Update write-tree to use cache-tree.

The updated write-tree reads from $GIT_DIR/index.aux to pick up
subtree objects information, updates the cache-tree with the
index, and updates index.aux file after writing a tree out of
the index file.

Until update-index and other programs that modify the index are
updated to maintain index.aux file, the index.aux file written
by the last write-tree will become stale immediately after they
update the index, which will result in the whole tree
recomputation just like the original write-tree.

The idea is to convert those commands to invalidate cache-tree
whenever they touch the index entries, and write updated
index.aux out.  After the index is updated with them, write-tree
will be able to reuse the parts of the cache-tree that have not
been touched.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/write-tree.c b/write-tree.c
index dcad6e6..cef0c5b 100644 (file)
--- a/write-tree.c
+++ b/write-tree.c
@@ -5,96 +5,23 @@
  */
 #include "cache.h"
 #include "tree.h"
+#include "cache-tree.h"
 
-static int missing_ok = 0;
-
-static int check_valid_sha1(unsigned char *sha1)
-{
-       int ret;
-
-       /* If we were anal, we'd check that the sha1 of the contents actually matches */
-       ret = has_sha1_file(sha1);
-       if (ret == 0)
-               perror(sha1_file_name(sha1));
-       return ret ? 0 : -1;
-}
-
-static int write_tree(struct cache_entry **cachep, int maxentries, const char *base, int baselen, unsigned char *returnsha1)
-{
-       unsigned char subdir_sha1[20];
-       unsigned long size, offset;
-       char *buffer;
-       int nr;
-
-       /* Guess at some random initial size */
-       size = 8192;
-       buffer = xmalloc(size);
-       offset = 0;
-
-       nr = 0;
-       while (nr < maxentries) {
-               struct cache_entry *ce = cachep[nr];
-               const char *pathname = ce->name, *filename, *dirname;
-               int pathlen = ce_namelen(ce), entrylen;
-               unsigned char *sha1;
-               unsigned int mode;
-
-               /* Did we hit the end of the directory? Return how many we wrote */
-               if (baselen >= pathlen || memcmp(base, pathname, baselen))
-                       break;
-
-               sha1 = ce->sha1;
-               mode = ntohl(ce->ce_mode);
-
-               /* Do we have _further_ subdirectories? */
-               filename = pathname + baselen;
-               dirname = strchr(filename, '/');
-               if (dirname) {
-                       int subdir_written;
-
-                       subdir_written = write_tree(cachep + nr, maxentries - nr, pathname, dirname-pathname+1, subdir_sha1);
-                       nr += subdir_written;
+static unsigned char active_cache_sha1[20];
+static struct cache_tree *active_cache_tree;
 
-                       /* Now we need to write out the directory entry into this tree.. */
-                       mode = S_IFDIR;
-                       pathlen = dirname - pathname;
-
-                       /* ..but the directory entry doesn't count towards the total count */
-                       nr--;
-                       sha1 = subdir_sha1;
-               }
-
-               if (!missing_ok && check_valid_sha1(sha1) < 0)
-                       exit(1);
-
-               entrylen = pathlen - baselen;
-               if (offset + entrylen + 100 > size) {
-                       size = alloc_nr(offset + entrylen + 100);
-                       buffer = xrealloc(buffer, size);
-               }
-               offset += sprintf(buffer + offset, "%o %.*s", mode, entrylen, filename);
-               buffer[offset++] = 0;
-               memcpy(buffer + offset, sha1, 20);
-               offset += 20;
-               nr++;
-       }
-
-       write_sha1_file(buffer, offset, tree_type, returnsha1);
-       free(buffer);
-       return nr;
-}
+static int missing_ok = 0;
 
 static const char write_tree_usage[] = "git-write-tree [--missing-ok]";
 
 int main(int argc, char **argv)
 {
-       int i, funny;
        int entries;
-       unsigned char sha1[20];
-       
+
        setup_git_directory();
 
-       entries = read_cache();
+       entries = read_cache_1(active_cache_sha1);
+       active_cache_tree = read_cache_tree(active_cache_sha1);
        if (argc == 2) {
                if (!strcmp(argv[1], "--missing-ok"))
                        missing_ok = 1;
@@ -108,51 +35,11 @@ int main(int argc, char **argv)
        if (entries < 0)
                die("git-write-tree: error reading cache");
 
-       /* Verify that the tree is merged */
-       funny = 0;
-       for (i = 0; i < entries; i++) {
-               struct cache_entry *ce = active_cache[i];
-               if (ce_stage(ce)) {
-                       if (10 < ++funny) {
-                               fprintf(stderr, "...\n");
-                               break;
-                       }
-                       fprintf(stderr, "%s: unmerged (%s)\n", ce->name, sha1_to_hex(ce->sha1));
-               }
-       }
-       if (funny)
-               die("git-write-tree: not able to write tree");
-
-       /* Also verify that the cache does not have path and path/file
-        * at the same time.  At this point we know the cache has only
-        * stage 0 entries.
-        */
-       funny = 0;
-       for (i = 0; i < entries - 1; i++) {
-               /* path/file always comes after path because of the way
-                * the cache is sorted.  Also path can appear only once,
-                * which means conflicting one would immediately follow.
-                */
-               const char *this_name = active_cache[i]->name;
-               const char *next_name = active_cache[i+1]->name;
-               int this_len = strlen(this_name);
-               if (this_len < strlen(next_name) &&
-                   strncmp(this_name, next_name, this_len) == 0 &&
-                   next_name[this_len] == '/') {
-                       if (10 < ++funny) {
-                               fprintf(stderr, "...\n");
-                               break;
-                       }
-                       fprintf(stderr, "You have both %s and %s\n",
-                               this_name, next_name);
-               }
-       }
-       if (funny)
-               die("git-write-tree: not able to write tree");
+       if (cache_tree_update(active_cache_tree, active_cache, active_nr,
+                             missing_ok))
+               die("git-write-tree: error building trees");
+       write_cache_tree(active_cache_sha1, active_cache_tree);
 
-       /* Ok, write it out */
-       if (write_tree(active_cache, entries, "", 0, sha1) != entries)
-               die("git-write-tree: internal error");
-       printf("%s\n", sha1_to_hex(sha1));
+       printf("%s\n", sha1_to_hex(active_cache_tree->sha1));
        return 0;
 }