Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "diff.h"
   3
   4static int recursive = 0;
   5static int line_termination = '\n';
   6static int generate_patch = 0;
   7
   8// What paths are we interested in?
   9static int nr_paths = 0;
  10static char **paths = NULL;
  11static int *pathlens = NULL;
  12
  13static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
  14
  15static void update_tree_entry(void **bufp, unsigned long *sizep)
  16{
  17        void *buf = *bufp;
  18        unsigned long size = *sizep;
  19        int len = strlen(buf) + 1 + 20;
  20
  21        if (size < len)
  22                die("corrupt tree file");
  23        *bufp = buf + len;
  24        *sizep = size - len;
  25}
  26
  27static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
  28{
  29        int len = strlen(tree)+1;
  30        const unsigned char *sha1 = tree + len;
  31        const char *path = strchr(tree, ' ');
  32
  33        if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
  34                die("corrupt tree file");
  35        *pathp = path+1;
  36        return sha1;
  37}
  38
  39static char *malloc_base(const char *base, const char *path, int pathlen)
  40{
  41        int baselen = strlen(base);
  42        char *newbase = xmalloc(baselen + pathlen + 2);
  43        memcpy(newbase, base, baselen);
  44        memcpy(newbase + baselen, path, pathlen);
  45        memcpy(newbase + baselen + pathlen, "/", 2);
  46        return newbase;
  47}
  48
  49static void show_file(const char *prefix, void *tree, unsigned long size, const char *base);
  50
  51/* A whole sub-tree went away or appeared */
  52static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
  53{
  54        while (size) {
  55                show_file(prefix, tree, size, base);
  56                update_tree_entry(&tree, &size);
  57        }
  58}
  59
  60/* A file entry went away or appeared */
  61static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
  62{
  63        unsigned mode;
  64        const char *path;
  65        const unsigned char *sha1 = extract(tree, size, &path, &mode);
  66
  67        if (recursive && S_ISDIR(mode)) {
  68                char type[20];
  69                unsigned long size;
  70                char *newbase = malloc_base(base, path, strlen(path));
  71                void *tree;
  72
  73                tree = read_sha1_file(sha1, type, &size);
  74                if (!tree || strcmp(type, "tree"))
  75                        die("corrupt tree sha %s", sha1_to_hex(sha1));
  76
  77                show_tree(prefix, tree, size, newbase);
  78                
  79                free(tree);
  80                free(newbase);
  81                return;
  82        }
  83
  84        if (generate_patch) {
  85                if (!S_ISDIR(mode))
  86                        diff_addremove(prefix[0], mode, sha1, base, path);
  87        }
  88        else
  89                printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
  90                       S_ISDIR(mode) ? "tree" : "blob",
  91                       sha1_to_hex(sha1), base, path,
  92                       line_termination);
  93}
  94
  95static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
  96{
  97        unsigned mode1, mode2;
  98        const char *path1, *path2;
  99        const unsigned char *sha1, *sha2;
 100        int cmp, pathlen1, pathlen2;
 101        char old_sha1_hex[50];
 102
 103        sha1 = extract(tree1, size1, &path1, &mode1);
 104        sha2 = extract(tree2, size2, &path2, &mode2);
 105
 106        pathlen1 = strlen(path1);
 107        pathlen2 = strlen(path2);
 108        cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
 109        if (cmp < 0) {
 110                show_file("-", tree1, size1, base);
 111                return -1;
 112        }
 113        if (cmp > 0) {
 114                show_file("+", tree2, size2, base);
 115                return 1;
 116        }
 117        if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
 118                return 0;
 119
 120        /*
 121         * If the filemode has changed to/from a directory from/to a regular
 122         * file, we need to consider it a remove and an add.
