add keys

Author: mamantoha

spec/redis_cache_store_spec.cr

@@ -150,8 +150,12 @@ describe Cache do
       store = Cache::RedisCacheStore(String, String).new(12.hours)
       store.write("foo", "bar", expires_in: 1.second)
 
+      store.keys.should eq(Set{"foo"})
+
       sleep 2.seconds
 
+      store.keys.should be_empty
+
       value = store.read("foo")
       value.should eq(nil)
     end
@@ -167,7 +171,7 @@ describe Cache do
 
       value = store.read("foo")
       value.should eq(nil)
-      store.keys.should eq(Set(String).new)
+      store.keys.should be_empty
     end
 
     it "deletes all items from the cache" do
@@ -247,10 +251,16 @@ describe Cache do
 
     context "with namespace" do
       it "write" do
-        store = Cache::RedisCacheStore(String, String).new(12.hours, namespace: "myapp-cache")
-        store.write("foo", "bar", expires_in: 1.minute)
+        store1 = Cache::RedisCacheStore(String, String).new(12.hours, namespace: "myapp-cache")
+        store1.write("foo1", "bar", expires_in: 1.minute)
+
+        store2 = Cache::RedisCacheStore(String, String).new(12.hours)
+        store2.write("foo2", "baz", expires_in: 1.minute)
+
+        store1.keys.should eq(Set{"myapp-cache:foo1"})
+        store2.keys.should eq(Set{"myapp-cache:foo1", "foo2"})
 
-        value = store.fetch("foo") { "bar" }
+        value = store1.fetch("foo") { "bar" }
         value.should eq("bar")
       end
 

src/redis_cache_store.cr

@@ -48,6 +48,11 @@ module Cache
     def initialize(@expires_in : Time::Span, @cache = Redis::Client.new, @namespace : String? = nil)
     end
 
+    def keys : Set(K)
+      pattern = namespace_key("*")
+      redis.keys(pattern).map(&.as(K)).to_set
+    end
+
     private def write_impl(key : K, value : V, *, expires_in = @expires_in)
       redis.set(key, value.to_s, ex: expires_in)
     end