From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-2.8 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD shortcircuit=no autolearn=no autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id BC2F81F424 for ; Sat, 31 Mar 2018 10:03:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753261AbeCaKD4 (ORCPT ); Sat, 31 Mar 2018 06:03:56 -0400 Received: from mail-lf0-f67.google.com ([209.85.215.67]:38364 "EHLO mail-lf0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753132AbeCaKDi (ORCPT ); Sat, 31 Mar 2018 06:03:38 -0400 Received: by mail-lf0-f67.google.com with SMTP id u3-v6so15106937lff.5 for ; Sat, 31 Mar 2018 03:03:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=sE4RWdw+dTcm3u7DFChNSZrpm5jILs1FgdpnSwS2qfc=; b=WwXkQ6xdrAxc+FjNx4gGxvYci68lKQCV7G2xU90mQ6Xj3bFo6+H8mUFI612/ypd+sk CXDlIkKYs1ryeHACdCeSyOF7y9nr9pK68PWAYSYo6NgKKqZazHz3kytz3B0rMfxWGC2h pTS5q7xNGL/TpkyHhiifWteW06IXxdCtmA+RVhsYrFsTK2ZYXbZMkBYLNcHbompcSt6r +wJ4eyAXAYI+hwasE8fKqrzR+vFD+uGWJeZ2+f//ykBVpEEX6QoliGa9rRtJA37Ovu5M HdqGmBWSYvYTB2zF5jeXd+7oA6pIAg2MYGVKWNAXYfM9Ma1CGOW6ILtr4+/J+vHJ/ycC kcpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=sE4RWdw+dTcm3u7DFChNSZrpm5jILs1FgdpnSwS2qfc=; b=D+HbmJje71FutdrRPlaLWaOUqRLe+vlZB37DCtWS6yHKEKETUDnTFTMNDce19hQ2u8 IhueDQACXcmhh0ZskXgx0H4490gb/rnMcVMiMb5snacraPRBFjkRaDr26dHXld4ic1oe UY/JaJIc8V224NlUfUHo3siYBYbFLMklRkAZAiaoWUdRRQAybFMYHbrS49C3U1cPR2Go Klct8D4mjToVdQX6JVG4EZt2+zHozk8y9QbAPsGj9edU6Z0Dj5tXxKI6HnxwXa0jVn+S BS2HEnDdQOJ7rF8kRHB4yFuNUvzUJ+Q+mpSwZA26jeIhUXTUThaEi2kWDbiJHPoKFjMG vrVw== X-Gm-Message-State: ALQs6tAWAf0JFjQ96/4h8eaLPGbs3Q5NOvqfJu9s1/4g52cCrCfORkk9 xb01v5nq7SPI+WXHfTERrC8= X-Google-Smtp-Source: AIpwx48CZZzDDA18UZYsTccelpTeTGNWXGFi23i6zUPBjw1TCrelN6zf91hvp0ChyAaZMwur0IRhCw== X-Received: by 10.46.137.71 with SMTP id b7mr1387410ljk.39.1522490616313; Sat, 31 Mar 2018 03:03:36 -0700 (PDT) Received: from localhost.localdomain (c80-216-12-205.bredband.comhem.se. [80.216.12.205]) by smtp.gmail.com with ESMTPSA id a1sm1799175ljj.90.2018.03.31.03.03.35 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 31 Mar 2018 03:03:35 -0700 (PDT) From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= To: pclouds@gmail.com Cc: avarab@gmail.com, e@80x24.org, git@vger.kernel.org, gitster@pobox.com, peff@peff.net Subject: [PATCH v8 12/15] pack-objects: shrink size field in struct object_entry Date: Sat, 31 Mar 2018 12:03:08 +0200 Message-Id: <20180331100311.32373-13-pclouds@gmail.com> X-Mailer: git-send-email 2.17.0.rc2.515.g4feb9b7923 In-Reply-To: <20180331100311.32373-1-pclouds@gmail.com> References: <20180324063353.24722-1-pclouds@gmail.com> <20180331100311.32373-1-pclouds@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org It's very very rare that an uncompressed object is larger than 4GB (partly because Git does not handle those large files very well to begin with). Let's optimize it for the common case where object size is smaller than this limit. Shrink size field down to 31 bits and one overflow bit. If the size is too large, we read it back from disk. As noted in the previous patch, we need to return the delta size instead of canonical size when the to-be-reused object entry type is a delta instead of a canonical one. Add two compare helpers that can take advantage of the overflow bit (e.g. if the file is 4GB+, chances are it's already larger than core.bigFileThreshold and there's no point in comparing the actual value). Another note about oe_get_size_slow(). This function MUST be thread safe because SIZE() macro is used inside try_delta() which may run in parallel. Outside parallel code, no-contention locking should be dirt cheap (or insignificant compared to i/o access anyway). To exercise this code, it's best to run the test suite with something like make test GIT_TEST_OE_SIZE=4 which forces this code on all objects larger than 3 bytes. Signed-off-by: Nguyễn Thái Ngọc Duy --- builtin/pack-objects.c | 105 +++++++++++++++++++++++++++++++---------- pack-objects.c | 3 ++ pack-objects.h | 57 +++++++++++++++++++++- t/README | 6 +++ 4 files changed, 146 insertions(+), 25 deletions(-) diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index 7a84c3f59a..b4ea6290f9 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -30,6 +30,8 @@ #include "packfile.h" #define IN_PACK(obj) oe_in_pack(&to_pack, obj) +#define SIZE(obj) oe_size(&to_pack, obj) +#define SET_SIZE(obj,size) oe_set_size(&to_pack, obj, size) #define DELTA(obj) oe_delta(&to_pack, obj) #define DELTA_CHILD(obj) oe_delta_child(&to_pack, obj) #define DELTA_SIBLING(obj) oe_delta_sibling(&to_pack, obj) @@ -274,7 +276,7 @@ static unsigned long write_no_reuse_object(struct hashfile *f, struct object_ent if (!usable_delta) { if (oe_type(entry) == OBJ_BLOB && - entry->size > big_file_threshold && + oe_size_greater_than(&to_pack, entry, big_file_threshold) && (st = open_istream(entry->idx.oid.hash, &type, &size, NULL)) != NULL) buf = NULL; else { @@ -384,12 +386,13 @@ static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry, unsigned char header[MAX_PACK_OBJECT_HEADER], dheader[MAX_PACK_OBJECT_HEADER]; unsigned hdrlen; + unsigned long entry_size = SIZE(entry); if (DELTA(entry)) type = (allow_ofs_delta && DELTA(entry)->idx.offset) ? OBJ_OFS_DELTA : OBJ_REF_DELTA; hdrlen = encode_in_pack_object_header(header, sizeof(header), - type, entry->size); + type, entry_size); offset = entry->in_pack_offset; revidx = find_pack_revindex(p, offset); @@ -406,7 +409,7 @@ static off_t write_reuse_object(struct hashfile *f, struct object_entry *entry, datalen -= entry->in_pack_header_size; if (!pack_to_stdout && p->index_version == 1 && - check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) { + check_pack_inflate(p, &w_curs, offset, datalen, entry_size)) { error("corrupt packed object for %s", oid_to_hex(&entry->idx.oid)); unuse_pack(&w_curs); @@ -1407,6 +1410,8 @@ static void cleanup_preferred_base(void) static void check_object(struct object_entry *entry) { + unsigned long canonical_size; + if (IN_PACK(entry)) { struct packed_git *p = IN_PACK(entry); struct pack_window *w_curs = NULL; @@ -1444,7 +1449,7 @@ static void check_object(struct object_entry *entry) default: /* Not a delta hence we've already got all we need. */ oe_set_type(entry, entry->in_pack_type); - entry->size = in_pack_size; + SET_SIZE(entry, in_pack_size); entry->in_pack_header_size = used; if (oe_type(entry) < OBJ_COMMIT || oe_type(entry) > OBJ_BLOB) goto give_up; @@ -1501,9 +1506,9 @@ static void check_object(struct object_entry *entry) * circular deltas. */ oe_set_type(entry, entry->in_pack_type); - entry->size = in_pack_size; /* delta size */ + SET_SIZE(entry, in_pack_size); /* delta size */ SET_DELTA(entry, base_entry); - entry->delta_size = entry->size; + entry->delta_size = in_pack_size; entry->delta_sibling_idx = base_entry->delta_child_idx; SET_DELTA_CHILD(base_entry, entry); unuse_pack(&w_curs); @@ -1519,9 +1524,10 @@ static void check_object(struct object_entry *entry) * object size from the delta header. */ delta_pos = entry->in_pack_offset + entry->in_pack_header_size; - entry->size = get_size_from_delta(p, &w_curs, delta_pos); - if (entry->size == 0) + canonical_size = get_size_from_delta(p, &w_curs, delta_pos); + if (canonical_size == 0) goto give_up; + SET_SIZE(entry, canonical_size); unuse_pack(&w_curs); return; } @@ -1535,13 +1541,18 @@ static void check_object(struct object_entry *entry) unuse_pack(&w_curs); } - oe_set_type(entry, sha1_object_info(entry->idx.oid.hash, &entry->size)); - /* - * The error condition is checked in prepare_pack(). This is - * to permit a missing preferred base object to be ignored - * as a preferred base. Doing so can result in a larger - * pack file, but the transfer will still take place. - */ + oe_set_type(entry, sha1_object_info(entry->idx.oid.hash, + &canonical_size)); + if (entry->type_valid) { + SET_SIZE(entry, canonical_size); + } else { + /* + * Bad object type is checked in prepare_pack(). This is + * to permit a missing preferred base object to be ignored + * as a preferred base. Doing so can result in a larger + * pack file, but the transfer will still take place. + */ + } } static int pack_offset_sort(const void *_a, const void *_b) @@ -1581,6 +1592,7 @@ static void drop_reused_delta(struct object_entry *entry) unsigned *idx = &to_pack.objects[entry->delta_idx - 1].delta_child_idx; struct object_info oi = OBJECT_INFO_INIT; enum object_type type; + unsigned long size; while (*idx) { struct object_entry *oe = &to_pack.objects[*idx - 1]; @@ -1593,7 +1605,7 @@ static void drop_reused_delta(struct object_entry *entry) SET_DELTA(entry, NULL); entry->depth = 0; - oi.sizep = &entry->size; + oi.sizep = &size; oi.typep = &type; if (packed_object_info(IN_PACK(entry), entry->in_pack_offset, &oi) < 0) { /* @@ -1603,10 +1615,11 @@ static void drop_reused_delta(struct object_entry *entry) * and dealt with in prepare_pack(). */ oe_set_type(entry, sha1_object_info(entry->idx.oid.hash, - &entry->size)); + &size)); } else { oe_set_type(entry, type); } + SET_SIZE(entry, size); } /* @@ -1746,7 +1759,8 @@ static void get_object_details(void) for (i = 0; i < to_pack.nr_objects; i++) { struct object_entry *entry = sorted_by_offset[i]; check_object(entry); - if (entry->type_valid && big_file_threshold < entry->size) + if (entry->type_valid && + oe_size_greater_than(&to_pack, entry, big_file_threshold)) entry->no_try_delta = 1; } @@ -1775,6 +1789,8 @@ static int type_size_sort(const void *_a, const void *_b) const struct object_entry *b = *(struct object_entry **)_b; enum object_type a_type = oe_type(a); enum object_type b_type = oe_type(b); + unsigned long a_size = SIZE(a); + unsigned long b_size = SIZE(b); if (a_type > b_type) return -1; @@ -1788,9 +1804,9 @@ static int type_size_sort(const void *_a, const void *_b) return -1; if (a->preferred_base < b->preferred_base) return 1; - if (a->size > b->size) + if (a_size > b_size) return -1; - if (a->size < b->size) + if (a_size < b_size) return 1; return a < b ? -1 : (a > b); /* newest first */ } @@ -1843,6 +1859,46 @@ static pthread_mutex_t progress_mutex; #endif +/* + * Return the size of the object without doing any delta + * reconstruction (so non-deltas are true object sizes, but deltas + * return the size of the delta data). + */ +unsigned long oe_get_size_slow(struct packing_data *pack, + const struct object_entry *e) +{ + struct packed_git *p; + struct pack_window *w_curs; + unsigned char *buf; + enum object_type type; + unsigned long used, avail, size; + + if (e->type_ != OBJ_OFS_DELTA && e->type_ != OBJ_REF_DELTA) { + read_lock(); + if (sha1_object_info(e->idx.oid.hash, &size) < 0) + die(_("unable to get size of %s"), + oid_to_hex(&e->idx.oid)); + read_unlock(); + return size; + } + + p = oe_in_pack(pack, e); + if (!p) + BUG("when e->type is a delta, it must belong to a pack"); + + read_lock(); + w_curs = NULL; + buf = use_pack(p, &w_curs, e->in_pack_offset, &avail); + used = unpack_object_header_buffer(buf, avail, &type, &size); + if (used == 0) + die(_("unable to parse object header of %s"), + oid_to_hex(&e->idx.oid)); + + unuse_pack(&w_curs); + read_unlock(); + return size; +} + static int try_delta(struct unpacked *trg, struct unpacked *src, unsigned max_depth, unsigned long *mem_usage) { @@ -1877,7 +1933,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src, return 0; /* Now some size filtering heuristics. */ - trg_size = trg_entry->size; + trg_size = SIZE(trg_entry); if (!DELTA(trg_entry)) { max_size = trg_size/2 - 20; ref_depth = 1; @@ -1889,7 +1945,7 @@ static int try_delta(struct unpacked *trg, struct unpacked *src, (max_depth - ref_depth + 1); if (max_size == 0) return 0; - src_size = src_entry->size; + src_size = SIZE(src_entry); sizediff = src_size < trg_size ? trg_size - src_size : 0; if (sizediff >= max_size) return 0; @@ -2009,7 +2065,7 @@ static unsigned long free_unpacked(struct unpacked *n) free_delta_index(n->index); n->index = NULL; if (n->data) { - freed_mem += n->entry->size; + freed_mem += SIZE(n->entry); FREE_AND_NULL(n->data); } n->entry = NULL; @@ -2459,7 +2515,8 @@ static void prepare_pack(int window, int depth) */ continue; - if (!entry->type_valid || entry->size < 50) + if (!entry->type_valid || + oe_size_less_than(&to_pack, entry, 50)) continue; if (entry->no_try_delta) diff --git a/pack-objects.c b/pack-objects.c index 09f0a88865..bf2e0a808d 100644 --- a/pack-objects.c +++ b/pack-objects.c @@ -144,6 +144,9 @@ void prepare_packing_data(struct packing_data *pdata) } else { prepare_in_pack_by_idx(pdata); } + + pdata->oe_size_limit = git_env_ulong("GIT_TEST_OE_SIZE", + 1U << OE_SIZE_BITS); } struct object_entry *packlist_alloc(struct packing_data *pdata, diff --git a/pack-objects.h b/pack-objects.h index 534f5a5e4d..27697be5c9 100644 --- a/pack-objects.h +++ b/pack-objects.h @@ -5,6 +5,11 @@ #define OE_DEPTH_BITS 12 #define OE_IN_PACK_BITS 10 #define OE_Z_DELTA_BITS 20 +/* + * Note that oe_set_size() becomes expensive when the given size is + * above this limit. Don't lower it too much. + */ +#define OE_SIZE_BITS 31 /* * State flags for depth-first search used for analyzing delta cycles. @@ -68,7 +73,8 @@ enum dfs_state { */ struct object_entry { struct pack_idx_entry idx; - unsigned long size; /* uncompressed size */ + unsigned size_:OE_SIZE_BITS; + unsigned size_valid:1; unsigned in_pack_idx:OE_IN_PACK_BITS; /* already in pack */ off_t in_pack_offset; uint32_t delta_idx; /* delta base object */ @@ -113,6 +119,8 @@ struct packing_data { */ struct packed_git **in_pack_by_idx; struct packed_git **in_pack; + + uintmax_t oe_size_limit; }; void prepare_packing_data(struct packing_data *pdata); @@ -252,4 +260,51 @@ static inline void oe_set_delta_sibling(struct packing_data *pack, e->delta_sibling_idx = 0; } +unsigned long oe_get_size_slow(struct packing_data *pack, + const struct object_entry *e); +static inline unsigned long oe_size(struct packing_data *pack, + const struct object_entry *e) +{ + if (e->size_valid) + return e->size_; + + return oe_get_size_slow(pack, e); +} + +static inline int oe_size_less_than(struct packing_data *pack, + const struct object_entry *lhs, + unsigned long rhs) +{ + if (lhs->size_valid) + return lhs->size_ < rhs; + if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */ + return 0; + return oe_get_size_slow(pack, lhs) < rhs; +} + +static inline int oe_size_greater_than(struct packing_data *pack, + const struct object_entry *lhs, + unsigned long rhs) +{ + if (lhs->size_valid) + return lhs->size_ > rhs; + if (rhs < pack->oe_size_limit) /* rhs < 2^x <= lhs ? */ + return 1; + return oe_get_size_slow(pack, lhs) > rhs; +} + +static inline void oe_set_size(struct packing_data *pack, + struct object_entry *e, + unsigned long size) +{ + if (size < pack->oe_size_limit) { + e->size_ = size; + e->size_valid = 1; + } else { + e->size_valid = 0; + if (oe_get_size_slow(pack, e) != size) + BUG("'size' is supposed to be the object size!"); + } +} + #endif diff --git a/t/README b/t/README index c6130ff16d..c01d210c15 100644 --- a/t/README +++ b/t/README @@ -306,6 +306,12 @@ GIT_TEST_FULL_IN_PACK_ARRAY exercises the uncommon pack-objects code path where there are more than 1024 packs even if the actual number of packs in repository is below this limit. +GIT_TEST_OE_SIZE= exercises the uncommon pack-objects code path +where we do not cache object size in memory and read it from existing +packs on demand. This normally only happens when the object size is +over 2GB. This variable forces the code path on any object larger than + bytes. + Naming Tests ------------ -- 2.17.0.rc2.515.g4feb9b7923