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