F9FC for ; Tue, 21 Dec 2021 11:54:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237322AbhLULyd (ORCPT ); Tue, 21 Dec 2021 06:54:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237320AbhLULyc (ORCPT ); Tue, 21 Dec 2021 06:54:32 -0500 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE2E3C061574 for ; Tue, 21 Dec 2021 03:54:31 -0800 (PST) Received: by mail-pg1-x536.google.com with SMTP id a23so12126507pgm.4 for ; Tue, 21 Dec 2021 03:54:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=L4iN/fUSOIzfCbZx26NYnzqWE8xvQjRvnk3kusvsTq4=; b=VO8/AnISlXw35/KuBTYm5/kBuL/f1ZCMp6Du45joxz/z1a1MBhoV69LP3xbMRmfwCg TIvEsYVbxTcJh9295Le64EqcUtjlrfMG4R2jAYSuHVrhX4PQVipSTivQTdOChfjXaZQC ZdXcQKwVynh0PEC6TcbJDjfrEKBq9eZrSTgfX5yX4OR0iBU/iwjNCvoSpDFNcH54v93P eoJXostqoTn2MNwmeTMexL6MSeC870igTP21fy4HEEIXH188/1Ocy5fpgBHKKggF7jDu Iosf11fSW2lkULUDxZompHhx+PZQSURbKswZ661X8MeMaUoFxSENO7vDPMCBkNkf81/C AK+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=L4iN/fUSOIzfCbZx26NYnzqWE8xvQjRvnk3kusvsTq4=; b=ndUaPSNaC8kznsG6ICugINl+D/aOKtvhdvzBIzFmNh0i+RDC4UNUflHRi5W5HIgYFE 2doRnwxdbYQpk6Tcs0agDLSSPHLbWEBgsNg3SlQE2OvURHwciJT7WogOIwYc1leDN0q3 1OAW1KNKx0BeJ+47lLYYH8KiOQNioOA3NnNoGzxBy+dScBYKVBUulyu3XIwx7bTPFN+N eICznZipTTgSr3ICDMVwGgjGOZSOHuzbiZYEtaod11gVuyU7tX3uag94lhmXKT+XK4ZQ hICcNqLZ2+hFkm3+S4d5j1GLW3F8ZyCNXno1PPi9iDmob358BJOkFRPNBK70PbJ36nHo 24aw== X-Gm-Message-State: AOAM530ARsUt7z4V9IyfLlNqSofuVTRpy2QeUk+ovkEpHp6P/wjfk6LM MHpbrr8j3d3FCWiEIjmWlLc= X-Google-Smtp-Source: ABdhPJyx5Pv+Ixqr+dyZ/aEQkm+0d/YtPZ6QBSWuhP/6ORG8OcAY0eC42KrOFSHFibA00nI0P78oxg== X-Received: by 2002:a63:f80f:: with SMTP id n15mr2601381pgh.394.1640087671404; Tue, 21 Dec 2021 03:54:31 -0800 (PST) Received: from localhost.localdomain ([205.204.117.103]) by smtp.gmail.com with ESMTPSA id s30sm20513742pfw.57.2021.12.21.03.54.28 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Dec 2021 03:54:30 -0800 (PST) From: Han Xin To: Junio C Hamano , Git List , Jeff King , Jiang Xin , Philip Oakley , =?UTF-8?q?=C3=86var=20Arnfj=C3=B6r=C3=B0=20Bjarmason?= , Derrick Stolee , =?UTF-8?q?Ren=C3=A9=20Scharfe?= Cc: Han Xin Subject: [PATCH v7 5/5] unpack-objects: unpack_non_delta_entry() read data in a stream Date: Tue, 21 Dec 2021 19:52:01 +0800 Message-Id: <20211221115201.12120-6-chiyutianyi@gmail.com> X-Mailer: git-send-email 2.34.1.52.g80008efde6.agit.6.5.6 In-Reply-To: <20211217112629.12334-1-chiyutianyi@gmail.com> References: <20211217112629.12334-1-chiyutianyi@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Han Xin We used to call "get_data()" in "unpack_non_delta_entry()" to read the entire contents of a blob object, no matter how big it is. This implementation may consume all the memory and cause OOM. By implementing a zstream version of input_stream interface, we can use a small fixed buffer for "unpack_non_delta_entry()". 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 "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' Summary './git -C dest.git -c core.bigfilethreshold=512m unpack-objects Helped-by: Derrick Stolee Helped-by: Jiang Xin Signed-off-by: Han Xin --- Documentation/config/core.txt | 11 +++++ builtin/unpack-objects.c | 73 ++++++++++++++++++++++++++++- cache.h | 1 + config.c | 5 ++ environment.c | 1 + t/t5590-unpack-non-delta-objects.sh | 36 +++++++++++++- 6 files changed, 125 insertions(+), 2 deletions(-) diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt index c04f62a54a..601b7a2418 100644 --- a/Documentation/config/core.txt +++ b/Documentation/config/core.txt @@ -424,6 +424,17 @@ 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 diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c index 9104eb48da..72d8616e00 100644 --- a/builtin/unpack-objects.c +++ b/builtin/unpack-objects.c @@ -331,11 +331,82 @@ static void added_object(unsigned nr, enum object_type type, } } +struct input_zstream_data { + git_zstream *zstream; + unsigned char buf[8192]; + int status; +}; + +static const void *feed_input_zstream(struct input_stream *in_stream, + unsigned long *readlen) +{ + struct