Commit Graph

215 Commits

Author SHA1 Message Date
Jeff King
75a9549047 avoid segfaults on parse_object failure
Many call-sites of parse_object assume that they will get a
non-NULL return value; this is not the case if we encounter
an error while parsing the object.

This patch adds a wrapper function around parse_object that
handles dying automatically, and uses it anywhere we
immediately try to access the return value as a non-NULL
pointer (i.e., anywhere that we would currently segfault).

This wrapper may also be useful in other places. The most
obvious one is code like:

  o = parse_object(sha1);
  if (!o)
	  die(...);

However, these should not be mechanically converted to
parse_object_or_die, as the die message is sometimes
customized. Later patches can address these sites on a
case-by-case basis.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-17 12:49:03 -07:00
Pete Wyckoff
82247e9bd5 remove superfluous newlines in error messages
The error handling routines add a newline.  Remove
the duplicate ones in error messages.

Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-04-30 15:45:51 -07:00
Junio C Hamano
419f2ecf78 Merge branch 'hv/submodule-recurse-push'
"git push --recurse-submodules" learns to optionally look into the
histories of submodules bound to the superproject and push them out.

By Heiko Voigt
* hv/submodule-recurse-push:
  push: teach --recurse-submodules the on-demand option
  Refactor submodule push check to use string list instead of integer
  Teach revision walking machinery to walk multiple times sequencially
2012-04-24 14:40:20 -07:00
Heiko Voigt
bcc0a3ea38 Teach revision walking machinery to walk multiple times sequencially
Previously it was not possible to iterate revisions twice using the
revision walking api. We add a reset_revision_walk() which clears the
used flags. This allows us to do multiple sequencial revision walks.

We add the appropriate calls to the existing submodule machinery doing
revision walks. This is done to avoid surprises if future code wants to
call these functions more than once during the processes lifetime.

Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-30 08:57:49 -07:00
Nguyễn Thái Ngọc Duy
090ea12671 parse_object: avoid putting whole blob in core
Traditionally, all the callers of check_sha1_signature() first
called read_sha1_file() to prepare the whole object data in core,
and called this function.  The function is used to revalidate what
we read from the object database actually matches the object name we
used to ask for the data from the object database.

Update the API to allow callers to pass NULL as the object data, and
have the function read and hash the object data using streaming API
to recompute the object name, without having to hold everything in
core at the same time.  This is most useful in parse_object() that
parses a blob object, because this caller does not have to keep the
actual blob data around in memory after a "struct blob" is returned.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-07 09:07:38 -08:00
Jeff King
ccdc6037fe parse_object: try internal cache before reading object db
When parse_object is called, we do the following:

  1. read the object data into a buffer via read_sha1_file

  2. call parse_object_buffer, which then:

     a. calls the appropriate lookup_{commit,tree,blob,tag}
	to either create a new "struct object", or to find
	an existing one. We know the appropriate type from
	the lookup in step 1.

     b. calls the appropriate parse_{commit,tree,blob,tag}
        to parse the buffer for the new (or existing) object

In step 2b, all of the called functions are no-ops for
object "X" if "X->object.parsed" is set. I.e., when we have
already parsed an object, we end up going to a lot of work
just to find out at a low level that there is nothing left
for us to do (and we throw away the data from read_sha1_file
unread).

We can optimize this by moving the check for "do we have an
in-memory object" from 2a before the expensive call to
read_sha1_file in step 1.

This might seem circular, since step 2a uses the type
information determined in step 1 to call the appropriate
lookup function. However, we can notice that all of the
lookup_* functions are backed by lookup_object. In other
words, all of the objects are kept in a master hash table,
and we don't actually need the type to do the "do we have
it" part of the lookup, only to do the "and create it if it
doesn't exist" part.

This can save time whenever we call parse_object on the same
sha1 twice in a single program. Some code paths already
perform this optimization manually, with either:

  if (!obj->parsed)
	  obj = parse_object(obj->sha1);

if you already have a "struct object", or:

  struct object *obj = lookup_unknown_object(sha1);
  if (!obj || !obj->parsed)
	  obj = parse_object(sha1);

if you don't.  This patch moves the optimization into
parse_object itself.

