merge: Use `git_index__fill` to populate the indexvmg/index-fill

Instead of calling `git_index_add` in a loop, use the new
`git_index_fill` internal API to fill the index with the initial staged
entries.

The new `fill` helper assumes that all the entries will be unique and
valid, so it can append them at the end of the entries vector and only
sort it once at the end. It performs no validation checks.

This prevents the quadratic behavior caused by having to sort the
entries list once after every insertion.

1 files changed, 37 insertions, 0 deletions

diff --git a/src/index.c b/src/index.c
index 26cd83851..60e4d443c 100644
--- a/src/index.c
+++ b/src/index.c
@@ -1542,6 +1542,43 @@ int git_index_remove_bypath(git_index *index, const char *path)
 	return 0;
 }
 
+int git_index__fill(git_index *index, const git_vector *source_entries)
+{
+	const git_index_entry *source_entry = NULL;
+	size_t i;
+	int ret = 0;
+
+	assert(index);
+
+	if (git_mutex_lock(&index->lock) < 0) {
+		giterr_set(GITERR_OS, "Unable to acquire index lock");
+		return -1;
+	}
+
+	git_vector_foreach(source_entries, i, source_entry) {
+		git_index_entry *entry = NULL;
+
+		if ((ret = index_entry_dup(&entry, index, source_entry)) < 0)
+			break;
+
+		entry->flags_extended |= GIT_IDXENTRY_UPTODATE;
+
+		ret = git_vector_insert(&index->entries, entry);
+		if (ret < 0)
+			break;
+
+		INSERT_IN_MAP(index, entry, ret);
+		if (ret < 0)
+			break;
+	}
+
+	if (!ret)
+		git_vector_sort(&index->entries);
+
+	git_mutex_unlock(&index->lock);
+	return ret;
+}
+
 
 int git_index_add(git_index *index, const git_index_entry *source_entry)
 {