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 try_to_free_t set_try_to_free_routine(try_to_free_t routine)
  14 {
  15         try_to_free_t old = try_to_free_routine;
  16         try_to_free_routine = routine;
  17         return old;
  18 }
  19
  20 char *xstrdup(const char *str)
  21 {
  22         char *ret = strdup(str);
  23         if (!ret) {
  24                 try_to_free_routine(strlen(str) + 1);
  25                 ret = strdup(str);
  26                 if (!ret)
  27                         die("Out of memory, strdup failed");
  28         }
  29         return ret;
  30 }
  31
  32 void *xmalloc(size_t size)
  33 {
  34         void *ret = malloc(size);
  35         if (!ret && !size)
  36                 ret = malloc(1);
  37         if (!ret) {
  38                 try_to_free_routine(size);
  39                 ret = malloc(size);
  40                 if (!ret && !size)
  41                         ret = malloc(1);
  42                 if (!ret)
  43                         die("Out of memory, malloc failed (tried to allocate %lu bytes)",
  44                             (unsigned long)size);
  45         }
  46 #ifdef XMALLOC_POISON
  47         memset(ret, 0xA5, size);
  48 #endif
  49         return ret;
  50 }
  51
  52 void *xmallocz(size_t size)
  53 {
  54         void *ret;
  55         if (size + 1 < size)
  56                 die("Data too large to fit into virtual memory space.");
  57         ret = xmalloc(size + 1);
  58         ((char*)ret)[size] = 0;
  59         return ret;
  60 }
  61
  62 /*
  63  * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
  64  * "data" to the allocated memory, zero terminates the allocated memory,
  65  * and returns a pointer to the allocated memory. If the allocation fails,
  66  * the program dies.
  67  */
  68 void *xmemdupz(const void *data, size_t len)
  69 {
  70         return memcpy(xmallocz(len), data, len);
  71 }
  72
  73 char *xstrndup(const char *str, size_t len)
  74 {
  75         char *p = memchr(str, '\0', len);
  76         return xmemdupz(str, p ? p - str : len);
  77 }
  78
  79 void *xrealloc(void *ptr, size_t size)
  80 {
  81         void *ret = realloc(ptr, size);
  82         if (!ret && !size)
  83                 ret = realloc(ptr, 1);
  84         if (!ret) {
  85                 try_to_free_routine(size);
  86                 ret = realloc(ptr, size);
  87                 if (!ret && !size)
  88                         ret = realloc(ptr, 1);
  89                 if (!ret)
  90                         die("Out of memory, realloc failed");
  91         }
  92         return ret;
  93 }
  94
  95 void *xcalloc(size_t nmemb, size_t size)
  96 {
  97         void *ret = calloc(nmemb, size);
  98         if (!ret && (!nmemb || !size))
  99                 ret = calloc(1, 1);
 100         if (!ret) {
 101                 try_to_free_routine(nmemb * size);
 102                 ret = calloc(nmemb, size);
 103                 if (!ret && (!nmemb || !size))
 104                         ret = calloc(1, 1);
 105                 if (!ret)
 106                         die("Out of memory, calloc failed");
 107         }
 108         return ret;
 109 }
 110
 111 void *xmmap(void *start, size_t length,
 112         int prot, int flags, int fd, off_t offset)
 113 {
 114         void *ret = mmap(start, length, prot, flags, fd, offset);
 115         if (ret == MAP_FAILED) {
 116                 if (!length)
 117                         return NULL;
 118                 release_pack_memory(length, fd);
 119                 ret = mmap(start, length, prot, flags, fd, offset);
 120                 if (ret == MAP_FAILED)
 121                         die_errno("Out of memory? mmap failed");
 122         }
 123         return ret;
 124 }
 125
 126 /*
 127  * xread() is the same a read(), but it automatically restarts read()
 128  * operations with a recoverable error (EAGAIN and EINTR). xread()
 129  * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
 130  */
 131 ssize_t xread(int fd, void *buf, size_t len)
 132 {
 133         ssize_t nr;
 134         while (1) {
 135                 nr = read(fd, buf, len);
 136                 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
 137                         continue;
 138                 return nr;
 139         }
 140 }
 141
 142 /*
 143  * xwrite() is the same a write(), but it automatically restarts write()
 144  * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
 145  * GUARANTEE that "len" bytes is written even if the operation is successful.