Most git operations won't notice any impact. Either they
don't parse a lot of duplicate sha1s, or the calling code
takes special care not to re-parse objects. I timed two
code paths that do benefit (there may be more, but these two
were immediately obvious and easy to time).

The first is fast-export, which calls parse_object on each
object it outputs, like this:

  object = parse_object(sha1);
  if (!object)
	  die(...);
  if (object->flags & SHOWN)
	  return;

which means that just to realize we have already shown an
object, we will read the whole object from disk!

With this patch, my best-of-five time for "fast-export --all" on
git.git dropped from 26.3s to 21.3s.

The second case is upload-pack, which will call parse_object
for each advertised ref (because it needs to peel tags to
show "^{}" entries). This doesn't matter for most
repositories, because they don't have a lot of refs pointing
to the same objects. However, if you have a big alternates
repository with a shared object db for a number of child
repositories, then the alternates repository will have
duplicated refs representing each of its children.

For example, GitHub's alternates repository for git.git has
~120,000 refs, of which only ~3200 are unique. The time for
upload-pack to print its list of advertised refs dropped
from 3.4s to 0.76s.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-01-05 13:30:54 -08:00
Junio C Hamano
68be2fea50 receive-pack, fetch-pack: reject bogus pack that records objects twice
When receive-pack & fetch-pack are run and store the pack obtained over
the wire to a local repository, they internally run the index-pack command
with the --strict option. Make sure that we reject incoming packfile that
records objects twice to avoid spreading such a damage.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-11-16 22:05:21 -08:00
Junio C Hamano
4bbf5a2615 read_sha1_file(): get rid of read_sha1_file_repl() madness
Most callers want to silently get a replacement object, and they do not
care what the real name of the replacement object is.  Worse yet, no sane
interface to return the underlying object without replacement is provided.

Remove the function and make only the few callers that want the name of
the replacement object find it themselves.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-05-15 15:23:33 -07:00
Junio C Hamano
4682693e9c Merge branch 'maint'
* maint:
  tag.c: whitespace breakages fix
  Fix whitespace issue in object.c
  t5505: add missing &&
2010-09-06 00:12:04 -07:00
Junio C Hamano
af24059fa2 Merge branch 'xx/trivial' into maint
* xx/trivial:
  tag.c: whitespace breakages fix
  Fix whitespace issue in object.c
  t5505: add missing &&
2010-09-06 00:11:59 -07:00
Jared Hance
55b4e9e432 Fix whitespace issue in object.c
Change some expanded tabs (spaces) to tabs in object.c.

Signed-off-by: Jared Hance <jaredhance@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-09-05 22:12:29 -07:00
Junio C Hamano
f92d62ec4e Merge branch 'nd/maint-fix-replace'
* nd/maint-fix-replace:
  parse_object: pass on the original sha1, not the replaced one
2010-09-03 22:23:13 -07:00
Nguyễn Thái Ngọc Duy
2e3400c052 parse_object: pass on the original sha1, not the replaced one
Commit 0e87c36 (object: call "check_sha1_signature" with the
replacement sha1) changed the first argument passed to
parse_object_buffer() from "sha1" to "repl". With that change,
the returned obj pointer has the replacement SHA1 in obj->sha1,
not the original one.

But when using lookup_commit() and then parse_commit() on a
commit, we get an object pointer with the original sha1, but
the commit content comes from the replacement commit.

So the result we get from using parse_object() is different
from the we get from using lookup_commit() followed by
parse_commit().

It looks much simpler and safer to fix this inconsistency by
passing "sha1" to parse_object_bufer() instead of "repl".

The commit comment should be used to tell the the replacement
commit is replacing another commit and why. So it should be
easy to see that we have a replacement commit instead of an
original one.

And it is not a problem if the content of the commit is not
consistent with the sha1 as cat-file piped to hash-object can
be used to see the difference.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-09-03 22:13:08 -07:00
Jonathan Nieder
97a20eea19 fix "bundle --stdin" segfault
When passed an empty list, objects_array_remove_duplicates() corrupts it
by changing the number of entries from 0 to 1.

The problem lies in the condition of its main loop:

	for (ref = 0; ref < array->nr - 1; ref++) {

The loop body manipulates the supplied object array.  In the case of an
empty array, it should not be doing anything at all.  But array->nr is an
unsigned quantity, so the code enters the loop, in particular increasing
array->nr.  Fix this by comparing (ref + 1 < array->nr) instead.

