1 | // Protocol Buffers - Google's data interchange format |
---|
2 | // Copyright 2008 Google Inc. All rights reserved. |
---|
3 | // http://code.google.com/p/protobuf/ |
---|
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.InputStream; |
---|
34 | import java.io.ByteArrayInputStream; |
---|
35 | import java.io.ByteArrayOutputStream; |
---|
36 | import java.io.FilterOutputStream; |
---|
37 | import java.io.UnsupportedEncodingException; |
---|
38 | import java.nio.ByteBuffer; |
---|
39 | import java.util.List; |
---|
40 | |
---|
41 | /** |
---|
42 | * Immutable array of bytes. |
---|
43 | * |
---|
44 | * @author crazybob@google.com Bob Lee |
---|
45 | * @author kenton@google.com Kenton Varda |
---|
46 | */ |
---|
47 | public final class ByteString { |
---|
48 | private final byte[] bytes; |
---|
49 | |
---|
50 | private ByteString(final byte[] bytes) { |
---|
51 | this.bytes = bytes; |
---|
52 | } |
---|
53 | |
---|
54 | /** |
---|
55 | * Gets the byte at the given index. |
---|
56 | * |
---|
57 | * @throws ArrayIndexOutOfBoundsException {@code index} is < 0 or >= size |
---|
58 | */ |
---|
59 | public byte byteAt(final int index) { |
---|
60 | return bytes[index]; |
---|
61 | } |
---|
62 | |
---|
63 | /** |
---|
64 | * Gets the number of bytes. |
---|
65 | */ |
---|
66 | public int size() { |
---|
67 | return bytes.length; |
---|
68 | } |
---|
69 | |
---|
70 | /** |
---|
71 | * Returns {@code true} if the size is {@code 0}, {@code false} otherwise. |
---|
72 | */ |
---|
73 | public boolean isEmpty() { |
---|
74 | return bytes.length == 0; |
---|
75 | } |
---|
76 | |
---|
77 | // ================================================================= |
---|
78 | // byte[] -> ByteString |
---|
79 | |
---|
80 | /** |
---|
81 | * Empty ByteString. |
---|
82 | */ |
---|
83 | public static final ByteString EMPTY = new ByteString(new byte[0]); |
---|
84 | |
---|
85 | /** |
---|
86 | * Copies the given bytes into a {@code ByteString}. |
---|
87 | */ |
---|
88 | public static ByteString copyFrom(final byte[] bytes, final int offset, |
---|
89 | final int size) { |
---|
90 | final byte[] copy = new byte[size]; |
---|
91 | System.arraycopy(bytes, offset, copy, 0, size); |
---|
92 | return new ByteString(copy); |
---|
93 | } |
---|
94 | |
---|
95 | /** |
---|
96 | * Copies the given bytes into a {@code ByteString}. |
---|
97 | */ |
---|
98 | public static ByteString copyFrom(final byte[] bytes) { |
---|
99 | return copyFrom(bytes, 0, bytes.length); |
---|
100 | } |
---|
101 | |
---|
102 | /** |
---|
103 | * Copies {@code size} bytes from a {@code java.nio.ByteBuffer} into |
---|
104 | * a {@code ByteString}. |
---|
105 | */ |
---|
106 | public static ByteString copyFrom(final ByteBuffer bytes, final int size) { |
---|
107 | final byte[] copy = new byte[size]; |
---|
108 | bytes.get(copy); |
---|
109 | return new ByteString(copy); |
---|
110 | } |
---|
111 | |
---|
112 | /** |
---|
113 | * Copies the remaining bytes from a {@code java.nio.ByteBuffer} into |
---|
114 | * a {@code ByteString}. |
---|
115 | */ |
---|
116 | public static ByteString copyFrom(final ByteBuffer bytes) { |
---|
117 | return copyFrom(bytes, bytes.remaining()); |
---|
118 | } |
---|
119 | |
---|
120 | /** |
---|
121 | * Encodes {@code text} into a sequence of bytes using the named charset |
---|
122 | * and returns the result as a {@code ByteString}. |
---|
123 | */ |
---|
124 | public static ByteString copyFrom(final String text, final String charsetName) |
