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git/wrapper.c
Linus Torvalds 39c68542fc Wrap inflate and other zlib routines for better error reporting
R. Tyler Ballance reported a mysterious transient repository corruption;
after much digging, it turns out that we were not catching and reporting
memory allocation errors from some calls we make to zlib.

This one _just_ wraps things; it doesn't do the "retry on low memory
error" part, at least not yet. It is an independent issue from the
reporting.  Some of the errors are expected and passed back to the caller,
but we die when zlib reports it failed to allocate memory for now.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-11 02:13:06 -08:00

258 lines
5.2 KiB
C

/*
* Various trivial helper wrappers around standard functions
*/
#include "cache.h"
char *xstrdup(const char *str)
{
char *ret = strdup(str);
if (!ret) {
release_pack_memory(strlen(str) + 1, -1);
ret = strdup(str);
if (!ret)
die("Out of memory, strdup failed");
}
return ret;
}
void *xmalloc(size_t size)
{
void *ret = malloc(size);
if (!ret && !size)
ret = malloc(1);
if (!ret) {
release_pack_memory(size, -1);
ret = malloc(size);
if (!ret && !size)
ret = malloc(1);
if (!ret)
die("Out of memory, malloc failed");
}
#ifdef XMALLOC_POISON
memset(ret, 0xA5, size);
#endif
return ret;
}
/*
* 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)
{
char *p = xmalloc(len + 1);
memcpy(p, data, len);
p[len] = '\0';
return p;
}
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 = realloc(ptr, size);
if (!ret && !size)
ret = realloc(ptr, 1);
if (!ret) {
release_pack_memory(size, -1);
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 = calloc(nmemb, size);
if (!ret && (!nmemb || !size))
ret = calloc(1, 1);
if (!ret) {
release_pack_memory(nmemb * size, -1);
ret = calloc(nmemb, size);
if (!ret && (!nmemb || !size))
ret = calloc(1, 1);
if (!ret)
die("Out of memory, calloc failed");
}
return ret;
}
void *xmmap(void *start, size_t length,
int prot, int flags, int fd, off_t offset)
{
void *ret = mmap(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED) {
if (!length)
return NULL;
release_pack_memory(length, fd);
ret = mmap(start, length, prot, flags, fd, offset);
if (ret == MAP_FAILED)
die("Out of memory? mmap failed: %s", strerror(errno));
}
return ret;
}
/*
* 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;
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;
while (1) {
nr = write(fd, buf, len);
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 total ? total : loaded;
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;
}
int xdup(int fd)
{
int ret = dup(fd);
if (ret < 0)
die("dup failed: %s", strerror(errno));
return ret;
}
FILE *xfdopen(int fd, const char *mode)
{
FILE *stream = fdopen(fd, mode);
if (stream == NULL)
die("Out of memory? fdopen failed: %s", strerror(errno));
return stream;
}
int xmkstemp(char *template)
{
int fd;
fd = mkstemp(template);
if (fd < 0)
die("Unable to create temporary file: %s", strerror(errno));
return fd;
}
/*
* zlib wrappers to make sure we don't silently miss errors
* at init time.
*/
void git_inflate_init(z_streamp strm)
{
const char *err;
switch (inflateInit(strm)) {
case Z_OK:
return;
case Z_MEM_ERROR:
err = "out of memory";
break;
case Z_VERSION_ERROR:
err = "wrong version";
break;
default:
err = "error";
}
die("inflateInit: %s (%s)", err, strm->msg ? strm->msg : "no message");
}
void git_inflate_end(z_streamp strm)
{
if (inflateEnd(strm) != Z_OK)
error("inflateEnd: %s", strm->msg ? strm->msg : "failed");
}
int git_inflate(z_streamp strm, int flush)
{
int ret = inflate(strm, flush);
const char *err;
switch (ret) {
/* Out of memory is fatal. */
case Z_MEM_ERROR:
die("inflate: out of memory");
/* Data corruption errors: we may want to recover from them (fsck) */
case Z_NEED_DICT:
err = "needs dictionary"; break;
case Z_DATA_ERROR:
err = "data stream error"; break;
case Z_STREAM_ERROR:
err = "stream consistency error"; break;
default:
err = "unknown error"; break;
/* Z_BUF_ERROR: normal, needs more space in the output buffer */
case Z_BUF_ERROR:
case Z_OK:
case Z_STREAM_END:
return ret;
}
error("inflate: %s (%s)", err, strm->msg ? strm->msg : "no message");
return ret;
}