This bug can be triggered by git bundle --stdin:

	$ echo HEAD | git bundle create some.bundle --stdin’
	Segmentation fault (core dumped)

The list of commits to bundle appears to be empty because of another bug:
by the time the revision-walking machinery gets to look at it, standard
input has already been consumed by rev-list, so this function gets an
empty list of revisions.

After this patch, git bundle --stdin still does not work; it just doesn’t
segfault any more.

Reported-by: Joey Hess <joey@kitenet.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-04-19 22:16:35 -07:00
Junio C Hamano
c76189875b object.c: remove unused functions
object_list_append() and object_list_length}() are not used anywhere.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-17 22:49:36 -08:00
Christian Couder
0e87c36763 object: call "check_sha1_signature" with the replacement sha1
Otherwise we get a "sha1 mismatch" error for replaced objects.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-31 17:02:59 -07:00
Dan McGee
91fe2f9091 Unify signedness in hashing calls
Our hash_obj and hashtable_index calls and functions were doing a lot of
funny things with signedness. Unify all of it to 'unsigned int'.

Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-20 00:02:24 -07:00
Dan McGee
b867d324ce Fix type-punning issues
In these two places we are casting part of our unsigned char sha1 array into
an unsigned int, which violates GCCs strict-aliasing rules (and probably
other compilers).

Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-16 22:41:18 -07:00
Junio C Hamano
b2a6d1c686 bundle: allow the same ref to be given more than once
"git bundle create x master master" used to create a bundle that lists
the same branch (master) twice.  Cloning from such a bundle resulted in
a needless warning "warning: Duplicated ref: refs/remotes/origin/master".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17 23:00:31 -08:00
Martin Koegler
d0b8c9e561 parse_object_buffer: don't ignore errors from the object specific parsing functions
In the case of an malformed object, the object specific parsing functions
would return an error, which is currently ignored. The object can be partial
initialized in this case.

This patch make parse_object_buffer propagate such errors.

Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-03 16:04:57 -08:00
Jim Meyering
cc21682793 Don't dereference NULL upon lookup failure.
Instead, signal the error just like the case we do upon encountering
an object with an unknown type.

Signed-off-by: Jim Meyering <meyering@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-12-22 11:15:38 -08:00
Sam Vilain
e2ac7cb5fb Don't assume tree entries that are not dirs are blobs
When scanning the trees in track_tree_refs() there is a "lazy" test
that assumes that entries are either directories or files.  Don't do
that.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-06 15:43:18 -07:00
Junio C Hamano
76026200ee Merge branch 'maint-1.5.1' into maint
* maint-1.5.1:
  fix memory leak in parse_object when check_sha1_signature fails
  name-rev: tolerate clock skew in committer dates
2007-05-24 19:01:50 -07:00
Carlos Rica
0b1f113075 fix memory leak in parse_object when check_sha1_signature fails
When check_sha1_signature fails, program is not terminated:
it prints an error message and returns NULL, so the
buffer returned by read_sha1_file should be freed before.

Signed-off-by: Carlos Rica <jasampler@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-24 18:56:06 -07:00
Martin Koegler
e5709a4a68 add add_object_array_with_mode
Each object in struct object_array is extended with the mode.
If not specified, S_IFINVALID is used. An object with an mode value
can be added with add_object_array_with_mode.

Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-24 00:08:49 -07:00
Linus Torvalds
100c5f3b0b Clean up object creation to use more common code
This replaces the fairly odd "created_object()" function that did _most_
of the object setup with a more complete "create_object()" function that
also has a more natural calling convention.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-16 23:36:16 -07:00
Linus Torvalds
2c1cbec1e2 Use proper object allocators for unknown object nodes too
We used to use a different allocator scheme for when we didn't know the
object type.  That meant that objects that were created without any
up-front knowledge of the type would not go through the same allocation
paths as normal object allocations, and would miss out on the statistics.

But perhaps more importantly than the statistics (that are useful when
looking at memory usage but not much else), if we want to make the
object hash tables use a denser object pointer representation, we need
to make sure that they all go through the same blocking allocator.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-16 23:36:11 -07:00
Linus Torvalds
acdeec62cb Don't ever return corrupt objects from "parse_object()"
Looking at the SHA1 validation code due to the corruption that Alexander
Litvinov is seeing under Cygwin, I notice that one of the most central
places where we read objects, we actually do end up verifying the SHA1 of
the result, but then we happily parse it anyway.

