Граф коммитов

23 Коммитов

Автор SHA1 Сообщение Дата
Jeff King 9540ce5030 refs: write packed_refs file using stdio
We write each line of a new packed-refs file individually
using a write() syscall (and sometimes 2, if the ref is
peeled). Since each line is only about 50-100 bytes long,
this creates a lot of system call overhead.

We can instead open a stdio handle around our descriptor and
use fprintf to write to it. The extra buffering is not a
problem for us, because nobody will read our new packed-refs
file until we call commit_lock_file (by which point we have
flushed everything).

On a pathological repository with 8.5 million refs, this
dropped the time to run `git pack-refs` from 20s to 6s.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-10 10:58:32 -07:00
Jeff King 756e676ca0 write_or_die: raise SIGPIPE when we get EPIPE
The write_or_die function will always die on an error,
including EPIPE. However, it currently treats EPIPE
specially by suppressing any error message, and by exiting
with exit code 0.

Suppressing the error message makes some sense; a pipe death
may just be a sign that the other side is not interested in
what we have to say. However, exiting with a successful
error code is not a good idea, as write_or_die is frequently
used in cases where we want to be careful about having
written all of the output, and we may need to signal to our
caller that we have done so (e.g., you would not want a push
whose other end has hung up to report success).

This distinction doesn't typically matter in git, because we
do not ignore SIGPIPE in the first place. Which means that
we will not get EPIPE, but instead will just die when we get
a SIGPIPE. But it's possible for a default handler to be set
by a parent process, or for us to add a callsite inside one
of our few SIGPIPE-ignoring blocks of code.

This patch converts write_or_die to actually raise SIGPIPE
when we see EPIPE, rather than exiting with zero. This
brings the behavior in line with the "normal" case that we
die from SIGPIPE (and any callers who want to check why we
died will see the same thing). We also give the same
treatment to other related functions, including
write_or_whine_pipe and maybe_flush_or_die.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20 13:42:21 -08:00
Johannes Sixt 84adb64154 maybe_flush_or_die: move a too-loose Windows specific error
check to compat

Commit b2f5e268 (Windows: Work around an oddity when a pipe with no reader
is written to) introduced a check for EINVAL after fflush() to fight
spurious "Invalid argument" errors on Windows when a pipe was broken. But
this check may hide real errors on systems that do not have the this odd
behavior. Introduce an fflush wrapper in compat/mingw.* so that the treatment
is only applied on Windows.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-17 00:33:42 -07:00
Thomas Rast d824cbba02 Convert existing die(..., strerror(errno)) to die_errno()
Change calls to die(..., strerror(errno)) to use the new die_errno().

In the process, also make slight style adjustments: at least state
_something_ about the function that failed (instead of just printing
the pathname), and put paths in single quotes.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-27 11:14:53 -07:00
Junio C Hamano 559e840b74 Move read_in_full() and write_in_full() to wrapper.c
A few compat/* layer functions call these functions, but we would really
want to keep them thin, without depending too much on the libgit proper.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-20 17:17:09 -07:00
Johannes Sixt b2f5e2684d Windows: Work around an oddity when a pipe with no reader is written to.
On Windows, write() is implemented using WriteFile(). After the reader
closed its end of the pipe, the first WriteFile() returns
ERROR_BROKEN_PIPE (which translates to EPIPE), subsequent WriteFile()s
return ERROR_NO_DATA, which is translated to EINVAL.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-26 08:47:15 +02:00
Linus Torvalds 4c81b03e30 Make pack creation always fsync() the result
This means that we can depend on packs always being stable on disk,
simplifying a lot of the object serialization worries.  And unlike loose
objects, serializing pack creation IO isn't going to be a performance
killer.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-31 14:46:57 -07:00
Heikki Orsila 0104ca09e3 Make read_in_full() and write_in_full() consistent with xread() and xwrite()
xread() and xwrite() return ssize_t values as their native POSIX
counterparts read(2) and write(2).

To be consistent, read_in_full() and write_in_full() should also return
ssize_t values.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-29 23:11:57 -07:00
Theodore Ts'o 06f59e9f5d Don't fflush(stdout) when it's not helpful
This patch arose from a discussion started by Jim Meyering's patch
whose intention was to provide better diagnostics for failed writes.
Linus proposed a better way to do things, which also had the added
benefit that adding a fflush() to git-log-* operations and incremental
git-blame operations could improve interactive respose time feel, at
the cost of making things a bit slower when we aren't piping the
output to a downstream program.

This patch skips the fflush() calls when stdout is a regular file, or
if the environment variable GIT_FLUSH is set to "0".  This latter can
speed up a command such as:

GIT_FLUSH=0 strace -c -f -e write time git-rev-list HEAD | wc -l

a tiny amount.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-30 20:16:12 -07:00
Junio C Hamano d848804a89 write_in_full: size_t is unsigned.
It received the return value from xwrite() in a size_t variable
'written' and expected comparison with 0 would catch an error
from xwrite().

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-26 17:39:03 -08:00
Shawn O. Pearce e6e2bd6201 Remove read_or_die in favor of better error messages.
Originally I introduced read_or_die for the purpose of reading
the pack header and trailer, and I was too lazy to print proper
error messages.

Linus Torvalds <torvalds@osdl.org>:
> For a read error, at the very least you have to say WHICH FILE
> couldn't be read, because it's usually a matter of some file just
> being too short, not some system-wide problem.

and of course Linus is right. Make it so.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-14 00:42:41 -08:00
Linus Torvalds 4494c656e2 Fix up totally buggered read_or_die()
The "read_or_die()" function would silently NOT die for a partial read,
and since it was of type "void" it obviously couldn't even return the
partial number of bytes read.

