add object commands

ENCODING, IDLETIME, FREQ, REFCOUNT
closes: #599

src/commands.rs

@@ -1008,6 +1008,28 @@ implement_commands! {
         cmd("PUBLISH").arg(channel).arg(message)
     }
 
+    // Object commands
+
+    /// Returns the encoding of a key.
+    fn object_encoding<K: ToRedisArgs>(key: K) {
+        cmd("OBJECT").arg("ENCODING").arg(key)
+    }
+
+    /// Returns the time in seconds since the last access of a key.
+    fn object_idletime<K: ToRedisArgs>(key: K) {
+        cmd("OBJECT").arg("IDLETIME").arg(key)
+    }
+
+    /// Returns the logarithmic access frequency counter of a key.
+    fn object_freq<K: ToRedisArgs>(key: K) {
+        cmd("OBJECT").arg("FREQ").arg(key)
+    }
+
+    /// Returns the reference count of a key.
+    fn object_refcount<K: ToRedisArgs>(key: K) {
+        cmd("OBJECT").arg("REFCOUNT").arg(key)
+    }
+
     // ACL commands
 
     /// When Redis is configured to use an ACL file (with the aclfile

tests/test_basic.rs

@@ -927,3 +927,38 @@ fn test_zrandmember() {
     let results: Vec<String> = con.zrandmember_withscores(setname, -5).unwrap();
     assert_eq!(results.len(), 10);
 }
+
+#[test]
+fn test_object_commands() {
+    let ctx = TestContext::new();
+    let mut con = ctx.connection();
+
+    let _: () = con.set("object_key_str", "object_value_str").unwrap();
+    let _: () = con.set("object_key_int", 42).unwrap();
+
+    assert_eq!(
+        con.object_encoding::<_, String>("object_key_str").unwrap(),
+        "embstr"
+    );
+
+    assert_eq!(
+        con.object_encoding::<_, String>("object_key_int").unwrap(),
+        "int"
+    );
+
+    assert_eq!(con.object_idletime::<_, i32>("object_key_str").unwrap(), 0);
+    assert_eq!(con.object_refcount::<_, i32>("object_key_str").unwrap(), 1);
+
+    // Needed for OBJECT FREQ and can't be set before object_idletime
+    // since that will break getting the idletime before idletime adjuts
+    redis::cmd("CONFIG")
+        .arg("SET")
+        .arg(b"maxmemory-policy")
+        .arg("allkeys-lfu")
+        .execute(&mut con);
+
+    let _: () = con.get("object_key_str").unwrap();
+    // since maxmemory-policy changed, freq should reset to 1 since we only called
+    // get after that
+    assert_eq!(con.object_freq::<_, i32>("object_key_str").unwrap(), 1);
+}