| /* |
| * Copyright 2006 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "include/core/SkStream.h" |
| |
| #include "include/core/SkData.h" |
| #include "include/core/SkString.h" |
| #include "include/core/SkTypes.h" |
| #include "include/private/SkFixed.h" |
| #include "include/private/SkTFitsIn.h" |
| #include "include/private/SkTo.h" |
| #include "src/core/SkMakeUnique.h" |
| #include "src/core/SkOSFile.h" |
| #include "src/core/SkSafeMath.h" |
| #include "src/core/SkStreamPriv.h" |
| |
| #include <limits> |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| bool SkStream::readS8(int8_t* i) { |
| return this->read(i, sizeof(*i)) == sizeof(*i); |
| } |
| |
| bool SkStream::readS16(int16_t* i) { |
| return this->read(i, sizeof(*i)) == sizeof(*i); |
| } |
| |
| bool SkStream::readS32(int32_t* i) { |
| return this->read(i, sizeof(*i)) == sizeof(*i); |
| } |
| |
| bool SkStream::readScalar(SkScalar* i) { |
| return this->read(i, sizeof(*i)) == sizeof(*i); |
| } |
| |
| #define SK_MAX_BYTE_FOR_U8 0xFD |
| #define SK_BYTE_SENTINEL_FOR_U16 0xFE |
| #define SK_BYTE_SENTINEL_FOR_U32 0xFF |
| |
| bool SkStream::readPackedUInt(size_t* i) { |
| uint8_t byte; |
| if (!this->read(&byte, 1)) { |
| return false; |
| } |
| if (SK_BYTE_SENTINEL_FOR_U16 == byte) { |
| uint16_t i16; |
| if (!this->readU16(&i16)) { return false; } |
| *i = i16; |
| } else if (SK_BYTE_SENTINEL_FOR_U32 == byte) { |
| uint32_t i32; |
| if (!this->readU32(&i32)) { return false; } |
| *i = i32; |
| } else { |
| *i = byte; |
| } |
| return true; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////////////// |
| |
| SkWStream::~SkWStream() |
| { |
| } |
| |
| void SkWStream::flush() |
| { |
| } |
| |
| bool SkWStream::writeDecAsText(int32_t dec) |
| { |
| char buffer[SkStrAppendS32_MaxSize]; |
| char* stop = SkStrAppendS32(buffer, dec); |
| return this->write(buffer, stop - buffer); |
| } |
| |
| bool SkWStream::writeBigDecAsText(int64_t dec, int minDigits) |
| { |
| char buffer[SkStrAppendU64_MaxSize]; |
| char* stop = SkStrAppendU64(buffer, dec, minDigits); |
| return this->write(buffer, stop - buffer); |
| } |
| |
| bool SkWStream::writeHexAsText(uint32_t hex, int digits) |
| { |
| SkString tmp; |
| tmp.appendHex(hex, digits); |
| return this->write(tmp.c_str(), tmp.size()); |
| } |
| |
| bool SkWStream::writeScalarAsText(SkScalar value) |
| { |
| char buffer[SkStrAppendScalar_MaxSize]; |
| char* stop = SkStrAppendScalar(buffer, value); |
| return this->write(buffer, stop - buffer); |
| } |
| |
| bool SkWStream::writeScalar(SkScalar value) { |
| return this->write(&value, sizeof(value)); |
| } |
| |
| int SkWStream::SizeOfPackedUInt(size_t value) { |
| if (value <= SK_MAX_BYTE_FOR_U8) { |
| return 1; |
| } else if (value <= 0xFFFF) { |
| return 3; |
| } |
| return 5; |
| } |
| |
| bool SkWStream::writePackedUInt(size_t value) { |
| uint8_t data[5]; |
| size_t len = 1; |
| if (value <= SK_MAX_BYTE_FOR_U8) { |
| data[0] = value; |
| len = 1; |
| } else if (value <= 0xFFFF) { |
| uint16_t value16 = value; |
| data[0] = SK_BYTE_SENTINEL_FOR_U16; |
| memcpy(&data[1], &value16, 2); |
| len = 3; |
| } else { |
| uint32_t value32 = SkToU32(value); |
