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      1 /*
      2  * Copyright 2012 Sebastian Annies, Hamburg
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the License);
      5  * you may not use this file except in compliance with the License.
      6  * 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,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package com.coremedia.iso;
     17 
     18 import java.io.EOFException;
     19 import java.io.IOException;
     20 import java.nio.ByteBuffer;
     21 import java.nio.channels.FileChannel;
     22 import java.nio.channels.ReadableByteChannel;
     23 import java.nio.channels.SelectionKey;
     24 import java.nio.channels.WritableByteChannel;
     25 
     26 import static com.googlecode.mp4parser.util.CastUtils.l2i;
     27 
     28 
     29 public class ChannelHelper {
     30     public static ByteBuffer readFully(final ReadableByteChannel channel, long size) throws IOException {
     31 
     32         if (channel instanceof FileChannel && size > 1024 * 1024) {
     33             ByteBuffer bb = ((FileChannel) channel).map(FileChannel.MapMode.READ_ONLY, ((FileChannel) channel).position(), size);
     34             ((FileChannel) channel).position(((FileChannel) channel).position() + size);
     35             return bb;
     36         } else {
     37             ByteBuffer buf = ByteBuffer.allocate(l2i(size));
     38             readFully(channel, buf, buf.limit());
     39             buf.rewind();
     40             assert buf.limit() == size;
     41 
     42             return buf;
     43         }
     44 
     45     }
     46 
     47 
     48     public static void readFully(final ReadableByteChannel channel, final ByteBuffer buf)
     49             throws IOException {
     50         readFully(channel, buf, buf.remaining());
     51     }
     52 
     53     public static int readFully(final ReadableByteChannel channel, final ByteBuffer buf, final int length)
     54             throws IOException {
     55         int n, count = 0;
     56         while (-1 != (n = channel.read(buf))) {
     57             count += n;
     58             if (count == length) {
     59                 break;
     60             }
     61         }
     62         if (n == -1) {
     63             throw new EOFException("End of file. No more boxes.");
     64         }
     65         return count;
     66     }
     67 
     68 
     69     public static void writeFully(final WritableByteChannel channel, final ByteBuffer buf)
     70             throws IOException {
     71         do {
     72             int written = channel.write(buf);
     73             if (written < 0) {
     74                 throw new EOFException();
     75             }
     76         } while (buf.hasRemaining());
     77     }
     78 
     79 
     80     public static void close(SelectionKey key) {
     81         try {
     82             key.channel().close();
     83         } catch (IOException e) {
     84             // nop
     85         }
     86 
     87     }
     88 
     89 
     90 }