wrapper.c

   1 /*
   2  * Various trivial helper wrappers around standard functions
   3  */
   4 #include "cache.h"
   5
   6 static void try_to_free_builtin(size_t size)
   7 {
   8         release_pack_memory(size, -1);
   9 }
  10
  11 static void (*try_to_free_routine)(size_t size) = try_to_free_builtin;
  12
  13 void set_try_to_free_routine(void (*routine)(size_t))
  14 {
  15         try_to_free_routine = (routine) ? routine : try_to_free_builtin;
  16 }
  17
  18 char *xstrdup(const char *str)
  19 {
  20         char *ret = strdup(str);
  21         if (!ret) {
  22                 try_to_free_routine(strlen(str) + 1);
  23                 ret = strdup(str);
  24                 if (!ret)
  25                         die("Out of memory, strdup failed");
  26         }
  27         return ret;
  28 }
  29
  30 void *xmalloc(size_t size)
  31 {
  32         void *ret = malloc(size);
  33         if (!ret && !size)
  34                 ret = malloc(1);
  35         if (!ret) {
  36                 try_to_free_routine(size);
  37                 ret = malloc(size);
  38                 if (!ret && !size)
  39                         ret = malloc(1);
  40                 if (!ret)
  41                         die("Out of memory, malloc failed");
  42         }
  43 #ifdef XMALLOC_POISON
  44         memset(ret, 0xA5, size);
  45 #endif
  46         return ret;
  47 }
  48
  49 void *xmallocz(size_t size)
  50 {
  51         void *ret;
  52         if (size + 1 < size)
  53                 die("Data too large to fit into virtual memory space.");
  54         ret = xmalloc(size + 1);
  55         ((char*)ret)[size] = 0;
  56         return ret;
  57 }
  58
  59 /*
  60  * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
  61  * "data" to the allocated memory, zero terminates the allocated memory,
  62  * and returns a pointer to the allocated memory. If the allocation fails,
  63  * the program dies.
  64  */
  65 void *xmemdupz(const void *data, size_t len)
  66 {
  67         return memcpy(xmallocz(len), data, len);
  68 }
  69
  70 char *xstrndup(const char *str, size_t len)
  71 {
  72         char *p = memchr(str, '\0', len);
  73         return xmemdupz(str, p ? p - str : len);
  74 }
  75
  76 void *xrealloc(void *ptr, size_t size)
  77 {
  78         void *ret = realloc(ptr, size);
  79         if (!ret && !size)
  80                 ret = realloc(ptr, 1);
  81         if (!ret) {
  82                 try_to_free_routine(size);
  83                 ret = realloc(ptr, size);
  84                 if (!ret && !size)
  85                         ret = realloc(ptr, 1);
  86                 if (!ret)
  87                         die("Out of memory, realloc failed");
  88         }
  89         return ret;
  90 }
  91
  92 void *xcalloc(size_t nmemb, size_t size)
  93 {
  94         void *ret = calloc(nmemb, size);
  95         if (!ret && (!nmemb || !size))
  96                 ret = calloc(1, 1);
  97         if (!ret) {
  98                 try_to_free_routine(nmemb * size);
  99                 ret = calloc(nmemb, size);
 100                 if (!ret && (!nmemb || !size))
 101                         ret = calloc(1, 1);
 102                 if (!ret)
 103                         die("Out of memory, calloc failed");
 104         }
 105         return ret;
 106 }
 107
 108 void *xmmap(void *start, size_t length,
 109         int prot, int flags, int fd, off_t offset)
 110 {
 111         void *ret = mmap(start, length, prot, flags, fd, offset);
 112         if (ret == MAP_FAILED) {
 113                 if (!length)
 114                         return NULL;
 115                 release_pack_memory(length, fd);
 116                 ret = mmap(start, length, prot, flags, fd, offset);
 117                 if (ret == MAP_FAILED)
 118                         die_errno("Out of memory? mmap failed");
 119         }
 120         return ret;
 121 }
 122
 123 /*
 124  * xread() is the same a read(), but it automatically restarts read()
 125  * operations with a recoverable error (EAGAIN and EINTR). xread()
 126  * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
 127  */
 128 ssize_t xread(int fd, void *buf, size_t len)
 129 {
 130         ssize_t nr;
 131         while (1) {
 132                 nr = read(fd, buf, len);
 133                 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
 134                         continue;
 135                 return nr;
 136         }
 137 }
 138
 139 /*
 140  * xwrite() is the same a write(), but it automatically restarts write()
 141  * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
 142  * GUARANTEE that "len" bytes is written even if the operation is successful.
