1
2 /*
3 * Copyright 2006 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10 #include "SkStream.h"
11 #include "SkStreamPriv.h"
12 #include "SkData.h"
13 #include "SkFixed.h"
14 #include "SkString.h"
15 #include "SkOSFile.h"
16 #include "SkTypes.h"
17
18 ///////////////////////////////////////////////////////////////////////////////
19
20
readS8()21 int8_t SkStream::readS8() {
22 int8_t value;
23 SkDEBUGCODE(size_t len =) this->read(&value, 1);
24 SkASSERT(1 == len);
25 return value;
26 }
27
readS16()28 int16_t SkStream::readS16() {
29 int16_t value;
30 SkDEBUGCODE(size_t len =) this->read(&value, 2);
31 SkASSERT(2 == len);
32 return value;
33 }
34
readS32()35 int32_t SkStream::readS32() {
36 int32_t value;
37 SkDEBUGCODE(size_t len =) this->read(&value, 4);
38 SkASSERT(4 == len);
39 return value;
40 }
41
readScalar()42 SkScalar SkStream::readScalar() {
43 SkScalar value;
44 SkDEBUGCODE(size_t len =) this->read(&value, sizeof(SkScalar));
45 SkASSERT(sizeof(SkScalar) == len);
46 return value;
47 }
48
49 #define SK_MAX_BYTE_FOR_U8 0xFD
50 #define SK_BYTE_SENTINEL_FOR_U16 0xFE
51 #define SK_BYTE_SENTINEL_FOR_U32 0xFF
52
readPackedUInt()53 size_t SkStream::readPackedUInt() {
54 uint8_t byte;
55 if (!this->read(&byte, 1)) {
56 return 0;
57 }
58 if (SK_BYTE_SENTINEL_FOR_U16 == byte) {
59 return this->readU16();
60 } else if (SK_BYTE_SENTINEL_FOR_U32 == byte) {
61 return this->readU32();
62 } else {
63 return byte;
64 }
65 }
66
67 //////////////////////////////////////////////////////////////////////////////////////
68
~SkWStream()69 SkWStream::~SkWStream()
70 {
71 }
72
newline()73 void SkWStream::newline()
74 {
75 this->write("\n", 1);
76 }
77
flush()78 void SkWStream::flush()
79 {
80 }
81
writeText(const char text[])82 bool SkWStream::writeText(const char text[])
83 {
84 SkASSERT(text);
85 return this->write(text, strlen(text));
86 }
87
writeDecAsText(int32_t dec)88 bool SkWStream::writeDecAsText(int32_t dec)
89 {
90 char buffer[SkStrAppendS32_MaxSize];
91 char* stop = SkStrAppendS32(buffer, dec);
92 return this->write(buffer, stop - buffer);
93 }
94
writeBigDecAsText(int64_t dec,int minDigits)95 bool SkWStream::writeBigDecAsText(int64_t dec, int minDigits)
96 {
97 char buffer[SkStrAppendU64_MaxSize];
98 char* stop = SkStrAppendU64(buffer, dec, minDigits);
99 return this->write(buffer, stop - buffer);
100 }
101
writeHexAsText(uint32_t hex,int digits)102 bool SkWStream::writeHexAsText(uint32_t hex, int digits)
103 {
104 SkString tmp;
105 tmp.appendHex(hex, digits);
106 return this->write(tmp.c_str(), tmp.size());
107 }
108
writeScalarAsText(SkScalar value)109 bool SkWStream::writeScalarAsText(SkScalar value)
110 {
111 char buffer[SkStrAppendScalar_MaxSize];
112 char* stop = SkStrAppendScalar(buffer, value);
113 return this->write(buffer, stop - buffer);
114 }
115
write8(U8CPU value)116 bool SkWStream::write8(U8CPU value) {
117 uint8_t v = SkToU8(value);
118 return this->write(&v, 1);
119 }
120
write16(U16CPU value)121 bool SkWStream::write16(U16CPU value) {
122 uint16_t v = SkToU16(value);
123 return this->write(&v, 2);
124 }
125
write32(uint32_t value)126 bool SkWStream::write32(uint32_t value) {
127 return this->write(&value, 4);
128 }
129
writeScalar(SkScalar value)130 bool SkWStream::writeScalar(SkScalar value) {
