qsort in Windows 2000 (and various other C libraries) is a Quicksort
with the usual O(n^2) worst case. Unfortunately, sorting Git trees
seems to get very close to that worst case quite often:
$ /git/gitbad runstatus
# On branch master
qsort, nmemb = 30842
done, 237838087 comparisons.
This patch adds a simplified version of the merge sort that is glibc's
qsort(3). As a merge sort, this needs a temporary array equal in size
to the array that is to be sorted, but has a worst-case performance of
O(n log n).
The complexity that was removed is:
* Doing direct stores for word-size and -aligned data.
* Falling back to quicksort if the allocation required to perform the
merge sort would likely push the machine into swap.
Even with these simplifications, this seems to outperform the Windows
qsort(3) implementation, even in Windows XP (where it is "fixed" and
doesn't trigger O(n^2) complexity on trees).
[jes: moved into compat/qsort.c, as per Johannes Sixt's suggestion]
[bcd: removed gcc-ism, thanks to Edgar Toernig. renamed make variable
per Junio's comment.]
Signed-off-by: Brian Downing <bdowning@lavos.net>
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
POSIX.1-2001 has declaration of select(2) in <sys/select.h>, but
in the previous version of SUS, it was declared in <sys/time.h>
(which is already included in git-compat-util.h).
This introduces NO_SYS_SELECT_H macro in the Makefile to be set
on older systems, to skip inclusion of <sys/select.h> that does
not exist on them.
We could check _POSIX_VERSION with 200112L and do this
automatically, but earlier it was reported that the approach
does not work well on some vintage of HP-UX. Other systems may
get _POSIX_VERSION itself wrong. At least for now, this manual
configuration is safer.
Signed-off-by: Robert Schiele <rschiele@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now the routine is an open-coded loop that avoids an extra
strlen() in the previous implementation, it got a bit too big to
be inlined. Uninlining it makes code footprint smaller but the
result still retains the avoidance of strlen() cost.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Certain codepaths (notably "git log --pretty=format...") use
prefixcmp() extensively, with very short prefixes. In those cases,
calling strlen() is a wasteful operation, so avoid it.
Initial patch by Marco Costalba.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
qsort in Windows 2000 (and possibly other older Windows' C libraries)
is a Quicksort with the usual O(n^2) worst case. Unfortunately, sorting
Git trees seems to get very close to that worst case quite often:
$ /git/gitbad runstatus
# On branch master
qsort, nmemb = 30842
done, 237838087 comparisons.
This patch adds a simplified version of the merge sort that is glibc's
qsort(3). As a merge sort, this needs a temporary array equal in size
to the array that is to be sorted.
The complexity that was removed is:
* Doing direct stores for word-size and -aligned data.
* Falling back to quicksort if the allocation required to perform the
merge sort would likely push the machine into swap.
Even with these simplifications, this seems to outperform the Windows
qsort(3) implementation, even in Windows XP (where it is "fixed" and
doesn't trigger O(n^2) complexity on trees).
[jes: moved into compat/qsort.c, as per Johannes Sixt's suggestion]
Signed-off-by: Brian Downing <bdowning@lavos.net>
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
A lookup routine is extracted from env_unsetenv() because we will need it
for env_setenv(). The environment data is now released, too.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
The entries are now arranged in categories.
inet_ntop(), kill(), and openlog() are unused and, hence, removed.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
By doing so the only external user of the path handling and functions
is removed, and these functions can be made static.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
* js/mingw-fallouts:
fetch-pack: Prepare for a side-band demultiplexer in a thread.
rehabilitate some t5302 tests on 32-bit off_t machines
Allow ETC_GITCONFIG to be a relative path.
Introduce git_etc_gitconfig() that encapsulates access of ETC_GITCONFIG.
Allow a relative builtin template directory.
Close files opened by lock_file() before unlinking.
builtin run_command: do not exit with -1.
Move #include <sys/select.h> and <sys/ioctl.h> to git-compat-util.h.
Use is_absolute_path() in sha1_file.c.
Skip t3902-quoted.sh if the file system does not support funny names.
t5302-pack-index: Skip tests of 64-bit offsets if necessary.
t7501-commit.sh: Not all seds understand option -i
t5300-pack-object.sh: Split the big verify-pack test into smaller parts.
gethostbyname() is the first function that calls into the Winsock library,
and it is wrapped only to initialize the library.
socket() is wrapped for two reasons:
- Windows's socket() creates things that are like low-level file handles,
and they must be converted into file descriptors first.
- And these handles cannot be used with plain ReadFile()/WriteFile()
because they are opened for "overlapped IO". We have to use WSASocket()
to create non-overlapped IO sockets.
connect() must be wrapped because Windows's connect() expects the low-level
sockets, not file descriptors, and we must first unwrap the file descriptor
before we can pass it on to Windows's connect().