| data[0] = SK_BYTE_SENTINEL_FOR_U32; |
| memcpy(&data[1], &value32, 4); |
| len = 5; |
| } |
| return this->write(data, len); |
| } |
| |
| bool SkWStream::writeStream(SkStream* stream, size_t length) { |
| char scratch[1024]; |
| const size_t MAX = sizeof(scratch); |
| |
| while (length != 0) { |
| size_t n = length; |
| if (n > MAX) { |
| n = MAX; |
| } |
| stream->read(scratch, n); |
| if (!this->write(scratch, n)) { |
| return false; |
| } |
| length -= n; |
| } |
| return true; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| SkFILEStream::SkFILEStream(std::shared_ptr<SkFile> file, size_t size, |
| size_t offset, size_t originalOffset) |
| : fFILE(std::move(file)) |
| , fSize(size) |
| , fOffset(SkTMin(offset, fSize)) |
| , fOriginalOffset(SkTMin(originalOffset, fSize)) |
| { } |
| |
| SkFILEStream::SkFILEStream(std::shared_ptr<SkFile> file, size_t size, size_t offset) |
| : SkFILEStream(std::move(file), size, offset, offset) |
| { } |
| |
| SkFILEStream::SkFILEStream(SkFile* file) |
| : SkFILEStream(std::shared_ptr<SkFile>(file, sk_fclose), |
| file ? sk_fgetsize(file) : 0, |
| file ? sk_ftell(file) : 0) |
| { } |
| |
| |
| SkFILEStream::SkFILEStream(const char path[]) |
| : SkFILEStream(path ? sk_fopen(path, kRead_SkFILE_Flag) : nullptr) |
| { } |
| |
| SkFILEStream::~SkFILEStream() { |
| this->close(); |
| } |
| |
| void SkFILEStream::close() { |
| fFILE.reset(); |
| fSize = 0; |
| fOffset = 0; |
| } |
| |
| size_t SkFILEStream::read(void* buffer, size_t size) { |
| if (size > fSize - fOffset) { |
| size = fSize - fOffset; |
| } |
| size_t bytesRead = size; |
| if (buffer) { |
| bytesRead = sk_qread(fFILE.get(), buffer, size, fOffset); |
| } |
| if (bytesRead == SIZE_MAX) { |
| return 0; |
| } |
| fOffset += bytesRead; |
| return bytesRead; |
| } |
| |
| bool SkFILEStream::isAtEnd() const { |
| if (fOffset == fSize) { |
| return true; |
| } |
| return fOffset >= sk_fgetsize(fFILE.get()); |
| } |
| |
| bool SkFILEStream::rewind() { |
| fOffset = fOriginalOffset; |
| return true; |
| } |
| |
| SkStreamAsset* SkFILEStream::onDuplicate() const { |
| return new SkFILEStream(fFILE, fSize, fOriginalOffset, fOriginalOffset); |
| } |
| |
| size_t SkFILEStream::getPosition() const { |
| SkASSERT(fOffset >= fOriginalOffset); |
| return fOffset - fOriginalOffset; |
| } |
| |
| bool SkFILEStream::seek(size_t position) { |
| fOffset = SkTMin(SkSafeMath::Add(position, fOriginalOffset), fSize); |
| return true; |
| } |
| |
| bool SkFILEStream::move(long offset) { |
| if (offset < 0) { |
| if (offset == std::numeric_limits<long>::min() |
| || !SkTFitsIn<size_t>(-offset) |
| || (size_t) (-offset) >= this->getPosition()) { |
| fOffset = fOriginalOffset; |
| } else { |
| fOffset += offset; |
| } |
| } else if (!SkTFitsIn<size_t>(offset)) { |
| fOffset = fSize; |
| } else { |
| fOffset = SkTMin(SkSafeMath::Add(fOffset, (size_t) offset), fSize); |
| } |
| |
| SkASSERT(fOffset >= fOriginalOffset && fOffset <= fSize); |
| return true; |
| } |
| |
| SkStreamAsset* SkFILEStream::onFork() const { |
| return new SkFILEStream(fFILE, fSize, fOffset, fOriginalOffset); |
| } |
| |
| size_t SkFILEStream::getLength() const { |