131 return this->write(&value, sizeof(value));
132 }
133
SizeOfPackedUInt(size_t value)134 int SkWStream::SizeOfPackedUInt(size_t value) {
135 if (value <= SK_MAX_BYTE_FOR_U8) {
136 return 1;
137 } else if (value <= 0xFFFF) {
138 return 3;
139 }
140 return 5;
141 }
142
writePackedUInt(size_t value)143 bool SkWStream::writePackedUInt(size_t value) {
144 uint8_t data[5];
145 size_t len = 1;
146 if (value <= SK_MAX_BYTE_FOR_U8) {
147 data[0] = value;
148 len = 1;
149 } else if (value <= 0xFFFF) {
150 uint16_t value16 = value;
151 data[0] = SK_BYTE_SENTINEL_FOR_U16;
152 memcpy(&data[1], &value16, 2);
153 len = 3;
154 } else {
155 uint32_t value32 = SkToU32(value);
156 data[0] = SK_BYTE_SENTINEL_FOR_U32;
157 memcpy(&data[1], &value32, 4);
158 len = 5;
159 }
160 return this->write(data, len);
161 }
162
writeStream(SkStream * stream,size_t length)163 bool SkWStream::writeStream(SkStream* stream, size_t length) {
164 char scratch[1024];
165 const size_t MAX = sizeof(scratch);
166
167 while (length != 0) {
168 size_t n = length;
169 if (n > MAX) {
170 n = MAX;
171 }
172 stream->read(scratch, n);
173 if (!this->write(scratch, n)) {
174 return false;
175 }
176 length -= n;
177 }
178 return true;
179 }
180
181 ///////////////////////////////////////////////////////////////////////////////
182
SkFILEStream(const char file[])183 SkFILEStream::SkFILEStream(const char file[]) : fName(file), fOwnership(kCallerPasses_Ownership) {
184 fFILE = file ? sk_fopen(fName.c_str(), kRead_SkFILE_Flag) : NULL;
185 }
186
SkFILEStream(FILE * file,Ownership ownership)187 SkFILEStream::SkFILEStream(FILE* file, Ownership ownership)
188 : fFILE((SkFILE*)file)
189 , fOwnership(ownership) {
190 }
191
~SkFILEStream()192 SkFILEStream::~SkFILEStream() {
193 if (fFILE && fOwnership != kCallerRetains_Ownership) {
194 sk_fclose(fFILE);
195 }
196 }
197
setPath(const char path[])198 void SkFILEStream::setPath(const char path[]) {
199 fName.set(path);
200 if (fFILE) {
201 sk_fclose(fFILE);
202 fFILE = NULL;
203 }
204 if (path) {
205 fFILE = sk_fopen(fName.c_str(), kRead_SkFILE_Flag);
206 }
207 }
208
read(void * buffer,size_t size)209 size_t SkFILEStream::read(void* buffer, size_t size) {
210 if (fFILE) {
211 return sk_fread(buffer, size, fFILE);
212 }
213 return 0;
214 }
215
isAtEnd() const216 bool SkFILEStream::isAtEnd() const {
217 return sk_feof(fFILE);
218 }
219
rewind()220 bool SkFILEStream::rewind() {
221 if (fFILE) {
222 if (sk_frewind(fFILE)) {
223 return true;
224 }
225 // we hit an error
226 sk_fclose(fFILE);
227 fFILE = NULL;
228 }
229 return false;
230 }
231
duplicate() const232 SkStreamAsset* SkFILEStream::duplicate() const {
233 if (NULL == fFILE) {
234 return new SkMemoryStream();
235 }
236
237 if (fData.get()) {
238 return new SkMemoryStream(fData);
239 }
240
241 if (!fName.isEmpty()) {
242 SkAutoTDelete<SkFILEStream> that(new SkFILEStream(fName.c_str()));
243 if (sk_fidentical(that->fFILE, this->fFILE)) {
244 return that.detach();
245 }
246 }
247
248 fData.reset(SkData::NewFromFILE(fFILE));
249 if (NULL == fData.get()) {
250 return NULL;
251 }
252 return new SkMemoryStream(fData);
253 }
254
getPosition() const255 size_t SkFILEStream::getPosition() const {
256 return sk_ftell(fFILE);
257 }
258
seek(size_t position)259 bool SkFILEStream::seek(size_t position) {
