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    1   /*
    2    * Copyright 2012 The Netty Project
    3    *
    4    * The Netty Project licenses this file to you under the Apache License,
    5    * version 2.0 (the "License"); you may not use this file except in compliance
    6    * with the 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.io.IOException;
    19  import java.io.InputStream;
    20  import java.io.OutputStream;
    21  import java.nio.ByteBuffer;
    22  import java.nio.ByteOrder;
    23  import java.nio.channels.ClosedChannelException;
    24  import java.nio.channels.GatheringByteChannel;
    25  import java.nio.channels.ScatteringByteChannel;
    26
    27  /**
    28   * A NIO {@link ByteBuffer} based buffer.  It is recommended to use {@link ChannelBuffers#directBuffer(int)}
    29   * and {@link ChannelBuffers#wrappedBuffer(ByteBuffer)} instead of calling the
    30   * constructor explicitly.
    31   */
    32  public class ByteBufferBackedChannelBuffer extends AbstractChannelBuffer {
    33
    34      private final ByteBuffer buffer;
    35      private final ByteOrder order;
    36      private final int capacity;
    37
    38      /**
    39       * Creates a new buffer which wraps the specified buffer's slice.
    40       */
    41      public ByteBufferBackedChannelBuffer(ByteBuffer buffer) {
    42          if (buffer == null) {
    43              throw new NullPointerException("buffer");
    44          }
    45
    46          order = buffer.order();
    47          this.buffer = buffer.slice().order(order);
    48          capacity = buffer.remaining();
    49          writerIndex(capacity);
    50      }
    51
    52      private ByteBufferBackedChannelBuffer(ByteBufferBackedChannelBuffer buffer) {
    53          this.buffer = buffer.buffer;
    54          order = buffer.order;
    55          capacity = buffer.capacity;
    56          setIndex(buffer.readerIndex(), buffer.writerIndex());
    57      }
    58
    59      public ChannelBufferFactory factory() {
    60          if (buffer.isDirect()) {
    61              return DirectChannelBufferFactory.getInstance(order());
    62          } else {
    63              return HeapChannelBufferFactory.getInstance(order());
    64          }
    65      }
    66
    67      public boolean isDirect() {
    68          return buffer.isDirect();
    69      }
    70
    71      public ByteOrder order() {
    72          return order;
    73      }
    74
    75      public int capacity() {
    76          return capacity;
    77      }
    78
    79      public boolean hasArray() {
    80          return buffer.hasArray();
    81      }
    82
    83      public byte[] array() {
    84          return buffer.array();
    85      }
    86
    87      public int arrayOffset() {
    88          return buffer.arrayOffset();
    89      }
    90
    91      public byte getByte(int index) {
    92          return buffer.get(index);
    93      }
    94
    95      public short getShort(int index) {
    96          return buffer.getShort(index);
    97      }
    98
    99      public int getUnsignedMedium(int index) {
    100         return  (getByte(index)     & 0xff) << 16 |
    101                 (getByte(index + 1) & 0xff) <<  8 |
    102                 (getByte(index + 2) & 0xff);
    103     }
    104
    105     public int getInt(int index) {
    106         return buffer.getInt(index);
    107     }
    108
    109     public long getLong(int index) {
    110         return buffer.getLong(index);
    111     }
    112
    113     public void getBytes(int index, ChannelBuffer dst, int dstIndex, int length) {
    114         if (dst instanceof ByteBufferBackedChannelBuffer) {
    115             ByteBufferBackedChannelBuffer bbdst = (ByteBufferBackedChannelBuffer) dst;
    116             ByteBuffer data = bbdst.buffer.duplicate();
    117
    118             data.limit(dstIndex + length).position(dstIndex);
    119             getBytes(index, data);
    120         } else if (buffer.hasArray()) {
    121             dst.setBytes(dstIndex, buffer.array(), index + buffer.arrayOffset(), length);
    122         } else {
    123             dst.setBytes(dstIndex, this, index, length);
    124         }
    125     }
    126
    127     public void getBytes(int index, byte[] dst, int dstIndex, int length) {
    128         ByteBuffer data = buffer.duplicate();
    129         try {
    130             data.limit(index + length).position(index);
    131         } catch (IllegalArgumentException e) {
    132             throw new IndexOutOfBoundsException("Too many bytes to read - Need "
    133                     + (index + length) + ", maximum is " + data.limit());
    134         }
    135         data.get(dst, dstIndex, length);
    136     }
    137
    138     public void getBytes(int index, ByteBuffer dst) {
    139         ByteBuffer data = buffer.duplicate();
    140         int bytesToCopy = Math.min(capacity() - index, dst.remaining());
    141         try {
    142             data.limit(index + bytesToCopy).position(index);
    143         } catch (IllegalArgumentException e) {
    144             throw new IndexOutOfBoundsException("Too many bytes to read - Need "
    145                     + (index + bytesToCopy) + ", maximum is " + data.limit());
    146         }
    147         dst.put(data);
    148     }
    149
    150     public void setByte(int index, int value) {
    151         buffer.put(index, (byte) value);
    152     }
    153
    154     public void setShort(int index, int value) {
    155         buffer.putShort(index, (short) value);
    156     }
    157
    158     public void setMedium(int index, int   value) {
    159         setByte(index,     (byte) (value >>> 16));
    160         setByte(index + 1, (byte) (value >>>  8));
    161         setByte(index + 2, (byte) value);
    162     }
    163
    164     public void setInt(int index, int   value) {
    165         buffer.putInt(index, value);
    166     }
    167
    168     public void setLong(int index, long  value) {
    169         buffer.putLong(index, value);
    170     }
    171
    172     public void setBytes(int index, ChannelBuffer src, int srcIndex, int length) {
    173         if (src instanceof ByteBufferBackedChannelBuffer) {
    174             ByteBufferBackedChannelBuffer bbsrc = (ByteBufferBackedChannelBuffer) src;
    175             ByteBuffer data = bbsrc.buffer.duplicate();
