Iteration on key-prefixing POC

- Demonstrated automatic key-prefixing for all subclasses of
  UnifiedJedis: JedisCluster, JedisPooled, and JedisSentineled
- Key-prefixing is possible as long as the underlying CommandObjects can
  be customized.
- CommandObjects cannot use commandArguments in its constructor since
  in the specific case of key-prefixing, commandArguments depends on the
  child constructor running first. So we lose caching of argument-less
  CommandObjects.
- Based on this POC, the minimum changes required to jedis would be:
  - public constructors that allow UnifiedJedis and its subclasses to
    take a custom CommandObjects.
  - Consistent use of supplied CommandObjects throughout code (e.g. in
    Pipeline, Transaction, etc).
  - Removal of caching of argument-less CommandObjects in the
    constructor of CommandObjects.
- Applications can then supply CommandObjects with custom behavior as
  necessary. Sample classes CommandObjectsWithPrefixedKeys that
  implement the behavior of prefixed keys, etc are provided but these
  can be supplied by the application as long as required constructors
  are available.

Author: R-J Lim

src/main/java/redis/clients/jedis/ClusterCommandObjectsWithPrefixedKeys.java

@@ -3,14 +3,14 @@
 import redis.clients.jedis.commands.ProtocolCommand;
 
 public class ClusterCommandObjectsWithPrefixedKeys extends ClusterCommandObjects {
-    // For the purposes of this demonstration, the prefix is assigned statically.
-    // Additional changes are required to prevent the parent class CommandObjects
-    // from calling commandArguments in its constructor, which would be a prerequisite
-    // to making this field into an instance field.
-    public static String PREFIX_STRING;
+    private final String prefixString;
+
+    public ClusterCommandObjectsWithPrefixedKeys(String prefixString) {
+        this.prefixString = prefixString;
+    }
 
     @Override
     protected ClusterCommandArguments commandArguments(ProtocolCommand command) {
-        return new ClusterCommandArgumentsWithPrefixedKeys(command, PREFIX_STRING);
+        return new ClusterCommandArgumentsWithPrefixedKeys(command, prefixString);
     }
 }

src/main/java/redis/clients/jedis/CommandArgumentsWithPrefixedKeys.java

@@ -0,0 +1,46 @@
+package redis.clients.jedis;
+
+import redis.clients.jedis.args.Rawable;
+import redis.clients.jedis.args.RawableFactory;
+import redis.clients.jedis.commands.ProtocolCommand;
+import redis.clients.jedis.util.SafeEncoder;
+
+public class CommandArgumentsWithPrefixedKeys extends CommandArguments {
+    private final byte[] prefix;
+    private final String prefixString;
+    
+    public CommandArgumentsWithPrefixedKeys(ProtocolCommand command, String prefixString) {
+        super(command);
+        this.prefixString = prefixString;
+        prefix = SafeEncoder.encode(prefixString);
+    }
+
+    public CommandArguments key(Object key) {
+        return super.key(namespacedKey(key));
+    }
+
+    private Object namespacedKey(Object key) {
+        if (key instanceof Rawable) {
+            byte[] raw = ((Rawable) key).getRaw();
+            return RawableFactory.from(namespacedKeyBytes(raw));
+        }
+
+        if (key instanceof byte[]) {
+            return namespacedKeyBytes((byte[]) key);
+        }
+
+        if (key instanceof String) {
+            String raw = (String) key;
+            return prefixString + raw;
+        }
+
+        throw new IllegalArgumentException("\"" + key.toString() + "\" is not a valid argument.");
+    }
+
+    private byte[] namespacedKeyBytes(byte[] key) {
+        byte[] namespaced = new byte[prefix.length + key.length];
+        System.arraycopy(prefix, 0, namespaced, 0, prefix.length);
+        System.arraycopy(key, 0, namespaced, prefix.length, key.length);
+        return namespaced;
+    }
+}

src/main/java/redis/clients/jedis/CommandObjects.java

@@ -63,22 +63,16 @@ protected CommandArguments commandArguments(ProtocolCommand command) {
     return new CommandArguments(command);
   }
 
