FEAT: Add gat(get and touch) command to get item & update item expiration

Author: singsangssong

src/main/java/net/spy/memcached/ArcusClientPool.java

@@ -242,6 +242,16 @@ public GetFuture<CASValue<Object>> asyncGets(String key) {
     return this.getClient().asyncGets(key);
   }
 
+  @Override
+  public <T> Future<T> asyncGetAndTouch(String key, int exp, Transcoder<T> tc) {
+    return this.getClient().asyncGetAndTouch(key, exp, tc);
+  }
+
+  @Override
+  public Future<Object> asyncGetAndTouch(String key, int exp) {
+    return this.getClient().asyncGetAndTouch(key, exp);
+  }
+
   @Override
   public <T> CASValue<T> gets(String key, Transcoder<T> tc)
           throws OperationTimeoutException {

src/main/java/net/spy/memcached/MemcachedClient.java

@@ -59,6 +59,7 @@
 import net.spy.memcached.ops.CancelledOperationStatus;
 import net.spy.memcached.ops.ConcatenationType;
 import net.spy.memcached.ops.DeleteOperation;
+import net.spy.memcached.ops.GetAndTouchOperation;
 import net.spy.memcached.ops.GetOperation;
 import net.spy.memcached.ops.GetsOperation;
 import net.spy.memcached.ops.Mutator;
@@ -986,6 +987,56 @@ public GetFuture<CASValue<Object>> asyncGets(final String key) {
     return asyncGets(key, transcoder);
   }
 
+  /**
+   * Get the given key to reset its expiration time.
+   *
+   * @param key the key to fetch
+   * @param exp the new expiration to set for the given key
+   * @param tc the transcoder to serialize and unserialize value
+   * @return a future that will hold the return value of the fetch
+   * @throws IllegalStateException in the rare circumstance where queue is too
+   *           full to accept any more requests
+   */
+  public <T> GetFuture<T> asyncGetAndTouch(final String key, final int exp,
+                                           final Transcoder<T> tc) {
+    final CountDownLatch latch = new CountDownLatch(1);
+    final GetFuture<T> rv = new GetFuture<>(latch, operationTimeout);
+
+    Operation op = opFact.getAndTouch(key, exp,
+      new GetAndTouchOperation.Callback() {
+        private GetResult<T> val;
+
+        public void receivedStatus(OperationStatus status) {
+          rv.set(val, status);
+        }
+
+        public void gotData(String k, int flags, byte[] data) {
+          assert k.equals(key) : "Wrong key returned";
+          val = new GetResultImpl<>(new CachedData(flags, data, tc.getMaxSize()), tc);
+        }
+
+        public void complete() {
+          latch.countDown();
+        }
+      });
+    rv.setOperation(op);
+    addOp(key, op);
+    return rv;
+  }
+
+  /**
+   * Get the given key to reset its expiration time.
+   *
+   * @param key the key to fetch
+   * @param exp the new expiration to set for the given key
+   * @return a future that will hold the return value of the fetch
+   * @throws IllegalStateException in the rare circumstance where queue is too
+   *           full to accept any more requests
+   */
+  public GetFuture<Object> asyncGetAndTouch(final String key, final int exp) {
+    return asyncGetAndTouch(key, exp, transcoder);
+  }
+
   /**
    * Gets (with CAS support) with a single key.
    *

src/main/java/net/spy/memcached/MemcachedClientIF.java

@@ -82,6 +82,10 @@ <T> Future<CASValue<T>> asyncGets(String key,
 
   Future<CASValue<Object>> asyncGets(String key);
 
+  <T> Future<T> asyncGetAndTouch(final String key, final int exp, final Transcoder<T> tc);
+
+  Future<Object> asyncGetAndTouch(final String key, final int exp);
+
   <T> CASValue<T> gets(String key, Transcoder<T> tc)
           throws OperationTimeoutException;
 

src/main/java/net/spy/memcached/OperationFactory.java

@@ -64,6 +64,7 @@
 import net.spy.memcached.ops.ConcatenationType;
 import net.spy.memcached.ops.DeleteOperation;
 import net.spy.memcached.ops.FlushOperation;
+import net.spy.memcached.ops.GetAndTouchOperation;
 import net.spy.memcached.ops.GetAttrOperation;
 import net.spy.memcached.ops.GetOperation;
 import net.spy.memcached.ops.GetsOperation;
@@ -152,6 +153,17 @@ public interface OperationFactory {
    */
   GetsOperation gets(Collection<String> keys, GetsOperation.Callback cb, boolean isMGet);
 