| return fSize - fOriginalOffset; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| static sk_sp<SkData> newFromParams(const void* src, size_t size, bool copyData) { |
| if (copyData) { |
| return SkData::MakeWithCopy(src, size); |
| } else { |
| return SkData::MakeWithoutCopy(src, size); |
| } |
| } |
| |
| SkMemoryStream::SkMemoryStream() { |
| fData = SkData::MakeEmpty(); |
| fOffset = 0; |
| } |
| |
| SkMemoryStream::SkMemoryStream(size_t size) { |
| fData = SkData::MakeUninitialized(size); |
| fOffset = 0; |
| } |
| |
| SkMemoryStream::SkMemoryStream(const void* src, size_t size, bool copyData) { |
| fData = newFromParams(src, size, copyData); |
| fOffset = 0; |
| } |
| |
| SkMemoryStream::SkMemoryStream(sk_sp<SkData> data) : fData(std::move(data)) { |
| if (nullptr == fData) { |
| fData = SkData::MakeEmpty(); |
| } |
| fOffset = 0; |
| } |
| |
| std::unique_ptr<SkMemoryStream> SkMemoryStream::MakeCopy(const void* data, size_t length) { |
| return skstd::make_unique<SkMemoryStream>(data, length, true); |
| } |
| |
| std::unique_ptr<SkMemoryStream> SkMemoryStream::MakeDirect(const void* data, size_t length) { |
| return skstd::make_unique<SkMemoryStream>(data, length, false); |
| } |
| |
| std::unique_ptr<SkMemoryStream> SkMemoryStream::Make(sk_sp<SkData> data) { |
| return skstd::make_unique<SkMemoryStream>(std::move(data)); |
| } |
| |
| void SkMemoryStream::setMemoryOwned(const void* src, size_t size) { |
| fData = SkData::MakeFromMalloc(src, size); |
| fOffset = 0; |
| } |
| |
| void SkMemoryStream::setMemory(const void* src, size_t size, bool copyData) { |
| fData = newFromParams(src, size, copyData); |
| fOffset = 0; |
| } |
| |
| void SkMemoryStream::setData(sk_sp<SkData> data) { |
| if (nullptr == data) { |
| fData = SkData::MakeEmpty(); |
| } else { |
| fData = data; |
| } |
| fOffset = 0; |
| } |
| |
| void SkMemoryStream::skipToAlign4() { |
| // cast to remove unary-minus warning |
| fOffset += -(int)fOffset & 0x03; |
| } |
| |
| size_t SkMemoryStream::read(void* buffer, size_t size) { |
| size_t dataSize = fData->size(); |
| |
| if (size > dataSize - fOffset) { |
| size = dataSize - fOffset; |
| } |
| if (buffer) { |
| memcpy(buffer, fData->bytes() + fOffset, size); |
| } |
| fOffset += size; |
| return size; |
| } |
| |
| size_t SkMemoryStream::peek(void* buffer, size_t size) const { |
| SkASSERT(buffer != nullptr); |
| |
| const size_t currentOffset = fOffset; |
| SkMemoryStream* nonConstThis = const_cast<SkMemoryStream*>(this); |
| const size_t bytesRead = nonConstThis->read(buffer, size); |
| nonConstThis->fOffset = currentOffset; |
| return bytesRead; |
| } |
| |
| bool SkMemoryStream::isAtEnd() const { |
| return fOffset == fData->size(); |
| } |
| |
| bool SkMemoryStream::rewind() { |
| fOffset = 0; |
| return true; |
| } |
| |
| SkMemoryStream* SkMemoryStream::onDuplicate() const { |
| return new SkMemoryStream(fData); |
| } |
| |
| size_t SkMemoryStream::getPosition() const { |
| return fOffset; |
| } |
| |
| bool SkMemoryStream::seek(size_t position) { |
| fOffset = position > fData->size() |
| ? fData->size() |
| : position; |
| return true; |
| } |
| |
| bool SkMemoryStream::move(long offset) { |
| return this->seek(fOffset + offset); |
