1 files changed, 62 insertions, 0 deletions
diff --git a/oidmap.c b/oidmap.c
new file mode 100644
index 0000000000..d9fb19ba6a
--- /dev/null
+++ b/oidmap.c
@@ -0,0 +1,62 @@
+#include "cache.h"
+#include "oidmap.h"
+
+static int cmpfn(const void *hashmap_cmp_fn_data,
+		 const void *entry, const void *entry_or_key,
+		 const void *keydata)
+{
+	const struct oidmap_entry *entry_ = entry;
+	if (keydata)
+		return oidcmp(&entry_->oid, (const struct object_id *) keydata);
+	return oidcmp(&entry_->oid,
+		      &((const struct oidmap_entry *) entry_or_key)->oid);
+}
+
+static int hash(const struct object_id *oid)
+{
+	int hash;
+	memcpy(&hash, oid->hash, sizeof(hash));
+	return hash;
+}
+
+void oidmap_init(struct oidmap *map, size_t initial_size)
+{
+	hashmap_init(&map->map, cmpfn, NULL, initial_size);
+}
+
+void oidmap_free(struct oidmap *map, int free_entries)
+{
+	if (!map)
+		return;
+	hashmap_free(&map->map, free_entries);
+}
+
+void *oidmap_get(const struct oidmap *map, const struct object_id *key)
+{
+	if (!map->map.cmpfn)
+		return NULL;
+
+	return hashmap_get_from_hash(&map->map, hash(key), key);
+}
+
+void *oidmap_remove(struct oidmap *map, const struct object_id *key)
+{
+	struct hashmap_entry entry;
+
+	if (!map->map.cmpfn)
+		oidmap_init(map, 0);
+
+	hashmap_entry_init(&entry, hash(key));
+	return hashmap_remove(&map->map, &entry, key);
+}
+
+void *oidmap_put(struct oidmap *map, void *entry)
+{
+	struct oidmap_entry *to_put = entry;
+
+	if (!map->map.cmpfn)
+		oidmap_init(map, 0);
+
+	hashmap_entry_init(&to_put->internal_entry, hash(&to_put->oid));
+	return hashmap_put(&map->map, to_put);
+}