---|
125 | throws UnsupportedEncodingException { |
---|
126 | return new ByteString(text.getBytes(charsetName)); |
---|
127 | } |
---|
128 | |
---|
129 | /** |
---|
130 | * Encodes {@code text} into a sequence of UTF-8 bytes and returns the |
---|
131 | * result as a {@code ByteString}. |
---|
132 | */ |
---|
133 | public static ByteString copyFromUtf8(final String text) { |
---|
134 | try { |
---|
135 | return new ByteString(text.getBytes("UTF-8")); |
---|
136 | } catch (UnsupportedEncodingException e) { |
---|
137 | throw new RuntimeException("UTF-8 not supported?", e); |
---|
138 | } |
---|
139 | } |
---|
140 | |
---|
141 | /** |
---|
142 | * Concatenates all byte strings in the list and returns the result. |
---|
143 | * |
---|
144 | * <p>The returned {@code ByteString} is not necessarily a unique object. |
---|
145 | * If the list is empty, the returned object is the singleton empty |
---|
146 | * {@code ByteString}. If the list has only one element, that |
---|
147 | * {@code ByteString} will be returned without copying. |
---|
148 | */ |
---|
149 | public static ByteString copyFrom(List<ByteString> list) { |
---|
150 | if (list.size() == 0) { |
---|
151 | return EMPTY; |
---|
152 | } else if (list.size() == 1) { |
---|
153 | return list.get(0); |
---|
154 | } |
---|
155 | |
---|
156 | int size = 0; |
---|
157 | for (ByteString str : list) { |
---|
158 | size += str.size(); |
---|
159 | } |
---|
160 | byte[] bytes = new byte[size]; |
---|
161 | int pos = 0; |
---|
162 | for (ByteString str : list) { |
---|
163 | System.arraycopy(str.bytes, 0, bytes, pos, str.size()); |
---|
164 | pos += str.size(); |
---|
165 | } |
---|
166 | return new ByteString(bytes); |
---|
167 | } |
---|
168 | |
---|
169 | // ================================================================= |
---|
170 | // ByteString -> byte[] |
---|
171 | |
---|
172 | /** |
---|
173 | * Copies bytes into a buffer at the given offset. |
---|
174 | * |
---|
175 | * @param target buffer to copy into |
---|
176 | * @param offset in the target buffer |
---|
177 | */ |
---|
178 | public void copyTo(final byte[] target, final int offset) { |
---|
179 | System.arraycopy(bytes, 0, target, offset, bytes.length); |
---|
180 | } |
---|
181 | |
---|
182 | /** |
---|
183 | * Copies bytes into a buffer. |
---|
184 | * |
---|
185 | * @param target buffer to copy into |
---|
186 | * @param sourceOffset offset within these bytes |
---|
187 | * @param targetOffset offset within the target buffer |
---|
188 | * @param size number of bytes to copy |
---|
189 | */ |
---|
190 | public void copyTo(final byte[] target, final int sourceOffset, |
---|
191 | final int targetOffset, |
---|
192 | final int size) { |
---|
193 | System.arraycopy(bytes, sourceOffset, target, targetOffset, size); |
---|
194 | } |
---|
195 | |
---|
196 | /** |
---|
197 | * Copies bytes into a ByteBuffer. |
---|
198 | * |
---|
199 | * @param target ByteBuffer to copy into. |
---|
200 | * @throws ReadOnlyBufferException if the {@code target} is read-only |
---|
201 | * @throws BufferOverflowException if the {@code target}'s remaining() |
---|
202 | * space is not large enough to hold the data. |
---|
203 | */ |
---|
204 | public void copyTo(ByteBuffer target) { |
---|
205 | target.put(bytes, 0, bytes.length); |
---|
206 | } |
---|
207 | |
---|
208 | /** |
---|
209 | * Copies bytes to a {@code byte[]}. |
---|
210 | */ |
---|
211 | public byte[] toByteArray() { |
---|