| } |
| |
| SkMemoryStream* SkMemoryStream::onFork() const { |
| std::unique_ptr<SkMemoryStream> that(this->duplicate()); |
| that->seek(fOffset); |
| return that.release(); |
| } |
| |
| size_t SkMemoryStream::getLength() const { |
| return fData->size(); |
| } |
| |
| const void* SkMemoryStream::getMemoryBase() { |
| return fData->data(); |
| } |
| |
| const void* SkMemoryStream::getAtPos() { |
| return fData->bytes() + fOffset; |
| } |
| |
| ///////////////////////////////////////////////////////////////////////////////////////////////////////// |
| ///////////////////////////////////////////////////////////////////////////////////////////////////////// |
| |
| SkFILEWStream::SkFILEWStream(const char path[]) |
| { |
| fFILE = sk_fopen(path, kWrite_SkFILE_Flag); |
| } |
| |
| SkFILEWStream::~SkFILEWStream() |
| { |
| if (fFILE) { |
| sk_fclose(fFILE); |
| } |
| } |
| |
| size_t SkFILEWStream::bytesWritten() const { |
| return sk_ftell(fFILE); |
| } |
| |
| bool SkFILEWStream::write(const void* buffer, size_t size) |
| { |
| if (fFILE == nullptr) { |
| return false; |
| } |
| |
| if (sk_fwrite(buffer, size, fFILE) != size) |
| { |
| SkDEBUGCODE(SkDebugf("SkFILEWStream failed writing %d bytes\n", size);) |
| sk_fclose(fFILE); |
| fFILE = nullptr; |
| return false; |
| } |
| return true; |
| } |
| |
| void SkFILEWStream::flush() |
| { |
| if (fFILE) { |
| sk_fflush(fFILE); |
| } |
| } |
| |
| void SkFILEWStream::fsync() |
| { |
| flush(); |
| if (fFILE) { |
| sk_fsync(fFILE); |
| } |
| } |
| |
| //////////////////////////////////////////////////////////////////////// |
| |
| static inline void sk_memcpy_4bytes(void* dst, const void* src, size_t size) { |
| if (size == 4) { |
| memcpy(dst, src, 4); |
| } else { |
| memcpy(dst, src, size); |
| } |
| } |
| |
| #define SkDynamicMemoryWStream_MinBlockSize 4096 |
| |
| struct SkDynamicMemoryWStream::Block { |
| Block* fNext; |
| char* fCurr; |
| char* fStop; |
| |
| const char* start() const { return (const char*)(this + 1); } |
| char* start() { return (char*)(this + 1); } |
| size_t avail() const { return fStop - fCurr; } |
| size_t written() const { return fCurr - this->start(); } |
| |
| void init(size_t size) { |
| fNext = nullptr; |
| fCurr = this->start(); |
| fStop = this->start() + size; |
| } |
| |
| const void* append(const void* data, size_t size) { |
| SkASSERT((size_t)(fStop - fCurr) >= size); |
| sk_memcpy_4bytes(fCurr, data, size); |
| fCurr += size; |
| return (const void*)((const char*)data + size); |
| } |
| }; |
| |
| SkDynamicMemoryWStream::SkDynamicMemoryWStream(SkDynamicMemoryWStream&& other) |
| : fHead(other.fHead) |
| , fTail(other.fTail) |
| , fBytesWrittenBeforeTail(other.fBytesWrittenBeforeTail) |
| { |
| other.fHead = nullptr; |
| other.fTail = nullptr; |
| other.fBytesWrittenBeforeTail = 0; |
| } |
| |
| SkDynamicMemoryWStream& SkDynamicMemoryWStream::operator=(SkDynamicMemoryWStream&& other) { |
| if (this != &other) { |
| this->~SkDynamicMemoryWStream(); |
| new (this) SkDynamicMemoryWStream(std::move(other)); |
| } |
| return *this; |
| } |
| |
| SkDynamicMemoryWStream::~SkDynamicMemoryWStream() { |
| this->reset(); |
| } |
| |
| void SkDynamicMemoryWStream::reset() { |
