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1   /*
2    * Copyright 2013 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.buffer;
17  
18  import io.netty.util.internal.StringUtil;
19  
20  import java.io.IOException;
21  import java.io.InputStream;
22  import java.io.OutputStream;
23  import java.nio.ByteBuffer;
24  import java.nio.ByteOrder;
25  import java.nio.ReadOnlyBufferException;
26  import java.nio.channels.GatheringByteChannel;
27  import java.nio.channels.ScatteringByteChannel;
28  
29  
30  /**
31   * Read-only ByteBuf which wraps a read-only ByteBuffer.
32   */
33  class ReadOnlyByteBufferBuf extends AbstractReferenceCountedByteBuf {
34  
35      protected final ByteBuffer buffer;
36      private final ByteBufAllocator allocator;
37      private ByteBuffer tmpNioBuf;
38  
39      ReadOnlyByteBufferBuf(ByteBufAllocator allocator, ByteBuffer buffer) {
40          super(buffer.remaining());
41          if (!buffer.isReadOnly()) {
42              throw new IllegalArgumentException("must be a readonly buffer: " + StringUtil.simpleClassName(buffer));
43          }
44  
45          this.allocator = allocator;
46          this.buffer = buffer.slice().order(ByteOrder.BIG_ENDIAN);
47          writerIndex(this.buffer.limit());
48      }
49  
50      @Override
51      protected void deallocate() { }
52  
53      @Override
54      public byte getByte(int index) {
55          ensureAccessible();
56          return _getByte(index);
57      }
58  
59      @Override
60      protected byte _getByte(int index) {
61          return buffer.get(index);
62      }
63  
64      @Override
65      public short getShort(int index) {
66          ensureAccessible();
67          return _getShort(index);
68      }
69  
70      @Override
71      protected short _getShort(int index) {
72          return buffer.getShort(index);
73      }
74  
75      @Override
76      public int getUnsignedMedium(int index) {
77          ensureAccessible();
78          return _getUnsignedMedium(index);
79      }
80  
81      @Override
82      protected int _getUnsignedMedium(int index) {
83          return (getByte(index) & 0xff)     << 16 |
84                 (getByte(index + 1) & 0xff) << 8  |
85                 getByte(index + 2) & 0xff;
86      }
87  
88      @Override
89      public int getInt(int index) {
90          ensureAccessible();
91          return _getInt(index);
92      }
93  
94      @Override
95      protected int _getInt(int index) {
96          return buffer.getInt(index);
97      }
98  
99      @Override
100     public long getLong(int index) {
101         ensureAccessible();
102         return _getLong(index);
103     }
104 
105     @Override
106     protected long _getLong(int index) {
107         return buffer.getLong(index);
108     }
109 
110     @Override
111     public ByteBuf getBytes(int index, ByteBuf dst, int dstIndex, int length) {
112         checkDstIndex(index, length, dstIndex, dst.capacity());
113         if (dst.hasArray()) {
114             getBytes(index, dst.array(), dst.arrayOffset() + dstIndex, length);
115         } else if (dst.nioBufferCount() > 0) {
116             for (ByteBuffer bb: dst.nioBuffers(dstIndex, length)) {
117                 int bbLen = bb.remaining();
118                 getBytes(index, bb);
119                 index += bbLen;
120             }
121         } else {
122             dst.setBytes(dstIndex, this, index, length);
123         }
124         return this;
125     }
126 
127     @Override
128     public ByteBuf getBytes(int index, byte[] dst, int dstIndex, int length) {
129         checkDstIndex(index, length, dstIndex, dst.length);
130 
131         if (dstIndex < 0 || dstIndex > dst.length - length) {
132             throw new IndexOutOfBoundsException(String.format(
133                     "dstIndex: %d, length: %d (expected: range(0, %d))", dstIndex, length, dst.length));
134         }
135 
136         ByteBuffer tmpBuf = internalNioBuffer();
137         tmpBuf.clear().position(index).limit(index + length);
138         tmpBuf.get(dst, dstIndex, length);
139         return this;
140     }
141 
142     @Override
143     public ByteBuf getBytes(int index, ByteBuffer dst) {
144         checkIndex(index);
145         if (dst == null) {
146             throw new NullPointerException("dst");
147         }
148 
149         int bytesToCopy = Math.min(capacity() - index, dst.remaining());
150         ByteBuffer tmpBuf = internalNioBuffer();
151         tmpBuf.clear().position(index).limit(index + bytesToCopy);
152         dst.put(tmpBuf);
153         return this;
154     }
155 
156     @Override
157     public ByteBuf setByte(int index, int value) {
158         throw new ReadOnlyBufferException();
159     }
160 
161     @Override
162     protected void _setByte(int index, int value) {
163         throw new ReadOnlyBufferException();
164     }
165 
166     @Override
167     public ByteBuf setShort(int index, int value) {
168         throw new ReadOnlyBufferException();
169     }
170 
171     @Override
172     protected void _setShort(int index, int value) {
173         throw new ReadOnlyBufferException();
174     }
175 
176     @Override
177     public ByteBuf setMedium(int index, int value) {
178         throw new ReadOnlyBufferException();
179     }
