diff-lib: refactor run_diff_index() and do_diff_cache()

The latter is meant to be an API for internal callers that want to inspect
the resulting diff-queue, while the former is an implementation of "git
diff-index" command. Extract the common logic into a single helper
function and make them thin wrappers around it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/diff-lib.c b/diff-lib.c
index b5bb58d1832db97fc87addbc19f2234424e52dd6..c7626554b85b7be3491eeaca32e534b6765dc5aa 100644 (file)
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -440,20 +440,19 @@ static int oneway_diff(struct cache_entry **src, struct unpack_trees_options *o)
        return 0;
 }
 
-int run_diff_index(struct rev_info *revs, int cached)
+static int diff_cache(struct rev_info *revs,
+                     const unsigned char *tree_sha1,
+                     const char *tree_name,
+                     int cached)
 {
-       struct object *ent;
        struct tree *tree;
-       const char *tree_name;
-       struct unpack_trees_options opts;
        struct tree_desc t;
+       struct unpack_trees_options opts;
 
-       ent = revs->pending.objects[0].item;
-       tree_name = revs->pending.objects[0].name;
-       tree = parse_tree_indirect(ent->sha1);
+       tree = parse_tree_indirect(tree_sha1);
        if (!tree)
-               return error("bad tree object %s", tree_name);
-
+               return error("bad tree object %s",
+                            tree_name ? tree_name : sha1_to_hex(tree_sha1));
        memset(&opts, 0, sizeof(opts));
        opts.head_idx = 1;
        opts.index_only = cached;
@@ -466,7 +465,15 @@ int run_diff_index(struct rev_info *revs, int cached)
        opts.dst_index = NULL;
 
        init_tree_desc(&t, tree->buffer, tree->size);
-       if (unpack_trees(1, &t, &opts))
+       return unpack_trees(1, &t, &opts);
+}
+
+int run_diff_index(struct rev_info *revs, int cached)
+{
+       struct object_array_entry *ent;
+
+       ent = revs->pending.objects;
+       if (diff_cache(revs, ent->item->sha1, ent->name, cached))
                exit(128);
 
        diff_set_mnemonic_prefix(&revs->diffopt, "c/", cached ? "i/" : "w/");
@@ -478,29 +485,13 @@ int run_diff_index(struct rev_info *revs, int cached)
 
 int do_diff_cache(const unsigned char *tree_sha1, struct diff_options *opt)
 {
-       struct tree *tree;
        struct rev_info revs;
-       struct unpack_trees_options opts;
-       struct tree_desc t;
 
        init_revisions(&revs, NULL);
        init_pathspec(&revs.prune_data, opt->pathspec.raw);
-       tree = parse_tree_indirect(tree_sha1);
-       if (!tree)
-               die("bad tree object %s", sha1_to_hex(tree_sha1));
+       revs.diffopt = *opt;
 
-       memset(&opts, 0, sizeof(opts));
-       opts.head_idx = 1;
-       opts.index_only = 1;
-       opts.diff_index_cached = !DIFF_OPT_TST(opt, FIND_COPIES_HARDER);
-       opts.merge = 1;
-       opts.fn = oneway_diff;
-       opts.unpack_data = &revs;
-       opts.src_index = &the_index;
-       opts.dst_index = NULL;
-
-       init_tree_desc(&t, tree->buffer, tree->size);
-       if (unpack_trees(1, &t, &opts))
+       if (diff_cache(&revs, tree_sha1, NULL, 1))
                exit(128);
        return 0;
 }