212 | final int size = bytes.length; |
---|
213 | final byte[] copy = new byte[size]; |
---|
214 | System.arraycopy(bytes, 0, copy, 0, size); |
---|
215 | return copy; |
---|
216 | } |
---|
217 | |
---|
218 | /** |
---|
219 | * Constructs a new read-only {@code java.nio.ByteBuffer} with the |
---|
220 | * same backing byte array. |
---|
221 | */ |
---|
222 | public ByteBuffer asReadOnlyByteBuffer() { |
---|
223 | final ByteBuffer byteBuffer = ByteBuffer.wrap(bytes); |
---|
224 | return byteBuffer.asReadOnlyBuffer(); |
---|
225 | } |
---|
226 | |
---|
227 | /** |
---|
228 | * Constructs a new {@code String} by decoding the bytes using the |
---|
229 | * specified charset. |
---|
230 | */ |
---|
231 | public String toString(final String charsetName) |
---|
232 | throws UnsupportedEncodingException { |
---|
233 | return new String(bytes, charsetName); |
---|
234 | } |
---|
235 | |
---|
236 | /** |
---|
237 | * Constructs a new {@code String} by decoding the bytes as UTF-8. |
---|
238 | */ |
---|
239 | public String toStringUtf8() { |
---|
240 | try { |
---|
241 | return new String(bytes, "UTF-8"); |
---|
242 | } catch (UnsupportedEncodingException e) { |
---|
243 | throw new RuntimeException("UTF-8 not supported?", e); |
---|
244 | } |
---|
245 | } |
---|
246 | |
---|
247 | // ================================================================= |
---|
248 | // equals() and hashCode() |
---|
249 | |
---|
250 | @Override |
---|
251 | public boolean equals(final Object o) { |
---|
252 | if (o == this) { |
---|
253 | return true; |
---|
254 | } |
---|
255 | |
---|
256 | if (!(o instanceof ByteString)) { |
---|
257 | return false; |
---|
258 | } |
---|
259 | |
---|
260 | final ByteString other = (ByteString) o; |
---|
261 | final int size = bytes.length; |
---|
262 | if (size != other.bytes.length) { |
---|
263 | return false; |
---|
264 | } |
---|
265 | |
---|
266 | final byte[] thisBytes = bytes; |
---|
267 | final byte[] otherBytes = other.bytes; |
---|
268 | for (int i = 0; i < size; i++) { |
---|
269 | if (thisBytes[i] != otherBytes[i]) { |
---|
270 | return false; |
---|
271 | } |
---|
272 | } |
---|
273 | |
---|
274 | return true; |
---|
275 | } |
---|
276 | |
---|
277 | private volatile int hash = 0; |
---|
278 | |
---|
279 | @Override |
---|
280 | public int hashCode() { |
---|
281 | int h = hash; |
---|
282 | |
---|
283 | if (h == 0) { |
---|
284 | final byte[] thisBytes = bytes; |
---|
285 | final int size = bytes.length; |
---|
286 | |
---|
287 | h = size; |
---|
288 | for (int i = 0; i < size; i++) { |
---|
289 | h = h * 31 + thisBytes[i]; |
---|
290 | } |
---|
291 | if (h == 0) { |
---|
292 | h = 1; |
---|
293 | } |
---|
294 | |
---|
295 | hash = h; |
---|
296 | } |
---|
297 | |
---|
298 | return h; |
---|
299 | } |
---|
300 | |
---|
301 | // ================================================================= |
---|
302 | // Input stream |
---|
303 | |
---|
304 | /** |
---|
305 | * Creates an {@code InputStream} which can be used to read the bytes. |
---|
306 | */ |
---|
307 | public InputStream newInput() { |
---|
308 | return new ByteArrayInputStream(bytes); |
---|
309 | } |
---|
310 | |
---|
311 | /** |
---|
312 | * Creates a {@link CodedInputStream} which can be used to read the bytes. |
---|
313 | * Using this is more efficient than creating a {@link CodedInputStream} |
---|
314 | * wrapping the result of {@link #newInput()}. |
---|
315 | */ |
---|
316 | public CodedInputStream newCodedInput() { |
---|