+  /**
+   * Gets the value of a key and resets its timeout.
+   *
+   * @param key the key to get a value for and reset its timeout
+   * @param expiration the new expiration for the key
+   * @param cb the callback that will contain the result
+   * @return a new GATOperation
+   */
+  GetAndTouchOperation getAndTouch(String key, int expiration,
+                                   GetAndTouchOperation.Callback cb);
+
   /**
    * Create a mutator operation.
    *

src/main/java/net/spy/memcached/ops/APIType.java

@@ -25,6 +25,7 @@ public enum APIType {
   INCR(OperationType.WRITE), DECR(OperationType.WRITE),
   DELETE(OperationType.WRITE),
   GET(OperationType.READ), GETS(OperationType.READ),
+  GAT(OperationType.WRITE),
 
   // List API Type
   LOP_CREATE(OperationType.WRITE),

src/main/java/net/spy/memcached/ops/BaseOperationFactory.java

@@ -60,6 +60,10 @@ public Collection<Operation> clone(KeyedOperation op) {
       for (String k : op.getKeys()) {
         rv.add(gets(k, getsCb));
       }
+    } else if (op instanceof GetAndTouchOperation) {
+      GetAndTouchOperation gt = (GetAndTouchOperation) op;
+      rv.add(getAndTouch(first(gt.getKeys()), gt.getExpiration(),
+              (GetAndTouchOperation.Callback) gt.getCallback()));
     } else if (op instanceof CASOperation) {
       CASOperation cop = (CASOperation) op;
       rv.add(cas(cop.getStoreType(), first(op.getKeys()),

src/main/java/net/spy/memcached/ops/GetAndTouchOperation.java

@@ -0,0 +1,44 @@
+/*
+ * arcus-java-client : Arcus Java client
+ * Copyright 2010-2014 NAVER Corp.
+ * Copyright 2014-present JaM2in Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.spy.memcached.ops;
+
+/**
+ * Gat operation.
+ */
+public interface GetAndTouchOperation extends KeyedOperation {
+
+  /**
+   * Operation callback for the gat request.
+   */
+  interface Callback extends OperationCallback {
+    /**
+     * Callback for each result from a gat.
+     *
+     * @param key the key that was retrieved
+     * @param flags the flags for this value
+     * @param data the data stored under this key
+     */
+    void gotData(String key, int flags, byte[] data);
+  }
+
+  /**
+   * Get the expiration to set in case of a new entry.
+   */
+  int getExpiration();
+}

src/main/java/net/spy/memcached/protocol/ascii/AsciiOperationFactory.java

@@ -64,6 +64,7 @@
 import net.spy.memcached.ops.ConcatenationType;
 import net.spy.memcached.ops.DeleteOperation;
 import net.spy.memcached.ops.FlushOperation;
+import net.spy.memcached.ops.GetAndTouchOperation;
 import net.spy.memcached.ops.GetAttrOperation;
 import net.spy.memcached.ops.GetOperation;
 import net.spy.memcached.ops.GetsOperation;
@@ -109,6 +110,11 @@ public GetsOperation gets(Collection<String> keys, GetsOperation.Callback cb, bo
     return new GetsOperationImpl(keys, cb, isMGet);
   }
 
+  public GetAndTouchOperation getAndTouch(String key, int expiration,
+                                          GetAndTouchOperation.Callback cb) {
+    return new GetAndTouchOperationImpl(key, expiration, cb);
+  }
+
   public MutatorOperation mutate(Mutator m, String key, int by,
                                  long def, int exp, OperationCallback cb) {
     return new MutatorOperationImpl(m, key, by, def, exp, cb);

src/main/java/net/spy/memcached/protocol/ascii/BaseGetOpImpl.java

@@ -22,6 +22,7 @@
 import java.util.Collection;
 import java.util.Iterator;
 
