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