tree.c

   1 #include "cache.h"
   2 #include "cache-tree.h"
   3 #include "tree.h"
   4 #include "blob.h"
   5 #include "commit.h"
   6 #include "tag.h"
   7 #include "tree-walk.h"
   8
   9 const char *tree_type = "tree";
  10
  11 static int read_one_entry_opt(const unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage, int opt)
  12 {
  13         int len;
  14         unsigned int size;
  15         struct cache_entry *ce;
  16
  17         if (S_ISDIR(mode))
  18                 return READ_TREE_RECURSIVE;
  19
  20         len = strlen(pathname);
  21         size = cache_entry_size(baselen + len);
  22         ce = xcalloc(1, size);
  23
  24         ce->ce_mode = create_ce_mode(mode);
  25         ce->ce_flags = create_ce_flags(baselen + len, stage);
  26         memcpy(ce->name, base, baselen);
  27         memcpy(ce->name + baselen, pathname, len+1);
  28         hashcpy(ce->sha1, sha1);
  29         return add_cache_entry(ce, opt);
  30 }
  31
  32 static int read_one_entry(const unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
  33 {
  34         return read_one_entry_opt(sha1, base, baselen, pathname, mode, stage,
  35                                   ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
  36 }
  37
  38 /*
  39  * This is used when the caller knows there is no existing entries at
  40  * the stage that will conflict with the entry being added.
  41  */
  42 static int read_one_entry_quick(const unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage)
  43 {
  44         return read_one_entry_opt(sha1, base, baselen, pathname, mode, stage,
  45                                   ADD_CACHE_JUST_APPEND);
  46 }
  47
  48 static int match_tree_entry(const char *base, int baselen, const char *path, unsigned int mode, const char **paths)
  49 {
  50         const char *match;
  51         int pathlen;
  52
  53         if (!paths)
  54                 return 1;
  55         pathlen = strlen(path);
  56         while ((match = *paths++) != NULL) {
  57                 int matchlen = strlen(match);
  58
  59                 if (baselen >= matchlen) {
  60                         /* If it doesn't match, move along... */
  61                         if (strncmp(base, match, matchlen))
  62                                 continue;
  63                         /* The base is a subdirectory of a path which was specified. */
  64                         return 1;
  65                 }
  66
  67                 /* Does the base match? */
  68                 if (strncmp(base, match, baselen))
  69                         continue;
  70
  71                 match += baselen;
  72                 matchlen -= baselen;
  73
  74                 if (pathlen > matchlen)
  75                         continue;
  76
  77                 if (matchlen > pathlen) {
  78                         if (match[pathlen] != '/')
  79                                 continue;
  80                         if (!S_ISDIR(mode))
  81                                 continue;
  82                 }
  83
  84                 if (strncmp(path, match, pathlen))
  85                         continue;
  86
  87                 return 1;
  88         }
  89         return 0;
  90 }
  91
  92 int read_tree_recursive(struct tree *tree,
  93                         const char *base, int baselen,
  94                         int stage, const char **match,
  95                         read_tree_fn_t fn)
  96 {
  97         struct tree_desc desc;
  98         struct name_entry entry;
  99
 100         if (parse_tree(tree))
 101                 return -1;
 102
 103         init_tree_desc(&desc, tree->buffer, tree->size);
 104
 105         while (tree_entry(&desc, &entry)) {
 106                 if (!match_tree_entry(base, baselen, entry.path, entry.mode, match))
 107                         continue;
 108
 109                 switch (fn(entry.sha1, base, baselen, entry.path, entry.mode, stage)) {
 110                 case 0:
 111                         continue;
 112                 case READ_TREE_RECURSIVE:
 113                         break;;
 114                 default:
 115                         return -1;
 116                 }
 117                 if (S_ISDIR(entry.mode)) {
 118                         int retval;
 119                         char *newbase;
 120                         unsigned int pathlen = tree_entry_len(entry.path, entry.sha1);
 121
 122                         newbase = xmalloc(baselen + 1 + pathlen);
 123                         memcpy(newbase, base, baselen);
 124                         memcpy(newbase + baselen, entry.path, pathlen);
 125                         newbase[baselen + pathlen] = '/';
 126                         retval = read_tree_recursive(lookup_tree(entry.sha1),
 127                                                      newbase,
 128                                                      baselen + pathlen + 1,
 129                                                      stage, match, fn);
 130                         free(newbase);
 131                         if (retval)
 132                                 return -1;
 133                         continue;
 134                 }
 135         }
 136         return 0;
 137 }
 138
 139 static int cmp_cache_name_compare(const void *a_, const void *b_)
 140 {
 141         const struct cache_entry *ce1, *ce2;
 142
 143         ce1 = *((const struct cache_entry **)a_);
 144         ce2 = *((const struct cache_entry **)b_);
 145         return cache_name_compare(ce1->name, ntohs(ce1->ce_flags),
 146                                   ce2->name, ntohs(ce2->ce_flags));
 147 }
 148
 149 int read_tree(struct tree *tree, int stage, const char **match)
 150 {
 151         read_tree_fn_t fn = NULL;
 152         int i, err;
 153
 154         /*
 155          * Currently the only existing callers of this function all
 156          * call it with stage=1 and after making sure there is nothing
 157          * at that stage; we could always use read_one_entry_quick().
