In some cases we did not even bother to check the return value of
mmap() and just assume it worked. This is bad, because if we are
out of virtual address space the kernel returned MAP_FAILED and we
would attempt to dereference that address, segfaulting without any
real error output to the user.
We are replacing all calls to mmap() with xmmap() and moving all
MAP_FAILED checking into that single location. If a mmap call
fails we try to release enough least-recently-used pack windows
to possibly succeed, then retry the mmap() attempt. If we cannot
mmap even after releasing pack memory then we die() as none of our
callers have any reasonable recovery strategy for a failed mmap.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If we are about to fail because this process has run out of memory we
should first try to automatically control our appetite for address
space by releasing enough least-recently-used pack windows to gain
back enough memory such that we might actually be able to meet the
current allocation request.
This should help users who have fairly large repositories but are
working on systems with relatively small virtual address space.
Many times we see reports on the mailing list of these users running
out of memory during various Git operations. Dynamically decreasing
the amount of pack memory used when the demand for heap memory is
increasing is an intelligent solution to this problem.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Much like the alloc_report() function can be useful to report on
object allocation statistics while debugging the new pack_report()
function can be useful to report on the behavior of the mmap window
code used for packfile access.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If a command opens a packfile for only temporary access and does not
install the struct packed_git* into the global packed_git list then
we are unable to unmap any inactive windows within that packed_git,
causing the overall process to exceed core.packedGitLimit.
We cannot force the callers to install their temporary packfile
into the packed_git chain as doing so would allow that (possibly
corrupt but currently being verified) temporary packfile to become
part of the local ODB, which may allow it to be considered for
object resolution when it may not actually be a valid packfile.
So to support unmapping the windows of these temporary packfiles we
also scan the windows of the struct packed_git which was supplied
to use_pack(). Since commands only work with one temporary packfile
at a time scanning the one supplied to use_pack() and all packs
installed into packed_git should cover everything available in
memory.
We also have to be careful to not close the file descriptor of
the packed_git which was handed to use_pack() when all of that
packfile's windows have been unmapped, as we are already past the
open call that would open the packfile and need the file descriptor
to be ready for mmap() after unuse_one_window returns.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If we are unable to mmap the a region of the packfile with the mmap()
system call there may be a good reason why, such as a closed file
descriptor or out of address space. Reporting the system level
error message can help to debug such problems.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This finally turns on the sliding window behavior for packfile data
access by mapping limited size windows and chaining them under the
packed_git->windows list.
We consider a given byte offset to be within the window only if there
would be at least 20 bytes (one hash worth of data) accessible after
the requested offset. This range selection relates to the contract
that use_pack() makes with its callers, allowing them to access
one hash or one object header without needing to call use_pack()
for every byte of data obtained.
In the worst case scenario we will map the same page of data twice
into memory: once at the end of one window and once again at the
start of the next window. This duplicate page mapping will happen
only when an object header or a delta base reference is spanned
over the end of a window and is always limited to just one page of
duplication, as no sane operating system will ever have a page size
smaller than a hash.
I am assuming that the possible wasted page of virtual address
space is going to perform faster than the alternatives, which
would be to copy the object header or ref delta into a temporary
buffer prior to parsing, or to check the window range on every byte
during header parsing. We may decide to revisit this decision in
the future since this is just a gut instinct decision and has not
actually been proven out by experimental testing.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
To support multiple windows per packfile we need to unmap only one
window at a time from that packfile, leaving any other windows in
place and available for reference.
We treat all windows from all packfiles equally; the least recently
used, not-in-use window across all packfiles will always be closed
first.
If we have unmapped all windows in a packfile then we can also close
the packfile's file descriptor as its possible we won't need to map
any window from that file in the near future. This decision about
when to close the pack file descriptor may need to be revisited in
the future after additional testing on several different platforms
can be performed.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When we parse the object header or the delta base reference we
don't bother to loop over use_pack() calls. The reason we don't
need to bother with calling use_pack for each byte accessed is that
use_pack will always promise us at least 20 bytes (really the hash
size) after the offset. This promise from use_pack simplifies a
lot of code in the header parsing logic, as well as helps out the
zlib library by ensuring there's always some data for it to consume
during an inflate call.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When multiple mmaps start getting used for all pack file access it
is not possible to get all data associated with a specific object
in one contiguous memory region. This limitation prevents simply
passing a single address and length to SHA1_Update or to inflate.
