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8e76f6ab | 1 | package be.nikiroo.utils.streams; |
33895a7b NR |
2 | |
3 | import java.io.IOException; | |
4 | import java.io.InputStream; | |
2e6426c0 NR |
5 | import java.util.AbstractMap; |
6 | import java.util.ArrayList; | |
7 | import java.util.List; | |
8 | import java.util.Map.Entry; | |
33895a7b | 9 | |
f8147a0e NR |
10 | import be.nikiroo.utils.StringUtils; |
11 | ||
33895a7b NR |
12 | /** |
13 | * A simple {@link InputStream} that is buffered with a bytes array. | |
14 | * <p> | |
15 | * It is mostly intended to be used as a base class to create new | |
16 | * {@link InputStream}s with special operation modes, and to give some default | |
17 | * methods. | |
18 | * | |
19 | * @author niki | |
20 | */ | |
21 | public class BufferedInputStream extends InputStream { | |
7194ac50 NR |
22 | /** |
23 | * The size of the internal buffer (can be different if you pass your own | |
2e6426c0 NR |
24 | * buffer, of course, and can also expand to search for longer "startsWith" |
25 | * data). | |
7194ac50 | 26 | * <p> |
2e6426c0 NR |
27 | * Note that special "push-back" buffers can also be created during the life |
28 | * of this stream. | |
7194ac50 NR |
29 | */ |
30 | static private final int BUFFER_SIZE = 4096; | |
31 | ||
eeaa5ebc | 32 | /** The current position in the buffer. */ |
a26188d3 | 33 | protected int start; |
eeaa5ebc | 34 | /** The index of the last usable position of the buffer. */ |
a26188d3 | 35 | protected int stop; |
eeaa5ebc | 36 | /** The buffer itself. */ |
33895a7b | 37 | protected byte[] buffer; |
7194ac50 | 38 | /** An End-Of-File (or {@link InputStream}, here) marker. */ |
33895a7b NR |
39 | protected boolean eof; |
40 | ||
41 | private boolean closed; | |
42 | private InputStream in; | |
43 | private int openCounter; | |
44 | ||
2e6426c0 NR |
45 | /** array + offset of pushed-back buffers */ |
46 | private List<Entry<byte[], Integer>> backBuffers; | |
33895a7b NR |
47 | |
48 | private long bytesRead; | |
49 | ||
50 | /** | |
2e6426c0 | 51 | * Create a new {@link BufferedInputStream2} that wraps the given |
33895a7b NR |
52 | * {@link InputStream}. |
53 | * | |
54 | * @param in | |
55 | * the {@link InputStream} to wrap | |
56 | */ | |
57 | public BufferedInputStream(InputStream in) { | |
58 | this.in = in; | |
59 | ||
7194ac50 | 60 | this.buffer = new byte[BUFFER_SIZE]; |
a26188d3 NR |
61 | this.start = 0; |
62 | this.stop = 0; | |
2e6426c0 | 63 | this.backBuffers = new ArrayList<Entry<byte[], Integer>>(); |
33895a7b NR |
64 | } |
65 | ||
66 | /** | |
2e6426c0 NR |
67 | * Create a new {@link BufferedInputStream2} that wraps the given bytes |
68 | * array as a data source. | |
33895a7b NR |
69 | * |
70 | * @param in | |
71 | * the array to wrap, cannot be NULL | |
72 | */ | |
73 | public BufferedInputStream(byte[] in) { | |
74 | this(in, 0, in.length); | |
75 | } | |
76 | ||
77 | /** | |
2e6426c0 NR |
78 | * Create a new {@link BufferedInputStream2} that wraps the given bytes |
79 | * array as a data source. | |
33895a7b NR |
80 | * |
81 | * @param in | |
82 | * the array to wrap, cannot be NULL | |
83 | * @param offset | |
84 | * the offset to start the reading at | |
85 | * @param length | |
86 | * the number of bytes to take into account in the array, | |
87 | * starting from the offset | |
88 | * | |
89 | * @throws NullPointerException | |
90 | * if the array is NULL | |
