You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

388 lines
9.1 KiB

#ifndef GIT_COMPAT_UTIL_H
#define GIT_COMPAT_UTIL_H
#define _FILE_OFFSET_BITS 64
#ifndef FLEX_ARRAY
/*
* See if our compiler is known to support flexible array members.
*/
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
# define FLEX_ARRAY /* empty */
#elif defined(__GNUC__)
# if (__GNUC__ >= 3)
# define FLEX_ARRAY /* empty */
# else
# define FLEX_ARRAY 0 /* older GNU extension */
# endif
#endif
/*
* Otherwise, default to safer but a bit wasteful traditional style
*/
#ifndef FLEX_ARRAY
# define FLEX_ARRAY 1
#endif
#endif
#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
#ifdef __GNUC__
#define TYPEOF(x) (__typeof__(x))
#else
#define TYPEOF(x)
#endif
#define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (sizeof(x) * 8 - (bits))))
#define HAS_MULTI_BITS(i) ((i) & ((i) - 1)) /* checks if an integer has more than 1 bit set */
/* Approximation of the length of the decimal representation of this type. */
#define decimal_length(x) ((int)(sizeof(x) * 2.56 + 0.5) + 1)
#if !defined(__APPLE__) && !defined(__FreeBSD__) && !defined(__USLC__) && !defined(_M_UNIX)
#define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */
#define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */
#endif
#define _ALL_SOURCE 1
#define _GNU_SOURCE 1
#define _BSD_SOURCE 1
#include <unistd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <sys/param.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>
#include <fnmatch.h>
#include <assert.h>
#include <regex.h>
#include <utime.h>
#ifndef __MINGW32__
#include <sys/wait.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#ifndef NO_SYS_SELECT_H
#include <sys/select.h>
#endif
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <pwd.h>
#include <inttypes.h>
#if defined(__CYGWIN__)
#undef _XOPEN_SOURCE
#include <grp.h>
#define _XOPEN_SOURCE 600
cygwin: Use native Win32 API for stat lstat/stat functions in Cygwin are very slow, because they try to emulate some *nix things that Git does not actually need. This patch adds Win32 specific implementation of these functions for Cygwin. This implementation handles most situation directly but in some rare cases it falls back on the implementation provided for Cygwin. This is necessary for two reasons: - Cygwin has its own file hierarchy, so absolute paths used in Cygwin is not suitable to be used Win32 API. cygwin_conv_to_win32_path can not be used because it automatically dereference Cygwin symbol links, also it causes extra syscall. Fortunately Git rarely use absolute paths, so we always use Cygwin implementation for absolute paths. - Support of symbol links. Cygwin stores symbol links as ordinary using one of two possible formats. Therefore, the fast implementation falls back to Cygwin functions if it detects potential use of symbol links. The speed of this implementation should be the same as mingw_lstat for common cases, but it is considerable slower when the specified file name does not exist. Despite all efforts to make the fast implementation as robust as possible, it may not work well for some very rare situations. I am aware only one situation: use Cygwin mount to bind unrelated paths inside repository together. Therefore, the core.ignoreCygwinFSTricks configuration option is provided, which controls whether native or Cygwin version of stat is used. Signed-off-by: Dmitry Potapov <dpotapov@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
16 years ago
#include "compat/cygwin.h"
#else
#undef _ALL_SOURCE /* AIX 5.3L defines a struct list with _ALL_SOURCE. */
#include <grp.h>
#define _ALL_SOURCE 1
#endif
#else /* __MINGW32__ */
/* pull in Windows compatibility stuff */
#include "compat/mingw.h"
#endif /* __MINGW32__ */
#ifndef NO_ICONV
#include <iconv.h>
#endif
#ifndef NO_OPENSSL
#include <openssl/ssl.h>
#include <openssl/err.h>
#endif
/* On most systems <limits.h> would have given us this, but
* not on some systems (e.g. GNU/Hurd).