Instead we need to loop until we have processed all data of interest.
As we loop over the data we are always interested in reusing the same
window 'cursor', as the prior window will no longer be of any use
to us. This allows the use_pack() call to automatically decrement
the use count of the prior window before setting up access for us
to the next window.
Within each loop we need to make use of the available length output
parameter of use_pack() to tell us how many bytes are available in
the current memory region, as we cannot tell otherwise.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Part of the implementation concept of the sliding mmap window for
pack access is to permit multiple windows per pack to be mapped
independently. Since the inuse_cnt is associated with the mmap and
not with the file, this value is in struct pack_window and needs to
be incremented/decremented for each pack_window accessed by any code.
To faciliate that implementation we need to replace all uses of
use_packed_git() and unuse_packed_git() with a different API that
follows struct pack_window objects rather than struct packed_git.
The way this works is when we need to start accessing a pack for
the first time we should setup a new window 'cursor' by declaring
a local and setting it to NULL:
struct pack_windows *w_curs = NULL;
To obtain the memory region which contains a specific section of
the pack file we invoke use_pack(), supplying the address of our
current window cursor:
unsigned int len;
unsigned char *addr = use_pack(p, &w_curs, offset, &len);
the returned address `addr` will be the first byte at `offset`
within the pack file. The optional variable len will also be
updated with the number of bytes remaining following the address.
Multiple calls to use_pack() with the same window cursor will
update the window cursor, moving it from one window to another
when necessary. In this way each window cursor variable maintains
only one struct pack_window inuse at a time.
Finally before exiting the scope which originally declared the window
cursor we must invoke unuse_pack() to unuse the current window (which
may be different from the one that was first obtained from use_pack):
unuse_pack(&w_curs);
This implementation is still not complete with regards to multiple
windows, as only one window per pack file is supported right now.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
To efficiently support mmaping of multiple regions of the same pack
file we want to keep the pack's file descriptor open while we are
actively working with that pack. So we are now keeping that file
descriptor in packed_git.pack_fd and closing it only after we unmap
the last window.
This is going to increase the number of file descriptors that are
in use at once, however that will be bounded by the total number of
pack files present and therefore should not be very high. It is
a small tradeoff which we may need to revisit after some testing
can be done on various repositories and systems.
For code clarity we also want to seperate out the implementation
of how we open a pack file from the implementation which locates
a suitable window (or makes a new one) from the given pack file.
Since this is a rather large delta I'm taking advantage of doing
it now, in a fairly isolated change.
When we open a pack file we need to examine the header and trailer
without having a mmap in place, as we may only need to mmap
the middle section of this particular pack. Consequently the
verification code has been refactored to make use of the new
read_or_die function.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The idea behind the sliding mmap window pack reader implementation
is to have multiple mmap regions active against the same pack file,
thereby allowing the process to mmap in only the active/hot sections
of the pack and reduce overall virtual address space usage.
To implement this we need to refactor the mmap related data
(pack_base, pack_use_cnt) out of struct packed_git and move them
into a new struct pack_window.
We are refactoring the code to support a single struct pack_window
per packfile, thereby emulating the prior behavior of mmap'ing the
entire pack file.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Rather than hardcoding the maximum number of bytes which can be
mmapped from pack files we should make this value configurable,
allowing the end user to increase or decrease this limit on a
per-repository basis depending on the size of the repository
and the capabilities of their operating system.
In general users should not need to manually tune such a low-level
setting within the core code, but being able to artifically limit
the number of bytes which we can mmap at once from pack files will
make it easier to craft test cases for the new mmap sliding window
implementation.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The unpack_entry_gently function currently has only two callers:
the delta base resolution in sha1_file.c and the main loop of
pack-check.c. Both of these must change to using unpack_entry
directly when we implement sliding window mmap logic, so I'm doing
it earlier to help break down the change set.
This may cause a slight performance decrease for delta base
resolution as well as for pack-check.c's verify_packfile(), as
the pack use counter will be incremented and decremented for every
object that is unpacked.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If ever new object types are added for future extensions then better
have current git version report them as "unknown" instead of
"corrupted".
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
We used to try loose objects first with sha1_object_info(), but packed
objects first with read_sha1_file(). Now, prefer packed objects over loose
ones with sha1_object_info(), too.