IOW, it was totally broken. This hopefully fixes it up.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-11 21:05:34 -08:00
Linus Torvalds d34cf19b89 Clean up write_in_full() users
With the new-and-improved write_in_full() semantics, where a partial write
simply always returns a real error (and always sets 'errno' when that
happens, including for the disk full case), a lot of the callers of
write_in_full() were just unnecessarily complex.

In particular, there's no reason to ever check for a zero length or
return: if the length was zero, we'll return zero, otherwise, if a disk
full resulted in the actual write() system call returning zero the
write_in_full() logic would have correctly turned that into a negative
return value, with 'errno' set to ENOSPC.

I really wish every "write_in_full()" user would just check against "<0"
now, but this fixes the nasty and stupid ones.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-11 21:02:58 -08:00
Eric Wong 3b97fee23d Avoid errors and warnings when attempting to do I/O on zero bytes
Unfortunately, while {read,write}_in_full do take into account
zero-sized reads/writes; their die and whine variants do not.

I have a repository where there are zero-sized files in
the history that was triggering these things.

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-11 14:49:45 -08:00
Linus Torvalds f6aa66cb95 write_in_full: really write in full or return error on disk full.
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-11 13:19:18 -08:00
Andy Whitcroft 93822c2239 short i/o: fix calls to write to use xwrite or write_in_full
We have a number of badly checked write() calls.  Often we are
expecting write() to write exactly the size we requested or fail,
this fails to handle interrupts or short writes.  Switch to using
the new write_in_full().  Otherwise we at a minimum need to check
for EINTR and EAGAIN, where this is appropriate use xwrite().

Note, the changes to config handling are much larger and handled
in the next patch in the sequence.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-08 15:44:47 -08:00
Andy Whitcroft 93d26e4cb9 short i/o: fix calls to read to use xread or read_in_full
We have a number of badly checked read() calls.  Often we are
expecting read() to read exactly the size we requested or fail, this
fails to handle interrupts or short reads.  Add a read_in_full()
providing those semantics.  Otherwise we at a minimum need to check
for EINTR and EAGAIN, where this is appropriate use xread().

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-08 15:44:47 -08:00
Andy Whitcroft e08140568a short i/o: clean up the naming for the write_{in,or}_xxx family
We recently introduced a write_in_full() which would either write
the specified object or emit an error message and fail.  In order
to fix the read side we now want to introduce a read_in_full()
but without an error emit.  This patch cleans up the naming
of this family of calls:

1) convert the existing write_or_whine() to write_or_whine_pipe()
   to better indicate its pipe specific nature,
2) convert the existing write_in_full() calls to write_or_whine()
   to better indicate its nature,
3) introduce a write_in_full() providing a write or fail semantic,
   and
4) convert write_or_whine() and write_or_whine_pipe() to use
   write_in_full().

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-08 15:44:47 -08:00
Junio C Hamano cf2999eb4c Merge branch 'sp/mmap'
* sp/mmap: (27 commits)
  Spell default packedgitlimit slightly differently
  Increase packedGit{Limit,WindowSize} on 64 bit systems.
  Update packedGit config option documentation.
  mmap: set FD_CLOEXEC for file descriptors we keep open for mmap()
  pack-objects: fix use of use_pack().
  Fix random segfaults in pack-objects.
  Cleanup read_cache_from error handling.
  Replace mmap with xmmap, better handling MAP_FAILED.
  Release pack windows before reporting out of memory.
  Default core.packdGitWindowSize to 1 MiB if NO_MMAP.
  Test suite for sliding window mmap implementation.
  Create pack_report() as a debugging aid.
  Support unmapping windows on 'temporary' packfiles.
  Improve error message when packfile mmap fails.
  Ensure core.packedGitWindowSize cannot be less than 2 pages.
  Load core configuration in git-verify-pack.
  Fully activate the sliding window pack access.
  Unmap individual windows rather than entire files.
  Document why header parsing won't exceed a window.
  Loop over pack_windows when inflating/accessing data.
  ...

Conflicts:

	cache.h
	pack-check.c
2007-01-07 00:12:47 -08:00
Andy Whitcroft 825cee7b28 send pack check for failure to send revisions list
When passing the revisions list to pack-objects we do not check for
errors nor short writes.  Introduce a new write_in_full which will
handle short writes and report errors to the caller.  Use this to
short cut the send on failure, allowing us to wait for and report
the child in case the failure is its fault.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-02 23:33:21 -08:00
Shawn O. Pearce 75025ccdb7 Create read_or_die utility routine.
Like write_or_die read_or_die reads the entire length requested
or it kills the current process with a die call.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-29 11:36:44 -08:00
Christian Couder 7cf67205ca Trace into open fd and refactor tracing code.
Now if GIT_TRACE is set to an integer value greater than 1
and lower than 10, we interpret this as an open fd value
and we trace into it. Note that this behavior is not
compatible with the previous one.

We also trace whole messages using one write(2) call to
make sure messages from processes do net get mixed up in
the middle.

It's now possible to run the tests like this:

	GIT_TRACE=9 make test 9>/var/tmp/trace.log

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-31 14:16:38 -07:00
Rene Scharfe 7230e6d042 Add write_or_die(), a helper function
The little helper write_or_die() won't come back with bad news about
full disks or broken pipes.  It either succeeds or terminates the
program, making additional error handling unnecessary.

This patch adds the new function and uses it to replace two similar
ones (the one in tar-tree originally has been copied from cat-file
btw.).  I chose to add the fd parameter which both lacked to make
write_or_die() just as flexible as write() and thus suitable for
lib-ification.

There is a regression: error messages emitted by this function don't
show the program name, while the replaced two functions did.  That's
acceptable, I think; a lot of other functions do the same.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-21 20:22:23 -07:00