*/
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
#ifndef PRIuMAX
#define PRIuMAX "llu"
#endif
#ifndef PRIu32
#define PRIu32 "u"
#endif
#ifndef PRIx32
#define PRIx32 "x"
#endif
#ifndef PATH_SEP
#define PATH_SEP ':'
#endif
#ifndef STRIP_EXTENSION
#define STRIP_EXTENSION ""
#endif
#ifndef has_dos_drive_prefix
#define has_dos_drive_prefix(path) 0
#endif
#ifndef is_dir_sep
#define is_dir_sep(c) ((c) == '/')
#endif
#ifdef __GNUC__
#define NORETURN __attribute__((__noreturn__))
#else
#define NORETURN
#ifndef __attribute__
#define __attribute__(x)
#endif
#endif
/* General helper functions */
extern void usage(const char *err) NORETURN;
extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1, 2)));
extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
extern int prefixcmp(const char *str, const char *prefix);
extern time_t tm_to_time_t(const struct tm *tm);
static inline const char *skip_prefix(const char *str, const char *prefix)
{
size_t len = strlen(prefix);
return strncmp(str, prefix, len) ? NULL : str + len;
}
#ifdef NO_MMAP
#ifndef PROT_READ
#define PROT_READ 1
#define PROT_WRITE 2
#define MAP_PRIVATE 1
#define MAP_FAILED ((void*)-1)
#endif
#define mmap git_mmap
#define munmap git_munmap
extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
extern int git_munmap(void *start, size_t length);
/* This value must be multiple of (pagesize * 2) */
#define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
#else /* NO_MMAP */
#include <sys/mman.h>
/* This value must be multiple of (pagesize * 2) */
#define DEFAULT_PACKED_GIT_WINDOW_SIZE \
(sizeof(void*) >= 8 \
? 1 * 1024 * 1024 * 1024 \
: 32 * 1024 * 1024)
#endif /* NO_MMAP */
#ifdef NO_ST_BLOCKS_IN_STRUCT_STAT
#define on_disk_bytes(st) ((st).st_size)
#else
#define on_disk_bytes(st) ((st).st_blocks * 512)
#endif
#define DEFAULT_PACKED_GIT_LIMIT \
((1024L * 1024L) * (sizeof(void*) >= 8 ? 8192 : 256))
#ifdef NO_PREAD
#define pread git_pread
extern ssize_t git_pread(int fd, void *buf, size_t count, off_t offset);
#endif
/*
* Forward decl that will remind us if its twin in cache.h changes.
* This function is used in compat/pread.c. But we can't include
* cache.h there.
*/
extern ssize_t read_in_full(int fd, void *buf, size_t count);
#ifdef NO_SETENV
#define setenv gitsetenv
extern int gitsetenv(const char *, const char *, int);
#endif
#ifdef NO_MKDTEMP
#define mkdtemp gitmkdtemp
extern char *gitmkdtemp(char *);
#endif
#ifdef NO_UNSETENV
#define unsetenv gitunsetenv
extern void gitunsetenv(const char *);
#endif
#ifdef NO_STRCASESTR
#define strcasestr gitstrcasestr
extern char *gitstrcasestr(const char *haystack, const char *needle);
#endif
#ifdef NO_STRLCPY
#define strlcpy gitstrlcpy
extern size_t gitstrlcpy(char *, const char *, size_t);
#endif
#ifdef NO_STRTOUMAX
#define strtoumax gitstrtoumax
extern uintmax_t gitstrtoumax(const char *, char **, int);
#endif
#ifdef NO_HSTRERROR
#define hstrerror githstrerror
extern const char *githstrerror(int herror);
#endif
#ifdef NO_MEMMEM
#define memmem gitmemmem
void *gitmemmem(const void *haystack, size_t haystacklen,
const void *needle, size_t needlelen);
#endif
#ifdef FREAD_READS_DIRECTORIES
#ifdef fopen
#undef fopen
#endif
#define fopen(a,b) git_fopen(a,b)
extern FILE *git_fopen(const char*, const char*);
#endif
#ifdef SNPRINTF_RETURNS_BOGUS
#define snprintf git_snprintf
extern int git_snprintf(char *str, size_t maxsize,
const char *format, ...);
#define vsnprintf git_vsnprintf
extern int git_vsnprintf(char *str, size_t maxsize,
const char *format, va_list ap);
#endif
#ifdef __GLIBC_PREREQ