Usually the old behaviour would pose no problem, but when you tried to fix
a fscked up repository by inserting a known-good pack,
git cat-file $(git cat-file -t <sha1>) <sha1>
could fail, even when
git cat-file blob <sha1>
would _not_ fail. Worse, a repack would fail, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Currently the error e.g. when pushing to a read-only repository is quite
confusing, this attempts to clean it up, unifies error reporting between
various object writers and uses error() on couple more places.
Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Since keeping a pushed pack or exploding it into loose objects
should be a local repository decision this teaches receive-pack
to decide if it should call unpack-objects or index-pack --stdin
--fix-thin based on the setting of receive.unpackLimit and the
number of objects contained in the received pack.
If the number of objects (hdr_entries) in the received pack is
below the value of receive.unpackLimit (which is 5000 by default)
then we unpack-objects as we have in the past.
If the hdr_entries >= receive.unpackLimit then we call index-pack and
ask it to include our pid and hostname in the .keep file to make it
easier to identify why a given pack has been kept in the repository.
Currently this leaves every received pack as a kept pack. We really
don't want that as received packs will tend to be small. Instead we
want to delete the .keep file automatically after all refs have
been updated. That is being left as room for future improvement.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
* master: (90 commits)
gitweb: Better support for non-CSS aware web browsers
gitweb: Output also empty patches in "commitdiff" view
gitweb: Use git-for-each-ref to generate list of heads and/or tags
for-each-ref: "creator" and "creatordate" fields
Add --global option to git-repo-config.
pack-refs: Store the full name of the ref even when packing only tags.
git-clone documentation didn't mention --origin as equivalent of -o
Minor grammar fixes for git-diff-index.txt
link_temp_to_file: call adjust_shared_perm() only when we created the directory
Remove uneccessarily similar printf() from print_ref_list() in builtin-branch
pack-objects doesn't create random pack names
branch: work in subdirectories.
gitweb: Use 's' regexp modifier to secure against filenames with LF
gitweb: Secure against commit-ish/tree-ish with the same name as path
gitweb: esc_html() author in blame
git-svnimport: support for partial imports
link_temp_to_file: don't leave the path truncated on adjust_shared_perm failure
Move deny_non_fast_forwards handling completely into receive-pack.
revision traversal: --unpacked does not limit commit list anymore.
Continue traversal when rev-list --unpacked finds a packed commit.
...
* maint:
git-clone documentation didn't mention --origin as equivalent of -o
Minor grammar fixes for git-diff-index.txt
link_temp_to_file: call adjust_shared_perm() only when we created the directory
This allows us to pass just the file name of a pack rather than
the complete path when we want pack-objects to consider its
contents as though they were loose objects. This can be helpful
if $GIT_OBJECT_DIRECTORY contains shell metacharacters which make
it cumbersome to pass complete paths safely in a shell script.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
* np/pack:
add the capability for index-pack to read from a stream
index-pack: compare only the first 20-bytes of the key.
git-repack: repo.usedeltabaseoffset
pack-objects: document --delta-base-offset option
allow delta data reuse even if base object is a preferred base
zap a debug remnant
let the GIT native protocol use offsets to delta base when possible
make pack data reuse compatible with both delta types
make git-pack-objects able to create deltas with offset to base
teach git-index-pack about deltas with offset to base
teach git-unpack-objects about deltas with offset to base
introduce delta objects with offset to base
Supposing that both the base and result sizes were both full size 64-bit
values, their encoding would occupy only 9.2 bytes each. Therefore
inflating 64 bytes is way overkill. Limit it to 20 bytes instead which
should be plenty enough for a couple years to come.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Move file name generation from write_sha1_file_prepare() to the one
caller that cares and make it a void function.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Most callers of write_sha1_file_prepare() are only interested in the
resulting hash but don't care about the returned file name or the header.
This patch adds a simple wrapper named hash_sha1_file() which does just
that, and converts potential callers.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This is the missing part to git-pack-objects allowing it to reuse delta
data to/from any of the two delta types. It can reuse delta from any
type, and it outputs base offsets when --allow-delta-base-offset is
provided and the base is also included in the pack. Otherwise it
outputs base sha1 references just like it always did.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This adds a new object, namely OBJ_OFS_DELTA, renames OBJ_DELTA to
OBJ_REF_DELTA to better make the distinction between those two delta
objects, and adds support for the handling of those new delta objects
in sha1_file.c only.
