update mod

vendor/github.com/siddontang/ledisdb/store/rocksdb/cache.go

@@ -0,0 +1,20 @@
+// +build rocksdb
+
+package rocksdb
+
+// #cgo LDFLAGS: -lrocksdb
+// #include <stdint.h>
+// #include "rocksdb/c.h"
+import "C"
+
+type Cache struct {
+	Cache *C.rocksdb_cache_t
+}
+
+func NewLRUCache(capacity int) *Cache {
+	return &Cache{C.rocksdb_cache_create_lru(C.size_t(capacity))}
+}
+
+func (c *Cache) Close() {
+	C.rocksdb_cache_destroy(c.Cache)
+}