#if __GLIBC_PREREQ(2, 1)
#define HAVE_STRCHRNUL
#endif
#endif
#ifndef HAVE_STRCHRNUL
#define strchrnul gitstrchrnul
static inline char *gitstrchrnul(const char *s, int c)
{
while (*s && *s != c)
s++;
return (char *)s;
}
#endif
Actually handle some-low memory conditions Tim Ansell discovered his Debian server didn't permit git-daemon to use as much memory as it needed to handle cloning a project with a 128 MiB packfile. Filtering the strace provided by Tim of the rev-list child showed this gem of a sequence: open("./objects/pack/pack-*.pack", O_RDONLY|O_LARGEFILE <unfinished ...> <... open resumed> ) = 5 OK, so the packfile is fd 5... mmap2(NULL, 33554432, PROT_READ, MAP_PRIVATE, 5, 0 <unfinished ...> <... mmap2 resumed> ) = 0xb5e2d000 and we mapped one 32 MiB window from it at position 0... mmap2(NULL, 31020635, PROT_READ, MAP_PRIVATE, 5, 0x6000 <unfinished ...> <... mmap2 resumed> ) = -1 ENOMEM (Cannot allocate memory) And we asked for another window further into the file. But got denied. In Tim's case this was due to a resource limit on the git-daemon process, and its children. Now where are we in the code? We're down inside use_pack(), after we have called unuse_one_window() enough times to make sure we stay within our allowed maximum window size. However since we didn't unmap the prior window at 0xb5e2d000 we aren't exceeding the current limit (which probably was just the defaults). But we're actually down inside xmmap()... So we release the window we do have (by calling release_pack_memory), assuming there is some memory pressure... munmap(0xb5e2d000, 33554432 <unfinished ...> <... munmap resumed> ) = 0 close(5 <unfinished ...> <... close resumed> ) = 0 And that was the last window in this packfile. So we closed it. Way to go us. Our xmmap did not expect release_pack_memory to close the fd its about to map... mmap2(NULL, 31020635, PROT_READ, MAP_PRIVATE, 5, 0x6000 <unfinished ...> <... mmap2 resumed> ) = -1 EBADF (Bad file descriptor) And so the Linux kernel happily tells us f' off. write(2, "fatal: ", 7 <unfinished ...> <... write resumed> ) = 7 write(2, "Out of memory? mmap failed: Bad "..., 47 <unfinished ...> <... write resumed> ) = 47 And we report the bad file descriptor error, and not the ENOMEM, and die, claiming we are out of memory. But actually that mmap should have succeeded, as we had enough memory for that window, seeing as how we released the prior one. Originally when I developed the sliding window mmap feature I had this exact same bug in fast-import, and I dealt with it by handing in the struct packed_git* we want to open the new window for, as the caller wasn't prepared to reopen the packfile if unuse_one_window closed it. The same is true here from xmmap, but the caller doesn't have the struct packed_git* handy. So I'm using the file descriptor instead to perform the same test. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
18 years ago
extern void release_pack_memory(size_t, int);
Shrink the git binary a bit by avoiding unnecessary inline functions So I was looking at the disgusting size of the git binary, and even with the debugging removed, and using -Os instead of -O2, the size of the text section was pretty high. In this day and age I guess almost a megabyte of text isn't really all that surprising, but it still doesn't exactly make me think "lean and mean". With -Os, a surprising amount of text space is wasted on inline functions that end up just being replicated multiple times, and where performance really isn't a valid reason to inline