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1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 //     * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 //     * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 //     * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31 package com.google.protobuf;
32 
33 import java.io.IOException;
34 import java.io.InputStream;
35 import java.io.InvalidObjectException;
36 import java.io.ObjectInputStream;
37 import java.io.OutputStream;
38 import java.nio.ByteBuffer;
39 import java.nio.ByteOrder;
40 import java.nio.InvalidMarkException;
41 import java.nio.charset.Charset;
42 import java.util.Collections;
43 import java.util.List;
44 
45 /**
46  * A {@link ByteString} that wraps around a {@link ByteBuffer}.
47  */
48 final class NioByteString extends ByteString.LeafByteString {
49   private final ByteBuffer buffer;
50 
NioByteString(ByteBuffer buffer)51   NioByteString(ByteBuffer buffer) {
52     if (buffer == null) {
53       throw new NullPointerException("buffer");
54     }
55 
56     this.buffer = buffer.slice().order(ByteOrder.nativeOrder());
57   }
58 
59   // =================================================================
60   // Serializable
61 
62   /**
63    * Magic method that lets us override serialization behavior.
64    */
writeReplace()65   private Object writeReplace() {
66     return ByteString.copyFrom(buffer.slice());
67   }
68 
69   /**
70    * Magic method that lets us override deserialization behavior.
71    */
readObject(@uppressWarnings"unused") ObjectInputStream in)72   private void readObject(@SuppressWarnings("unused") ObjectInputStream in) throws IOException {
73     throw new InvalidObjectException("NioByteString instances are not to be serialized directly");
74   }
75 
76   // =================================================================
77 
78   @Override
byteAt(int index)79   public byte byteAt(int index) {
80     try {
81       return buffer.get(index);
82     } catch (ArrayIndexOutOfBoundsException e) {
83       throw e;
84     } catch (IndexOutOfBoundsException e) {
85       throw new ArrayIndexOutOfBoundsException(e.getMessage());
86     }
87   }
88 
89   @Override
size()90   public int size() {
91     return buffer.remaining();
92   }
93 
94   @Override
substring(int beginIndex, int endIndex)95   public ByteString substring(int beginIndex, int endIndex) {
96     try {
97       ByteBuffer slice = slice(beginIndex, endIndex);
98       return new NioByteString(slice);
99     } catch (ArrayIndexOutOfBoundsException e) {
100       throw e;
101     } catch (IndexOutOfBoundsException e) {
102       throw new ArrayIndexOutOfBoundsException(e.getMessage());
103     }
104   }
105 
106   @Override
copyToInternal( byte[] target, int sourceOffset, int targetOffset, int numberToCopy)107   protected void copyToInternal(
108       byte[] target, int sourceOffset, int targetOffset, int numberToCopy) {
109     ByteBuffer slice = buffer.slice();
110     slice.position(sourceOffset);
111     slice.get(target, targetOffset, numberToCopy);
112   }
113 
114   @Override
copyTo(ByteBuffer target)115   public void copyTo(ByteBuffer target) {
116     target.put(buffer.slice());
117   }
118 
119   @Override
writeTo(OutputStream out)120   public void writeTo(OutputStream out) throws IOException {
121     out.write(toByteArray());
122   }
123 
124   @Override
equalsRange(ByteString other, int offset, int length)125   boolean equalsRange(ByteString other, int offset, int length) {
126     return substring(0, length).equals(other.substring(offset, offset + length));
127   }
128 
129   @Override
writeToInternal(OutputStream out, int sourceOffset, int numberToWrite)130   void writeToInternal(OutputStream out, int sourceOffset, int numberToWrite) throws IOException {
131     if (buffer.hasArray()) {
132       // Optimized write for array-backed buffers.
133       // Note that we're taking the risk that a malicious OutputStream could modify the array.