91 | * @throws IndexOutOfBoundsException | |
92 | * if the offset and length do not correspond to the given array | |
93 | */ | |
94 | public BufferedInputStream(byte[] in, int offset, int length) { | |
95 | if (in == null) { | |
96 | throw new NullPointerException(); | |
97 | } else if (offset < 0 || length < 0 || length > in.length - offset) { | |
98 | throw new IndexOutOfBoundsException(); | |
99 | } | |
100 | ||
101 | this.in = null; | |
102 | ||
103 | this.buffer = in; | |
a26188d3 NR |
104 | this.start = offset; |
105 | this.stop = length; | |
2e6426c0 | 106 | this.backBuffers = new ArrayList<Entry<byte[], Integer>>(); |
33895a7b NR |
107 | } |
108 | ||
dce410fe | 109 | /** |
2e6426c0 | 110 | * Return this very same {@link BufferedInputStream2}, but keep a counter of |
33895a7b | 111 | * how many streams were open this way. When calling |
2e6426c0 | 112 | * {@link BufferedInputStream2#close()}, decrease this counter if it is not |
33895a7b NR |
113 | * already zero instead of actually closing the stream. |
114 | * <p> | |
115 | * You are now responsible for it — you <b>must</b> close it. | |
116 | * <p> | |
117 | * This method allows you to use a wrapping stream around this one and still | |
118 | * close the wrapping stream. | |
119 | * | |
120 | * @return the same stream, but you are now responsible for closing it | |
121 | * | |
122 | * @throws IOException | |
123 | * in case of I/O error or if the stream is closed | |
124 | */ | |
125 | public synchronized InputStream open() throws IOException { | |
126 | checkClose(); | |
127 | openCounter++; | |
128 | return this; | |
129 | } | |
130 | ||
dce410fe NR |
131 | /** |
132 | * Check if the current content (until eof) is equal to the given search | |
133 | * term. | |
134 | * <p> | |
135 | * Note: the search term size <b>must</b> be smaller or equal the internal | |
136 | * buffer size. | |
137 | * | |
138 | * @param search | |
139 | * the term to search for | |
140 | * | |
141 | * @return TRUE if the content that will be read starts with it | |
142 | * | |
143 | * @throws IOException | |
144 | * in case of I/O error or if the size of the search term is | |
145 | * greater than the internal buffer | |
146 | */ | |
147 | public boolean is(String search) throws IOException { | |
148 | return is(StringUtils.getBytes(search)); | |
149 | } | |
150 | ||
151 | /** | |
152 | * Check if the current content (until eof) is equal to the given search | |
153 | * term. | |
154 | * <p> | |
155 | * Note: the search term size <b>must</b> be smaller or equal the internal | |
156 | * buffer size. | |
157 | * | |
158 | * @param search | |
159 | * the term to search for | |
160 | * | |
161 | * @return TRUE if the content that will be read starts with it | |
162 | * | |
163 | * @throws IOException | |
164 | * in case of I/O error or if the size of the search term is | |
165 | * greater than the internal buffer | |
166 | */ | |
167 | public boolean is(byte[] search) throws IOException { | |
168 | if (startsWith(search)) { | |
2e6426c0 | 169 | return available() == search.length; |
dce410fe NR |
170 | } |
171 | ||
172 | return false; | |
173 | } | |
174 | ||
eeaa5ebc NR |
175 | /** |
176 | * Check if the current content (what will be read next) starts with the | |
177 | * given search term. | |
178 | * <p> | |
179 | * Note: the search term size <b>must</b> be smaller or equal the internal | |
180 | * buffer size. | |
181 | * | |
182 | * @param search | |
