git/wrapper.c
Jeff King e850194c83 ident: make xgetpwuid_self() a static local helper
This function is defined in wrapper.c, but nobody besides
ident.c uses it. And nobody is likely to in the future,
either, as anything that cares about the user's name should
be going through the ident code.

Moving it here is a cleanup of the global namespace, but it
will also enable further cleanups inside ident.c.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-10 15:38:59 -08:00

668 lines
14 KiB
C

/*
* Various trivial helper wrappers around standard functions
*/
#include "cache.h"
static void do_nothing(size_t size)
{
}
static void (*try_to_free_routine)(size_t size) = do_nothing;
static int memory_limit_check(size_t size, int gentle)
{
static size_t limit = 0;
if (!limit) {
limit = git_env_ulong("GIT_ALLOC_LIMIT", 0);
if (!limit)
limit = SIZE_MAX;
}
if (size > limit) {
if (gentle) {
error("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,
(uintmax_t)size, (uintmax_t)limit);
return -1;
} else
die("attempting to allocate %"PRIuMAX" over limit %"PRIuMAX,
(uintmax_t)size, (uintmax_t)limit);
}
return 0;
}
try_to_free_t set_try_to_free_routine(try_to_free_t routine)
{
try_to_free_t old = try_to_free_routine;
if (!routine)
routine = do_nothing;
try_to_free_routine = routine;
return old;
}
char *xstrdup(const char *str)
{
char *ret = strdup(str);
if (!ret) {
try_to_free_routine(strlen(str) + 1);
ret = strdup(str);
if (!ret)
die("Out of memory, strdup failed");
}
return ret;
}
static void *do_xmalloc(size_t size, int gentle)
{
void *ret;
if (memory_limit_check(size, gentle))
return NULL;
ret = malloc(size);
if (!ret && !size)
ret = malloc(1);
if (!ret) {
try_to_free_routine(size);
ret = malloc(size);
if (!ret && !size)
ret = malloc(1);
if (!ret) {
if (!gentle)
die("Out of memory, malloc failed (tried to allocate %lu bytes)",
(unsigned long)size);
else {
error("Out of memory, malloc failed (tried to allocate %lu bytes)",
(unsigned long)size);
return NULL;
}
}
}
#ifdef XMALLOC_POISON
memset(ret, 0xA5, size);
#endif
return ret;
}
void *xmalloc(size_t size)
{
return do_xmalloc(size, 0);
}
static void *do_xmallocz(size_t size, int gentle)
{
void *ret;
if (unsigned_add_overflows(size, 1)) {
if (gentle) {
error("Data too large to fit into virtual memory space.");
return NULL;
} else
die("Data too large to fit into virtual memory space.");
}
ret = do_xmalloc(size + 1, gentle);
if (ret)
((char*)ret)[size] = 0;
return ret;
}
void *xmallocz(size_t size)
{
return do_xmallocz(size, 0);
}
void *xmallocz_gently(size_t size)
{
return do_xmallocz(size, 1);
}
/*
* xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
* "data" to the allocated memory, zero terminates the allocated memory,
* and returns a pointer to the allocated memory. If the allocation fails,
* the program dies.
*/
void *xmemdupz(const void *data, size_t len)
{
return memcpy(xmallocz(len), data, len);
}
char *xstrndup(const char *str, size_t len)
{
char *p = memchr(str, '\0', len);
return xmemdupz(str, p ? p - str : len);
}
void *xrealloc(void *ptr, size_t size)
{
void *ret;
memory_limit_check(size, 0);
ret = realloc(ptr, size);
if (!ret && !size)
ret = realloc(ptr, 1);
if (!ret) {
try_to_free_routine(size);
ret = realloc(ptr, size);
if (!ret && !size)
ret = realloc(ptr, 1);
if (!ret)
die("Out of memory, realloc failed");
}
return ret;
}
void *xcalloc(size_t nmemb, size_t size)
{
void *ret;
memory_limit_check(size * nmemb, 0);
ret = calloc(nmemb, size);
if (!ret && (!nmemb || !size))
ret = calloc(1, 1);
if (!ret) {
try_to_free_routine(nmemb * size);
ret = calloc(nmemb, size);
if (!ret && (!nmemb || !size))
ret = calloc(1, 1);
if (!ret)
die("Out of memory, calloc failed");
}
return ret;
}
/*
* Limit size of IO chunks, because huge chunks only cause pain. OS X
* 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
* the absence of bugs, large chunks can result in bad latencies when
* you decide to kill the process.
