Andrew's git - gitweb.git/blob

   1/*
   2 * Various trivial helper wrappers around standard functions
   3 */
   4#include "cache.h"
   5
   6static void try_to_free_builtin(size_t size)
   7{
   8        release_pack_memory(size, -1);
   9}
  10
  11static void (*try_to_free_routine)(size_t size) = try_to_free_builtin;
  12
  13void set_try_to_free_routine(void (*routine)(size_t))
  14{
  15        try_to_free_routine = (routine) ? routine : try_to_free_builtin;
  16}
  17
  18char *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
  30void *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
  49void *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 */
  65void *xmemdupz(const void *data, size_t len)
  66{
  67        return memcpy(xmallocz(len), data, len);
  68}
  69
  70char *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
  76void *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
  92void *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
 108void *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 */
 128ssize_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 */
 144ssize_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
 155ssize_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
 172ssize_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
 193int xdup(int fd)
 194{
 195        int ret = dup(fd);
 196        if (ret < 0)
 197                die_errno("dup failed");
 198        return ret;
 199}
 200
 201FILE *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
 209int 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
 219int 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 */
 233void 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
 253void git_inflate_end(z_streamp strm)
 254{
 255        if (inflateEnd(strm) != Z_OK)
 256                error("inflateEnd: %s", strm->msg ? strm->msg : "failed");
 257}
 258
 259int 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
 289int 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
 311int 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
 326static 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
 339int unlink_or_warn(const char *file)
 340{
 341        return warn_if_unremovable("unlink", file, unlink(file));
 342}
 343
 344int rmdir_or_warn(const char *file)
 345{
 346        return warn_if_unremovable("rmdir", file, rmdir(file));
 347}
 348
 349int remove_or_warn(unsigned int mode, const char *file)
 350{
 351        return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
 352}