input_zstream_data *data = in_stream->data; + git_zstream *zstream = data->zstream; + void *in = fill(1); + + if (!len || data->status == Z_STREAM_END) { + *readlen = 0; + return NULL; + } + + zstream->next_out = data->buf; + zstream->avail_out = sizeof(data->buf); + zstream->next_in = in; + zstream->avail_in = len; + + data->status = git_inflate(zstream, 0); + use(len - zstream->avail_in); + *readlen = sizeof(data->buf) - zstream->avail_out; + + return data->buf; +} + +static void write_stream_blob(unsigned nr, size_t size) +{ + git_zstream zstream; + struct input_zstream_data data; + struct input_stream in_stream = { + .read = feed_input_zstream, + .data = &data, + }; + + memset(&zstream, 0, sizeof(zstream)); + memset(&data, 0, sizeof(data)); + data.zstream = &zstream; + git_inflate_init(&zstream); + + if (write_stream_object_file(&in_stream, size, OBJ_BLOB, 0, 0, + &obj_list[nr].oid)) + die(_("failed to write object in stream")); + + if (zstream.total_out != size || data.status != Z_STREAM_END) + die(_("inflate returned %d"), data.status); + git_inflate_end(&zstream); + + if (strict) { + struct blob *blob = + lookup_blob(the_repository, &obj_list[nr].oid); + if (blob) + blob->object.flags |= FLAG_WRITTEN; + else + die(_("invalid blob object from stream")); + } + obj_list[nr].obj = NULL; +} + static void unpack_non_delta_entry(enum object_type type, unsigned long size, unsigned nr) { - void *buf = get_data(size, dry_run); + void *buf; + + /* Write large blob in stream without allocating full buffer. */ + if (!dry_run && type == OBJ_BLOB && + size > big_file_streaming_threshold) { + write_stream_blob(nr, size); + return; + } + buf = get_data(size, dry_run); if (!dry_run && buf) write_object(nr, type, buf, size); else diff --git a/cache.h b/cache.h index 64071a8d80..8c9123cb5d 100644 --- a/cache.h +++ b/cache.h @@ -974,6 +974,7 @@ 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; /* diff --git a/config.c b/config.c index c5873f3a70..7b122a142a 100644 --- a/config.c +++ b/config.c @@ -1408,6 +1408,11 @@ static int git_default_core_config(const char *var, const char *value, void *cb) return 0; } + if (!strcmp(var, "core.bigfilestreamingthreshold")) { + big_file_streaming_threshold = git_config_ulong(var, value); + return 0; + } + if (!strcmp(var, "core.packedgitlimit")) { packed_git_limit = git_config_ulong(var, value); return 0; diff --git a/environment.c b/environment.c index 0d06a31024..04bba593de 100644 --- a/environment.c +++ b/environment.c @@ -47,6 +47,7 @@ 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; diff --git a/t/t5590-unpack-non-delta-objects.sh b/t/t5590-unpack-non-delta-objects.sh index 48c4fb1ba3..8436cbf8db 100755 --- a/t/t5590-unpack-non-delta-objects.sh +++ b/t/t5590-unpack-non-delta-objects.sh @@ -13,6 +13,11 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME prepare_dest () { test_when_finished "rm -rf dest.git" && git init --bare dest.git + if test -n "$1" + then + git -C dest.git config core.bigFileStreamingThreshold $1 + git -C dest.git config core.bigFileThreshold $1 + fi } test_expect_success "setup repo with big blobs (1.5 MB)" ' @@ -33,7 +38,7 @@ test_expect_success 'setup env: GIT_ALLOC_LIMIT to 1MB' ' ' test_expect_success 'fail to unpack-objects: cannot allocate' ' - prepare_dest && + prepare_dest 2m && test_must_fail git -C dest.git unpack-objects err && grep "fatal: attempting to allocate" err && ( @@ -44,6 +49,35 @@ test_expect_success 'fail to unpack-objects: cannot allocate' ' ! test_cmp expect actual ' +test_expect_success 'unpack big object in stream' ' + prepare_dest 1m && + mkdir -p dest.git/objects/05 && + git -C dest.git unpack-objects actual && + test_cmp expect actual +' + +test_expect_success 'unpack big object in stream with existing oids' ' + prepare_dest 1m && + git -C dest.git index-pack --stdin actual && + test_must_be_empty actual && + git -C dest.git unpack-objects actual && + test_must_be_empty actual +' + test_expect_success 'unpack-objects dry-run' ' prepare_dest && git -C dest.git unpack-objects -n