The OBJ_OFS_DELTA contains a relative offset from the delta object's
position in a pack instead of the 20-byte SHA1 reference to identify
the base object. Since the base is likely to be not so far away, the
relative offset is more likely to have a smaller encoding on average
than an absolute offset. And for those delta objects the base must
always be stored first because there is no way to know the distance of
later objects when streaming a pack. Hence this relative offset is
always meant to be negative.
The offset encoding is slightly denser than the one used for object
size -- credits to <linux@horizon.com> (whoever this is) for bringing
it to my attention.
This allows for pack size reduction between 3.2% (Linux-2.6) to over 5%
(linux-historic). Runtime pack access should be faster too since delta
replay does skip a search in the pack index for each delta in a chain.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Those cleanups are mainly to set the table for the support of deltas
with base objects referenced by offsets instead of sha1. This means
that many pack lookup functions are converted to take a pack/offset
tuple instead of a sha1.
This eliminates many struct pack_entry usages since this structure
carried redundent information in many cases, and it increased stack
footprint needlessly for a couple recursively called functions that used
to declare a local copy of it for every recursion loop.
In the process, packed_object_info_detail() has been reorganized as well
so to look much saner and more amenable to deltas with offset support.
Finally the appropriate adjustments have been made to functions that
depend on the above changes. But there is no functionality changes yet
simply some code refactoring at this point.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
builtin-mailinfo.c has its own hexval implementaiton but it can
share the table-lookup one recently implemented in sha1_file.c
Signed-off-by: Junio C Hamano <junkio@cox.net>
* jc/pack:
pack-objects: document --revs, --unpacked and --all.
pack-objects --unpacked=<existing pack> option.
pack-objects: further work on internal rev-list logic.
pack-objects: run rev-list equivalent internally.
Separate object listing routines out of rev-list
The function appeared high on a gprof output for a rev-list run of
a non-trivial size, and it was an obvious low-hanging fruit.
The code is from Linus.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Incremental repack without -a essentially boils down to:
rev-list --objects --unpacked --all |
pack-objects $new_pack
which picks up all loose objects that are still live and creates
a new pack.
This implements --unpacked=<existing pack> option to tell the
revision walking machinery to pretend as if objects in such a
pack are unpacked for the purpose of object listing. With this,
we could say:
rev-list --objects --unpacked=$active_pack --all |
pack-objects $new_pack
instead, to mean "all live loose objects but pretend as if
objects that are in this pack are also unpacked". The newly
created pack would be perfect for updating $active_pack by
replacing it.
Since pack-objects now knows how to do the rev-list's work
itself internally, you can also write the above example by:
pack-objects --unpacked=$active_pack --all $new_pack </dev/null
Signed-off-by: Junio C Hamano <junkio@cox.net>
When copying from an existing pack and when copying from a loose
object with new style header, the code makes sure that the piece
we are going to copy out inflates well and inflate() consumes
the data in full while doing so.
The check to see if the xdelta really apply is quite expensive
as you described, because you would need to have the image of
the base object which can be represented as a delta against
something else.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Like xmalloc and xrealloc xstrdup dies with a useful message if
the native strdup() implementation returns NULL rather than a
valid pointer.
I just tried to use xstrdup in new code and found it to be missing.
However I expected it to be present as xmalloc and xrealloc are
already commonly used throughout the code.
[jc: removed the part that deals with last_XXX, which I am
finding more and more dubious these days.]
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Also while we are at it, remove redundant typename[] array from
unpack_sha1_header. The only reason it is different from the
type_names[] array in object.c module is that this code cares
about the subset of object types that are valid in a loose
object, so prepare a separate array of boolean that tells us
which types are valid, and share the name translation with the
others.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Change places that use realloc, without a proper error path, to instead use
xrealloc. Drop an erroneous error path in the daemon code that used errno
in the die message in favour of the simpler xrealloc.
Signed-off-by: Jonas Fonseca <fonseca@diku.dk>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Change unpack_entry_gently and its helper functions to use offsets
rather than addresses and left counts to supply pack position
information. In most cases this makes the code easier to follow,
and it reduces the number of local variables in a few functions.
It also better prepares this code for mapping partial segments of
packs and altering what regions of a pack are mapped while unpacking
an entry.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If we're always incrementing both the offset and the pointer we
aren't gaining anything by keeping both. Instead just use the
offset since that's what we were given and what we are expected
to return. Also using offset is likely to make it easier to remap
the pack in the future should partial mapping of very large packs
get implemented.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
[PATCH 3/5] Cleanup unpack_entry_gently and friends to use type_name array.
