/*

  * #%L

  * KillCursors.java - mongodb-async-driver - Allanbank Consulting, Inc.

  * %%

  * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.

  * %%

  * 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.

  * #L%

  */

 package com.allanbank.mongodb.client.message;

 import java.io.IOException;

 import java.util.Arrays;

 import com.allanbank.mongodb.ReadPreference;

 import com.allanbank.mongodb.bson.io.BsonInputStream;

 import com.allanbank.mongodb.bson.io.BsonOutputStream;

 import com.allanbank.mongodb.bson.io.BufferingBsonOutputStream;

 import com.allanbank.mongodb.client.Message;

 import com.allanbank.mongodb.client.Operation;

 import com.allanbank.mongodb.error.DocumentToLargeException;

 /**

  * Message to <a href=

  * "http://www.mongodb.org/display/DOCS/Mongo+Wire+Protocol#MongoWireProtocol-OPKILLCURSORS"

  * >killcursor</a>s that a client no longer needs.

  * 

  * <pre>

  * <code>

  * struct {

  *     MsgHeader header;            // standard message header

  *     int32     ZERO;              // 0 - reserved for future use

  *     int32     numberOfCursorIDs; // number of cursorIDs in message

  *     int64*    cursorIDs;         // sequence of cursorIDs to close

  * }

  * </code>

  * </pre>

  * 

  * @api.no This class is <b>NOT</b> part of the drivers API. This class may be

  *         mutated in incompatible ways between any two releases of the driver.

  * @copyright 2011-2013, Allanbank Consulting, Inc., All Rights Reserved

  */

 public class KillCursors extends AbstractMessage {

     /** The ids of the cursors to be killed. */

     private final long[] myCursorIds;

     /**

      * Creates a new KillCursors.

      * 

      * @param in

      *            The stream to read the kill_cursors message from.

      * @throws IOException

      *             On a failure reading the kill_cursors message.

      */

     public KillCursors(final BsonInputStream in) throws IOException {

         init(".");

         in.readInt(); // 0 - reserved.

         final int numberOfCursors = in.readInt();

         myCursorIds = new long[numberOfCursors];

         for (int i = 0; i < numberOfCursors; ++i) {

             myCursorIds[i] = in.readLong();

         }

     }

     /**

      * Creates a new KillCursors.

      * 

      * @param cursorIds

      *            The ids of the cursors to kill.

      * @param readPreference

      *            The preferences for which server to send the request.

      */

     public KillCursors(final long[] cursorIds,

             final ReadPreference readPreference) {

         super("", "", readPreference);

         myCursorIds = Arrays.copyOf(cursorIds, cursorIds.length);

     }

     /**

      * Determines if the passed object is of this same type as this object and

      * if so that its fields are equal.

      * 

      * @param object

      *            The object to compare to.

      * 

      * @see java.lang.Object#equals(java.lang.Object)

      */

     @Override

     public boolean equals(final Object object) {

         boolean result = false;

         if (this == object) {

             result = true;

         }

         else if ((object != null) && (getClass() == object.getClass())) {

             final KillCursors other = (KillCursors) object;

             // Base class fields are always the same ""."".

             result = Arrays.equals(myCursorIds, other.myCursorIds);

         }

         return result;

     }

     /**

      * Returns the ids of the cursors to be killed.

      * 

      * @return The ids of the cursors to be killed.

      */

     public long[] getCursorIds() {

         return Arrays.copyOf(myCursorIds, myCursorIds.length);

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to return the name of the operation: "KILL_CURSORS".

      * </p>

      */

     @Override

     public String getOperationName() {

         return Operation.KILL_CURSORS.name();

     }

     /**

      * Computes a reasonable hash code.

      * 

      * @return The hash code value.

      */

     @Override

     public int hashCode() {

         int result = 1;

         result = (31 * result) + super.hashCode();

         result = (31 * result) + Arrays.hashCode(myCursorIds);

         return result;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to return the size of the {@link KillCursors}.

      * </p>

      */

     @Override

     public int size() {

         int size = HEADER_SIZE + 8; // See below.

         // size += 4; // 0 - reserved

         // size += 4; // number of cursors.

         size += (8 * myCursorIds.length);

         return size;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overrridden to ensure the size of the cursors ids array is not too large.

      * </p>

      */

     @Override

     public void validateSize(final int maxDocumentSize)

             throws DocumentToLargeException {

         if (maxDocumentSize < (myCursorIds.length * 8)) {

             throw new DocumentToLargeException((myCursorIds.length * 8),

                     maxDocumentSize, null);

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to write the kill_cursors message.

      * </p>

      * 

      * @see Message#write(int, BsonOutputStream)

      */

     @Override

     public void write(final int messageId, final BsonOutputStream out)

             throws IOException {

         int size = HEADER_SIZE;

         size += 4; // 0 - reserved

         size += 4; // number of cursors.

         size += (8 * myCursorIds.length);

         writeHeader(out, messageId, 0, Operation.KILL_CURSORS, size);

         out.writeInt(0);

         out.writeInt(myCursorIds.length);

         for (final long myCursorId : myCursorIds) {

             out.writeLong(myCursorId);

         }

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to write the kill_cursors message.

      * </p>

      * 

      * @see Message#write(int, BsonOutputStream)

      */

     @Override

     public void write(final int messageId, final BufferingBsonOutputStream out)

             throws IOException {

         final long start = writeHeader(out, messageId, 0,

                 Operation.KILL_CURSORS);

         out.writeInt(0);

         out.writeInt(myCursorIds.length);

         for (final long myCursorId : myCursorIds) {

             out.writeLong(myCursorId);

         }

         finishHeader(out, start);

         out.flushBuffer();

     }

 }