| Block* block = fHead; |
| while (block != nullptr) { |
| Block* next = block->fNext; |
| sk_free(block); |
| block = next; |
| } |
| fHead = fTail = nullptr; |
| fBytesWrittenBeforeTail = 0; |
| } |
| |
| size_t SkDynamicMemoryWStream::bytesWritten() const { |
| this->validate(); |
| |
| if (fTail) { |
| return fBytesWrittenBeforeTail + fTail->written(); |
| } |
| return 0; |
| } |
| |
| bool SkDynamicMemoryWStream::write(const void* buffer, size_t count) { |
| if (count > 0) { |
| SkASSERT(buffer); |
| size_t size; |
| |
| if (fTail) { |
| if (fTail->avail() > 0) { |
| size = SkTMin(fTail->avail(), count); |
| buffer = fTail->append(buffer, size); |
| SkASSERT(count >= size); |
| count -= size; |
| if (count == 0) { |
| return true; |
| } |
| } |
| // If we get here, we've just exhausted fTail, so update our tracker |
| fBytesWrittenBeforeTail += fTail->written(); |
| } |
| |
| size = SkTMax<size_t>(count, SkDynamicMemoryWStream_MinBlockSize - sizeof(Block)); |
| size = SkAlign4(size); // ensure we're always a multiple of 4 (see padToAlign4()) |
| |
| Block* block = (Block*)sk_malloc_throw(sizeof(Block) + size); |
| block->init(size); |
| block->append(buffer, count); |
| |
| if (fTail != nullptr) { |
| fTail->fNext = block; |
| } else { |
| fHead = fTail = block; |
| } |
| fTail = block; |
| this->validate(); |
| } |
| return true; |
| } |
| |
| bool SkDynamicMemoryWStream::writeToAndReset(SkDynamicMemoryWStream* dst) { |
| SkASSERT(dst); |
| SkASSERT(dst != this); |
| if (0 == this->bytesWritten()) { |
| return true; |
| } |
| if (0 == dst->bytesWritten()) { |
| *dst = std::move(*this); |
| return true; |
| } |
| dst->fTail->fNext = fHead; |
| dst->fBytesWrittenBeforeTail += fBytesWrittenBeforeTail + dst->fTail->written(); |
| dst->fTail = fTail; |
| fHead = fTail = nullptr; |
| fBytesWrittenBeforeTail = 0; |
| return true; |
| } |
| |
| void SkDynamicMemoryWStream::prependToAndReset(SkDynamicMemoryWStream* dst) { |
| SkASSERT(dst); |
| SkASSERT(dst != this); |
| if (0 == this->bytesWritten()) { |
| return; |
| } |
| if (0 == dst->bytesWritten()) { |
| *dst = std::move(*this); |
| return; |
| } |
| fTail->fNext = dst->fHead; |
| dst->fHead = fHead; |
| dst->fBytesWrittenBeforeTail += fBytesWrittenBeforeTail + fTail->written(); |
| fHead = fTail = nullptr; |
| fBytesWrittenBeforeTail = 0; |
| return; |
| } |
| |
| |
| bool SkDynamicMemoryWStream::read(void* buffer, size_t offset, size_t count) { |
| if (offset + count > this->bytesWritten()) { |
| return false; // test does not partially modify |
| } |
| Block* block = fHead; |
| while (block != nullptr) { |
| size_t size = block->written(); |
| if (offset < size) { |
| size_t part = offset + count > size ? size - offset : count; |
| memcpy(buffer, block->start() + offset, part); |
| if (count <= part) { |
| return true; |
| } |
| count -= part; |
| buffer = (void*) ((char* ) buffer + part); |
| } |
| offset = offset > size ? offset - size : 0; |
| block = block->fNext; |
| } |
| return false; |
| } |
| |
| void SkDynamicMemoryWStream::copyTo(void* dst) const { |
| SkASSERT(dst); |
| Block* block = fHead; |
| while (block != nullptr) { |
| size_t size = block->written(); |