260 return sk_fseek(fFILE, position);
261 }
262
move(long offset)263 bool SkFILEStream::move(long offset) {
264 return sk_fmove(fFILE, offset);
265 }
266
fork() const267 SkStreamAsset* SkFILEStream::fork() const {
268 SkAutoTDelete<SkStreamAsset> that(this->duplicate());
269 that->seek(this->getPosition());
270 return that.detach();
271 }
272
getLength() const273 size_t SkFILEStream::getLength() const {
274 return sk_fgetsize(fFILE);
275 }
276
getMemoryBase()277 const void* SkFILEStream::getMemoryBase() {
278 if (NULL == fData.get()) {
279 return NULL;
280 }
281 return fData->data();
282 }
283
284 ///////////////////////////////////////////////////////////////////////////////
285
newFromParams(const void * src,size_t size,bool copyData)286 static SkData* newFromParams(const void* src, size_t size, bool copyData) {
287 if (copyData) {
288 return SkData::NewWithCopy(src, size);
289 } else {
290 return SkData::NewWithoutCopy(src, size);
291 }
292 }
293
SkMemoryStream()294 SkMemoryStream::SkMemoryStream() {
295 fData = SkData::NewEmpty();
296 fOffset = 0;
297 }
298
SkMemoryStream(size_t size)299 SkMemoryStream::SkMemoryStream(size_t size) {
300 fData = SkData::NewUninitialized(size);
301 fOffset = 0;
302 }
303
SkMemoryStream(const void * src,size_t size,bool copyData)304 SkMemoryStream::SkMemoryStream(const void* src, size_t size, bool copyData) {
305 fData = newFromParams(src, size, copyData);
306 fOffset = 0;
307 }
308
SkMemoryStream(SkData * data)309 SkMemoryStream::SkMemoryStream(SkData* data) {
310 if (NULL == data) {
311 fData = SkData::NewEmpty();
312 } else {
313 fData = data;
314 fData->ref();
315 }
316 fOffset = 0;
317 }
318
~SkMemoryStream()319 SkMemoryStream::~SkMemoryStream() {
320 fData->unref();
321 }
322
setMemoryOwned(const void * src,size_t size)323 void SkMemoryStream::setMemoryOwned(const void* src, size_t size) {
324 fData->unref();
325 fData = SkData::NewFromMalloc(src, size);
326 fOffset = 0;
327 }
328
setMemory(const void * src,size_t size,bool copyData)329 void SkMemoryStream::setMemory(const void* src, size_t size, bool copyData) {
330 fData->unref();
331 fData = newFromParams(src, size, copyData);
332 fOffset = 0;
333 }
334
copyToData() const335 SkData* SkMemoryStream::copyToData() const {
336 fData->ref();
337 return fData;
338 }
339
setData(SkData * data)340 SkData* SkMemoryStream::setData(SkData* data) {
341 fData->unref();
342 if (NULL == data) {
343 fData = SkData::NewEmpty();
344 } else {
345 fData = data;
346 fData->ref();
347 }
348 fOffset = 0;
349 return data;
350 }
351
skipToAlign4()352 void SkMemoryStream::skipToAlign4() {
353 // cast to remove unary-minus warning
354 fOffset += -(int)fOffset & 0x03;
355 }
356
read(void * buffer,size_t size)357 size_t SkMemoryStream::read(void* buffer, size_t size) {
358 size_t dataSize = fData->size();
359
360 if (size > dataSize - fOffset) {
361 size = dataSize - fOffset;
362 }
363 if (buffer) {
364 memcpy(buffer, fData->bytes() + fOffset, size);
365 }
366 fOffset += size;
367 return size;
368 }
369
peek(void * buffer,size_t size) const370 bool SkMemoryStream::peek(void* buffer, size_t size) const {
371 SkASSERT(buffer != NULL);
372 const size_t position = fOffset;
373 if (size > fData->size() - position) {
374 // The stream is not large enough to satisfy this request.