 158          *
 159          * But when we decide to straighten out git-read-tree not to
 160          * use unpack_trees() in some cases, this will probably start
 161          * to matter.
 162          */
 163
 164         /*
 165          * See if we have cache entry at the stage.  If so,
 166          * do it the original slow way, otherwise, append and then
 167          * sort at the end.
 168          */
 169         for (i = 0; !fn && i < active_nr; i++) {
 170                 struct cache_entry *ce = active_cache[i];
 171                 if (ce_stage(ce) == stage)
 172                         fn = read_one_entry;
 173         }
 174
 175         if (!fn)
 176                 fn = read_one_entry_quick;
 177         err = read_tree_recursive(tree, "", 0, stage, match, fn);
 178         if (fn == read_one_entry || err)
 179                 return err;
 180
 181         /*
 182          * Sort the cache entry -- we need to nuke the cache tree, though.
 183          */
 184         cache_tree_free(&active_cache_tree);
 185         qsort(active_cache, active_nr, sizeof(active_cache[0]),
 186               cmp_cache_name_compare);
 187         return 0;
 188 }
 189
 190 struct tree *lookup_tree(const unsigned char *sha1)
 191 {
 192         struct object *obj = lookup_object(sha1);
 193         if (!obj)
 194                 return create_object(sha1, OBJ_TREE, alloc_tree_node());
 195         if (!obj->type)
 196                 obj->type = OBJ_TREE;
 197         if (obj->type != OBJ_TREE) {
 198                 error("Object %s is a %s, not a tree",
 199                       sha1_to_hex(sha1), typename(obj->type));
 200                 return NULL;
 201         }
 202         return (struct tree *) obj;
 203 }
 204
 205 /*
 206  * NOTE! Tree refs to external git repositories
 207  * (ie gitlinks) do not count as real references.
 208  *
 209  * You don't have to have those repositories
 210  * available at all, much less have the objects
 211  * accessible from the current repository.
 212  */
 213 static void track_tree_refs(struct tree *item)
 214 {
 215         int n_refs = 0, i;
 216         struct object_refs *refs;
 217         struct tree_desc desc;
 218         struct name_entry entry;
 219
 220         /* Count how many entries there are.. */
 221         init_tree_desc(&desc, item->buffer, item->size);
 222         while (tree_entry(&desc, &entry)) {
 223                 if (S_ISGITLINK(entry.mode))
 224                         continue;
 225                 n_refs++;
 226         }
 227
 228         /* Allocate object refs and walk it again.. */
 229         i = 0;
 230         refs = alloc_object_refs(n_refs);
 231         init_tree_desc(&desc, item->buffer, item->size);
 232         while (tree_entry(&desc, &entry)) {
 233                 struct object *obj;
 234
 235                 if (S_ISGITLINK(entry.mode))
 236                         continue;
 237                 if (S_ISDIR(entry.mode))
 238                         obj = &lookup_tree(entry.sha1)->object;
 239                 else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode))
 240                         obj = &lookup_blob(entry.sha1)->object;
 241                 else {
 242                         warning("in tree %s: entry %s has bad mode %.6o\n",
 243                              sha1_to_hex(item->object.sha1), entry.path, entry.mode);
 244                         obj = lookup_unknown_object(entry.sha1);
 245                 }
 246                 refs->ref[i++] = obj;
 247         }
 248         set_object_refs(&item->object, refs);
 249 }
 250
 251 int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
 252 {
 253         if (item->object.parsed)
 254                 return 0;
 255         item->object.parsed = 1;
 256         item->buffer = buffer;
 257         item->size = size;
 258
 259         if (track_object_refs)
 260                 track_tree_refs(item);
 261         return 0;
 262 }
 263
 264 int parse_tree(struct tree *item)
 265 {
 266          enum object_type type;
 267          void *buffer;
 268          unsigned long size;
 269
 270         if (item->object.parsed)
 271                 return 0;
 272         buffer = read_sha1_file(item->object.sha1, &type, &size);
 273         if (!buffer)
 274                 return error("Could not read %s",
 275                              sha1_to_hex(item->object.sha1));
 276         if (type != OBJ_TREE) {
 277                 free(buffer);
 278                 return error("Object %s not a tree",
 279                              sha1_to_hex(item->object.sha1));
 280         }
 281         return parse_tree_buffer(item, buffer, size);
 282 }
 283
 284 struct tree *parse_tree_indirect(const unsigned char *sha1)
 285 {
 286         struct object *obj = parse_object(sha1);
 287         do {
 288                 if (!obj)
 289                         return NULL;
 290                 if (obj->type == OBJ_TREE)
 291                         return (struct tree *) obj;
 292                 else if (obj->type == OBJ_COMMIT)
 293                         obj = &(((struct commit *) obj)->tree->object);
 294                 else if (obj->type == OBJ_TAG)
 295                         obj = ((struct tag *) obj)->tagged;
 296                 else
 297                         return NULL;
 298                 if (!obj->parsed)
 299                         parse_object(obj->sha1);
 300         } while (1);
 301 }