    176
    177             data.limit(srcIndex + length).position(srcIndex);
    178             setBytes(index, data);
    179         } else if (buffer.hasArray()) {
    180             src.getBytes(srcIndex, buffer.array(), index + buffer.arrayOffset(), length);
    181         } else {
    182             src.getBytes(srcIndex, this, index, length);
    183         }
    184     }
    185
    186     public void setBytes(int index, byte[] src, int srcIndex, int length) {
    187         ByteBuffer data = buffer.duplicate();
    188         data.limit(index + length).position(index);
    189         data.put(src, srcIndex, length);
    190     }
    191
    192     public void setBytes(int index, ByteBuffer src) {
    193         ByteBuffer data = buffer.duplicate();
    194         data.limit(index + src.remaining()).position(index);
    195         data.put(src);
    196     }
    197
    198     public void getBytes(int index, OutputStream out, int length) throws IOException {
    199         if (length == 0) {
    200             return;
    201         }
    202
    203         if (buffer.hasArray()) {
    204             out.write(
    205                     buffer.array(),
    206                     index + buffer.arrayOffset(),
    207                     length);
    208         } else {
    209             byte[] tmp = new byte[length];
    210             ((ByteBuffer) buffer.duplicate().position(index)).get(tmp);
    211             out.write(tmp);
    212         }
    213     }
    214
    215     public int getBytes(int index, GatheringByteChannel out, int length) throws IOException {
    216         if (length == 0) {
    217             return 0;
    218         }
    219
    220         return out.write((ByteBuffer) buffer.duplicate().position(index).limit(index + length));
    221     }
    222
    223     public int setBytes(int index, InputStream in, int length)
    224             throws IOException {
    225
    226         int readBytes = 0;
    227
    228         if (buffer.hasArray()) {
    229             index += buffer.arrayOffset();
    230             do {
    231                 int localReadBytes = in.read(buffer.array(), index, length);
    232                 if (localReadBytes < 0) {
    233                     if (readBytes == 0) {
    234                         return -1;
    235                     } else {
    236                         break;
    237                     }
    238                 }
    239                 readBytes += localReadBytes;
    240                 index += localReadBytes;
    241                 length -= localReadBytes;
    242             } while (length > 0);
    243         } else {
    244             byte[] tmp = new byte[length];
    245             int i = 0;
    246             do {
    247                 int localReadBytes = in.read(tmp, i, tmp.length - i);
    248                 if (localReadBytes < 0) {
    249                     if (readBytes == 0) {
    250                         return -1;
    251                     } else {
    252                         break;
    253                     }
    254                 }
    255                 readBytes += localReadBytes;
    256                 i += readBytes;
    257             } while (i < tmp.length);
    258             ((ByteBuffer) buffer.duplicate().position(index)).put(tmp);
    259         }
    260
    261         return readBytes;
    262     }
    263
    264     public int setBytes(int index, ScatteringByteChannel in, int length)
    265             throws IOException {
    266
    267         ByteBuffer slice = (ByteBuffer) buffer.duplicate().limit(index + length).position(index);
    268         int readBytes = 0;
    269
    270         while (readBytes < length) {
    271             int localReadBytes;
    272             try {
    273                 localReadBytes = in.read(slice);
    274             } catch (ClosedChannelException e) {
    275                 localReadBytes = -1;
    276             }
    277             if (localReadBytes < 0) {
    278                 if (readBytes == 0) {
    279                     return -1;
    280                 } else {
    281                     return readBytes;
    282                 }
    283             } else if (localReadBytes == 0) {
    284                 break;
    285             }
    286             readBytes += localReadBytes;
    287         }
    288
    289         return readBytes;
    290     }
    291
    292     public ByteBuffer toByteBuffer(int index, int length) {
    293         if (index == 0 && length == capacity()) {
    294             return buffer.duplicate().order(order());
    295         } else {
    296             return ((ByteBuffer) buffer.duplicate().position(
    297                     index).limit(index + length)).slice().order(order());
    298         }
    299     }
    300
    301     public ChannelBuffer slice(int index, int length) {
    302         if (index == 0 && length == capacity()) {
    303             ChannelBuffer slice = duplicate();
    304             slice.setIndex(0, length);
    305             return slice;
    306         } else {
    307             if (index >= 0 && length == 0) {
    308                 return ChannelBuffers.EMPTY_BUFFER;
    309             }
    310             return new ByteBufferBackedChannelBuffer(
    311                     ((ByteBuffer) buffer.duplicate().position(
    312                             index).limit(index + length)).order(order()));
    313         }
    314     }
    315
    316     public ChannelBuffer duplicate() {
    317         return new ByteBufferBackedChannelBuffer(this);
    318     }
    319
    320     public ChannelBuffer copy(int index, int length) {
    321         ByteBuffer src;
    322         try {
    323             src = (ByteBuffer) buffer.duplicate().position(index).limit(index + length);
    324         } catch (IllegalArgumentException e) {
    325             throw new IndexOutOfBoundsException("Too many bytes to read - Need "
    326                     + (index + length));
    327         }
    328
    329         ByteBuffer dst = buffer.isDirect() ? ByteBuffer.allocateDirect(length) : ByteBuffer.allocate(length);
    330         dst.put(src);
    331         dst.order(order());
    332         dst.clear();
    333         return new ByteBufferBackedChannelBuffer(dst);
    334     }
    335 }