375 return false;
376 }
377 SkMemoryStream* nonConstThis = const_cast<SkMemoryStream*>(this);
378 SkDEBUGCODE(const size_t bytesRead =) nonConstThis->read(buffer, size);
379 SkASSERT(bytesRead == size);
380 nonConstThis->fOffset = position;
381 return true;
382 }
383
isAtEnd() const384 bool SkMemoryStream::isAtEnd() const {
385 return fOffset == fData->size();
386 }
387
rewind()388 bool SkMemoryStream::rewind() {
389 fOffset = 0;
390 return true;
391 }
392
duplicate() const393 SkMemoryStream* SkMemoryStream::duplicate() const {
394 return SkNEW_ARGS(SkMemoryStream, (fData));
395 }
396
getPosition() const397 size_t SkMemoryStream::getPosition() const {
398 return fOffset;
399 }
400
seek(size_t position)401 bool SkMemoryStream::seek(size_t position) {
402 fOffset = position > fData->size()
403 ? fData->size()
404 : position;
405 return true;
406 }
407
move(long offset)408 bool SkMemoryStream::move(long offset) {
409 return this->seek(fOffset + offset);
410 }
411
fork() const412 SkMemoryStream* SkMemoryStream::fork() const {
413 SkAutoTDelete<SkMemoryStream> that(this->duplicate());
414 that->seek(fOffset);
415 return that.detach();
416 }
417
getLength() const418 size_t SkMemoryStream::getLength() const {
419 return fData->size();
420 }
421
getMemoryBase()422 const void* SkMemoryStream::getMemoryBase() {
423 return fData->data();
424 }
425
getAtPos()426 const void* SkMemoryStream::getAtPos() {
427 return fData->bytes() + fOffset;
428 }
429
430 /////////////////////////////////////////////////////////////////////////////////////////////////////////
431 /////////////////////////////////////////////////////////////////////////////////////////////////////////
432
SkFILEWStream(const char path[])433 SkFILEWStream::SkFILEWStream(const char path[])
434 {
435 fFILE = sk_fopen(path, kWrite_SkFILE_Flag);
436 }
437
~SkFILEWStream()438 SkFILEWStream::~SkFILEWStream()
439 {
440 if (fFILE) {
441 sk_fclose(fFILE);
442 }
443 }
444
bytesWritten() const445 size_t SkFILEWStream::bytesWritten() const {
446 return sk_ftell(fFILE);
447 }
448
write(const void * buffer,size_t size)449 bool SkFILEWStream::write(const void* buffer, size_t size)
450 {
451 if (fFILE == NULL) {
452 return false;
453 }
454
455 if (sk_fwrite(buffer, size, fFILE) != size)
456 {
457 SkDEBUGCODE(SkDebugf("SkFILEWStream failed writing %d bytes\n", size);)
458 sk_fclose(fFILE);
459 fFILE = NULL;
460 return false;
461 }
462 return true;
463 }
464
flush()465 void SkFILEWStream::flush()
466 {
467 if (fFILE) {
468 sk_fflush(fFILE);
469 }
470 }
471
472 ////////////////////////////////////////////////////////////////////////
473
SkMemoryWStream(void * buffer,size_t size)474 SkMemoryWStream::SkMemoryWStream(void* buffer, size_t size)
475 : fBuffer((char*)buffer), fMaxLength(size), fBytesWritten(0)
476 {
477 }
478
write(const void * buffer,size_t size)479 bool SkMemoryWStream::write(const void* buffer, size_t size) {
480 size = SkTMin(size, fMaxLength - fBytesWritten);
481 if (size > 0) {
482 memcpy(fBuffer + fBytesWritten, buffer, size);
483 fBytesWritten += size;
484 return true;
485 }
486 return false;
487 }
488
489 ////////////////////////////////////////////////////////////////////////
490
491 #define SkDynamicMemoryWStream_MinBlockSize 256
492
493 struct SkDynamicMemoryWStream::Block {
494 Block* fNext;
495 char* fCurr;
496 char* fStop;
497
startSkDynamicMemoryWStream::Block498 const char* start() const { return (const char*)(this + 1); }
startSkDynamicMemoryWStream::Block499 char* start() { return (char*)(this + 1); }
availSkDynamicMemoryWStream::Block500 size_t avail() const { return fStop - fCurr; }