*
* We pick 8 MiB as our default, but if the platform defines SSIZE_MAX
* that is smaller than that, clip it to SSIZE_MAX, as a call to
* read(2) or write(2) larger than that is allowed to fail. As the last
* resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value"
* to override this, if the definition of SSIZE_MAX given by the platform
* is broken.
*/
#ifndef MAX_IO_SIZE
# define MAX_IO_SIZE_DEFAULT (8*1024*1024)
# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT)
# define MAX_IO_SIZE SSIZE_MAX
# else
# define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT
# endif
#endif
/**
* xopen() is the same as open(), but it die()s if the open() fails.
*/
int xopen(const char *path, int oflag, ...)
{
mode_t mode = 0;
va_list ap;
/*
* va_arg() will have undefined behavior if the specified type is not
* compatible with the argument type. Since integers are promoted to
* ints, we fetch the next argument as an int, and then cast it to a
* mode_t to avoid undefined behavior.
*/
va_start(ap, oflag);
if (oflag & O_CREAT)
mode = va_arg(ap, int);
va_end(ap);
for (;;) {
int fd = open(path, oflag, mode);
if (fd >= 0)
return fd;
if (errno == EINTR)
continue;
if ((oflag & O_RDWR) == O_RDWR)
die_errno(_("could not open '%s' for reading and writing"), path);
else if ((oflag & O_WRONLY) == O_WRONLY)
die_errno(_("could not open '%s' for writing"), path);
else
die_errno(_("could not open '%s' for reading"), path);
}
}
/*
* xread() is the same a read(), but it automatically restarts read()
* operations with a recoverable error (EAGAIN and EINTR). xread()
* DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
*/
ssize_t xread(int fd, void *buf, size_t len)
{
ssize_t nr;
if (len > MAX_IO_SIZE)
len = MAX_IO_SIZE;
while (1) {
nr = read(fd, buf, len);
if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
continue;
return nr;
}
}
/*
* xwrite() is the same a write(), but it automatically restarts write()
* operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
* GUARANTEE that "len" bytes is written even if the operation is successful.
*/
ssize_t xwrite(int fd, const void *buf, size_t len)
{
ssize_t nr;
if (len > MAX_IO_SIZE)
len = MAX_IO_SIZE;
while (1) {
nr = write(fd, buf, len);
if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
continue;
return nr;
}
}
/*
* xpread() is the same as pread(), but it automatically restarts pread()
* operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
* NOT GUARANTEE that "len" bytes is read even if the data is available.
*/
ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
{
ssize_t nr;
if (len > MAX_IO_SIZE)
len = MAX_IO_SIZE;
while (1) {
nr = pread(fd, buf, len, offset);
if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
continue;
return nr;
}
}
ssize_t read_in_full(int fd, void *buf, size_t count)
{
char *p = buf;
ssize_t total = 0;
while (count > 0) {
ssize_t loaded = xread(fd, p, count);
if (loaded < 0)
return -1;
if (loaded == 0)
return total;
count -= loaded;
p += loaded;
total += loaded;
}
return total;
}
ssize_t write_in_full(int fd, const void *buf, size_t count)
{
const char *p = buf;
ssize_t total = 0;
while (count > 0) {
ssize_t written = xwrite(fd, p, count);
if (written < 0)
return -1;
if (!written) {
errno = ENOSPC;
return -1;
}
count -= written;
p += written;
total += written;
}
return total;
}
ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
{
char *p = buf;
ssize_t total = 0;
while (count > 0) {
ssize_t loaded = xpread(fd, p, count, offset);
if (loaded < 0)
return -1;
if (loaded == 0)
return total;
count -= loaded;
p += loaded;
total += loaded;
offset += loaded;
}
return total;
}
int xdup(int fd)
{
int ret = dup(fd);
if (ret < 0)
die_errno("dup failed");
return ret;
}
/**
* xfopen() is the same as fopen(), but it die()s if the fopen() fails.