183 | * the term to search for | |
184 | * | |
185 | * @return TRUE if the content that will be read starts with it | |
186 | * | |
187 | * @throws IOException | |
188 | * in case of I/O error or if the size of the search term is | |
189 | * greater than the internal buffer | |
190 | */ | |
d251f3dd | 191 | public boolean startsWith(String search) throws IOException { |
f8147a0e | 192 | return startsWith(StringUtils.getBytes(search)); |
33895a7b NR |
193 | } |
194 | ||
eeaa5ebc NR |
195 | /** |
196 | * Check if the current content (what will be read next) starts with the | |
197 | * given search term. | |
198 | * <p> | |
d251f3dd NR |
199 | * An empty string will always return true (unless the stream is closed, |
200 | * which would throw an {@link IOException}). | |
201 | * <p> | |
eeaa5ebc NR |
202 | * Note: the search term size <b>must</b> be smaller or equal the internal |
203 | * buffer size. | |
204 | * | |
205 | * @param search | |
206 | * the term to search for | |
207 | * | |
208 | * @return TRUE if the content that will be read starts with it | |
209 | * | |
210 | * @throws IOException | |
211 | * in case of I/O error or if the size of the search term is | |
212 | * greater than the internal buffer | |
213 | */ | |
33895a7b | 214 | public boolean startsWith(byte[] search) throws IOException { |
33895a7b NR |
215 | checkClose(); |
216 | ||
2e6426c0 | 217 | while (consolidatePushBack(search.length) < search.length) { |
33895a7b | 218 | preRead(); |
2e6426c0 NR |
219 | if (start >= stop) { |
220 | // Not enough data left to start with that | |
221 | return false; | |
33895a7b NR |
222 | } |
223 | ||
2e6426c0 NR |
224 | byte[] newBuffer = new byte[stop - start]; |
225 | System.arraycopy(buffer, start, newBuffer, 0, stop - start); | |
226 | pushback(newBuffer, 0); | |
227 | start = stop; | |
33895a7b NR |
228 | } |
229 | ||
2e6426c0 NR |
230 | Entry<byte[], Integer> bb = backBuffers.get(backBuffers.size() - 1); |
231 | byte[] bbBuffer = bb.getKey(); | |
232 | int bbOffset = bb.getValue(); | |
233 | ||
234 | return StreamUtils.startsWith(search, bbBuffer, bbOffset, | |
235 | bbBuffer.length); | |
33895a7b NR |
236 | } |
237 | ||
238 | /** | |
239 | * The number of bytes read from the under-laying {@link InputStream}. | |
240 | * | |
241 | * @return the number of bytes | |
242 | */ | |
243 | public long getBytesRead() { | |
244 | return bytesRead; | |
245 | } | |
246 | ||
247 | /** | |
2e6426c0 | 248 | * Check if this stream is spent (no more data to read or to process). |
33895a7b NR |
249 | * |
250 | * @return TRUE if it is | |
028ff7c2 NR |
251 | * |
252 | * @throws IOException | |
253 | * in case of I/O error | |
33895a7b | 254 | */ |
028ff7c2 NR |
255 | public boolean eof() throws IOException { |
256 | if (closed) { | |
257 | return true; | |
258 | } | |
259 | ||
260 | preRead(); | |
261 | return !hasMoreData(); | |
33895a7b NR |
262 | } |
263 | ||
d251f3dd NR |
264 | /** |
265 | * Read the whole {@link InputStream} until the end and return the number of | |
266 | * bytes read. | |
267 | * | |
268 | * @return the number of bytes read | |
269 | * | |
270 | * @throws IOException | |
271 | * in case of I/O error | |
272 | */ | |
273 | public long end() throws IOException { | |
274 | long skipped = 0; | |
275 | while (hasMoreData()) { | |
276 | skipped += skip(buffer.length); | |
277 | } | |
278 | ||
279 | return skipped; | |
280 | } | |
281 | ||
33895a7b NR |
282 | @Override |
