Cumulative update of merge-recursive in C
[gitweb.git] / cache-tree.c
index 2146723e90ffc0b52387bf44cbd60908b3261b26..d9f7e1e3dd598d34e08d6370544b562daf4640d2 100644 (file)
@@ -19,41 +19,84 @@ void cache_tree_free(struct cache_tree **it_p)
        if (!it)
                return;
        for (i = 0; i < it->subtree_nr; i++)
-               cache_tree_free(&it->down[i]->cache_tree);
+               if (it->down[i])
+                       cache_tree_free(&it->down[i]->cache_tree);
        free(it->down);
        free(it);
        *it_p = NULL;
 }
 
+static int subtree_name_cmp(const char *one, int onelen,
+                           const char *two, int twolen)
+{
+       if (onelen < twolen)
+               return -1;
+       if (twolen < onelen)
+               return 1;
+       return memcmp(one, two, onelen);
+}
+
+static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
+{
+       struct cache_tree_sub **down = it->down;
+       int lo, hi;
+       lo = 0;
+       hi = it->subtree_nr;
+       while (lo < hi) {
+               int mi = (lo + hi) / 2;
+               struct cache_tree_sub *mdl = down[mi];
+               int cmp = subtree_name_cmp(path, pathlen,
+                                          mdl->name, mdl->namelen);
+               if (!cmp)
+                       return mi;
+               if (cmp < 0)
+                       hi = mi;
+               else
+                       lo = mi + 1;
+       }
+       return -lo-1;
+}
+
 static struct cache_tree_sub *find_subtree(struct cache_tree *it,
                                           const char *path,
                                           int pathlen,
                                           int create)
 {
-       int i;
        struct cache_tree_sub *down;
-       for (i = 0; i < it->subtree_nr; i++) {
-               down = it->down[i];
-               if (down->namelen == pathlen &&
-                   !memcmp(down->name, path, pathlen))
-                       return down;
-       }
+       int pos = subtree_pos(it, path, pathlen);
+       if (0 <= pos)
+               return it->down[pos];
        if (!create)
                return NULL;
+
+       pos = -pos-1;
        if (it->subtree_alloc <= it->subtree_nr) {
                it->subtree_alloc = alloc_nr(it->subtree_alloc);
                it->down = xrealloc(it->down, it->subtree_alloc *
                                    sizeof(*it->down));
        }
+       it->subtree_nr++;
+
        down = xmalloc(sizeof(*down) + pathlen + 1);
-       down->cache_tree = NULL; /* cache_tree(); */
+       down->cache_tree = NULL;
        down->namelen = pathlen;
        memcpy(down->name, path, pathlen);
-       down->name[pathlen] = 0; /* not strictly needed */
-       it->down[it->subtree_nr++] = down;
+       down->name[pathlen] = 0;
+
+       if (pos < it->subtree_nr)
+               memmove(it->down + pos + 1,
+                       it->down + pos,
+                       sizeof(down) * (it->subtree_nr - pos - 1));
+       it->down[pos] = down;
        return down;
 }
 
+struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
+{
+       int pathlen = strlen(path);
+       return find_subtree(it, path, pathlen, 1);
+}
+
 void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
 {
        /* a/b/c
@@ -67,30 +110,30 @@ void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
        int namelen;
        struct cache_tree_sub *down;
 
+#if DEBUG
+       fprintf(stderr, "cache-tree invalidate <%s>\n", path);
+#endif
+
        if (!it)
                return;
        slash = strchr(path, '/');
        it->entry_count = -1;
        if (!slash) {
-               int i;
+               int pos;
                namelen = strlen(path);
-               for (i = 0; i < it->subtree_nr; i++) {
-                       if (it->down[i]->namelen == namelen &&
-                           !memcmp(it->down[i]->name, path, namelen))
-                               break;
-               }
-               if (i < it->subtree_nr) {
-                       cache_tree_free(&it->down[i]->cache_tree);
-                       free(it->down[i]);
+               pos = subtree_pos(it, path, namelen);
+               if (0 <= pos) {
+                       cache_tree_free(&it->down[pos]->cache_tree);
+                       free(it->down[pos]);
                        /* 0 1 2 3 4 5
                         *       ^     ^subtree_nr = 6
-                        *       i
+                        *       pos
                         * move 4 and 5 up one place (2 entries)
-                        * 2 = 6 - 3 - 1 = subtree_nr - i - 1
+                        * 2 = 6 - 3 - 1 = subtree_nr - pos - 1
                         */
-                       memmove(it->down+i, it->down+i+1,
+                       memmove(it->down+pos, it->down+pos+1,
                                sizeof(struct cache_tree_sub *) *
-                               (it->subtree_nr - i - 1));
+                               (it->subtree_nr - pos - 1));
                        it->subtree_nr--;
                }
                return;
@@ -187,7 +230,8 @@ static int update_one(struct cache_tree *it,
                      int entries,
                      const char *base,
                      int baselen,
-                     int missing_ok)
+                     int missing_ok,
+                     int dryrun)
 {
        unsigned long size, offset;
        char *buffer;
@@ -234,7 +278,8 @@ static int update_one(struct cache_tree *it,
                                    cache + i, entries - i,
                                    path,
                                    baselen + sublen + 1,
-                                   missing_ok);
+                                   missing_ok,
+                                   dryrun);
                i += subcnt - 1;
                sub->used = 1;
        }
@@ -294,16 +339,23 @@ static int update_one(struct cache_tree *it,
                offset += 20;
 