-  private final CommandObject<String> PING_COMMAND_OBJECT = new CommandObject<>(commandArguments(PING), BuilderFactory.STRING);
-
   public final CommandObject<String> ping() {
-    return PING_COMMAND_OBJECT;
+    return new CommandObject<>(commandArguments(PING), BuilderFactory.STRING);
   }
 
-  private final CommandObject<String> FLUSHALL_COMMAND_OBJECT = new CommandObject<>(commandArguments(FLUSHALL), BuilderFactory.STRING);
-
   public final CommandObject<String> flushAll() {
-    return FLUSHALL_COMMAND_OBJECT;
+    return new CommandObject<>(commandArguments(FLUSHALL), BuilderFactory.STRING);
   }
 
-  private final CommandObject<String> FLUSHDB_COMMAND_OBJECT = new CommandObject<>(commandArguments(FLUSHDB), BuilderFactory.STRING);
-
   public final CommandObject<String> flushDB() {
-    return FLUSHDB_COMMAND_OBJECT;
+    return new CommandObject<>(commandArguments(FLUSHDB), BuilderFactory.STRING);
   }
 
   public final CommandObject<String> configSet(String parameter, String value) {
@@ -2818,10 +2812,8 @@ public final CommandObject<String> scriptLoad(String script, String sampleKey) {
     return new CommandObject<>(commandArguments(SCRIPT).add(LOAD).add(script).processKey(sampleKey), BuilderFactory.STRING);
   }
 
-  private final CommandObject<String> SCRIPT_FLUSH_COMMAND_OBJECT = new CommandObject<>(commandArguments(SCRIPT).add(FLUSH), BuilderFactory.STRING);
-
   public final CommandObject<String> scriptFlush() {
-    return SCRIPT_FLUSH_COMMAND_OBJECT;
+    return new CommandObject<>(commandArguments(SCRIPT).add(FLUSH), BuilderFactory.STRING);
   }
 
   public final CommandObject<String> scriptFlush(String sampleKey) {
@@ -2832,10 +2824,8 @@ public final CommandObject<String> scriptFlush(String sampleKey, FlushMode flush
     return new CommandObject<>(commandArguments(SCRIPT).add(FLUSH).add(flushMode).processKey(sampleKey), BuilderFactory.STRING);
   }
 
-  private final CommandObject<String> SCRIPT_KILL_COMMAND_OBJECT = new CommandObject<>(commandArguments(SCRIPT).add(KILL), BuilderFactory.STRING);
-
   public final CommandObject<String> scriptKill() {
-    return SCRIPT_KILL_COMMAND_OBJECT;
+    return new CommandObject<>(commandArguments(SCRIPT).add(KILL), BuilderFactory.STRING);
   }
 
   public final CommandObject<String> scriptKill(String sampleKey) {
@@ -2863,11 +2853,8 @@ public final CommandObject<String> scriptKill(byte[] sampleKey) {
     return new CommandObject<>(commandArguments(SCRIPT).add(KILL).processKey(sampleKey), BuilderFactory.STRING);
   }
 
-  private final CommandObject<String> SLOWLOG_RESET_COMMAND_OBJECT
-      = new CommandObject<>(commandArguments(SLOWLOG).add(Keyword.RESET), BuilderFactory.STRING);
-
   public final CommandObject<String> slowlogReset() {
-    return SLOWLOG_RESET_COMMAND_OBJECT;
+    return new CommandObject<>(commandArguments(SLOWLOG).add(Keyword.RESET), BuilderFactory.STRING);
   }
 
   public final CommandObject<Object> fcall(String name, List<String> keys, List<String> args) {

src/main/java/redis/clients/jedis/CommandObjectsWithPrefixedKeys.java

@@ -0,0 +1,16 @@
+package redis.clients.jedis;
+
+import redis.clients.jedis.commands.ProtocolCommand;
+
+public class CommandObjectsWithPrefixedKeys extends CommandObjects {
+    private final String prefixString;
+
+    public CommandObjectsWithPrefixedKeys(String prefixString) {
+        this.prefixString = prefixString;
+    }
+
+    @Override
+    protected CommandArguments commandArguments(ProtocolCommand command) {
+        return new CommandArgumentsWithPrefixedKeys(command, prefixString);
+    }
+}

src/main/java/redis/clients/jedis/JedisCluster.java

@@ -7,6 +7,7 @@
 
 import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
 
+import redis.clients.jedis.executors.ClusterCommandExecutor;
 import redis.clients.jedis.providers.ClusterConnectionProvider;
 import redis.clients.jedis.util.JedisClusterCRC16;
 