writtenSkDynamicMemoryWStream::Block501 size_t written() const { return fCurr - this->start(); }
502
initSkDynamicMemoryWStream::Block503 void init(size_t size)
504 {
505 fNext = NULL;
506 fCurr = this->start();
507 fStop = this->start() + size;
508 }
509
appendSkDynamicMemoryWStream::Block510 const void* append(const void* data, size_t size)
511 {
512 SkASSERT((size_t)(fStop - fCurr) >= size);
513 memcpy(fCurr, data, size);
514 fCurr += size;
515 return (const void*)((const char*)data + size);
516 }
517 };
518
SkDynamicMemoryWStream()519 SkDynamicMemoryWStream::SkDynamicMemoryWStream()
520 : fHead(NULL), fTail(NULL), fBytesWritten(0), fCopy(NULL)
521 {
522 }
523
~SkDynamicMemoryWStream()524 SkDynamicMemoryWStream::~SkDynamicMemoryWStream()
525 {
526 reset();
527 }
528
reset()529 void SkDynamicMemoryWStream::reset()
530 {
531 this->invalidateCopy();
532
533 Block* block = fHead;
534
535 while (block != NULL) {
536 Block* next = block->fNext;
537 sk_free(block);
538 block = next;
539 }
540 fHead = fTail = NULL;
541 fBytesWritten = 0;
542 }
543
write(const void * buffer,size_t count)544 bool SkDynamicMemoryWStream::write(const void* buffer, size_t count)
545 {
546 if (count > 0) {
547 this->invalidateCopy();
548
549 fBytesWritten += count;
550
551 size_t size;
552
553 if (fTail != NULL && fTail->avail() > 0) {
554 size = SkTMin(fTail->avail(), count);
555 buffer = fTail->append(buffer, size);
556 SkASSERT(count >= size);
557 count -= size;
558 if (count == 0)
559 return true;
560 }
561
562 size = SkTMax<size_t>(count, SkDynamicMemoryWStream_MinBlockSize);
563 Block* block = (Block*)sk_malloc_throw(sizeof(Block) + size);
564 block->init(size);
565 block->append(buffer, count);
566
567 if (fTail != NULL)
568 fTail->fNext = block;
569 else
570 fHead = fTail = block;
571 fTail = block;
572 }
573 return true;
574 }
575
write(const void * buffer,size_t offset,size_t count)576 bool SkDynamicMemoryWStream::write(const void* buffer, size_t offset, size_t count)
577 {
578 if (offset + count > fBytesWritten) {
579 return false; // test does not partially modify
580 }
581
582 this->invalidateCopy();
583
584 Block* block = fHead;
585 while (block != NULL) {
586 size_t size = block->written();
587 if (offset < size) {
588 size_t part = offset + count > size ? size - offset : count;
589 memcpy(block->start() + offset, buffer, part);
590 if (count <= part)
591 return true;
592 count -= part;
593 buffer = (const void*) ((char* ) buffer + part);
594 }
595 offset = offset > size ? offset - size : 0;
596 block = block->fNext;
597 }
598 return false;
599 }
600
read(void * buffer,size_t offset,size_t count)601 bool SkDynamicMemoryWStream::read(void* buffer, size_t offset, size_t count)
602 {
603 if (offset + count > fBytesWritten)
604 return false; // test does not partially modify
605 Block* block = fHead;
606 while (block != NULL) {
607 size_t size = block->written();
608 if (offset < size) {
609 size_t part = offset + count > size ? size - offset : count;
610 memcpy(buffer, block->start() + offset, part);
611 if (count <= part)
612 return true;
613 count -= part;
614 buffer = (void*) ((char* ) buffer + part);
615 }
616 offset = offset > size ? offset - size : 0;
617 block = block->fNext;
618 }
619 return false;
620 }
621
copyTo(void * dst) const622 void SkDynamicMemoryWStream::copyTo(void* dst) const
623 {
624 if (fCopy) {
625 memcpy(dst, fCopy->data(), fBytesWritten);
626 } else {
627 Block* block = fHead;
628
629 while (block != NULL) {
630 size_t size = block->written();
631 memcpy(dst, block->start(), size);