This change allows combining all of the non-delta entries into a
single case, as well as to remove an unnecessary local variable
in unpack_entry_gently.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
[PATCH 2/5] Reuse compression code in unpack_compressed_entry.
This cleans up the code by reusing a perfectly good decompression
implementation at the expense of 1 extra byte of memory allocated in
temporary memory while the delta is being decompressed and applied
to the base.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This function was moved above unpack_delta_entry so we can call it
from within unpack_delta_entry without a forward declaration.
This change looks worse than it is. Its really just a relocation
of unpack_non_delta_entry to earlier in the file and renaming the
function to unpack_compressed_entry. No other changes were made.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
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>
This declaration probably used to be necessary but the code has
been refactored since to use unpack_entry_gently instead.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If the pack format were to ever change or be extended in the future
there is no assurance that just because the pack file lives in
objects/pack and doesn't end in .idx that we can read and decompress
its contents properly.
If we encounter what we think is a pack file and it isn't or we don't
recognize its version then die and suggest to the user that they
upgrade to a newer version of GIT which can handle that pack file.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
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>
[jc: I needed to hand merge the changes to the updated codebase,
so the result needs to be checked.]
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
As Fredrik points out the current interface of has_extension() is
potentially confusing. Its parameters include both a nul-terminated
string and a length-limited string.
This patch drops the length argument, requiring two nul-terminated
strings; all callsites are updated. I checked that all of them indeed
provide nul-terminated strings. Filenames need to be nul-terminated
anyway if they are to be passed to open() etc. The performance penalty
of the additional strlen() is negligible compared to the system calls
which inevitably surround has_extension() calls.
Additionally, change has_extension() to use size_t inside instead of
int, as that is the exact type strlen() returns and memcmp() expects.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The little helper has_extension() documents through its name what we are
trying to do and makes sure we don't forget the underrun check.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This exposes map_sha1_file() interface to mmap a loose object file,
and legacy_loose_object() function, split from unpack_sha1_header().
They will be used in the next patch to reuse the deflated data from
new-style loose object files when generating packs.
Signed-off-by: Junio C Hamano <junkio@cox.net>
The pack-file format is slightly different from the traditional git
object format, in that it has a much denser binary header encoding.
The traditional format uses an ASCII string with type and length
information, which is somewhat wasteful.
A new object format starts with uncompressed binary header
followed by compressed payload -- this will allow us later to
copy the payload straight to packfiles.
Obviously they cannot be read by older versions of git, so for
now new object files are created with the traditional format.
core.legacyheaders configuration item, when set to false makes
the code write in new format for people to experiment with.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Linus Torvalds <torvalds@osdl.org> wrote:
It's entirely possible that we should just make that whole
if (ret == ENOENT)
go away. Yes, it's the right error code if a subdirectory is missing, and
yes, POSIX requires it, and yes, WXP is probably just a horrible piece of
sh*t, but on the other hand, I don't think git really has any serious
reason to even care.
Nobody else uses them, and I'm going to start changing them.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This doesn't make the code uglier or harder to read, yet it makes the
code more portable. This also simplifies checking for other potential
incompatibilities. "gcc -std=c89 -pedantic" can flag many incompatible
constructs as warnings, but C99 comments will cause it to emit an error.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
The only visible change is that git-blame doesn't understand
"--compability" anymore, but it does accept "--compatibility" instead,
which is already documented.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
With the change in default, "git add ." on kernel dir is about
twice as fast as before, with only minimal (0.5%) change in
object size. The speed difference is even more noticeable
when committing large files, which is now up to 8 times faster.
The configurability is through setting core.compression = [-1..9]
which maps to the zlib constants; -1 is the default, 0 is no
compression, and 1..9 are various speed/size tradeoffs, 9
being slowest.
Signed-off-by: Joachim B Haga (cjhaga@fys.uio.no)
Acked-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
ANSI C99 doesn't allow void-pointer arithmetic. This patch fixes this in
various ways. Usually the strategy that required the least changes was used.
Signed-off-by: Florian Forster <octo@verplant.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
There were a few calls to adjust_shared_perm() that were
missing:
- init-db creates refs, refs/heads, and refs/tags before
reading from templates that could specify sharedrepository in
the config file;
- updating config file created it under user's umask without
adjusting;
- updating refs created it under user's umask without
adjusting;
- switching branches created .git/HEAD under user's umask
without adjusting.