@@ -222,6 +223,10 @@ private JedisCluster(ClusterConnectionProvider provider, int maxAttempts, Durati
     super(provider, maxAttempts, maxTotalRetriesDuration, protocol);
   }
 
+  public JedisCluster(ClusterCommandExecutor executor, ClusterConnectionProvider provider, ClusterCommandObjects commandObjects, RedisProtocol protocol) {
+    super(executor, provider, commandObjects, protocol);
+  }
+
   public Map<String, ConnectionPool> getClusterNodes() {
     return ((ClusterConnectionProvider) provider).getNodes();
   }

src/main/java/redis/clients/jedis/JedisClusterWithPrefixedKeys.java

@@ -8,6 +8,7 @@
 import org.apache.commons.pool2.PooledObjectFactory;
 import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
 
+import redis.clients.jedis.executors.CommandExecutor;
 import redis.clients.jedis.providers.PooledConnectionProvider;
 import redis.clients.jedis.util.JedisURIHelper;
 import redis.clients.jedis.util.Pool;
@@ -394,6 +395,11 @@ public JedisPooled(PooledConnectionProvider provider) {
     super(provider);
   }
 
+  public JedisPooled(CommandExecutor executor, PooledConnectionProvider provider, CommandObjects commandObjects,
+                     RedisProtocol redisProtocol) {
+    super(executor, provider, commandObjects, redisProtocol);
+  }
+
   public final Pool<Connection> getPool() {
     return ((PooledConnectionProvider) provider).getPool();
   }

src/main/java/redis/clients/jedis/JedisPooled.java

@@ -2,6 +2,7 @@
 
 import java.util.Set;
 import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
+import redis.clients.jedis.executors.CommandExecutor;
 import redis.clients.jedis.providers.SentineledConnectionProvider;
 
 public class JedisSentineled extends UnifiedJedis {
@@ -23,6 +24,10 @@ public JedisSentineled(SentineledConnectionProvider sentineledConnectionProvider
     super(sentineledConnectionProvider);
   }
 
+  public JedisSentineled(CommandExecutor executor, SentineledConnectionProvider sentineledConnectionProvider, CommandObjects commandObjects, RedisProtocol redisProtocol) {
+    super(executor, sentineledConnectionProvider, commandObjects, redisProtocol);
+  }
+
   public HostAndPort getCurrentMaster() {
     return ((SentineledConnectionProvider) provider).getCurrentMaster();
   }

src/main/java/redis/clients/jedis/JedisSentineled.java

@@ -28,7 +28,11 @@ public Pipeline(Connection connection) {
   }
 
   public Pipeline(Connection connection, boolean closeConnection) {
-    super(new CommandObjects());
+    this(connection, new CommandObjects(), closeConnection);
+  }
+
+  public Pipeline(Connection connection, CommandObjects commandObjects, boolean closeConnection) {
+    super(commandObjects);
     this.connection = connection;
     this.closeConnection = closeConnection;
     RedisProtocol proto = this.connection.getRedisProtocol();

src/main/java/redis/clients/jedis/Pipeline.java

@@ -4859,7 +4859,7 @@ public PipelineBase pipelined() {
     } else if (provider instanceof MultiClusterPooledConnectionProvider) {
       return new MultiClusterPipeline((MultiClusterPooledConnectionProvider) provider, commandObjects);
     } else {
-      return new Pipeline(provider.getConnection(), true);
+      return new Pipeline(provider.getConnection(), commandObjects, true);
     }
   }