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
On Windows, ntohl() returns unsinged long. On Unix it returns
uint32_t. This makes choosing a suitable printf format string
hard.
This commit introduces a mingw specific helper function
git_ntohl() that casts to unsigned int before returning. This
makes gcc's printf format check happy. It should be safe because
we expect ntohl to use 32-bit numbers.
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
read_in_full()'s is used in compat/pread.c. read_in_full() is
declared in cache.h. But we can't include cache.h because too
many macros are defined there. Using read_in_full() without
including cache.h is dangerous because we wouldn't recognize if
its prototyp changed. gcc issues a warning about that.
This commit adds a forward decl to git-compat-util.h.
git-compat-util.h is included by compat/pread.c _and_ cache.h.
Hence, changes in cache.h would be detected.
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
This changes the prototypes to match
http://www.opengroup.org/onlinepubs/7990989775/xsh/exec.html
Note, spawnvpe uses a different type for argv and envp
than execve. So at some point we need to cast. This
commit shifts the cast into the compat functions. From
the outside, execve and execvp match Posix.
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
On Windows, ntohl() returns unsinged long. On Unix it returns
uint32_t. This makes choosing a suitable printf format string
hard.
This commit introduces a mingw specific helper function
git_ntohl() that casts to unsigned int before returning. This
makes gcc's printf format check happy. It should be safe because
we expect ntohl to use 32-bit numbers.
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
read_in_full()'s is used in compat/pread.c. read_in_full() is
declared in cache.h. But we can't include cache.h because too
many macros are defined there. Using read_in_full() without
including cache.h is dangerous because we wouldn't recognize if
its prototyp changed. gcc issues a warning about that.
This commit adds a forward decl to git-compat-util.h.
git-compat-util.h is included by compat/pread.c _and_ cache.h.
Hence, changes in cache.h would be detected.
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
When declaring a structure with a flexible array member, instead
of defaulting to the c99 syntax for non-gnu compilers (which
burned people with older compilers), default to the traditional
and more portable "member[1]; /* more */" syntax.
At the same time, other c99 compilers should be able to take
advantage of the modern syntax to flexible array members without
being gcc. Check __STDC_VERSION__ for that.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ph/diffopts:
Reorder diff_opt_parse options more logically per topics.
Make the diff_options bitfields be an unsigned with explicit masks.
Use OPT_BIT in builtin-pack-refs
Use OPT_BIT in builtin-for-each-ref
Use OPT_SET_INT and OPT_BIT in builtin-branch
parse-options new features.
We want to get rid of spawn-pipe.*, but these functions will be needed.
On the way, the function signature was changed to avoid warnings about
incompatible pointer types when the argument is the global variable
"environ".
Remove getpagesize() from sha1_file.c because is it now
included in git-compat-util.h.
Conflicts:
Makefile
compat/mingw.c
git-compat-util.h
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
The wrapper does two things:
- Requests to open /dev/null are redirected to open the nul pseudo file.
- A request to open a file that currently exists as a directory, then
Windows's open fails with EACCES; this is changed to EISDIR.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
... since all system headers are pulled in via git-compat-util.h
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Quite a lot of stuff has accumulated or is now obsolete. The stubs of
POSIX functions that are not implemented or that always fail are now
implemented as inline functions so that they exist in only one place.
Apart from the error in the condition (&& should actually be ||), the
construct
#if !defined(A) || !A
leads to a syntax error in the C preprocessor if A is indeed not defined.
Tested-by: David Symonds <dsymonds@gmail.com>
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Windows's struct stat does not have a st_blocks member. Since we already
have our own stat/lstat/fstat implementations, we can just as well use
a customized struct stat. This patch introduces just that, and also fills
in the st_blocks member. On the other hand, we don't provide members that
are never used.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
getpwuid() is kept as simple as possible so that no errors are generated.
Since the information that it returns is not very useful, users are still
required to set up user.name and user.email configuration.
All uses of getpwuid() are like getpwuid(getuid()), hence, the return value
of getpwuid() is irrelevant. getpwnam() is only used to resolve '~' and
'~username' paths, which is an idiom not known on Windows, hence, we
don't implement it, either.
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
options flags:
~~~~~~~~~~~~~
PARSE_OPT_NONEG allow the caller to disallow the negated option to exists.
option types:
~~~~~~~~~~~~
OPTION_BIT: ORs (or NANDs) a mask.
OPTION_SET_INT: force the value to be set to this integer.
OPTION_SET_PTR: force the value to be set to this pointer.
helper:
~~~~~~
HAS_MULTI_BITS (in git-compat-util.h) is a bit-hack to check if an
unsigned integer has more than one bit set, useful to check if conflicting
options have been used.
Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This hack was introduced to work around missing Unix-like user database.
But it turns out that the functionality required can easily be faked,
Which happens in a follow-up patch.
