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