them. In particular, the trivial wrapper functions like "xmalloc()" are used _everywhere_, and making them inline just duplicates the text (and the string we use to 'die()' on failure) unnecessarily. So this just moves them into a "wrapper.c" file, getting rid of a tiny bit of unnecessary bloat. The following numbers are both with "CFLAGS=-Os": Before: [torvalds@woody git]$ size git text data bss dec hex filename 700460 15160 292184 1007804 f60bc git After: [torvalds@woody git]$ size git text data bss dec hex filename 670540 15160 292184 977884 eebdc git so it saves almost 30k of text-space (it actually saves more than that with the default -O2, but I don't think that's necessarily a very relevant number from a "try to shrink git" standpoint). It might conceivably have a performance impact, but none of this should be _that_ performance critical. The real cost is not generally in the wrapper anyway, but in the code it wraps (ie the cost of "xread()" is all in the read itself, not in the trivial wrapping of it). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
17 years ago
extern char *xstrdup(const char *str);
extern void *xmalloc(size_t size);
extern void *xmemdupz(const void *data, size_t len);
extern char *xstrndup(const char *str, size_t len);
extern void *xrealloc(void *ptr, size_t size);
extern void *xcalloc(size_t nmemb, size_t size);
extern void *xmmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
extern ssize_t xread(int fd, void *buf, size_t len);
extern ssize_t xwrite(int fd, const void *buf, size_t len);
extern int xdup(int fd);
extern FILE *xfdopen(int fd, const char *mode);
extern int xmkstemp(char *template);
static inline size_t xsize_t(off_t len)
{
return (size_t)len;
}
static inline int has_extension(const char *filename, const char *ext)
{
size_t len = strlen(filename);
size_t extlen = strlen(ext);
return len > extlen && !memcmp(filename + len - extlen, ext, extlen);
}
/* Sane ctype - no locale, and works with signed chars */
#undef isspace
#undef isdigit
#undef isalpha
#undef isalnum
#undef tolower
#undef toupper
extern unsigned char sane_ctype[256];
#define GIT_SPACE 0x01
#define GIT_DIGIT 0x02
#define GIT_ALPHA 0x04
#define GIT_GLOB_SPECIAL 0x08
#define GIT_REGEX_SPECIAL 0x10
#define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
#define isspace(x) sane_istest(x,GIT_SPACE)
#define isdigit(x) sane_istest(x,GIT_DIGIT)
#define isalpha(x) sane_istest(x,GIT_ALPHA)
#define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
#define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
#define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
#define tolower(x) sane_case((unsigned char)(x), 0x20)
#define toupper(x) sane_case((unsigned char)(x), 0)
static inline int sane_case(int x, int high)
{
if (sane_istest(x, GIT_ALPHA))
x = (x & ~0x20) | high;
return x;
}
static inline int strtoul_ui(char const *s, int base, unsigned int *result)
{
unsigned long ul;
char *p;
errno = 0;
ul = strtoul(s, &p, base);
if (errno || *p || p == s || (unsigned int) ul != ul)
return -1;
*result = ul;
return 0;
}
static inline int strtol_i(char const *s, int base, int *result)
{
long ul;
char *p;
errno = 0;
ul = strtol(s, &p, base);
if (errno || *p || p == s || (int) ul != ul)
return -1;
*result = ul;
return 0;
}
#ifdef INTERNAL_QSORT
void git_qsort(void *base, size_t nmemb, size_t size,
int(*compar)(const void *, const void *));
#define qsort git_qsort
#endif
#ifndef DIR_HAS_BSD_GROUP_SEMANTICS
# define FORCE_DIR_SET_GID S_ISGID
#else
# define FORCE_DIR_SET_GID 0
#endif
#endif