And using "printf" to write the error message means that it not only can
get lost, but will actually mess up stdout, and cause other strange and
hard-to-debug failures downstream.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-20 22:17:17 -07:00
Nicolas Pitre
0ab179504a get rid of lookup_object_type()
This function is called only once in the whole source tree.  Let's move
its code inline instead, which is also in the spirit of removing as much
object type char arrays as possible (not that this patch does anything for
that but at least it is now a local matter).

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-27 01:34:21 -08:00
Nicolas Pitre
21666f1aae convert object type handling from a string to a number
We currently have two parallel notation for dealing with object types
in the code: a string and a numerical value.  One of them is obviously
redundent, and the most used one requires more stack space and a bunch
of strcmp() all over the place.

This is an initial step for the removal of the version using a char array
found in object reading code paths.  The patch is unfortunately large but
there is no sane way to split it in smaller parts without breaking the
system.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-27 01:34:21 -08:00
Nicolas Pitre
df8436622f formalize typename(), and add its reverse type_from_string()
Sometime typename() is used, sometimes type_names[] is accessed directly.
Let's enforce typename() all the time which allows for validating the
type.

Also let's add a function to go from a name to a type and use it instead
of manual memcpy() when appropriate.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-27 01:34:21 -08:00
Junio C Hamano
9f613ddd21 Add git-for-each-ref: helper for language bindings
This adds a new command, git-for-each-ref.  You can have it iterate
over refs and have it output various aspects of the objects they
refer to.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-16 10:22:02 -07:00
Jonas Fonseca
b3c952f838 Use xcalloc instead of calloc
Signed-off-by: Jonas Fonseca <fonseca@diku.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-27 20:49:43 -07:00
Shawn Pearce
e702496e43 Convert memcpy(a,b,20) to hashcpy(a,b).
This abstracts away the size of the hash values when copying them
from memory location to memory location, much as the introduction
of hashcmp abstracted away hash value comparsion.

A few call sites were using char* rather than unsigned char* so
I added the cast rather than open hashcpy to be void*.  This is a
reasonable tradeoff as most call sites already use unsigned char*
and the existing hashcmp is also declared to be unsigned char*.

[jc: Splitted the patch to "master" part, to be followed by a
 patch for merge-recursive.c which is not in "master" yet.

 Fixed the cast in the latter hunk to combine-diff.c which was
 wrong in the original.

 Also converted ones left-over in combine-diff.c, diff-lib.c and
 upload-pack.c ]

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-23 13:53:10 -07:00
David Rientjes
a89fccd281 Do not use memcmp(sha1_1, sha1_2, 20) with hardcoded length.
Introduces global inline:

	hashcmp(const unsigned char *sha1, const unsigned char *sha2)

Uses memcmp for comparison and returns the result based on the length of
the hash name (a future runtime decision).

Acked-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-17 14:23:53 -07:00
Linus Torvalds
1974632c66 Remove TYPE_* constant macros and use object_type enums consistently.
This updates the type-enumeration constants introduced to reduce
the memory footprint of "struct object" to match the type bits
already used in the packfile format, by removing the former
(i.e. TYPE_* constant macros) and using the latter (i.e. enum
object_type) throughout the code for consistency.

Eventually we can stop passing around the "type strings"
entirely, and this will help - no confusion about two different
integer enumeration.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-07-12 23:18:03 -07:00
Linus Torvalds
0556a11a0d git object hash cleanups
This IMNSHO cleans up the object hashing.

The hash expansion is separated out into a function of its own, the hash
array (and size) names are made more obvious, and the code is generally
made to look a bit more like the object-ref hashing.

It also gets rid of "find_object()" returning an index (or negative
position if no object is found), since that is made redundant by the
simplified object rehashing. The basic operation is now "lookup_object()"
which just returns the object itself.

There's an almost unmeasurable speed increase, but more importantly, I
think the end result is more readable.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-07-01 18:28:15 -07:00
Linus Torvalds
fc046a75d5 Abstract out accesses to object hash array
There are a few special places where some programs accessed the object
hash array directly, which bothered me because I wanted to play with some
simple re-organizations.

