1 files changed, 95 insertions, 0 deletions
diff --git a/src/cache.c b/src/cache.c
new file mode 100644
index 0000000..1ffb31c
--- /dev/null
+++ b/src/cache.c
@@ -0,0 +1,95 @@
+#include <uthash.h>
+
+#include "compiler.h"
+#include "utils.h"
+#include "cache.h"
+
+struct cache_entry {
+	char *key;
+	void *value;
+	UT_hash_handle hh;
+};
+
+struct cache {
+	cache_getter_t getter;
+	cache_free_t free;
+	void *user_data;
+	struct cache_entry *entries;
+};
+
+void cache_set(struct cache *c, const char *key, void *data) {
+	struct cache_entry *e = NULL;
+	HASH_FIND_STR(c->entries, key, e);
+	CHECK(!e);
+
+	e = ccalloc(1, struct cache_entry);
+	e->key = strdup(key);
+	e->value = data;
+	HASH_ADD_STR(c->entries, key, e);
+}
+
+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, err);
+	if (*err) {
+		free(e->key);
+		free(e);
+		return NULL;
+	}
+
+	HASH_ADD_STR(c->entries, key, e);
+	return e->value;
+}
+
+static inline void _cache_invalidate(struct cache *c, struct cache_entry *e) {
+	if (c->free) {
+		c->free(c->user_data, e->value);
+	}
+	free(e->key);
+	HASH_DEL(c->entries, e);
+	free(e);
+}
+
+void cache_invalidate(struct cache *c, const char *key) {
+	struct cache_entry *e;
+	HASH_FIND_STR(c->entries, key, e);
+
+	if (e) {
+		_cache_invalidate(c, e);
+	}
+}
+
+void cache_invalidate_all(struct cache *c) {
+	struct cache_entry *e, *tmpe;
+	HASH_ITER(hh, c->entries, e, tmpe) {
+		_cache_invalidate(c, e);
+	}
+}
+
+void *cache_free(struct cache *c) {
+	void *ret = c->user_data;
+	cache_invalidate_all(c);
+	free(c);
+	return ret;
+}
+
+struct cache *new_cache(void *ud, cache_getter_t getter, cache_free_t f) {
+	auto c = ccalloc(1, struct cache);
+	c->user_data = ud;
+	c->getter = getter;
+	c->free = f;
+	return c;
+}