wrapper.c

   1 /*
   2  * Various trivial helper wrappers around standard functions
   3  */
   4 #include "cache.h"
   5
   6 char *xstrdup(const char *str)
   7 {
   8         char *ret = strdup(str);
   9         if (!ret) {
  10                 release_pack_memory(strlen(str) + 1, -1);
  11                 ret = strdup(str);
  12                 if (!ret)
  13                         die("Out of memory, strdup failed");
  14         }
  15         return ret;
  16 }
  17
  18 void *xmalloc(size_t size)
  19 {
  20         void *ret = malloc(size);
  21         if (!ret && !size)
  22                 ret = malloc(1);
  23         if (!ret) {
  24                 release_pack_memory(size, -1);
  25                 ret = malloc(size);
  26                 if (!ret && !size)
  27                         ret = malloc(1);
  28                 if (!ret)
  29                         die("Out of memory, malloc failed");
  30         }
  31 #ifdef XMALLOC_POISON
  32         memset(ret, 0xA5, size);
  33 #endif
  34         return ret;
  35 }
  36
  37 void *xmallocz(size_t size)
  38 {
  39         void *ret;
  40         if (size + 1 < size)
  41                 die("Data too large to fit into virtual memory space.");
  42         ret = xmalloc(size + 1);
  43         ((char*)ret)[size] = 0;
  44         return ret;
  45 }
  46
  47 /*
  48  * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
  49  * "data" to the allocated memory, zero terminates the allocated memory,
  50  * and returns a pointer to the allocated memory. If the allocation fails,
  51  * the program dies.
  52  */
  53 void *xmemdupz(const void *data, size_t len)
  54 {
  55         return memcpy(xmallocz(len), data, len);
  56 }
  57
  58 char *xstrndup(const char *str, size_t len)
  59 {
  60         char *p = memchr(str, '\0', len);
  61         return xmemdupz(str, p ? p - str : len);
  62 }
  63
  64 void *xrealloc(void *ptr, size_t size)
  65 {
  66         void *ret = realloc(ptr, size);
  67         if (!ret && !size)
  68                 ret = realloc(ptr, 1);
  69         if (!ret) {
  70                 release_pack_memory(size, -1);
  71                 ret = realloc(ptr, size);
  72                 if (!ret && !size)
  73                         ret = realloc(ptr, 1);
  74                 if (!ret)
  75                         die("Out of memory, realloc failed");
  76         }
  77         return ret;
  78 }
  79
  80 void *xcalloc(size_t nmemb, size_t size)
  81 {
  82         void *ret = calloc(nmemb, size);
  83         if (!ret && (!nmemb || !size))
  84                 ret = calloc(1, 1);
  85         if (!ret) {
  86                 release_pack_memory(nmemb * size, -1);
  87                 ret = calloc(nmemb, size);
  88                 if (!ret && (!nmemb || !size))
  89                         ret = calloc(1, 1);
  90                 if (!ret)
  91                         die("Out of memory, calloc failed");
  92         }
  93         return ret;
  94 }
  95
  96 void *xmmap(void *start, size_t length,
  97         int prot, int flags, int fd, off_t offset)
  98 {
  99         void *ret = mmap(start, length, prot, flags, fd, offset);
 100         if (ret == MAP_FAILED) {
 101                 if (!length)
 102                         return NULL;
 103                 release_pack_memory(length, fd);
 104                 ret = mmap(start, length, prot, flags, fd, offset);
 105                 if (ret == MAP_FAILED)
 106                         die_errno("Out of memory? mmap failed");
 107         }
 108         return ret;
 109 }
 110
 111 /*
 112  * xread() is the same a read(), but it automatically restarts read()
 113  * operations with a recoverable error (EAGAIN and EINTR). xread()
 114  * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
 115  */
 116 ssize_t xread(int fd, void *buf, size_t len)
 117 {
 118         ssize_t nr;
 119         while (1) {
 120                 nr = read(fd, buf, len);
 121                 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
 122                         continue;
 123                 return nr;
 124         }
 125 }
 126
 127 /*
 128  * xwrite() is the same a write(), but it automatically restarts write()
 129  * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
 130  * GUARANTEE that "len" bytes is written even if the operation is successful.