283 | public int read() throws IOException { | |
284 | checkClose(); | |
285 | ||
286 | preRead(); | |
287 | if (eof) { | |
288 | return -1; | |
289 | } | |
290 | ||
a26188d3 | 291 | return buffer[start++]; |
33895a7b NR |
292 | } |
293 | ||
294 | @Override | |
295 | public int read(byte[] b) throws IOException { | |
296 | return read(b, 0, b.length); | |
297 | } | |
298 | ||
299 | @Override | |
300 | public int read(byte[] b, int boff, int blen) throws IOException { | |
301 | checkClose(); | |
302 | ||
303 | if (b == null) { | |
304 | throw new NullPointerException(); | |
305 | } else if (boff < 0 || blen < 0 || blen > b.length - boff) { | |
306 | throw new IndexOutOfBoundsException(); | |
307 | } else if (blen == 0) { | |
308 | return 0; | |
309 | } | |
310 | ||
2e6426c0 NR |
311 | // Read from the pushed-back buffers if any |
312 | if (!backBuffers.isEmpty()) { | |
313 | int read = 0; | |
314 | ||
315 | Entry<byte[], Integer> bb = backBuffers | |
316 | .remove(backBuffers.size() - 1); | |
317 | byte[] bbBuffer = bb.getKey(); | |
318 | int bbOffset = bb.getValue(); | |
319 | int bbSize = bbBuffer.length - bbOffset; | |
320 | ||
321 | if (bbSize > blen) { | |
322 | read = blen; | |
323 | System.arraycopy(bbBuffer, bbOffset, b, boff, read); | |
324 | pushback(bbBuffer, bbOffset + read); | |
325 | } else { | |
326 | read = bbSize; | |
327 | System.arraycopy(bbBuffer, bbOffset, b, boff, read); | |
328 | } | |
329 | ||
330 | return read; | |
331 | } | |
332 | ||
33895a7b NR |
333 | int done = 0; |
334 | while (hasMoreData() && done < blen) { | |
335 | preRead(); | |
336 | if (hasMoreData()) { | |
f04d5e49 | 337 | int now = Math.min(blen - done, stop - start); |
33895a7b | 338 | if (now > 0) { |
a26188d3 NR |
339 | System.arraycopy(buffer, start, b, boff + done, now); |
340 | start += now; | |
33895a7b NR |
341 | done += now; |
342 | } | |
343 | } | |
344 | } | |
345 | ||
346 | return done > 0 ? done : -1; | |
347 | } | |
348 | ||
349 | @Override | |
350 | public long skip(long n) throws IOException { | |
351 | if (n <= 0) { | |
352 | return 0; | |
353 | } | |
354 | ||
355 | long skipped = 0; | |
2e6426c0 NR |
356 | while (!backBuffers.isEmpty() && n > 0) { |
357 | Entry<byte[], Integer> bb = backBuffers | |
358 | .remove(backBuffers.size() - 1); | |
359 | byte[] bbBuffer = bb.getKey(); | |
360 | int bbOffset = bb.getValue(); | |
361 | int bbSize = bbBuffer.length - bbOffset; | |
362 | ||
363 | int localSkip = 0; | |
364 | localSkip = (int) Math.min(n, bbSize); | |
365 | ||
366 | n -= localSkip; | |
367 | bbSize -= localSkip; | |
368 | ||
369 | if (bbSize > 0) { | |
370 | pushback(bbBuffer, bbOffset + localSkip); | |
371 | } | |
372 | } | |
33895a7b NR |
373 | while (hasMoreData() && n > 0) { |
374 | preRead(); | |
375 | ||
376 | long inBuffer = Math.min(n, available()); | |
a26188d3 | 377 | start += inBuffer; |
33895a7b NR |
378 | n -= inBuffer; |
379 | skipped += inBuffer; | |
380 | } | |
381 | ||
382 | return skipped; | |
383 | } | |
384 | ||
385 | @Override | |
386 | public int available() { | |
387 | if (closed) { | |
388 | return 0; | |
389 | } | |
390 | ||
2e6426c0 NR |
391 | int avail = 0; |
392 | for (Entry<byte[], Integer> entry : backBuffers) { | |
393 | avail += entry.getKey().length - entry.getValue(); | |
394 | } | |
395 | ||
396 | return avail + Math.max(0, stop - start); | |
33895a7b NR |
397 | } |
398 | ||
399 | /** | |