| memcpy(dst, block->start(), size); |
| dst = (void*)((char*)dst + size); |
| block = block->fNext; |
| } |
| } |
| |
| bool SkDynamicMemoryWStream::writeToStream(SkWStream* dst) const { |
| SkASSERT(dst); |
| for (Block* block = fHead; block != nullptr; block = block->fNext) { |
| if (!dst->write(block->start(), block->written())) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| void SkDynamicMemoryWStream::padToAlign4() { |
| // The contract is to write zeros until the entire stream has written a multiple of 4 bytes. |
| // Our Blocks are guaranteed always be (a) full (except the tail) and (b) a multiple of 4 |
| // so it is sufficient to just examine the tail (if present). |
| |
| if (fTail) { |
| // cast to remove unary-minus warning |
| int padBytes = -(int)fTail->written() & 0x03; |
| if (padBytes) { |
| int zero = 0; |
| fTail->append(&zero, padBytes); |
| } |
| } |
| } |
| |
| |
| void SkDynamicMemoryWStream::copyToAndReset(void* ptr) { |
| if (!ptr) { |
| this->reset(); |
| return; |
| } |
| // By looping through the source and freeing as we copy, we |
| // can reduce real memory use with large streams. |
| char* dst = reinterpret_cast<char*>(ptr); |
| Block* block = fHead; |
| while (block != nullptr) { |
| size_t len = block->written(); |
| memcpy(dst, block->start(), len); |
| dst += len; |
| Block* next = block->fNext; |
| sk_free(block); |
| block = next; |
| } |
| fHead = fTail = nullptr; |
| fBytesWrittenBeforeTail = 0; |
| } |
| |
| bool SkDynamicMemoryWStream::writeToAndReset(SkWStream* dst) { |
| SkASSERT(dst); |
| // By looping through the source and freeing as we copy, we |
| // can reduce real memory use with large streams. |
| bool dstStreamGood = true; |
| for (Block* block = fHead; block != nullptr; ) { |
| if (dstStreamGood && !dst->write(block->start(), block->written())) { |
| dstStreamGood = false; |
| } |
| Block* next = block->fNext; |
| sk_free(block); |
| block = next; |
| } |
| fHead = fTail = nullptr; |
| fBytesWrittenBeforeTail = 0; |
| return dstStreamGood; |
| } |
| |
| sk_sp<SkData> SkDynamicMemoryWStream::detachAsData() { |
| const size_t size = this->bytesWritten(); |
| if (0 == size) { |
| return SkData::MakeEmpty(); |
| } |
| sk_sp<SkData> data = SkData::MakeUninitialized(size); |
| this->copyToAndReset(data->writable_data()); |
| return data; |
| } |
| |
| #ifdef SK_DEBUG |
| void SkDynamicMemoryWStream::validate() const { |
| if (!fHead) { |
| SkASSERT(!fTail); |
| SkASSERT(fBytesWrittenBeforeTail == 0); |
| return; |
| } |
| SkASSERT(fTail); |
| |
| size_t bytes = 0; |
| const Block* block = fHead; |
| while (block) { |
| if (block->fNext) { |
| bytes += block->written(); |
| } |
| block = block->fNext; |
| } |
| SkASSERT(bytes == fBytesWrittenBeforeTail); |
| } |
| #endif |
| |
| //////////////////////////////////////////////////////////////////////////////////////////////// |
| |
| class SkBlockMemoryRefCnt : public SkRefCnt { |
| public: |
| explicit SkBlockMemoryRefCnt(SkDynamicMemoryWStream::Block* head) : fHead(head) { } |
| |
| virtual ~SkBlockMemoryRefCnt() { |
| SkDynamicMemoryWStream::Block* block = fHead; |
| while (block != nullptr) { |