 131  */
 132 ssize_t xwrite(int fd, const void *buf, size_t len)
 133 {
 134         ssize_t nr;
 135         while (1) {
 136                 nr = write(fd, buf, len);
 137                 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
 138                         continue;
 139                 return nr;
 140         }
 141 }
 142
 143 ssize_t read_in_full(int fd, void *buf, size_t count)
 144 {
 145         char *p = buf;
 146         ssize_t total = 0;
 147
 148         while (count > 0) {
 149                 ssize_t loaded = xread(fd, p, count);
 150                 if (loaded <= 0)
 151                         return total ? total : loaded;
 152                 count -= loaded;
 153                 p += loaded;
 154                 total += loaded;
 155         }
 156
 157         return total;
 158 }
 159
 160 ssize_t write_in_full(int fd, const void *buf, size_t count)
 161 {
 162         const char *p = buf;
 163         ssize_t total = 0;
 164
 165         while (count > 0) {
 166                 ssize_t written = xwrite(fd, p, count);
 167                 if (written < 0)
 168                         return -1;
 169                 if (!written) {
 170                         errno = ENOSPC;
 171                         return -1;
 172                 }
 173                 count -= written;
 174                 p += written;
 175                 total += written;
 176         }
 177
 178         return total;
 179 }
 180
 181 int xdup(int fd)
 182 {
 183         int ret = dup(fd);
 184         if (ret < 0)
 185                 die_errno("dup failed");
 186         return ret;
 187 }
 188
 189 FILE *xfdopen(int fd, const char *mode)
 190 {
 191         FILE *stream = fdopen(fd, mode);
 192         if (stream == NULL)
 193                 die_errno("Out of memory? fdopen failed");
 194         return stream;
 195 }
 196
 197 int xmkstemp(char *template)
 198 {
 199         int fd;
 200
 201         fd = mkstemp(template);
 202         if (fd < 0)
 203                 die_errno("Unable to create temporary file");
 204         return fd;
 205 }
 206
 207 int xmkstemp_mode(char *template, int mode)
 208 {
 209         int fd;
 210
 211         fd = git_mkstemp_mode(template, mode);
 212         if (fd < 0)
 213                 die_errno("Unable to create temporary file");
 214         return fd;
 215 }
 216
 217 /*
 218  * zlib wrappers to make sure we don't silently miss errors
 219  * at init time.
 220  */
 221 void git_inflate_init(z_streamp strm)
 222 {
 223         const char *err;
 224
 225         switch (inflateInit(strm)) {
 226         case Z_OK:
 227                 return;
 228
 229         case Z_MEM_ERROR:
 230                 err = "out of memory";
 231                 break;
 232         case Z_VERSION_ERROR:
 233                 err = "wrong version";
 234                 break;
 235         default:
 236                 err = "error";
 237         }
 238         die("inflateInit: %s (%s)", err, strm->msg ? strm->msg : "no message");
 239 }
 240
 241 void git_inflate_end(z_streamp strm)
 242 {
 243         if (inflateEnd(strm) != Z_OK)
 244                 error("inflateEnd: %s", strm->msg ? strm->msg : "failed");
 245 }
 246
 247 int git_inflate(z_streamp strm, int flush)
 248 {
 249         int ret = inflate(strm, flush);
 250         const char *err;
 251
 252         switch (ret) {
 253         /* Out of memory is fatal. */
 254         case Z_MEM_ERROR:
 255                 die("inflate: out of memory");
 256
 257         /* Data corruption errors: we may want to recover from them (fsck) */
 258         case Z_NEED_DICT:
 259                 err = "needs dictionary"; break;
 260         case Z_DATA_ERROR:
 261                 err = "data stream error"; break;
 262         case Z_STREAM_ERROR:
 263                 err = "stream consistency error"; break;
 264         default:
 265                 err = "unknown error"; break;
 266
 267         /* Z_BUF_ERROR: normal, needs more space in the output buffer */
 268         case Z_BUF_ERROR:
 269         case Z_OK:
 270         case Z_STREAM_END:
 271                 return ret;
 272         }
 273         error("inflate: %s (%s)", err, strm->msg ? strm->msg : "no message");
 274         return ret;
 275 }
 276
 277 int odb_mkstemp(char *template, size_t limit, const char *pattern)
 278 {
 279         int fd;
 280         /*
 281          * we let the umask do its job, don't try to be more
 282          * restrictive except to remove write permission.
 283          */
 284         int mode = 0444;
 285         snprintf(template, limit, "%s/%s",
 286                  get_object_directory(), pattern);
 287         fd = git_mkstemp_mode(template, mode);
 288         if (0 <= fd)
 289                 return fd;
 290
 291         /* slow path */
 292         /* some mkstemp implementations erase template on failure */
 293         snprintf(template, limit, "%s/%s",
 294                  get_object_directory(), pattern);
 295         safe_create_leading_directories(template);
 296         return xmkstemp_mode(template, mode);
 297 }
 298
 299 int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1)
 300 {
 301         int fd;
 302
 303         snprintf(name, namesz, "%s/pack/pack-%s.keep",
 304                  get_object_directory(), sha1_to_hex(sha1));
 305         fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 306         if (0 <= fd)
 307                 return fd;
 308
 309         /* slow path */
 310         safe_create_leading_directories(name);
 311         return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 312 }
 313
 314 static int warn_if_unremovable(const char *op, const char *file, int rc)
 315 {
 316         if (rc < 0) {
 317                 int err = errno;
 318                 if (ENOENT != err) {
 319                         warning("unable to %s %s: %s",
 320                                 op, file, strerror(errno));
 321                         errno = err;
 322                 }
 323         }
 324         return rc;
 325 }
 326
 327 int unlink_or_warn(const char *file)
 328 {
 329         return warn_if_unremovable("unlink", file, unlink(file));
 330 }
 331
 332 int rmdir_or_warn(const char *file)
 333 {
 334         return warn_if_unremovable("rmdir", file, rmdir(file));
 335 }
 336
 337 int remove_or_warn(unsigned int mode, const char *file)
 338 {
 339         return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
 340 }