strmap: introduce `git_strmap_get` and use it throughout the tree

The current way of looking up an entry from a map is tightly coupled with the
map implementation, as one first has to look up the index of the key and then
retrieve the associated value by using the index. As a caller, you usually do
not care about any indices at all, though, so this is more complicated than
really necessary. Furthermore, it invites for errors to happen if the correct
error checking sequence is not being followed.

Introduce a new high-level function `git_strmap_get` that takes a map and a key
and returns a pointer to the associated value if such a key exists. Otherwise,
a `NULL` pointer is returned. Adjust all callers that can trivially be
converted.

1 files changed, 2 insertions, 8 deletions

diff --git a/src/sortedcache.c b/src/sortedcache.c
index 3967bce15..f58764479 100644
--- a/src/sortedcache.c
+++ b/src/sortedcache.c
@@ -276,11 +276,8 @@ int git_sortedcache_upsert(void **out, git_sortedcache *sc, const char *key)
 	size_t keylen, itemlen;
 	char *item_key;
 
-	pos = git_strmap_lookup_index(sc->map, key);
-	if (git_strmap_valid_index(sc->map, pos)) {
-		item = git_strmap_value_at(sc->map, pos);
+	if ((item = git_strmap_get(sc->map, key)) != NULL)
 		goto done;
-	}
 
 	keylen  = strlen(key);
 	itemlen = sc->item_path_offset + keylen + 1;
@@ -320,10 +317,7 @@ done:
 /* lookup item by key */
 void *git_sortedcache_lookup(const git_sortedcache *sc, const char *key)
 {
-	size_t pos = git_strmap_lookup_index(sc->map, key);
-	if (git_strmap_valid_index(sc->map, pos))
-		return git_strmap_value_at(sc->map, pos);
-	return NULL;
+	return git_strmap_get(sc->map, key);
 }
 
 /* find out how many items are in the cache */