134       int bufferOffset = buffer.arrayOffset() + buffer.position() + sourceOffset;
135       out.write(buffer.array(), bufferOffset, numberToWrite);
136       return;
137     }
138 
139     ByteBufferWriter.write(slice(sourceOffset, sourceOffset + numberToWrite), out);
140   }
141 
142   @Override
writeTo(ByteOutput output)143   void writeTo(ByteOutput output) throws IOException {
144     output.writeLazy(buffer.slice());
145   }
146 
147   @Override
asReadOnlyByteBuffer()148   public ByteBuffer asReadOnlyByteBuffer() {
149     return buffer.asReadOnlyBuffer();
150   }
151 
152   @Override
asReadOnlyByteBufferList()153   public List<ByteBuffer> asReadOnlyByteBufferList() {
154     return Collections.singletonList(asReadOnlyByteBuffer());
155   }
156 
157   @Override
toStringInternal(Charset charset)158   protected String toStringInternal(Charset charset) {
159     final byte[] bytes;
160     final int offset;
161     final int length;
162     if (buffer.hasArray()) {
163       bytes = buffer.array();
164       offset = buffer.arrayOffset() + buffer.position();
165       length = buffer.remaining();
166     } else {
167       // TODO(nathanmittler): Can we optimize this?
168       bytes = toByteArray();
169       offset = 0;
170       length = bytes.length;
171     }
172     return new String(bytes, offset, length, charset);
173   }
174 
175   @Override
isValidUtf8()176   public boolean isValidUtf8() {
177     return Utf8.isValidUtf8(buffer);
178   }
179 
180   @Override
partialIsValidUtf8(int state, int offset, int length)181   protected int partialIsValidUtf8(int state, int offset, int length) {
182     return Utf8.partialIsValidUtf8(state, buffer, offset, offset + length);
183   }
184 
185   @Override
equals(Object other)186   public boolean equals(Object other) {
187     if (other == this) {
188       return true;
189     }
190     if (!(other instanceof ByteString)) {
191       return false;
192     }
193     ByteString otherString = ((ByteString) other);
194     if (size() != otherString.size()) {
195       return false;
196     }
197     if (size() == 0) {
198       return true;
199     }
200     if (other instanceof NioByteString) {
201       return buffer.equals(((NioByteString) other).buffer);
202     }
203     if (other instanceof RopeByteString) {
204       return other.equals(this);
205     }
206     return buffer.equals(otherString.asReadOnlyByteBuffer());
207   }
208 
209   @Override
partialHash(int h, int offset, int length)210   protected int partialHash(int h, int offset, int length) {
211     for (int i = offset; i < offset + length; i++) {
212       h = h * 31 + buffer.get(i);
213     }
214     return h;
215   }
216 
217   @Override
newInput()218   public InputStream newInput() {
219     return new InputStream() {
220       private final ByteBuffer buf = buffer.slice();
221 
222       @Override
223       public void mark(int readlimit) {
224         buf.mark();
225       }
226 
227       @Override
228       public boolean markSupported() {
229         return true;
230       }
231 
232       @Override
233       public void reset() throws IOException {
234         try {
235           buf.reset();
236         } catch (InvalidMarkException e) {
237           throw new IOException(e);
238         }
239       }
240 
241       @Override
242       public int available() throws IOException {
243         return buf.remaining();
244       }
245 
246       @Override
247       public int read() throws IOException {
248         if (!buf.hasRemaining()) {
249           return -1;
250         }
251         return buf.get() & 0xFF;
252       }
253 
254       @Override
255       public int read(byte[] bytes, int off, int len) throws IOException {
256         if (!buf.hasRemaining()) {
257           return -1;
258         }
259 
260         len = Math.min(len, buf.remaining());
261         buf.get(bytes, off, len);
262         return len;
263       }
264     };
265   }
266 
267   @Override
newCodedInput()268   public CodedInputStream newCodedInput() {
269     return CodedInputStream.newInstance(buffer);
270   }
271 
272   /**
273    * Creates a slice of a range of this buffer.
274    *
275    * @param beginIndex the beginning index of the slice (inclusive).
276    * @param endIndex the end index of the slice (exclusive).
277    * @return the requested slice.
278    */
slice(int beginIndex, int endIndex)279   private ByteBuffer slice(int beginIndex, int endIndex) {
280     if (beginIndex < buffer.position() || endIndex > buffer.limit() || beginIndex > endIndex) {
281       throw new IllegalArgumentException(
282           String.format("Invalid indices [%d, %d]", beginIndex, endIndex));
283     }
284 
285     ByteBuffer slice = buffer.slice();
286     slice.position(beginIndex - buffer.position());
287     slice.limit(endIndex - buffer.position());
288     return slice;
289   }
290 }
291