This moves adjust_shared_perm() from sha1_file.c to path.c,
since a few SIMPLE_PROGRAM need to call repository configuration
functions which in turn need to call adjust_shared_perm().
sha1_file.c needs to link with SHA1 computation library which
is usually not linked to SIMPLE_PROGRAM.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When adding packs, skip the pack if we already have it in the packed_git
list. This might happen if we are re-preparing our packs because of a
missing object.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch causes read_sha1_file and sha1_object_info to re-examine the
list of packs if an object cannot be found. It works by re-running
prepare_packed_git() after an object fails to be found.
It does not attempt to clean up the old pack list. Old packs which are in
use can continue to be used (until unused by lru selection). New packs
are placed at the front of the list and will thus be examined before old
packs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This cleans up and future-proofs the sha1 file writing in sha1_file.c.
In particular, instead of doing a simple "write()" call and just verifying
that it succeeds (or - as in one place - just assuming it does), it uses
"write_buffer()" to write data to the file descriptor while correctly
checking for partial writes, EINTR etc.
It also splits up write_sha1_to_fd() to be a lot more readable: if we need
to re-create the compressed object, we do so in a separate helper
function, making the logic a whole lot more modular and obvious.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
* fix:
Fix pack-index issue on 64-bit platforms a bit more portably.
Install git-send-email by default
Fix compilation on newer NetBSD systems
git config syntax updates
Another config file parsing fix.
checkout: use --aggressive when running a 3-way merge (-m).
Apparently <stdint.h> is not enough for uint32_t on OpenBSD; use
"unsigned int" -- hopefully that would stay 32-bit on every
platform we care about, at least until we update the pack-index
file format.
Our sha1 routines optimized for architectures use uint32_t and
expects '#include <stdint.h>' to be enough, so OpenBSD on arm or
ppc might have similar issues down the road, I dunno.
Signed-off-by: Junio C Hamano <junkio@cox.net>
The offset of an object in the pack is recorded as a 4-byte integer
in the index file. When reading the offset from the mmap'ed index
in prepare_pack_revindex(), the address is dereferenced as a long*.
This works fine as long as the long type is four bytes wide. On
NetBSD/sparc64, however, a long is 8 bytes wide and so dereferencing
the offset produces garbage.
[jc: taking suggestion by Linus to use uint32_t]
Signed-off-by: Dennis Stosberg <dennis@stosberg.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
When adding an alternate object store then add entries from its
info/alternates files, too.
Relative entries are only allowed in the current repository.
Loops and duplicate alternates through multiple repositories are ignored.
Just to be sure that nothing breaks it is not allow to build deep
nesting levels using info/alternates.
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Somebody on the #git channel complained that the sha1_to_hex() thing uses
a static buffer which caused an error message to show the same hex output
twice instead of showing two different ones.
That's pretty easily rectified by making it uses a simple LRU of a few
buffers, which also allows some other users (that were aware of the buffer
re-use) to be written in a more straightforward manner.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Serge E. Hallyn noticed that we compute how many input bytes are
still left, but did not use it for sanity checking.
Signed-off-by: Junio C Hamano <junkio@cox.net>
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>
Currently we unpack the delta data from the pack and then unpack
the base object to apply that delta data to it. When getting an
object that is deeply deltified, we can reduce memory footprint
by unpacking the base object first and then unpacking the delta
data, because we will need to keep at most one delta data in
memory that way.
Signed-off-by: Junio C Hamano <junkio@cox.net>
When generating a new pack, notice if we have already needed
objects in existing packs. If an object is stored deltified,
and its base object is also what we are going to pack, then
reuse the existing deltified representation unconditionally,
bypassing all the expensive find_deltas() and try_deltas()
calls.
Also, notice if what we are going to write out exactly match
what is already in an existing pack (either deltified or just
compressed). In such a case, we can just copy it instead of
going through the usual uncompressing & recompressing cycle.
Without this patch, in linux-2.6 repository with about 1500
loose objects and a single mega pack:
$ git-rev-list --objects v2.6.16-rc3 >RL
$ wc -l RL
184141 RL
$ time git-pack-objects p <RL
Generating pack...
Done counting 184141 objects.
