tree.con commit sha1-lookup: make selection of 'middle' less aggressive (12ecb01)
   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
   9const char *tree_type = "tree";
  10
  11static 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
  32static 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 */
  42static 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
  48static 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
  92int 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
 139static 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, ce1->ce_flags,
 146                                  ce2->name, ce2->ce_flags);
 147}
 148
 149int 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
 190struct 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
 205int parse_tree_buffer(struct tree *item, void *buffer, unsigned long size)
 206{
 207        if (item->object.parsed)
 208                return 0;
 209        item->object.parsed = 1;
 210        item->buffer = buffer;
 211        item->size = size;
 212
 213        return 0;
 214}
 215
 216int parse_tree(struct tree *item)
 217{
 218         enum object_type type;
 219         void *buffer;
 220         unsigned long size;
 221
 222        if (item->object.parsed)
 223                return 0;
 224        buffer = read_sha1_file(item->object.sha1, &type, &size);
 225        if (!buffer)
 226                return error("Could not read %s",
 227                             sha1_to_hex(item->object.sha1));
 228        if (type != OBJ_TREE) {
 229                free(buffer);
 230                return error("Object %s not a tree",
 231                             sha1_to_hex(item->object.sha1));
 232        }
 233        return parse_tree_buffer(item, buffer, size);
 234}
 235
 236struct tree *parse_tree_indirect(const unsigned char *sha1)
 237{
 238        struct object *obj = parse_object(sha1);
 239        do {
 240                if (!obj)
 241                        return NULL;
 242                if (obj->type == OBJ_TREE)
 243                        return (struct tree *) obj;
 244                else if (obj->type == OBJ_COMMIT)
 245                        obj = &(((struct commit *) obj)->tree->object);
 246                else if (obj->type == OBJ_TAG)
 247                        obj = ((struct tag *) obj)->tagged;
 248                else
 249                        return NULL;
 250                if (!obj->parsed)
 251                        parse_object(obj->sha1);
 252        } while (1);
 253}