400 | * Closes this stream and releases any system resources associated with the | |
401 | * stream. | |
402 | * <p> | |
403 | * Including the under-laying {@link InputStream}. | |
404 | * <p> | |
2e6426c0 | 405 | * <b>Note:</b> if you called the {@link BufferedInputStream2#open()} method |
33895a7b NR |
406 | * prior to this one, it will just decrease the internal count of how many |
407 | * open streams it held and do nothing else. The stream will actually be | |
2e6426c0 NR |
408 | * closed when you have called {@link BufferedInputStream2#close()} once |
409 | * more than {@link BufferedInputStream2#open()}. | |
33895a7b NR |
410 | * |
411 | * @exception IOException | |
412 | * in case of I/O error | |
413 | */ | |
414 | @Override | |
415 | public synchronized void close() throws IOException { | |
416 | close(true); | |
417 | } | |
418 | ||
419 | /** | |
420 | * Closes this stream and releases any system resources associated with the | |
421 | * stream. | |
422 | * <p> | |
423 | * Including the under-laying {@link InputStream} if | |
424 | * <tt>incudingSubStream</tt> is true. | |
425 | * <p> | |
426 | * You can call this method multiple times, it will not cause an | |
427 | * {@link IOException} for subsequent calls. | |
428 | * <p> | |
2e6426c0 | 429 | * <b>Note:</b> if you called the {@link BufferedInputStream2#open()} method |
33895a7b NR |
430 | * prior to this one, it will just decrease the internal count of how many |
431 | * open streams it held and do nothing else. The stream will actually be | |
2e6426c0 NR |
432 | * closed when you have called {@link BufferedInputStream2#close()} once |
433 | * more than {@link BufferedInputStream2#open()}. | |
33895a7b | 434 | * |
eeaa5ebc NR |
435 | * @param includingSubStream |
436 | * also close the under-laying stream | |
437 | * | |
33895a7b NR |
438 | * @exception IOException |
439 | * in case of I/O error | |
440 | */ | |
441 | public synchronized void close(boolean includingSubStream) | |
442 | throws IOException { | |
443 | if (!closed) { | |
444 | if (openCounter > 0) { | |
445 | openCounter--; | |
446 | } else { | |
447 | closed = true; | |
448 | if (includingSubStream && in != null) { | |
449 | in.close(); | |
450 | } | |
451 | } | |
452 | } | |
453 | } | |
454 | ||
2e6426c0 NR |
455 | /** |
456 | * Consolidate the push-back buffers so the last one is at least the given | |
457 | * size, if possible. | |
458 | * <p> | |
459 | * If there is not enough data in the push-back buffers, they will all be | |
460 | * consolidated. | |
461 | * | |
462 | * @param size | |
463 | * the minimum size of the consolidated buffer, or -1 to force | |
464 | * the consolidation of all push-back buffers | |
465 | * | |
466 | * @return the size of the last, consolidated buffer; can be less than the | |
467 | * requested size if not enough data | |
468 | */ | |
469 | protected int consolidatePushBack(int size) { | |
470 | int bbIndex = -1; | |
471 | int bbUpToSize = 0; | |
472 | for (Entry<byte[], Integer> entry : backBuffers) { | |
473 | bbIndex++; | |
474 | bbUpToSize += entry.getKey().length - entry.getValue(); | |
475 | ||
476 | if (size >= 0 && bbUpToSize >= size) { | |
477 | break; | |
478 | } | |
479 | } | |
480 | ||
481 | // Index 0 means "the last buffer is already big enough" | |
482 | if (bbIndex > 0) { | |
483 | byte[] consolidatedBuffer = new byte[bbUpToSize]; | |
484 | int consolidatedPos = 0; | |
485 | for (int i = 0; i <= bbIndex; i++) { | |