 146  */
 147 ssize_t xwrite(int fd, const void *buf, size_t len)
 148 {
 149         ssize_t nr;
 150         while (1) {
 151                 nr = write(fd, buf, len);
 152                 if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
 153                         continue;
 154                 return nr;
 155         }
 156 }
 157
 158 ssize_t read_in_full(int fd, void *buf, size_t count)
 159 {
 160         char *p = buf;
 161         ssize_t total = 0;
 162
 163         while (count > 0) {
 164                 ssize_t loaded = xread(fd, p, count);
 165                 if (loaded <= 0)
 166                         return total ? total : loaded;
 167                 count -= loaded;
 168                 p += loaded;
 169                 total += loaded;
 170         }
 171
 172         return total;
 173 }
 174
 175 ssize_t write_in_full(int fd, const void *buf, size_t count)
 176 {
 177         const char *p = buf;
 178         ssize_t total = 0;
 179
 180         while (count > 0) {
 181                 ssize_t written = xwrite(fd, p, count);
 182                 if (written < 0)
 183                         return -1;
 184                 if (!written) {
 185                         errno = ENOSPC;
 186                         return -1;
 187                 }
 188                 count -= written;
 189                 p += written;
 190                 total += written;
 191         }
 192
 193         return total;
 194 }
 195
 196 int xdup(int fd)
 197 {
 198         int ret = dup(fd);
 199         if (ret < 0)
 200                 die_errno("dup failed");
 201         return ret;
 202 }
 203
 204 FILE *xfdopen(int fd, const char *mode)
 205 {
 206         FILE *stream = fdopen(fd, mode);
 207         if (stream == NULL)
 208                 die_errno("Out of memory? fdopen failed");
 209         return stream;
 210 }
 211
 212 int xmkstemp(char *template)
 213 {
 214         int fd;
 215
 216         fd = mkstemp(template);
 217         if (fd < 0)
 218                 die_errno("Unable to create temporary file");
 219         return fd;
 220 }
 221
 222 int xmkstemp_mode(char *template, int mode)
 223 {
 224         int fd;
 225
 226         fd = git_mkstemp_mode(template, mode);
 227         if (fd < 0)
 228                 die_errno("Unable to create temporary file");
 229         return fd;
 230 }
 231
 232 /*
 233  * zlib wrappers to make sure we don't silently miss errors
 234  * at init time.
 235  */
 236 void git_inflate_init(z_streamp strm)
 237 {
 238         const char *err;
 239
 240         switch (inflateInit(strm)) {
 241         case Z_OK:
 242                 return;
 243
 244         case Z_MEM_ERROR:
 245                 err = "out of memory";
 246                 break;
 247         case Z_VERSION_ERROR:
 248                 err = "wrong version";
 249                 break;
 250         default:
 251                 err = "error";
 252         }
 253         die("inflateInit: %s (%s)", err, strm->msg ? strm->msg : "no message");
 254 }
 255
 256 void git_inflate_end(z_streamp strm)
 257 {
 258         if (inflateEnd(strm) != Z_OK)
 259                 error("inflateEnd: %s", strm->msg ? strm->msg : "failed");
 260 }
 261
 262 int git_inflate(z_streamp strm, int flush)
 263 {
 264         int ret = inflate(strm, flush);
 265         const char *err;
 266
 267         switch (ret) {
 268         /* Out of memory is fatal. */
 269         case Z_MEM_ERROR:
 270                 die("inflate: out of memory");
 271
 272         /* Data corruption errors: we may want to recover from them (fsck) */
 273         case Z_NEED_DICT:
 274                 err = "needs dictionary"; break;
 275         case Z_DATA_ERROR:
 276                 err = "data stream error"; break;
 277         case Z_STREAM_ERROR:
 278                 err = "stream consistency error"; break;
 279         default:
 280                 err = "unknown error"; break;
 281
 282         /* Z_BUF_ERROR: normal, needs more space in the output buffer */
 283         case Z_BUF_ERROR:
 284         case Z_OK:
 285         case Z_STREAM_END:
 286                 return ret;
 287         }
 288         error("inflate: %s (%s)", err, strm->msg ? strm->msg : "no message");
 289         return ret;
 290 }
 291
 292 int odb_mkstemp(char *template, size_t limit, const char *pattern)
 293 {
 294         int fd;
 295         /*
 296          * we let the umask do its job, don't try to be more
 297          * restrictive except to remove write permission.
 298          */
 299         int mode = 0444;
 300         snprintf(template, limit, "%s/%s",
 301                  get_object_directory(), pattern);
 302         fd = git_mkstemp_mode(template, mode);
 303         if (0 <= fd)
 304                 return fd;
 305
 306         /* slow path */
 307         /* some mkstemp implementations erase template on failure */
 308         snprintf(template, limit, "%s/%s",
 309                  get_object_directory(), pattern);
 310         safe_create_leading_directories(template);
 311         return xmkstemp_mode(template, mode);
 312 }
 313
 314 int odb_pack_keep(char *name, size_t namesz, unsigned char *sha1)
 315 {
 316         int fd;
 317
 318         snprintf(name, namesz, "%s/pack/pack-%s.keep",
 319                  get_object_directory(), sha1_to_hex(sha1));
 320         fd = open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 321         if (0 <= fd)
 322                 return fd;
 323
 324         /* slow path */
 325         safe_create_leading_directories(name);
 326         return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 327 }
 328
 329 static int warn_if_unremovable(const char *op, const char *file, int rc)
 330 {
 331         if (rc < 0) {
 332                 int err = errno;
 333                 if (ENOENT != err) {
 334                         warning("unable to %s %s: %s",
 335                                 op, file, strerror(errno));
 336                         errno = err;
 337                 }
 338         }
 339         return rc;
 340 }
 341
 342 int unlink_or_warn(const char *file)
 343 {
 344         return warn_if_unremovable("unlink", file, unlink(file));
 345 }
 346
 347 int rmdir_or_warn(const char *file)
 348 {
 349         return warn_if_unremovable("rmdir", file, rmdir(file));
 350 }
 351
 352 int remove_or_warn(unsigned int mode, const char *file)
 353 {
 354         return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
 355 }