180 
181     @Override
182     protected void _setMedium(int index, int value) {
183         throw new ReadOnlyBufferException();
184     }
185 
186     @Override
187     public ByteBuf setInt(int index, int value) {
188         throw new ReadOnlyBufferException();
189     }
190 
191     @Override
192     protected void _setInt(int index, int value) {
193         throw new ReadOnlyBufferException();
194     }
195 
196     @Override
197     public ByteBuf setLong(int index, long value) {
198         throw new ReadOnlyBufferException();
199     }
200 
201     @Override
202     protected void _setLong(int index, long value) {
203         throw new ReadOnlyBufferException();
204     }
205 
206     @Override
207     public int capacity() {
208         return maxCapacity();
209     }
210 
211     @Override
212     public ByteBuf capacity(int newCapacity) {
213         throw new ReadOnlyBufferException();
214     }
215 
216     @Override
217     public ByteBufAllocator alloc() {
218         return allocator;
219     }
220 
221     @Override
222     public ByteOrder order() {
223         return ByteOrder.BIG_ENDIAN;
224     }
225 
226     @Override
227     public ByteBuf unwrap() {
228         return null;
229     }
230 
231     @Override
232     public boolean isDirect() {
233         return buffer.isDirect();
234     }
235 
236     @Override
237     public ByteBuf getBytes(int index, OutputStream out, int length) throws IOException {
238         ensureAccessible();
239         if (length == 0) {
240             return this;
241         }
242 
243         if (buffer.hasArray()) {
244             out.write(buffer.array(), index + buffer.arrayOffset(), length);
245         } else {
246             byte[] tmp = new byte[length];
247             ByteBuffer tmpBuf = internalNioBuffer();
248             tmpBuf.clear().position(index);
249             tmpBuf.get(tmp);
250             out.write(tmp);
251         }
252         return this;
253     }
254 
255     @Override
256     public int getBytes(int index, GatheringByteChannel out, int length) throws IOException {
257         ensureAccessible();
258         if (length == 0) {
259             return 0;
260         }
261 
262         ByteBuffer tmpBuf = internalNioBuffer();
263         tmpBuf.clear().position(index).limit(index + length);
264         return out.write(tmpBuf);
265     }
266 
267     @Override
268     public ByteBuf setBytes(int index, ByteBuf src, int srcIndex, int length) {
269         throw new ReadOnlyBufferException();
270     }
271 
272     @Override
273     public ByteBuf setBytes(int index, byte[] src, int srcIndex, int length) {
274         throw new ReadOnlyBufferException();
275     }
276 
277     @Override
278     public ByteBuf setBytes(int index, ByteBuffer src) {
279         throw new ReadOnlyBufferException();
280     }
281 
282     @Override
283     public int setBytes(int index, InputStream in, int length) throws IOException {
284         throw new ReadOnlyBufferException();
285     }
286 
287     @Override
288     public int setBytes(int index, ScatteringByteChannel in, int length) throws IOException {
289         throw new ReadOnlyBufferException();
290     }
291 
292     protected final ByteBuffer internalNioBuffer() {
293         ByteBuffer tmpNioBuf = this.tmpNioBuf;
294         if (tmpNioBuf == null) {
295             this.tmpNioBuf = tmpNioBuf = buffer.duplicate();
296         }
297         return tmpNioBuf;
298     }
299 
300     @Override
301     public ByteBuf copy(int index, int length) {
302         ensureAccessible();
303         ByteBuffer src;
304         try {
305             src = (ByteBuffer) internalNioBuffer().clear().position(index).limit(index + length);
306         } catch (IllegalArgumentException ignored) {
307             throw new IndexOutOfBoundsException("Too many bytes to read - Need " + (index + length));
308         }
309 
310         ByteBuf dst = src.isDirect() ? alloc().directBuffer(length) : alloc().heapBuffer(length);
311         dst.writeBytes(src);
312         return dst;
313     }
314 
315     @Override
316     public int nioBufferCount() {
317         return 1;
318     }
319 
320     @Override
321     public ByteBuffer[] nioBuffers(int index, int length) {
322         return new ByteBuffer[] { nioBuffer(index, length) };
323     }
324 
325     @Override
326     public ByteBuffer nioBuffer(int index, int length) {
327         return (ByteBuffer) buffer.duplicate().position(index).limit(index + length);
328     }
329 
330     @Override
331     public ByteBuffer internalNioBuffer(int index, int length) {
332         ensureAccessible();
333         return (ByteBuffer) internalNioBuffer().clear().position(index).limit(index + length);
334     }
335 
336     @Override
337     public boolean hasArray() {
338         return buffer.hasArray();
339     }
340 
341     @Override
342     public byte[] array() {
343         return buffer.array();
344     }
345 
346     @Override
347     public int arrayOffset() {
348         return buffer.arrayOffset();
349     }
350 
351     @Override
352     public boolean hasMemoryAddress() {
353         return false;
354     }
355 
356     @Override
357     public long memoryAddress() {
358         throw new UnsupportedOperationException();
359     }
360 }