317 | // We trust CodedInputStream not to modify the bytes, or to give anyone |
---|
318 | // else access to them. |
---|
319 | return CodedInputStream.newInstance(bytes); |
---|
320 | } |
---|
321 | |
---|
322 | // ================================================================= |
---|
323 | // Output stream |
---|
324 | |
---|
325 | /** |
---|
326 | * Creates a new {@link Output} with the given initial capacity. |
---|
327 | */ |
---|
328 | public static Output newOutput(final int initialCapacity) { |
---|
329 | return new Output(new ByteArrayOutputStream(initialCapacity)); |
---|
330 | } |
---|
331 | |
---|
332 | /** |
---|
333 | * Creates a new {@link Output}. |
---|
334 | */ |
---|
335 | public static Output newOutput() { |
---|
336 | return newOutput(32); |
---|
337 | } |
---|
338 | |
---|
339 | /** |
---|
340 | * Outputs to a {@code ByteString} instance. Call {@link #toByteString()} to |
---|
341 | * create the {@code ByteString} instance. |
---|
342 | */ |
---|
343 | public static final class Output extends FilterOutputStream { |
---|
344 | private final ByteArrayOutputStream bout; |
---|
345 | |
---|
346 | /** |
---|
347 | * Constructs a new output with the given initial capacity. |
---|
348 | */ |
---|
349 | private Output(final ByteArrayOutputStream bout) { |
---|
350 | super(bout); |
---|
351 | this.bout = bout; |
---|
352 | } |
---|
353 | |
---|
354 | /** |
---|
355 | * Creates a {@code ByteString} instance from this {@code Output}. |
---|
356 | */ |
---|
357 | public ByteString toByteString() { |
---|
358 | final byte[] byteArray = bout.toByteArray(); |
---|
359 | return new ByteString(byteArray); |
---|
360 | } |
---|
361 | } |
---|
362 | |
---|
363 | /** |
---|
364 | * Constructs a new ByteString builder, which allows you to efficiently |
---|
365 | * construct a {@code ByteString} by writing to a {@link CodedOutputStream}. |
---|
366 | * Using this is much more efficient than calling {@code newOutput()} and |
---|
367 | * wrapping that in a {@code CodedOutputStream}. |
---|
368 | * |
---|
369 | * <p>This is package-private because it's a somewhat confusing interface. |
---|
370 | * Users can call {@link Message#toByteString()} instead of calling this |
---|
371 | * directly. |
---|
372 | * |
---|
373 | * @param size The target byte size of the {@code ByteString}. You must |
---|
374 | * write exactly this many bytes before building the result. |
---|
375 | */ |
---|
376 | static CodedBuilder newCodedBuilder(final int size) { |
---|
377 | return new CodedBuilder(size); |
---|
378 | } |
---|
379 | |
---|
380 | /** See {@link ByteString#newCodedBuilder(int)}. */ |
---|
381 | static final class CodedBuilder { |
---|
382 | private final CodedOutputStream output; |
---|
383 | private final byte[] buffer; |
---|
384 | |
---|
385 | private CodedBuilder(final int size) { |
---|
386 | buffer = new byte[size]; |
---|
387 | output = CodedOutputStream.newInstance(buffer); |
---|
388 | } |
---|
389 | |
---|
390 | public ByteString build() { |
---|
391 | output.checkNoSpaceLeft(); |
---|
392 | |
---|
393 | // We can be confident that the CodedOutputStream will not modify the |
---|
394 | // underlying bytes anymore because it already wrote all of them. So, |
---|
395 | // no need to make a copy. |
---|
396 | return new ByteString(buffer); |
---|
397 | } |
---|
398 | |
---|
399 | public CodedOutputStream getCodedOutput() { |
---|
400 | return output; |
---|
401 | } |
---|
402 | } |
---|
403 | } |
---|