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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    *   https://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 io.netty.handler.stream;
17  
18  import static io.netty.util.internal.ObjectUtil.checkPositive;
19  import static io.netty.util.internal.ObjectUtil.checkNotNull;
20  
21  import io.netty.buffer.ByteBuf;
22  import io.netty.buffer.ByteBufAllocator;
23  import io.netty.channel.ChannelHandlerContext;
24  
25  import java.nio.ByteBuffer;
26  import java.nio.channels.ReadableByteChannel;
27  
28  /**
29   * A {@link ChunkedInput} that fetches data from a {@link ReadableByteChannel}
30   * chunk by chunk.  Please note that the {@link ReadableByteChannel} must
31   * operate in blocking mode.  Non-blocking mode channels are not supported.
32   */
33  public class ChunkedNioStream implements ChunkedInput<ByteBuf> {
34  
35      private final ReadableByteChannel in;
36  
37      private final int chunkSize;
38      private long offset;
39  
40      /**
41       * Associated ByteBuffer
42       */
43      private final ByteBuffer byteBuffer;
44  
45      /**
46       * Creates a new instance that fetches data from the specified channel.
47       */
48      public ChunkedNioStream(ReadableByteChannel in) {
49          this(in, ChunkedStream.DEFAULT_CHUNK_SIZE);
50      }
51  
52      /**
53       * Creates a new instance that fetches data from the specified channel.
54       *
55       * @param chunkSize the number of bytes to fetch on each
56       *                  {@link #readChunk(ChannelHandlerContext)} call
57       */
58      public ChunkedNioStream(ReadableByteChannel in, int chunkSize) {
59          this.in = checkNotNull(in, "in");
60          this.chunkSize = checkPositive(chunkSize, "chunkSize");
61          byteBuffer = ByteBuffer.allocate(chunkSize);
62      }
63  
64      /**
65       * Returns the number of transferred bytes.
66       */
67      public long transferredBytes() {
68          return offset;
69      }
70  
71      @Override
72      public boolean isEndOfInput() throws Exception {
73          if (byteBuffer.position() > 0) {
74              // A previous read was not over, so there is a next chunk in the buffer at least
75              return false;
76          }
77          if (in.isOpen()) {
78              // Try to read a new part, and keep this part (no rewind)
79              int b = in.read(byteBuffer);
80              if (b < 0) {
81                  return true;
82              } else {
83                  offset += b;
84                  return false;
85              }
86          }
87          return true;
88      }
89  
90      @Override
91      public void close() throws Exception {
92          in.close();
93      }
94  
95      @Deprecated
96      @Override
97      public ByteBuf readChunk(ChannelHandlerContext ctx) throws Exception {
98          return readChunk(ctx.alloc());
99      }
100 
101     @Override
102     public ByteBuf readChunk(ByteBufAllocator allocator) throws Exception {
103         if (isEndOfInput()) {
104             return null;
105         }
106         // buffer cannot be not be empty from there
107         int readBytes = byteBuffer.position();
108         for (;;) {
109             int localReadBytes = in.read(byteBuffer);
110             if (localReadBytes < 0) {
111                 break;
112             }
113             readBytes += localReadBytes;
114             offset += localReadBytes;
115             if (readBytes == chunkSize) {
116                 break;
117             }
118         }
119         byteBuffer.flip();
120         boolean release = true;
121         ByteBuf buffer = allocator.buffer(byteBuffer.remaining());
122         try {
123             buffer.writeBytes(byteBuffer);
124             byteBuffer.clear();
125             release = false;
126             return buffer;
127         } finally {
128             if (release) {
129                 buffer.release();
130             }
131         }
132     }
133 
134     @Override
135     public long length() {
136         return -1;
137     }
138 
139     @Override
140     public long progress() {
141         return offset;
142     }
143 }