*/
FILE *xfopen(const char *path, const char *mode)
{
for (;;) {
FILE *fp = fopen(path, mode);
if (fp)
return fp;
if (errno == EINTR)
continue;
if (*mode && mode[1] == '+')
die_errno(_("could not open '%s' for reading and writing"), path);
else if (*mode == 'w' || *mode == 'a')
die_errno(_("could not open '%s' for writing"), path);
else
die_errno(_("could not open '%s' for reading"), path);
}
}
FILE *xfdopen(int fd, const char *mode)
{
FILE *stream = fdopen(fd, mode);
if (stream == NULL)
die_errno("Out of memory? fdopen failed");
return stream;
}
int xmkstemp(char *template)
{
int fd;
char origtemplate[PATH_MAX];
strlcpy(origtemplate, template, sizeof(origtemplate));
fd = mkstemp(template);
if (fd < 0) {
int saved_errno = errno;
const char *nonrelative_template;
if (strlen(template) != strlen(origtemplate))
template = origtemplate;
nonrelative_template = absolute_path(template);
errno = saved_errno;
die_errno("Unable to create temporary file '%s'",
nonrelative_template);
}
return fd;
}
/* git_mkstemp() - create tmp file honoring TMPDIR variable */
int git_mkstemp(char *path, size_t len, const char *template)
{
const char *tmp;
size_t n;
tmp = getenv("TMPDIR");
if (!tmp)
tmp = "/tmp";
n = snprintf(path, len, "%s/%s", tmp, template);
if (len <= n) {
errno = ENAMETOOLONG;
return -1;
}
return mkstemp(path);
}
/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
{
const char *tmp;
size_t n;
tmp = getenv("TMPDIR");
if (!tmp)
tmp = "/tmp";
n = snprintf(path, len, "%s/%s", tmp, template);
if (len <= n) {
errno = ENAMETOOLONG;
return -1;
}
return mkstemps(path, suffix_len);
}
/* Adapted from libiberty's mkstemp.c. */
#undef TMP_MAX
#define TMP_MAX 16384
int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
{
static const char letters[] =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789";
static const int num_letters = 62;
uint64_t value;
struct timeval tv;
char *template;
size_t len;
int fd, count;
len = strlen(pattern);
if (len < 6 + suffix_len) {
errno = EINVAL;
return -1;
}
if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
errno = EINVAL;
return -1;
}
/*
* Replace pattern's XXXXXX characters with randomness.
* Try TMP_MAX different filenames.
*/
gettimeofday(&tv, NULL);
value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
template = &pattern[len - 6 - suffix_len];
for (count = 0; count < TMP_MAX; ++count) {
uint64_t v = value;
/* Fill in the random bits. */
template[0] = letters[v % num_letters]; v /= num_letters;
template[1] = letters[v % num_letters]; v /= num_letters;
template[2] = letters[v % num_letters]; v /= num_letters;
template[3] = letters[v % num_letters]; v /= num_letters;
template[4] = letters[v % num_letters]; v /= num_letters;
template[5] = letters[v % num_letters]; v /= num_letters;
fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, mode);
if (fd >= 0)
return fd;
/*
* Fatal error (EPERM, ENOSPC etc).
* It doesn't make sense to loop.
*/
if (errno != EEXIST)
break;
/*
* This is a random value. It is only necessary that
* the next TMP_MAX values generated by adding 7777 to
* VALUE are different with (module 2^32).