632 dst = (void*)((char*)dst + size);
633 block = block->fNext;
634 }
635 }
636 }
637
writeToStream(SkWStream * dst) const638 void SkDynamicMemoryWStream::writeToStream(SkWStream* dst) const {
639 for (Block* block = fHead; block != NULL; block = block->fNext) {
640 dst->write(block->start(), block->written());
641 }
642 }
643
padToAlign4()644 void SkDynamicMemoryWStream::padToAlign4()
645 {
646 // cast to remove unary-minus warning
647 int padBytes = -(int)fBytesWritten & 0x03;
648 if (padBytes == 0)
649 return;
650 int zero = 0;
651 write(&zero, padBytes);
652 }
653
copyToData() const654 SkData* SkDynamicMemoryWStream::copyToData() const {
655 if (NULL == fCopy) {
656 SkData* data = SkData::NewUninitialized(fBytesWritten);
657 // be sure to call copyTo() before we assign to fCopy
658 this->copyTo(data->writable_data());
659 fCopy = data;
660 }
661 return SkRef(fCopy);
662 }
663
invalidateCopy()664 void SkDynamicMemoryWStream::invalidateCopy() {
665 if (fCopy) {
666 fCopy->unref();
667 fCopy = NULL;
668 }
669 }
670
671 class SkBlockMemoryRefCnt : public SkRefCnt {
672 public:
SkBlockMemoryRefCnt(SkDynamicMemoryWStream::Block * head)673 explicit SkBlockMemoryRefCnt(SkDynamicMemoryWStream::Block* head) : fHead(head) { }
674
~SkBlockMemoryRefCnt()675 virtual ~SkBlockMemoryRefCnt() {
676 SkDynamicMemoryWStream::Block* block = fHead;
677 while (block != NULL) {
678 SkDynamicMemoryWStream::Block* next = block->fNext;
679 sk_free(block);
680 block = next;
681 }
682 }
683
684 SkDynamicMemoryWStream::Block* const fHead;
685 };
686
687 class SkBlockMemoryStream : public SkStreamAsset {
688 public:
SkBlockMemoryStream(SkDynamicMemoryWStream::Block * head,size_t size)689 SkBlockMemoryStream(SkDynamicMemoryWStream::Block* head, size_t size)
690 : fBlockMemory(SkNEW_ARGS(SkBlockMemoryRefCnt, (head))), fCurrent(head)
691 , fSize(size) , fOffset(0), fCurrentOffset(0) { }
692
SkBlockMemoryStream(SkBlockMemoryRefCnt * headRef,size_t size)693 SkBlockMemoryStream(SkBlockMemoryRefCnt* headRef, size_t size)
694 : fBlockMemory(SkRef(headRef)), fCurrent(fBlockMemory->fHead)
695 , fSize(size) , fOffset(0), fCurrentOffset(0) { }
696
read(void * buffer,size_t rawCount)697 size_t read(void* buffer, size_t rawCount) override {
698 size_t count = rawCount;
699 if (fOffset + count > fSize) {
700 count = fSize - fOffset;
701 }
702 size_t bytesLeftToRead = count;
703 while (fCurrent != NULL) {
704 size_t bytesLeftInCurrent = fCurrent->written() - fCurrentOffset;
705 size_t bytesFromCurrent = SkTMin(bytesLeftToRead, bytesLeftInCurrent);
706 if (buffer) {
707 memcpy(buffer, fCurrent->start() + fCurrentOffset, bytesFromCurrent);
708 buffer = SkTAddOffset<void>(buffer, bytesFromCurrent);
709 }
710 if (bytesLeftToRead <= bytesFromCurrent) {
711 fCurrentOffset += bytesFromCurrent;
712 fOffset += count;
713 return count;
714 }
715 bytesLeftToRead -= bytesFromCurrent;
716 fCurrent = fCurrent->fNext;
717 fCurrentOffset = 0;
718 }
719 SkASSERT(false);
720 return 0;
721 }
722
isAtEnd() const723 bool isAtEnd() const override {
724 return fOffset == fSize;
725 }
726
rewind()727 bool rewind() override {
728 fCurrent = fBlockMemory->fHead;
729 fOffset = 0;
730 fCurrentOffset = 0;
731 return true;
732 }
733
duplicate() const734 SkBlockMemoryStream* duplicate() const override {
735 return SkNEW_ARGS(SkBlockMemoryStream, (fBlockMemory.get(), fSize));
736 }
737
getPosition() const738 size_t getPosition() const override {
739 return fOffset;
740 }
741
seek(size_t position)742 bool seek(size_t position) override {
743 // If possible, skip forward.
