# [PATCH] Optimize sha1_object_info for loose objects, not concurrent repacks 2 messages from 2008-08-05 to 2008-08-05. Participants: Steven Grimm, Shawn O. Pearce. Thread: https://gitlist.dev/t/14846 ## Steven Grimm, 2008-08-05 20:08 Subject: [PATCH] Optimize sha1_object_info for loose objects, not concurrent repacks Message-ID: <20080805200841.GA23121@midwinter.com> URL: https://gitlist.dev/e/20080805200841.GA23121%40midwinter.com ``` When dealing with a repository with lots of loose objects, sha1_object_info would rescan the packs directory every time an unpacked object was referenced before finally giving up and looking for the loose object. This caused a lot of extra unnecessary system calls during git pack-objects; the code was rereading the entire pack directory once for each loose object file. This patch looks for a loose object before falling back to rescanning the pack directory, rather than the other way around. Signed-off-by: Steven Grimm --- I discovered this by running strace on a pack-objects that was taking especially long to run; it was making more system calls to scan the pack directory than to do stuff with the loose objects, which didn't seem right. sha1_file.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/sha1_file.c b/sha1_file.c index e281c14..32e4664 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -1929,11 +1929,18 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) { struct pack_entry e; + int status; if (!find_pack_entry(sha1, &e, NULL)) { + /* Most likely it's a loose object. */ + status = sha1_loose_object_info(sha1, sizep); + if (status >= 0) + return status; + + /* Not a loose object; someone else may have just packed it. */ reprepare_packed_git(); if (!find_pack_entry(sha1, &e, NULL)) - return sha1_loose_object_info(sha1, sizep); + return status; } return packed_object_info(e.p, e.offset, sizep); } -- 1.6.0.rc1.66.gc78d7 ``` ## Shawn O. Pearce, 2008-08-05 20:18 Subject: Re: [PATCH] Optimize sha1_object_info for loose objects, not concurrent repacks Message-ID: <20080805201853.GG27207@spearce.org> URL: https://gitlist.dev/e/20080805201853.GG27207%40spearce.org In-Reply-To: <20080805200841.GA23121@midwinter.com> ``` Steven Grimm wrote: > When dealing with a repository with lots of loose objects, sha1_object_info > would rescan the packs directory every time an unpacked object was referenced > before finally giving up and looking for the loose object. This caused a lot > of extra unnecessary system calls during git pack-objects; the code was > rereading the entire pack directory once for each loose object file. > > This patch looks for a loose object before falling back to rescanning the > pack directory, rather than the other way around. > > Signed-off-by: Steven Grimm Heh. Cute bug. ACK. > diff --git a/sha1_file.c b/sha1_file.c > index e281c14..32e4664 100644 > --- a/sha1_file.c > +++ b/sha1_file.c > @@ -1929,11 +1929,18 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size > int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) > { > struct pack_entry e; > + int status; > > if (!find_pack_entry(sha1, &e, NULL)) { > + /* Most likely it's a loose object. */ > + status = sha1_loose_object_info(sha1, sizep); > + if (status >= 0) > + return status; > + > + /* Not a loose object; someone else may have just packed it. */ > reprepare_packed_git(); > if (!find_pack_entry(sha1, &e, NULL)) > - return sha1_loose_object_info(sha1, sizep); > + return status; > } > return packed_object_info(e.p, e.offset, sizep); > } -- Shawn. ```