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    1   /*
    2    * Copyright 2009 Red Hat, Inc.
    3    *
    4    * Red Hat licenses this file to you under the Apache License, version 2.0
    5    * (the "License"); you may not use this file except in compliance with the
    6    * License.  You may obtain a copy of the License at:
    7    *
    8    *    http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
    13   * License for the specific language governing permissions and limitations
    14   * under the License.
    15   */
    16  package org.jboss.netty.buffer;
    17
    18  import java.nio.ByteBuffer;
    19  import java.nio.ByteOrder;
    20
    21  /**
    22   * A {@link ChannelBufferFactory} which merely allocates a heap buffer with
    23   * the specified capacity.  {@link HeapChannelBufferFactory} should perform
    24   * very well in most situations because it relies on the JVM garbage collector,
    25   * which is highly optimized for heap allocation.
    26   *
    27   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
    28   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
    29   * @version $Rev: 2197 $, $Date: 2010-02-23 09:43:15 +0900 (Tue, 23 Feb 2010) $
    30   */
    31  public class HeapChannelBufferFactory extends AbstractChannelBufferFactory {
    32
    33      private static final HeapChannelBufferFactory INSTANCE_BE =
    34          new HeapChannelBufferFactory(ByteOrder.BIG_ENDIAN);
    35
    36      private static final HeapChannelBufferFactory INSTANCE_LE =
    37          new HeapChannelBufferFactory(ByteOrder.LITTLE_ENDIAN);
    38
    39      public static ChannelBufferFactory getInstance() {
    40          return INSTANCE_BE;
    41      }
    42
    43      public static ChannelBufferFactory getInstance(ByteOrder endianness) {
    44          if (endianness == ByteOrder.BIG_ENDIAN) {
    45              return INSTANCE_BE;
    46          } else if (endianness == ByteOrder.LITTLE_ENDIAN) {
    47              return INSTANCE_LE;
    48          } else if (endianness == null) {
    49              throw new NullPointerException("endianness");
    50          } else {
    51              throw new IllegalStateException("Should not reach here");
    52          }
    53      }
    54
    55      /**
    56       * Creates a new factory whose default {@link ByteOrder} is
    57       * {@link ByteOrder#BIG_ENDIAN}.
    58       */
    59      public HeapChannelBufferFactory() {
    60          super();
    61      }
    62
    63      /**
    64       * Creates a new factory with the specified default {@link ByteOrder}.
    65       *
    66       * @param defaultOrder the default {@link ByteOrder} of this factory
    67       */
    68      public HeapChannelBufferFactory(ByteOrder defaultOrder) {
    69          super(defaultOrder);
    70      }
    71
    72      public ChannelBuffer getBuffer(ByteOrder order, int capacity) {
    73          return ChannelBuffers.buffer(order, capacity);
    74      }
    75
    76      public ChannelBuffer getBuffer(ByteOrder order, byte[] array, int offset, int length) {
    77          return ChannelBuffers.wrappedBuffer(order, array, offset, length);
    78      }
    79
    80      public ChannelBuffer getBuffer(ByteBuffer nioBuffer) {
    81          if (nioBuffer.hasArray()) {
    82              return ChannelBuffers.wrappedBuffer(nioBuffer);
    83          }
    84
    85          ChannelBuffer buf = getBuffer(nioBuffer.order(), nioBuffer.remaining());
    86          int pos = nioBuffer.position();
    87          buf.writeBytes(nioBuffer);
    88          nioBuffer.position(pos);
    89          return buf;
    90      }
    91  }