blame: large-scale performance rewrite

diff --git a/match-trees.c b/match-trees.c
index 2bb734d51cbe59e3eed7c82e7522c594d5efa579..e80b4af354f87caa7a5130660e9c9c530246b8be 100644 (file)
--- a/match-trees.c
+++ b/match-trees.c
@@ -47,6 +47,22 @@ static int score_matches(unsigned mode1, unsigned mode2, const char *path)
        return score;
 }
 
+static void *fill_tree_desc_strict(struct tree_desc *desc,
+                                  const unsigned char *hash)
+{
+       void *buffer;
+       enum object_type type;
+       unsigned long size;
+
+       buffer = read_sha1_file(hash, &type, &size);
+       if (!buffer)
+               die("unable to read tree (%s)", sha1_to_hex(hash));
+       if (type != OBJ_TREE)
+               die("%s is not a tree", sha1_to_hex(hash));
+       init_tree_desc(desc, buffer, size);
+       return buffer;
+}
+
 static int base_name_entries_compare(const struct name_entry *a,
                                     const struct name_entry *b)
 {
@@ -61,23 +77,10 @@ static int score_trees(const unsigned char *hash1, const unsigned char *hash2)
 {
        struct tree_desc one;
        struct tree_desc two;
-       void *one_buf, *two_buf;
+       void *one_buf = fill_tree_desc_strict(&one, hash1);
+       void *two_buf = fill_tree_desc_strict(&two, hash2);
        int score = 0;
-       enum object_type type;
-       unsigned long size;
 
-       one_buf = read_sha1_file(hash1, &type, &size);
-       if (!one_buf)
-               die("unable to read tree (%s)", sha1_to_hex(hash1));
-       if (type != OBJ_TREE)
-               die("%s is not a tree", sha1_to_hex(hash1));
-       init_tree_desc(&one, one_buf, size);
-       two_buf = read_sha1_file(hash2, &type, &size);
-       if (!two_buf)
-               die("unable to read tree (%s)", sha1_to_hex(hash2));
-       if (type != OBJ_TREE)
-               die("%s is not a tree", sha1_to_hex(hash2));
-       init_tree_desc(&two, two_buf, size);
        for (;;) {
                struct name_entry e1, e2;
                int got_entry_from_one = tree_entry(&one, &e1);
@@ -124,16 +127,7 @@ static void match_trees(const unsigned char *hash1,
                        int recurse_limit)
 {
        struct tree_desc one;
-       void *one_buf;
-       enum object_type type;
-       unsigned long size;
-
-       one_buf = read_sha1_file(hash1, &type, &size);
-       if (!one_buf)
-               die("unable to read tree (%s)", sha1_to_hex(hash1));
-       if (type != OBJ_TREE)
-               die("%s is not a tree", sha1_to_hex(hash1));
-       init_tree_desc(&one, one_buf, size);
+       void *one_buf = fill_tree_desc_strict(&one, hash1);
 
        while (one.size) {
                const char *path;
@@ -188,13 +182,10 @@ static int splice_tree(const unsigned char *hash1,
        enum object_type type;
        int status;
 
-       subpath = strchr(prefix, '/');
-       if (!subpath)
-               toplen = strlen(prefix);
-       else {
-               toplen = subpath - prefix;
+       subpath = strchrnul(prefix, '/');
+       toplen = subpath - prefix;
+       if (*subpath)
                subpath++;
-       }
 
        buf = read_sha1_file(hash1, &type, &sz);
        if (!buf)
@@ -221,7 +212,7 @@ static int splice_tree(const unsigned char *hash1,
        if (!rewrite_here)
                die("entry %.*s not found in tree %s",
                    toplen, prefix, sha1_to_hex(hash1));
-       if (subpath) {
+       if (*subpath) {
                status = splice_tree(rewrite_here, subpath, hash2, subtree);
                if (status)
                        return status;