So this patch makes the object hash array data structures all entirely
local to object.c, and the few users who wanted to look at it now get to
use a function to query how many object index entries there can be, and to
actually access the array.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-29 23:48:31 -07:00
Linus Torvalds
1f1e895fcc Add "named object array" concept
We've had this notion of a "object_list" for a long time, which eventually
grew a "name" member because some users (notably git-rev-list) wanted to
name each object as it is generated.

That object_list is great for some things, but it isn't all that wonderful
for others, and the "name" member is generally not used by everybody.

This patch splits the users of the object_list array up into two: the
traditional list users, who want the list-like format, and who don't
actually use or want the name. And another class of users that really used
the list as an extensible array, and generally wanted to name the objects.

The patch is fairly straightforward, but it's also biggish. Most of it
really just cleans things up: switching the revision parsing and listing
over to the array makes things like the builtin-diff usage much simpler
(we now see exactly how many members the array has, and we don't get the
objects reversed from the order they were on the command line).

One of the main reasons for doing this at all is that the malloc overhead
of the simple object list was actually pretty high, and the array is just
a lot denser. So this patch brings down memory usage by git-rev-list by
just under 3% (on top of all the other memory use optimizations) on the
mozilla archive.

It does add more lines than it removes, and more importantly, it adds a
whole new infrastructure for maintaining lists of objects, but on the
other hand, the new dynamic array code is pretty obvious. The change to
builtin-diff-tree.c shows a fairly good example of why an array interface
is sometimes more natural, and just much simpler for everybody.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-19 18:45:48 -07:00
Linus Torvalds
3e4339e6f9 Remove "refs" field from "struct object"
This shrinks "struct object" to the absolutely minimal size possible.
It now contains /only/ the object flags and the SHA1 hash name of the
object.

The "refs" field, which is really needed only for fsck, is maintained in
a separate hashed lookup-table, allowing all normal users to totally
ignore it.

This helps memory usage, although not as much as I hoped: it looks like
the allocation overhead of malloc (and the alignment constraints in
particular) means that while the structure size shrinks, the actual
allocation overhead mostly does not.

[ That said: memory usage is actually down, but not as much as it should
  be: I suspect just one of the object types actually ended up shrinking
  its effective allocation size.

  To get to the next level, we probably need specialized allocators that
  don't pad the allocation more than necessary. ]

The separation makes for some code cleanup, though, and makes the ref
tracking that fsck wants a clearly separate thing.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-18 13:51:27 -07:00
Linus Torvalds
885a86abe2 Shrink "struct object" a bit
This shrinks "struct object" by a small amount, by getting rid of the
"struct type *" pointer and replacing it with a 3-bit bitfield instead.

In addition, we merge the bitfields and the "flags" field, which
incidentally should also remove a useless 4-byte padding from the object
when in 64-bit mode.

Now, our "struct object" is still too damn large, but it's now less
obviously bloated, and of the remaining fields, only the "util" (which is
not used by most things) is clearly something that should be eventually
discarded.

This shrinks the "git-rev-list --all" memory use by about 2.5% on the
kernel archive (and, perhaps more importantly, on the larger mozilla
archive). That may not sound like much, but I suspect it's more on a
64-bit platform.

There are other remaining inefficiencies (the parent lists, for example,
probably have horrible malloc overhead), but this was pretty obvious.

Most of the patch is just changing the comparison of the "type" pointer
from one of the constant string pointers to the appropriate new TYPE_xxx
small integer constant.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-17 18:49:18 -07:00
Linus Torvalds
3a7c352bd0 Make "tree_entry" have a SHA1 instead of a union of object pointers
This is preparatory work for further cleanups, where we try to make
tree_entry look more like the more efficient tree-walk descriptor.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-29 19:05:06 -07:00
Linus Torvalds
136f2e548a Make "struct tree" contain the pointer to the tree buffer
This allows us to avoid allocating information for names etc, because
we can just use the information from the tree buffer directly.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-29 19:05:02 -07:00
Peter Eriksen
90321c106c Replace xmalloc+memset(0) with xcalloc.
Signed-off-by: Peter Eriksen <s022018@student.dtu.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-04 00:11:19 -07:00
Peter Eriksen
8e44025925 Use blob_, commit_, tag_, and tree_type throughout.
This replaces occurences of "blob", "commit", "tag", and "tree",
where they're really used as type specifiers, which we already
have defined global constants for.

