diffcore-rename, merge-ort: add wrapper functions for filepair alloc/dealloc

We want to be able to allocate filespecs and filepairs using a mem_pool.
However, filespec data will still remain outside the pool (perhaps in
the future we could plumb the pool through the various diff APIs to
allocate the filespec data too, but for now we are limiting the scope).
Add some extra functions to allocate these appropriately based on the
non-NULL-ness of opt->priv->pool, as well as some extra functions to
handle correctly deallocating the relevant parts of them.  A future
commit will make use of these new functions.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/merge-ort.c b/merge-ort.c
index 99c7569085..e79830f918 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -690,6 +690,48 @@ static void path_msg(struct merge_options *opt,
 	strbuf_addch(sb, '\n');
 }
 
+MAYBE_UNUSED
+static struct diff_filespec *pool_alloc_filespec(struct mem_pool *pool,
+						 const char *path)
+{
+	struct diff_filespec *spec;
+	size_t len;
+
+	if (!pool)
+		return alloc_filespec(path);
+
+	/* Same code as alloc_filespec, except allocate from pool */
+	len = strlen(path);
+
+	spec = mem_pool_calloc(pool, 1, st_add3(sizeof(*spec), len, 1));
+	memcpy(spec+1, path, len);
+	spec->path = (void*)(spec+1);
+
+	spec->count = 1;
+	spec->is_binary = -1;
+	return spec;
+}
+
+MAYBE_UNUSED
+static struct diff_filepair *pool_diff_queue(struct mem_pool *pool,
+					     struct diff_queue_struct *queue,
+					     struct diff_filespec *one,
+					     struct diff_filespec *two)
+{
+	struct diff_filepair *dp;
+
+	if (!pool)
+		return diff_queue(queue, one, two);
+
+	/* Same code as diff_queue, except allocate from pool */
+	dp = mem_pool_calloc(pool, 1, sizeof(*dp));
+	dp->one = one;
+	dp->two = two;
+	if (queue)
+		diff_q(queue, dp);
+	return dp;
+}
+
 static void *pool_calloc(struct mem_pool *pool, size_t count, size_t size)
 {
 	if (!pool)