744 if (position >= fOffset) {
745 size_t skipAmount = position - fOffset;
746 return this->skip(skipAmount) == skipAmount;
747 }
748 // If possible, move backward within the current block.
749 size_t moveBackAmount = fOffset - position;
750 if (moveBackAmount <= fCurrentOffset) {
751 fCurrentOffset -= moveBackAmount;
752 fOffset -= moveBackAmount;
753 return true;
754 }
755 // Otherwise rewind and move forward.
756 return this->rewind() && this->skip(position) == position;
757 }
758
move(long offset)759 bool move(long offset) override {
760 return seek(fOffset + offset);
761 }
762
fork() const763 SkBlockMemoryStream* fork() const override {
764 SkAutoTDelete<SkBlockMemoryStream> that(this->duplicate());
765 that->fCurrent = this->fCurrent;
766 that->fOffset = this->fOffset;
767 that->fCurrentOffset = this->fCurrentOffset;
768 return that.detach();
769 }
770
getLength() const771 size_t getLength() const override {
772 return fSize;
773 }
774
getMemoryBase()775 const void* getMemoryBase() override {
776 if (NULL == fBlockMemory->fHead->fNext) {
777 return fBlockMemory->fHead->start();
778 }
779 return NULL;
780 }
781
782 private:
783 SkAutoTUnref<SkBlockMemoryRefCnt> const fBlockMemory;
784 SkDynamicMemoryWStream::Block const * fCurrent;
785 size_t const fSize;
786 size_t fOffset;
787 size_t fCurrentOffset;
788 };
789
detachAsStream()790 SkStreamAsset* SkDynamicMemoryWStream::detachAsStream() {
791 if (fCopy) {
792 SkMemoryStream* stream = SkNEW_ARGS(SkMemoryStream, (fCopy));
793 this->reset();
794 return stream;
795 }
796 SkBlockMemoryStream* stream = SkNEW_ARGS(SkBlockMemoryStream, (fHead, fBytesWritten));
797 fHead = 0;
798 this->reset();
799 return stream;
800 }
801
802 ///////////////////////////////////////////////////////////////////////////////
803
newline()804 void SkDebugWStream::newline()
805 {
806 #if defined(SK_DEBUG) || defined(SK_DEVELOPER)
807 SkDebugf("\n");
808 fBytesWritten++;
809 #endif
810 }
811
write(const void * buffer,size_t size)812 bool SkDebugWStream::write(const void* buffer, size_t size)
813 {
814 #if defined(SK_DEBUG) || defined(SK_DEVELOPER)
815 char* s = new char[size+1];
816 memcpy(s, buffer, size);
817 s[size] = 0;
818 SkDebugf("%s", s);
819 delete[] s;
820 fBytesWritten += size;
821 #endif
822 return true;
823 }
824
825 ///////////////////////////////////////////////////////////////////////////////
826 ///////////////////////////////////////////////////////////////////////////////
827
828
mmap_filename(const char path[])829 static SkData* mmap_filename(const char path[]) {
830 SkFILE* file = sk_fopen(path, kRead_SkFILE_Flag);
831 if (NULL == file) {
832 return NULL;
833 }
834
835 SkData* data = SkData::NewFromFILE(file);
836 sk_fclose(file);
837 return data;
838 }
839
NewFromFile(const char path[])840 SkStreamAsset* SkStream::NewFromFile(const char path[]) {
841 SkAutoTUnref<SkData> data(mmap_filename(path));
842 if (data.get()) {
843 return SkNEW_ARGS(SkMemoryStream, (data.get()));
844 }
845
846 // If we get here, then our attempt at using mmap failed, so try normal
847 // file access.