*/
value += 7777;
}
/* We return the null string if we can't find a unique file name. */
pattern[0] = '\0';
return -1;
}
int git_mkstemp_mode(char *pattern, int mode)
{
/* mkstemp is just mkstemps with no suffix */
return git_mkstemps_mode(pattern, 0, mode);
}
#ifdef NO_MKSTEMPS
int gitmkstemps(char *pattern, int suffix_len)
{
return git_mkstemps_mode(pattern, suffix_len, 0600);
}
#endif
int xmkstemp_mode(char *template, int mode)
{
int fd;
char origtemplate[PATH_MAX];
strlcpy(origtemplate, template, sizeof(origtemplate));
fd = git_mkstemp_mode(template, mode);
if (fd < 0) {
int saved_errno = errno;
const char *nonrelative_template;
if (!template[0])
template = origtemplate;
nonrelative_template = absolute_path(template);
errno = saved_errno;
die_errno("Unable to create temporary file '%s'",
nonrelative_template);
}
return fd;
}
static int warn_if_unremovable(const char *op, const char *file, int rc)
{
int err;
if (!rc || errno == ENOENT)
return 0;
err = errno;
warning("unable to %s %s: %s", op, file, strerror(errno));
errno = err;
return rc;
}
int unlink_or_msg(const char *file, struct strbuf *err)
{
int rc = unlink(file);
assert(err);
if (!rc || errno == ENOENT)
return 0;
strbuf_addf(err, "unable to unlink %s: %s",
file, strerror(errno));
return -1;
}
int unlink_or_warn(const char *file)
{
return warn_if_unremovable("unlink", file, unlink(file));
}
int rmdir_or_warn(const char *file)
{
return warn_if_unremovable("rmdir", file, rmdir(file));
}
int remove_or_warn(unsigned int mode, const char *file)
{
return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
}
void warn_on_inaccessible(const char *path)
{
warning(_("unable to access '%s': %s"), path, strerror(errno));
}
static int access_error_is_ok(int err, unsigned flag)
{
return err == ENOENT || err == ENOTDIR ||
((flag & ACCESS_EACCES_OK) && err == EACCES);
}
int access_or_warn(const char *path, int mode, unsigned flag)
{
int ret = access(path, mode);
if (ret && !access_error_is_ok(errno, flag))
warn_on_inaccessible(path);
return ret;
}
int access_or_die(const char *path, int mode, unsigned flag)
{
int ret = access(path, mode);
if (ret && !access_error_is_ok(errno, flag))
die_errno(_("unable to access '%s'"), path);
return ret;
}
char *xgetcwd(void)
{
struct strbuf sb = STRBUF_INIT;
if (strbuf_getcwd(&sb))
die_errno(_("unable to get current working directory"));
return strbuf_detach(&sb, NULL);
}
static int write_file_v(const char *path, int fatal,
const char *fmt, va_list params)
{
struct strbuf sb = STRBUF_INIT;
int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
if (fd < 0) {
if (fatal)
die_errno(_("could not open %s for writing"), path);
return -1;
}
strbuf_vaddf(&sb, fmt, params);
strbuf_complete_line(&sb);
if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
int err = errno;
close(fd);
strbuf_release(&sb);
errno = err;
if (fatal)
die_errno(_("could not write to %s"), path);
return -1;
}
strbuf_release(&sb);
if (close(fd)) {
if (fatal)
die_errno(_("could not close %s"), path);
return -1;
}
return 0;
}
int write_file(const char *path, const char *fmt, ...)
{
int status;
va_list params;
va_start(params, fmt);
status = write_file_v(path, 1, fmt, params);
va_end(params);
return status;
}
int write_file_gently(const char *path, const char *fmt, ...)
{
int status;
va_list params;
va_start(params, fmt);
status = write_file_v(path, 0, fmt, params);
va_end(params);
return status;
}
void sleep_millisec(int millisec)
{
poll(NULL, 0, millisec);
}