Signed-off-by: Peter Eriksen <s022018@student.dtu.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-04 00:11:19 -07:00
Linus Torvalds
d7ee090d0d Fix object re-hashing
The hashed object lookup had a subtle bug in re-hashing: it did

	for (i = 0; i < count; i++)
		if (objs[i]) {
			.. rehash ..

where "count" was the old hash couny. Oon the face of it is obvious, since
it clearly re-hashes all the old objects.

However, it's wrong.

If the last old hash entry before re-hashing was in use (or became in use
by the re-hashing), then when re-hashing could have inserted an object
into the hash entries with idx >= count due to overflow. When we then
rehash the last old entry, that old entry might become empty, which means
that the overflow entries should be re-hashed again.

In other words, the loop has to be fixed to either traverse the whole
array, rather than just the old count.

(There's room for a slight optimization: instead of counting all the way
up, we can break when we see the first empty slot that is above the old
"count". At that point we know we don't have any collissions that we might
have to fix up any more. This patch only does the trivial fix)

[jc: with trivial fix on trivial fix]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-12 11:24:50 -08:00
Junio C Hamano
2b796360ac hashtable-based objects: minimum fixups.
Calling hashtable_index from find_object before objs is created
would result in division by zero failure.  Avoid it.

Also the given object name may not be aligned suitably for
unsigned int; avoid dereferencing casted pointer.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-12 05:12:39 -08:00
Johannes Schindelin
070879ca93 Use a hashtable for objects instead of a sorted list
In a simple test, this brings down the CPU time from 47 sec to 22 sec.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-02-12 05:12:39 -08:00
Junio C Hamano
8f1d2e6f49 [PATCH] Compilation: zero-length array declaration.
ISO C99 (and GCC 3.x or later) lets you write a flexible array
at the end of a structure, like this:

	struct frotz {
		int xyzzy;
		char nitfol[]; /* more */
	};

GCC 2.95 and 2.96 let you to do this with "char nitfol[0]";
unfortunately this is not allowed by ISO C90.

This declares such construct like this:

	struct frotz {
		int xyzzy;
		char nitfol[FLEX_ARRAY]; /* more */
	};

and git-compat-util.h defines FLEX_ARRAY to 0 for gcc 2.95 and
empty for others.

If you are using a C90 C compiler, you should be able
to override this with CFLAGS=-DFLEX_ARRAY=1 from the
command line of "make".

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-07 10:51:06 -08:00
Junio C Hamano
e23eff8be9 qsort() ptrdiff_t may be larger than int
Morten Welinder <mwelinder@gmail.com> writes:

> The code looks wrong.  It assumes that pointers are no larger than ints.
> If pointers are larger than ints, the code does not necessarily compute
> a consistent ordering and qsort is allowed to do whatever it wants.
>
> Morten
>
> static int compare_object_pointers(const void *a, const void *b)
> {
> 	const struct object * const *pa = a;
> 	const struct object * const *pb = b;
> 	return *pa - *pb;
> }

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-06 17:28:26 -08:00
Sergey Vlasov
4a4e6fd74f Rework object refs tracking to reduce memory usage
Store pointers to referenced objects in a variable sized array instead
of linked list.  This cuts down memory usage of utilities which use
object references; e.g., git-fsck-objects --full on the git.git
repository consumes about 2 MB of memory tracked by Massif instead of
7 MB before the change.  Object refs are still the biggest consumer of
memory (57%), but the malloc overhead for a single block instead of a
linked list is substantially smaller.

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-11-15 11:42:29 -08:00
Linus Torvalds
8805ccac40 [PATCH] Avoid building object ref lists when not needed
The object parsing code builds a generic "this object references that
object" because doing a full connectivity check for fsck requires it.

However, nothing else really needs it, and it's quite expensive for
git-rev-list that can have tons of objects in flight.

So, exactly like the commit buffer save thing, add a global flag to
disable it, and use it in git-rev-list.