848 SkFILEStream* stream = SkNEW_ARGS(SkFILEStream, (path));
849 if (!stream->isValid()) {
850 SkDELETE(stream);
851 stream = NULL;
852 }
853 return stream;
854 }
855
856 // Declared in SkStreamPriv.h:
SkCopyStreamToStorage(SkAutoMalloc * storage,SkStream * stream)857 size_t SkCopyStreamToStorage(SkAutoMalloc* storage, SkStream* stream) {
858 SkASSERT(storage != NULL);
859 SkASSERT(stream != NULL);
860
861 if (stream->hasLength()) {
862 const size_t length = stream->getLength();
863 void* dst = storage->reset(length);
864 if (stream->read(dst, length) != length) {
865 return 0;
866 }
867 return length;
868 }
869
870 SkDynamicMemoryWStream tempStream;
871 // Arbitrary buffer size.
872 const size_t bufferSize = 256 * 1024; // 256KB
873 char buffer[bufferSize];
874 SkDEBUGCODE(size_t debugLength = 0;)
875 do {
876 size_t bytesRead = stream->read(buffer, bufferSize);
877 tempStream.write(buffer, bytesRead);
878 SkDEBUGCODE(debugLength += bytesRead);
879 SkASSERT(tempStream.bytesWritten() == debugLength);
880 } while (!stream->isAtEnd());
881 const size_t length = tempStream.bytesWritten();
882 void* dst = storage->reset(length);
883 tempStream.copyTo(dst);
884 return length;
885 }
886
887 // Declared in SkStreamPriv.h:
SkCopyStreamToData(SkStream * stream)888 SkData* SkCopyStreamToData(SkStream* stream) {
889 SkASSERT(stream != NULL);
890
891 if (stream->hasLength()) {
892 return SkData::NewFromStream(stream, stream->getLength());
893 }
894
895 SkDynamicMemoryWStream tempStream;
896 const size_t bufferSize = 4096;
897 char buffer[bufferSize];
898 do {
899 size_t bytesRead = stream->read(buffer, bufferSize);
900 tempStream.write(buffer, bytesRead);
901 } while (!stream->isAtEnd());
902 return tempStream.copyToData();
903 }
904
SkStreamRewindableFromSkStream(SkStream * stream)905 SkStreamRewindable* SkStreamRewindableFromSkStream(SkStream* stream) {
906 if (!stream) {
907 return NULL;
908 }
909 SkAutoTDelete<SkStreamRewindable> dupStream(stream->duplicate());
910 if (dupStream) {
911 return dupStream.detach();
912 }
913 stream->rewind();
914 if (stream->hasLength()) {
915 size_t length = stream->getLength();
916 if (stream->hasPosition()) { // If stream has length, but can't rewind.
917 length -= stream->getPosition();
918 }
919 SkAutoTUnref<SkData> data(SkData::NewFromStream(stream, length));
920 return SkNEW_ARGS(SkMemoryStream, (data.get()));
921 }
922 SkDynamicMemoryWStream tempStream;
923 const size_t bufferSize = 4096;
924 char buffer[bufferSize];
925 do {
926 size_t bytesRead = stream->read(buffer, bufferSize);
927 tempStream.write(buffer, bytesRead);
928 } while (!stream->isAtEnd());
929 return tempStream.detachAsStream(); // returns a SkBlockMemoryStream,
930 // cheaper than copying to SkData
931 }
932