+import net.spy.memcached.ops.GetAndTouchOperation;
 import net.spy.memcached.ops.GetOperation;
 import net.spy.memcached.ops.GetsOperation;
 import net.spy.memcached.ops.OperationCallback;
@@ -41,6 +42,7 @@ abstract class BaseGetOpImpl extends OperationImpl {
   private final String cmd;
   private final Collection<String> keys;
   private String currentKey = null;
+  protected final int exp;
   private long casValue = 0;
   private int currentFlags = 0;
   private byte[] data = null;
@@ -55,9 +57,19 @@ public BaseGetOpImpl(String c,
     super(cb);
     cmd = c;
     keys = k;
+    exp = 0;
     setOperationType(OperationType.READ);
   }
 
+  public BaseGetOpImpl(String c, int e,
+                       OperationCallback cb, Collection<String> k) {
+    super(cb);
+    cmd = c;
+    keys = k;
+    exp = e;
+    setOperationType(OperationType.WRITE);
+  }
+
   /**
    * Get the keys this GetOperation is looking for.
    */
@@ -131,12 +143,18 @@ public final void handleRead(ByteBuffer bb) {
     if (readOffset == data.length && lookingFor == '\0') {
       // The callback is most likely a get callback.  If it's not, then
       // it's a gets callback.
-      try {
-        GetOperation.Callback gcb = (GetOperation.Callback) getCallback();
+      OperationCallback cb = getCallback();
+      if (cb instanceof GetOperation.Callback) {
+        GetOperation.Callback gcb = (GetOperation.Callback) cb;
         gcb.gotData(currentKey, currentFlags, data);
-      } catch (ClassCastException e) {
-        GetsOperation.Callback gcb = (GetsOperation.Callback) getCallback();
+      } else if (cb instanceof GetsOperation.Callback) {
+        GetsOperation.Callback gcb = (GetsOperation.Callback) cb;
         gcb.gotData(currentKey, currentFlags, casValue, data);
+      } else if (cb instanceof GetAndTouchOperation.Callback) {
+        GetAndTouchOperation.Callback gcb = (GetAndTouchOperation.Callback) cb;
+        gcb.gotData(currentKey, currentFlags, data);
+      } else {
+        throw new ClassCastException("Couldn't convert " + cb + "to a relevent op");
       }
       lookingFor = '\r';
     }
@@ -184,6 +202,14 @@ public final void initialize() {
       commandBuilder.append(' ');
       commandBuilder.append(keysString);
       commandBuilder.append(RN_STRING);
+    } else if (cmd.equals("gat")) {
+      // syntax: get <exp> <key>\r\n
+      commandBuilder.append(cmd);
+      commandBuilder.append(' ');
+      commandBuilder.append(exp);
+      commandBuilder.append(' ');
+      commandBuilder.append(keysString);
+      commandBuilder.append(RN_STRING);
     } else {
       assert (cmd.equals("mget") || cmd.equals("mgets"))
           : "Unknown Command " + cmd;

src/main/java/net/spy/memcached/protocol/ascii/GetAndTouchOperationImpl.java

@@ -0,0 +1,43 @@
+/*
+ * arcus-java-client : Arcus Java client
+ * Copyright 2010-2014 NAVER Corp.
+ * Copyright 2014-present JaM2in Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.spy.memcached.protocol.ascii;
+
+import java.util.Collections;
+
+import net.spy.memcached.ops.APIType;
+import net.spy.memcached.ops.GetAndTouchOperation;
+
+/**
+ * Implementation of the get and touch operation.
+ */
+public class GetAndTouchOperationImpl extends BaseGetOpImpl
+        implements GetAndTouchOperation {
+  private static final String CMD = "gat";
+
+  public GetAndTouchOperationImpl(String k, int e,
+                                  GetAndTouchOperation.Callback cb) {
+    super(CMD, e, cb, Collections.singleton(k));
+    setAPIType(APIType.GAT);
+  }
+
+  @Override
+  public int getExpiration() {
+    return exp;
+  }
+}