From 6d6d658b5c5ea474fd551f63ff28d6da355c8cfd Mon Sep 17 00:00:00 2001
From: Yuxuan Shui <yshuiv7@gmail.com>
Date: Mon, 6 May 2019 00:28:22 +0100
Subject: [PATCH] cache: cache_get can now return error

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
---
 src/cache.c | 16 ++++++++++++++--
 src/cache.h |  4 ++--
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/cache.c b/src/cache.c
index e455032f..d1ddda72 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -16,16 +16,28 @@ struct cache {
 	struct cache_entry *entries;
 };
 
-void *cache_get(struct cache *c, const char *key) {
+void *cache_get(struct cache *c, const char *key, int *err) {
 	struct cache_entry *e;
 	HASH_FIND_STR(c->entries, key, e);
 	if (e) {
 		return e->value;
 	}
 
+	int tmperr;
+	if (!err) {
+		err = &tmperr;
+	}
+
+	*err = 0;
 	e = ccalloc(1, struct cache_entry);
 	e->key = strdup(key);
-	e->value = c->getter(c->user_data, key);
+	e->value = c->getter(c->user_data, key, err);
+	if (*err) {
+		free(e->key);
+		free(e);
+		return NULL;
+	}
+
 	HASH_ADD_STR(c->entries, key, e);
 	return e->value;
 }
diff --git a/src/cache.h b/src/cache.h
index 440f92f2..5876ee21 100644
--- a/src/cache.h
+++ b/src/cache.h
@@ -2,11 +2,11 @@
 
 struct cache;
 
-typedef void *(*cache_getter_t)(void *user_data, const char *key);
+typedef void *(*cache_getter_t)(void *user_data, const char *key, int *err);
 typedef void (*cache_free_t)(void *user_data, void *data);
 struct cache *new_cache(void *user_data, cache_getter_t getter, cache_free_t f);
 
-void *cache_get(struct cache *, const char *key);
+void *cache_get(struct cache *, const char *key, int *err);
 void cache_invalidate(struct cache *, const char *key);
 void cache_invalidate_all(struct cache *);