 123         */
 124        if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
 125                show_file("-", tree1, size1, base);
 126                show_file("+", tree2, size2, base);
 127                return 0;
 128        }
 129
 130        if (recursive && S_ISDIR(mode1)) {
 131                int retval;
 132                char *newbase = malloc_base(base, path1, pathlen1);
 133                retval = diff_tree_sha1(sha1, sha2, newbase);
 134                free(newbase);
 135                return retval;
 136        }
 137
 138        if (generate_patch) {
 139                if (!S_ISDIR(mode1))
 140                        diff_change(mode1, mode2, sha1, sha2, base, path1);
 141        }
 142        else {
 143                strcpy(old_sha1_hex, sha1_to_hex(sha1));
 144                printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
 145                       S_ISDIR(mode1) ? "tree" : "blob",
 146                       old_sha1_hex, sha1_to_hex(sha2), base, path1,
 147                       line_termination);
 148        }
 149        return 0;
 150}
 151
 152static int interesting(void *tree, unsigned long size, const char *base)
 153{
 154        const char *path;
 155        unsigned mode;
 156        int i;
 157        int baselen, pathlen;
 158
 159        if (!nr_paths)
 160                return 1;
 161
 162        (void)extract(tree, size, &path, &mode);
 163
 164        pathlen = strlen(path);
 165        baselen = strlen(base);
 166
 167        for (i=0; i < nr_paths; i++) {
 168                const char *match = paths[i];
 169                int matchlen = pathlens[i];
 170
 171                if (baselen >= matchlen) {
 172                        /* If it doesn't match, move along... */
 173                        if (strncmp(base, match, matchlen))
 174                                continue;
 175
 176                        /* The base is a subdirectory of a path which was specified. */
 177                        return 1;
 178                }
 179
 180                /* Does the base match? */
 181                if (strncmp(base, match, baselen))
 182                        continue;
 183
 184                match += baselen;
 185                matchlen -= baselen;
 186
 187                if (pathlen > matchlen)
 188                        continue;
 189
 190                if (strncmp(path, match, pathlen))
 191                        continue;
 192
 193                return 1;
 194        }
 195        return 0; /* No matches */
 196}
 197
 198static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 199{
 200        while (size1 | size2) {
 201                if (nr_paths && size1 && !interesting(tree1, size1, base)) {
 202                        update_tree_entry(&tree1, &size1);
 203                        continue;
 204                }
 205                if (nr_paths && size2 && !interesting(tree2, size2, base)) {
 206                        update_tree_entry(&tree2, &size2);
 207                        continue;
 208                }
 209                if (!size1) {
 210                        show_file("+", tree2, size2, base);
 211                        update_tree_entry(&tree2, &size2);
 212                        continue;
 213                }
 214                if (!size2) {
 215                        show_file("-", tree1, size1, base);
 216                        update_tree_entry(&tree1, &size1);
 217                        continue;
 218                }
 219                switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
 220                case -1:
 221                        update_tree_entry(&tree1, &size1);
 222                        continue;
 223                case 0:
 224                        update_tree_entry(&tree1, &size1);
 225                        /* Fallthrough */
 226                case 1:
 227                        update_tree_entry(&tree2, &size2);
 228                        continue;
 229                }
 230                die("diff-tree: internal error");
 231        }
 232        return 0;
 233}
 234
 235static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 236{
 237        void *tree1, *tree2;
 238        unsigned long size1, size2;
 239        int retval;
 240
 241        tree1 = read_object_with_reference(old, "tree", &size1, 0);
 242        if (!tree1)
 243                die("unable to read source tree (%s)", sha1_to_hex(old));
 244        tree2 = read_object_with_reference(new, "tree", &size2, 0);
 245        if (!tree2)
 246                die("unable to read destination tree (%s)", sha1_to_hex(new));
 247        retval = diff_tree(tree1, size1, tree2, size2, base);
 248        free(tree1);
 249        free(tree2);
 250        return retval;
 251}
 252
 253static char *diff_tree_usage = "diff-tree [-r] [-z] <tree sha1> <tree sha1>";
 254
 255int main(int argc, char **argv)
 256{
 257        unsigned char old[20], new[20];
 258
 259        for (;;) {
 260                char *arg = argv[1];
 261
 262                if (!arg || *arg != '-')
 263                        break;
 264
 265                argv++;
 266                argc--;
 267                if (!strcmp(arg, "-r")) {
 268                        recursive = 1;
 269                        continue;
 270                }
 271                if (!strcmp(arg, "-p")) {
 272                        recursive = generate_patch = 1;
 273                        continue;
 274                }
 275                if (!strcmp(arg, "-z")) {
 276                        line_termination = '\0';
 277                        continue;
 278                }
 279                usage(diff_tree_usage);
 280        }
 281
 282        if (argc < 3 || get_sha1_hex(argv[1], old) || get_sha1_hex(argv[2], new))
 283                usage(diff_tree_usage);
 284
 285        if (argc > 3) {
 286                int i;
 287
 288                paths = &argv[3];
 289                nr_paths = argc - 3;
 290                pathlens = xmalloc(nr_paths * sizeof(int));
 291                for (i=0; i<nr_paths; i++)
 292                        pathlens[i] = strlen(paths[i]);
 293        }
 294
 295        return diff_tree_sha1(old, new, "");
 296}