Before:

	$ /usr/bin/time git-rev-list --objects v2.6.12..HEAD | wc -l
	12.28user 0.29system 0:12.57elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
	0inputs+0outputs (0major+26718minor)pagefaults 0swaps
	59124

After this change:

	$ /usr/bin/time git-rev-list --objects v2.6.12..HEAD | wc -l
	10.33user 0.18system 0:10.54elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
	0inputs+0outputs (0major+18509minor)pagefaults 0swaps
	59124

and note how the number of pages touched by git-rev-list for this
particular object list has shrunk from 26,718 (104 MB) to 18,509 (72 MB).

Calculating the total object difference between two git revisions is still
clearly the most expensive git operation (both in memory and CPU time),
but it's now less than 40% of what it used to be.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-09-16 15:32:23 -07:00
Daniel Barkalow
680bab3d9a [PATCH] Add function to append to an object_list.
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-09-10 18:27:40 -07:00
barkalow@iabervon.org
66e481b007 [PATCH] Object library enhancements
Add function to look up an object which is entirely unknown, so that
it can be put in a list. Various other functions related to lists of
objects.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-08-02 22:53:07 -07:00
Junio C Hamano
c4584ae3fd [PATCH] Remove "delta" object representation.
Packed delta files created by git-pack-objects seems to be the
way to go, and existing "delta" object handling code has exposed
the object representation details to too many places.  Remove it
while we refactor code to come up with a proper interface in
sha1_file.c.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27 15:27:51 -07:00
Daniel Barkalow
89e4202f98 [PATCH] Parse tags for absent objects
Handle parsing a tag for a non-present object. This adds a function to lookup
an object with lookup_* for * in a string, so that it can get the right storage
based on the "type" line in the tag.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21 18:29:12 -07:00
Jason McMullan
5d6ccf5ce7 [PATCH] Anal retentive 'const unsigned char *sha1'
Make 'sha1' parameters const where possible

Signed-off-by: Jason McMullan <jason.mcmullan@timesys.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-08 13:04:53 -07:00
Linus Torvalds
bd1e17e245 Make "parse_object()" also fill in commit message buffer data.
And teach fsck to free it to save memory.
2005-05-25 19:26:28 -07:00
Linus Torvalds
6b0c312106 Include file cleanups..
Add <limits.h> to the include files handled by "cache.h", and remove
extraneous #include directives from various .c files. The rule is that
"cache.h" gets all the basic stuff, so that we'll have as few system
dependencies as possible.
2005-05-22 11:54:17 -07:00
Nicolas Pitre
d1af002dc6 [PATCH] delta check
This adds knowledge of delta objects to fsck-cache and various object
parsing code.  A new switch to git-fsck-cache is provided to display the
maximum delta depth found in a repository.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-20 15:41:45 -07:00
Nicolas Pitre
bd2c39f58f [PATCH] don't load and decompress objects twice with parse_object()
It turns out that parse_object() is loading and decompressing given
object to free it just before calling the specific object parsing
function which does mmap and decompress the same object again. This
patch introduces the ability to parse specific objects directly from a
memory buffer.

Without this patch, running git-fsck-cache on the kernel repositorytake:

	real    0m13.006s
	user    0m11.421s
	sys     0m1.218s

With this patch applied:

	real    0m8.060s
	user    0m7.071s
	sys     0m0.710s

The performance increase is significant, and this is kind of a
prerequisite for sane delta object support with fsck.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-06 11:02:01 -07:00
Sergey Vlasov
13019d4136 [PATCH] Fix memory leaks in git-fsck-cache
This patch fixes memory leaks in parse_object() and related functions;
these leaks were very noticeable when running git-fsck-cache.

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-04 10:58:15 -07:00
Daniel Barkalow
e9eefa6761 [PATCH] Add function to parse an object of unspecified type (take 2)
This adds a function that parses an object from the database when we have
to look up its actual type. It also checks the hash of the file, due to
its heritage as part of fsck-cache.

Signed-Off-By: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-28 07:46:33 -07:00
Christopher Li
812666c8e6 [PATCH] introduce xmalloc and xrealloc
Introduce xmalloc and xrealloc to die gracefully with a descriptive
message when out of memory, rather than taking a SIGSEGV. 

Signed-off-by: Christopher Li<chrislgit@chrisli.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-26 12:00:58 -07:00
Daniel Barkalow
175785e5ff [PATCH] Implementations of parsing functions
This implements the parsing functions.

Signed-Off-By: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-18 11:39:48 -07:00