 #if DEBUG
-               fprintf(stderr, "cache-tree %o %.*s\n",
+               fprintf(stderr, "cache-tree update-one %o %.*s\n",
                        mode, entlen, path + baselen);
 #endif
        }
 
-       write_sha1_file(buffer, offset, tree_type, it->sha1);
+       if (dryrun) {
+               unsigned char hdr[200];
+               int hdrlen;
+               write_sha1_file_prepare(buffer, offset, tree_type, it->sha1,
+                                       hdr, &hdrlen);
+       }
+       else
+               write_sha1_file(buffer, offset, tree_type, it->sha1);
        free(buffer);
        it->entry_count = i;
 #if DEBUG
-       fprintf(stderr, "cache-tree (%d ent, %d subtree) %s\n",
+       fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
                it->entry_count, it->subtree_nr,
                sha1_to_hex(it->sha1));
 #endif
@@ -313,13 +365,14 @@ static int update_one(struct cache_tree *it,
 int cache_tree_update(struct cache_tree *it,
                      struct cache_entry **cache,
                      int entries,
-                     int missing_ok)
+                     int missing_ok,
+                     int dryrun)
 {
        int i;
        i = verify_cache(cache, entries);
        if (i)
                return i;
-       i = update_one(it, cache, entries, "", 0, missing_ok);
+       i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
        if (i < 0)
                return i;
        return 0;
@@ -364,6 +417,12 @@ static void *write_one(struct cache_tree *it,
        }
        for (i = 0; i < it->subtree_nr; i++) {
                struct cache_tree_sub *down = it->down[i];
+               if (i) {
+                       struct cache_tree_sub *prev = it->down[i-1];
+                       if (subtree_name_cmp(down->name, down->namelen,
+                                            prev->name, prev->namelen) <= 0)
+                               die("fatal - unsorted cache subtree");
+               }
                buffer = write_one(down->cache_tree, down->name, down->namelen,
                                   buffer, size, offset);
        }
@@ -385,6 +444,8 @@ static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
 {
        const char *buf = *buffer;
        unsigned long size = *size_p;
+       const char *cp;
+       char *ep;
        struct cache_tree *it;
        int i, subtree_nr;
 
@@ -398,7 +459,14 @@ static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
                goto free_return;
        buf++; size--;
        it = cache_tree();
-       if (sscanf(buf, "%d %d\n", &it->entry_count, &subtree_nr) != 2)
+
+       cp = buf;
+       it->entry_count = strtol(cp, &ep, 10);
+       if (cp == ep)
+               goto free_return;
+       cp = ep;
+       subtree_nr = strtol(cp, &ep, 10);
+       if (cp == ep)
                goto free_return;
        while (size && *buf && *buf != '\n') {
                size--;
@@ -435,14 +503,14 @@ static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
        for (i = 0; i < subtree_nr; i++) {
                /* read each subtree */
                struct cache_tree *sub;
+               struct cache_tree_sub *subtree;
                const char *name = buf;
-               int namelen;
+
                sub = read_one(&buf, &size);
                if (!sub)
                        goto free_return;
-               namelen = strlen(name);
-               it->down[i] = find_subtree(it, name, namelen, 1);
-               it->down[i]->cache_tree = sub;
+               subtree = cache_tree_sub(it, name);
+               subtree->cache_tree = sub;
        }
        if (subtree_nr != it->subtree_nr)
                die("cache-tree: internal error");
@@ -461,3 +529,29 @@ struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
                return NULL; /* not the whole tree */
        return read_one(&buffer, &size);
 }
+
+struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
+{
+       while (*path) {
+               const char *slash;
+               struct cache_tree_sub *sub;
+
+               slash = strchr(path, '/');
+               if (!slash)
+                       slash = path + strlen(path);
+               /* between path and slash is the name of the
+                * subtree to look for.
+                */
+               sub = find_subtree(it, path, slash - path, 0);
+               if (!sub)
+                       return NULL;
+               it = sub->cache_tree;
+               if (slash)
+                       while (*slash && *slash == '/')
+                               slash++;
+               if (!slash || !*slash)
+                       return it; /* prefix ended with slashes */
+               path = slash;
+       }
+       return it;
+}