Packing 184141 objects....................
a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2
real 12m4.323s
user 11m2.560s
sys 0m55.950s
With this patch, the same input:
$ time ../git.junio/git-pack-objects q <RL
Generating pack...
Done counting 184141 objects.
Packing 184141 objects.....................
a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2
Total 184141, written 184141, reused 182441
real 1m2.608s
user 0m55.090s
sys 0m1.830s
Signed-off-by: Junio C Hamano <junkio@cox.net>
The real problem triggered an earlier fix was that an alternate
entry was pointing at a removed directory. Complaining on
object/pack directory that cannot be opendir-ed produces noise
in an ancient repository that does not have object/pack
directory and has never been packed.
Detect the real user error and report it. Also if opendir
failed for other reasons (e.g. no read permissions), report that
as well.
Spotted by Andrew Vasquez <andrew.vasquez@qlogic.com>.
Signed-off-by: Junio C Hamano <junkio@cox.net>
* jc/pack-reuse:
pack-objects: avoid delta chains that are too long.
git-repack: allow passing a couple of flags to pack-objects.
pack-objects: finishing touches.
pack-objects: reuse data from existing packs.
When generating a new pack, notice if we have already needed
objects in existing packs. If an object is stored deltified,
and its base object is also what we are going to pack, then
reuse the existing deltified representation unconditionally,
bypassing all the expensive find_deltas() and try_deltas()
calls.
Also, notice if what we are going to write out exactly match
what is already in an existing pack (either deltified or just
compressed). In such a case, we can just copy it instead of
going through the usual uncompressing & recompressing cycle.
Without this patch, in linux-2.6 repository with about 1500
loose objects and a single mega pack:
$ git-rev-list --objects v2.6.16-rc3 >RL
$ wc -l RL
184141 RL
$ time git-pack-objects p <RL
Generating pack...
Done counting 184141 objects.
Packing 184141 objects....................
a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2
real 12m4.323s
user 11m2.560s
sys 0m55.950s
With this patch, the same input:
$ time ../git.junio/git-pack-objects q <RL
Generating pack...
Done counting 184141 objects.
Packing 184141 objects.....................
a1fc7b3e537fcb9b3c46b7505df859f0a11e79d2
Total 184141, written 184141, reused 182441
real 1m2.608s
user 0m55.090s
sys 0m1.830s
Signed-off-by: Junio C Hamano <junkio@cox.net>
Use stat() to explicitly check for existence rather than
relying on the non-portable EEXIST error in sha1_file.c's
safe_create_leading_directories(). There certainly are
optimizations possible, but then the code becomes almost
the same as that in coreutil's lib/mkdir-p.c.
Other uses of EEXIST seem ok. Tested on Solaris 8, AIX 5.2L,
and a few Linux versions. AIX has some unrelated (I think)
failures right now; I haven't tried many recent gits there.
Anyone have an old Ultrix box to break everything? ;)
Also remove extraneous #includes. Everything's already in
git-compat-util.h, included through cache.h.
Signed-off-by: Jason Riedy <ejr@cs.berkeley.edu>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This reverts c5ced64578 commit.
It turns out that doing this check every time we map the idx file
is quite expensive. A corrupt idx file is caught by git-fsck-objects,
so this check is not strictly necessary.
In one unscientific test, 0.99.9m spent 10 seconds usertime for
the same task 1.1.3 takes 37 seconds usertime. Reverting this gives
us the performance of 0.99.9 back.
If the config variable 'core.sharedrepository' is set, the directories
$GIT_DIR/objects/
$GIT_DIR/objects/??
$GIT_DIR/objects/pack
$GIT_DIR/refs
$GIT_DIR/refs/heads
$GIT_DIR/refs/heads/tags
are set group writable (and g+s, since the git group may be not the primary
group of all users).
Since all files are written as lock files first, and then moved to
their destination, they do not have to be group writable. Indeed, if
this leads to problems you found a bug.
Note that -- as in my first attempt -- the config variable is set in the
function which checks the repository format. If this were done in
git_default_config instead, a lot of programs would need to be modified
to call git_config(git_default_config) first.
[jc: git variables should be in environment.c unless there is a
compelling reason to do otherwise.]
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Although pack-check.c had routine to verify the checksum for the
pack index file itself, the core did not check it before using
it.
This is stolen from the patch to tighten packname requirements.
Signed-off-by: Junio C Hamano <junkio@cox.net>
(cherry picked from 797bd6f490 commit)
