refs.con commit Fix sparse warnings. (6da4016)
   1#include "refs.h"
   2#include "cache.h"
   3
   4#include <errno.h>
   5
   6static int read_ref(const char *path, unsigned char *sha1)
   7{
   8        int ret = -1;
   9        int fd = open(path, O_RDONLY);
  10
  11        if (fd >= 0) {
  12                char buffer[60];
  13                if (read(fd, buffer, sizeof(buffer)) >= 40)
  14                        ret = get_sha1_hex(buffer, sha1);
  15                close(fd);
  16        }
  17        return ret;
  18}
  19
  20static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1))
  21{
  22        int retval = 0;
  23        DIR *dir = opendir(base);
  24
  25        if (dir) {
  26                struct dirent *de;
  27                int baselen = strlen(base);
  28                char *path = xmalloc(baselen + 257);
  29                memcpy(path, base, baselen);
  30                if (baselen && base[baselen-1] != '/')
  31                        path[baselen++] = '/';
  32
  33                while ((de = readdir(dir)) != NULL) {
  34                        unsigned char sha1[20];
  35                        struct stat st;
  36                        int namelen;
  37
  38                        if (de->d_name[0] == '.')
  39                                continue;
  40                        namelen = strlen(de->d_name);
  41                        if (namelen > 255)
  42                                continue;
  43                        memcpy(path + baselen, de->d_name, namelen+1);
  44                        if (lstat(path, &st) < 0)
  45                                continue;
  46                        if (S_ISDIR(st.st_mode)) {
  47                                retval = do_for_each_ref(path, fn);
  48                                if (retval)
  49                                        break;
  50                                continue;
  51                        }
  52                        if (read_ref(path, sha1) < 0)
  53                                continue;
  54                        if (!has_sha1_file(sha1))
  55                                continue;
  56                        retval = fn(path, sha1);
  57                        if (retval)
  58                                break;
  59                }
  60                free(path);
  61                closedir(dir);
  62        }
  63        return retval;
  64}
  65
  66int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1))
  67{
  68        return do_for_each_ref(get_refs_directory(), fn);
  69}
  70
  71static char *ref_file_name(const char *ref)
  72{
  73        char *base = get_refs_directory();
  74        int baselen = strlen(base);
  75        int reflen = strlen(ref);
  76        char *ret = xmalloc(baselen + 2 + reflen);
  77        sprintf(ret, "%s/%s", base, ref);
  78        return ret;
  79}
  80
  81static char *ref_lock_file_name(const char *ref)
  82{
  83        char *base = get_refs_directory();
  84        int baselen = strlen(base);
  85        int reflen = strlen(ref);
  86        char *ret = xmalloc(baselen + 7 + reflen);
  87        sprintf(ret, "%s/%s.lock", base, ref);
  88        return ret;
  89}
  90
  91static int read_ref_file(const char *filename, unsigned char *sha1) {
  92        int fd = open(filename, O_RDONLY);
  93        char hex[41];
  94        if (fd < 0) {
  95                return error("Couldn't open %s\n", filename);
  96        }
  97        if ((read(fd, hex, 41) < 41) ||
  98            (hex[40] != '\n') ||
  99            get_sha1_hex(hex, sha1)) {
 100                error("Couldn't read a hash from %s\n", filename);
 101                close(fd);
 102                return -1;
 103        }
 104        close(fd);
 105        return 0;
 106}
 107
 108int get_ref_sha1(const char *ref, unsigned char *sha1)
 109{
 110        char *filename;
 111        int retval;
 112        if (check_ref_format(ref))
 113                return -1;
 114        filename = ref_file_name(ref);
 115        retval = read_ref_file(filename, sha1);
 116        free(filename);
 117        return retval;
 118}
 119
 120static int lock_ref_file(const char *filename, const char *lock_filename,
 121                         const unsigned char *old_sha1)
 122{
 123        int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
 124        unsigned char current_sha1[20];
 125        int retval;
 126        if (fd < 0) {
 127                return error("Couldn't open lock file for %s: %s",
 128                             filename, strerror(errno));
 129        }
 130        retval = read_ref_file(filename, current_sha1);
 131        if (old_sha1) {
 132                if (retval) {
 133                        close(fd);
 134                        unlink(lock_filename);
 135                        return error("Could not read the current value of %s",
 136                                     filename);
 137                }
 138                if (memcmp(current_sha1, old_sha1, 20)) {
 139                        close(fd);
 140                        unlink(lock_filename);
 141                        error("The current value of %s is %s",
 142                              filename, sha1_to_hex(current_sha1));
 143                        return error("Expected %s",
 144                                     sha1_to_hex(old_sha1));
 145                }
 146        } else {
 147                if (!retval) {
 148                        close(fd);
 149                        unlink(lock_filename);
 150                        return error("Unexpectedly found a value of %s for %s",
 151                                     sha1_to_hex(current_sha1), filename);
 152                }
 153        }
 154        return fd;
 155}
 156
 157int lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
 158{
 159        char *filename;
 160        char *lock_filename;
 161        int retval;
 162        if (check_ref_format(ref))
 163                return -1;
 164        filename = ref_file_name(ref);
 165        lock_filename = ref_lock_file_name(ref);
 166        retval = lock_ref_file(filename, lock_filename, old_sha1);
 167        free(filename);
 168        free(lock_filename);
 169        return retval;
 170}
 171
 172static int write_ref_file(const char *filename,
 173                          const char *lock_filename, int fd,
 174                          const unsigned char *sha1)
 175{
 176        char *hex = sha1_to_hex(sha1);
 177        char term = '\n';
 178        if (write(fd, hex, 40) < 40 ||
 179            write(fd, &term, 1) < 1) {
 180                error("Couldn't write %s\n", filename);
 181                close(fd);
 182                return -1;
 183        }
 184        close(fd);
 185        rename(lock_filename, filename);
 186        return 0;
 187}
 188
 189int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1)
 190{
 191        char *filename;
 192        char *lock_filename;
 193        int retval;
 194        if (fd < 0)
 195                return -1;
 196        if (check_ref_format(ref))
 197                return -1;
 198        filename = ref_file_name(ref);
 199        lock_filename = ref_lock_file_name(ref);
 200        retval = write_ref_file(filename, lock_filename, fd, sha1);
 201        free(filename);
 202        free(lock_filename);
 203        return retval;
 204}
 205
 206int check_ref_format(const char *ref)
 207{
 208        char *middle;
 209        if (ref[0] == '.' || ref[0] == '/')
 210                return -1;
 211        middle = strchr(ref, '/');
 212        if (!middle || !middle[1])
 213                return -1;
 214        if (strchr(middle + 1, '/'))
 215                return -1;
 216        return 0;
 217}
 218
 219int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1)
 220{
 221        char *filename;
 222        char *lock_filename;
 223        int fd;
 224        int retval;
 225        if (check_ref_format(ref))
 226                return -1;
 227        filename = ref_file_name(ref);
 228        lock_filename = ref_lock_file_name(ref);
 229        fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
 230        if (fd < 0) {
 231                error("Writing %s", lock_filename);
 232                perror("Open");
 233        }
 234        retval = write_ref_file(filename, lock_filename, fd, sha1);
 235        free(filename);
 236        free(lock_filename);
 237        return retval;
 238}