 143  */
 144 ssize_t xwrite(int fd, const void *buf, size_t len)
 145 {
 146         ssize_t nr;
 147         while (1) {
 148                 nr = write(fd, buf, len);
 149                 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
 150                         continue;
 151                 return nr;
 152         }
 153 }
 154
 155 ssize_t read_in_full(int fd, void *buf, size_t count)
 156 {
 157         char *p = buf;
 158         ssize_t total = 0;
 159
 160         while (count > 0) {
 161                 ssize_t loaded = xread(fd, p, count);
 162                 if (loaded <= 0)
 163                         return total ? total : loaded;
 164                 count -= loaded;
 165                 p += loaded;
 166                 total += loaded;
 167         }
 168
 169         return total;
 170 }
 171
 172 ssize_t write_in_full(int fd, const void *buf, size_t count)
 173 {
 174         const char *p = buf;
 175         ssize_t total = 0;
 176
 177         while (count > 0) {
 178                 ssize_t written = xwrite(fd, p, count);
 179                 if (written < 0)
 180                         return -1;
 181                 if (!written) {
 182                         errno = ENOSPC;
 183                         return -1;
 184                 }
 185                 count -= written;
 186                 p += written;
 187                 total += written;
 188         }
 189
 190         return total;
 191 }
 192
 193 int xdup(int fd)
 194 {
 195         int ret = dup(fd);
 196         if (ret < 0)
 197                 die_errno("dup failed");
 198         return ret;
 199 }
 200
 201 FILE *xfdopen(int fd, const char *mode)
 202 {
 203         FILE *stream = fdopen(fd, mode);
 204         if (stream == NULL)
 205                 die_errno("Out of memory? fdopen failed");
 206         return stream;
 207 }
 208
 209 int xmkstemp(char *template)
 210 {
 211         int fd;
 212
 213         fd = mkstemp(template);
 214         if (fd < 0)
 215                 die_errno("Unable to create temporary file");
 216         return fd;
 217 }
 218
 219 int xmkstemp_mode(char *template, int mode)
 220 {
 221         int fd;
 222
 223         fd = git_mkstemp_mode(template, mode);
 224         if (fd < 0)
 225                 die_errno("Unable to create temporary file");
 226         return fd;
 227 }
 228
 229 /*
 230  * zlib wrappers to make sure we don't silently miss errors
 231  * at init time.
 232  */
 233 void git_inflate_init(z_streamp strm)
 234 {
 235         const char *err;
 236
 237         switch (inflateInit(strm)) {
 238         case Z_OK:
 239                 return;
 240
 241         case Z_MEM_ERROR:
 242                 err = "out of memory";
 243                 break;
 244         case Z_VERSION_ERROR:
 245                 err = "wrong version";
 246                 break;
 247         default:
 248                 err = "error";
 249         }
 250         die("inflateInit: %s (%s)", err, strm->msg ? strm->msg : "no message");
 251 }
 252
 253 void git_inflate_end(z_streamp strm)
 254 {
 255         if (inflateEnd(strm) != Z_OK)
 256                 error("inflateEnd: %s", strm->msg ? strm->msg : "failed");
 257 }
 258
 259 int git_inflate(z_streamp strm, int flush)
 260 {
 261         int ret = inflate(strm, flush);
 262         const char *err;
 263
 264         switch (ret) {
 265         /* Out of memory is fatal. */
 266         case Z_MEM_ERROR:
 267                 die("inflate: out of memory");
 268
 269         /* Data corruption errors: we may want to recover from them (fsck) */
 270         case Z_NEED_DICT:
 271                 err = "needs dictionary"; break;
 272         case Z_DATA_ERROR:
 273                 err = "data stream error"; break;
 274         case Z_STREAM_ERROR:
 275                 err = "stream consistency error"; break;
 276         default:
 277                 err = "unknown error"; break;
 278
 279         /* Z_BUF_ERROR: normal, needs more space in the output buffer */
 280         case Z_BUF_ERROR:
 281         case Z_OK:
 282         case Z_STREAM_END:
 283                 return ret;
 284         }
 285         error("inflate: %s (%s)", err, strm->msg ? strm->msg : "no message");
 286         return ret;
 287 }
 288
 289 int odb_mkstemp(char *template, size_t limit, const char *pattern)
 290 {
 291         int fd;
 292         /*
 293          * we let the umask do its job, don't try to be more
 294          * restrictive except to remove write permission.
 295          */
 296         int mode = 0444;
 297         snprintf(template, limit, "%s/%s",
 298                  get_object_directory(), pattern);
 299         fd = git_mkstemp_mode(template, mode);
 300         if (0 <= fd)
 301                 return fd;
 302
 303         /* slow path */
 304         /* some mkstemp implementations erase template on failure */
 305         snprintf(template, limit, "%s/%s",
 306                  get_object_directory(), pattern);
 307         safe_create_leading_directories(template);
 308         return xmkstemp_mode(template, mode);
 309 }
 310
 311 int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1)
 312 {
 313         int fd;
 314
 315         snprintf(name, namesz, "%s/pack/pack-%s.keep",
 316                  get_object_directory(), sha1_to_hex(sha1));
 317         fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 318         if (0 <= fd)
 319                 return fd;
 320
 321         /* slow path */
 322         safe_create_leading_directories(name);
 323         return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 324 }
 325
 326 static int warn_if_unremovable(const char *op, const char *file, int rc)
 327 {
 328         if (rc < 0) {
 329                 int err = errno;
 330                 if (ENOENT != err) {
 331                         warning("unable to %s %s: %s",
 332                                 op, file, strerror(errno));
 333                         errno = err;
 334                 }
 335         }
 336         return rc;
 337 }
 338
 339 int unlink_or_warn(const char *file)
 340 {
 341         return warn_if_unremovable("unlink", file, unlink(file));
 342 }
 343
 344 int rmdir_or_warn(const char *file)
 345 {
 346         return warn_if_unremovable("rmdir", file, rmdir(file));
 347 }
 348
 349 int remove_or_warn(unsigned int mode, const char *file)
 350 {
 351         return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
 352 }