486 | Entry<byte[], Integer> bb = backBuffers | |
487 | .remove(backBuffers.size() - 1); | |
488 | byte[] bbBuffer = bb.getKey(); | |
489 | int bbOffset = bb.getValue(); | |
490 | int bbSize = bbBuffer.length - bbOffset; | |
491 | System.arraycopy(bbBuffer, bbOffset, consolidatedBuffer, | |
492 | consolidatedPos, bbSize); | |
493 | } | |
494 | ||
495 | pushback(consolidatedBuffer, 0); | |
496 | } | |
497 | ||
498 | return bbUpToSize; | |
499 | } | |
500 | ||
33895a7b NR |
501 | /** |
502 | * Check if we still have some data in the buffer and, if not, fetch some. | |
503 | * | |
504 | * @return TRUE if we fetched some data, FALSE if there are still some in | |
505 | * the buffer | |
506 | * | |
507 | * @throws IOException | |
508 | * in case of I/O error | |
509 | */ | |
510 | protected boolean preRead() throws IOException { | |
511 | boolean hasRead = false; | |
028ff7c2 | 512 | if (in != null && !eof && start >= stop) { |
a26188d3 | 513 | start = 0; |
2e6426c0 NR |
514 | stop = read(in, buffer, 0, buffer.length); |
515 | if (stop > 0) { | |
516 | bytesRead += stop; | |
33895a7b NR |
517 | } |
518 | ||
519 | hasRead = true; | |
520 | } | |
521 | ||
a26188d3 | 522 | if (start >= stop) { |
33895a7b NR |
523 | eof = true; |
524 | } | |
525 | ||
526 | return hasRead; | |
527 | } | |
528 | ||
529 | /** | |
2e6426c0 NR |
530 | * Push back some data that will be read again at the next read call. |
531 | * | |
532 | * @param buffer | |
533 | * the buffer to push back | |
534 | * @param offset | |
535 | * the offset at which to start reading in the buffer | |
536 | */ | |
537 | protected void pushback(byte[] buffer, int offset) { | |
538 | backBuffers.add( | |
539 | new AbstractMap.SimpleEntry<byte[], Integer>(buffer, offset)); | |
540 | } | |
541 | ||
542 | /** | |
543 | * Read the under-laying stream into the given local buffer. | |
33895a7b NR |
544 | * |
545 | * @param in | |
546 | * the under-laying {@link InputStream} | |
547 | * @param buffer | |
2e6426c0 | 548 | * the buffer we use in this {@link BufferedInputStream2} |
028ff7c2 NR |
549 | * @param off |
550 | * the offset | |
551 | * @param len | |
552 | * the length in bytes | |
33895a7b NR |
553 | * |
554 | * @return the number of bytes read | |
555 | * | |
556 | * @throws IOException | |
557 | * in case of I/O error | |
558 | */ | |
028ff7c2 NR |
559 | protected int read(InputStream in, byte[] buffer, int off, int len) |
560 | throws IOException { | |
561 | return in.read(buffer, off, len); | |
33895a7b NR |
562 | } |
563 | ||
564 | /** | |
028ff7c2 NR |
565 | * We have more data available in the buffer <b>or</b> we can, maybe, fetch |
566 | * more. | |
33895a7b NR |
567 | * |
568 | * @return TRUE if it is the case, FALSE if not | |
569 | */ | |
570 | protected boolean hasMoreData() { | |
028ff7c2 NR |
571 | if (closed) { |
572 | return false; | |
573 | } | |
574 | ||
2e6426c0 | 575 | return !backBuffers.isEmpty() || (start < stop) || !eof; |
33895a7b NR |
576 | } |
577 | ||
578 | /** | |
579 | * Check that the stream was not closed, and throw an {@link IOException} if | |
580 | * it was. | |
581 | * | |
582 | * @throws IOException | |
583 | * if it was closed | |
584 | */ | |
585 | protected void checkClose() throws IOException { | |
586 | if (closed) { | |
587 | throw new IOException( | |
eeaa5ebc | 588 | "This BufferedInputStream was closed, you cannot use it anymore."); |
33895a7b NR |
589 | } |
590 | } | |
33895a7b | 591 | } |