| SkDynamicMemoryWStream::Block* next = block->fNext; |
| sk_free(block); |
| block = next; |
| } |
| } |
| |
| SkDynamicMemoryWStream::Block* const fHead; |
| }; |
| |
| class SkBlockMemoryStream : public SkStreamAsset { |
| public: |
| SkBlockMemoryStream(sk_sp<SkBlockMemoryRefCnt> headRef, size_t size) |
| : fBlockMemory(std::move(headRef)), fCurrent(fBlockMemory->fHead) |
| , fSize(size) , fOffset(0), fCurrentOffset(0) { } |
| |
| size_t read(void* buffer, size_t rawCount) override { |
| size_t count = rawCount; |
| if (fOffset + count > fSize) { |
| count = fSize - fOffset; |
| } |
| size_t bytesLeftToRead = count; |
| while (fCurrent != nullptr) { |
| size_t bytesLeftInCurrent = fCurrent->written() - fCurrentOffset; |
| size_t bytesFromCurrent = SkTMin(bytesLeftToRead, bytesLeftInCurrent); |
| if (buffer) { |
| memcpy(buffer, fCurrent->start() + fCurrentOffset, bytesFromCurrent); |
| buffer = SkTAddOffset<void>(buffer, bytesFromCurrent); |
| } |
| if (bytesLeftToRead <= bytesFromCurrent) { |
| fCurrentOffset += bytesFromCurrent; |
| fOffset += count; |
| return count; |
| } |
| bytesLeftToRead -= bytesFromCurrent; |
| fCurrent = fCurrent->fNext; |
| fCurrentOffset = 0; |
| } |
| SkASSERT(false); |
| return 0; |
| } |
| |
| bool isAtEnd() const override { |
| return fOffset == fSize; |
| } |
| |
| size_t peek(void* buff, size_t bytesToPeek) const override { |
| SkASSERT(buff != nullptr); |
| |
| bytesToPeek = SkTMin(bytesToPeek, fSize - fOffset); |
| |
| size_t bytesLeftToPeek = bytesToPeek; |
| char* buffer = static_cast<char*>(buff); |
| const SkDynamicMemoryWStream::Block* current = fCurrent; |
| size_t currentOffset = fCurrentOffset; |
| while (bytesLeftToPeek) { |
| SkASSERT(current); |
| size_t bytesFromCurrent = SkTMin(current->written() - currentOffset, bytesLeftToPeek); |
| memcpy(buffer, current->start() + currentOffset, bytesFromCurrent); |
| bytesLeftToPeek -= bytesFromCurrent; |
| buffer += bytesFromCurrent; |
| current = current->fNext; |
| currentOffset = 0; |
| } |
| return bytesToPeek; |
| } |
| |
| bool rewind() override { |
| fCurrent = fBlockMemory->fHead; |
| fOffset = 0; |
| fCurrentOffset = 0; |
| return true; |
| } |
| |
| SkBlockMemoryStream* onDuplicate() const override { |
| return new SkBlockMemoryStream(fBlockMemory, fSize); |
| } |
| |
| size_t getPosition() const override { |
| return fOffset; |
| } |
| |
| bool seek(size_t position) override { |
| // If possible, skip forward. |
| if (position >= fOffset) { |
| size_t skipAmount = position - fOffset; |
| return this->skip(skipAmount) == skipAmount; |
| } |
| // If possible, move backward within the current block. |
| size_t moveBackAmount = fOffset - position; |
| if (moveBackAmount <= fCurrentOffset) { |
| fCurrentOffset -= moveBackAmount; |
| fOffset -= moveBackAmount; |
| return true; |
| } |
| // Otherwise rewind and move forward. |
| return this->rewind() && this->skip(position) == position; |
| } |
| |
| bool move(long offset) override { |
| return seek(fOffset + offset); |
| } |
| |
| SkBlockMemoryStream* onFork() const override { |
| SkBlockMemoryStream* that = this->onDuplicate(); |
| that->fCurrent = this->fCurrent; |
| that->fOffset = this->fOffset; |
| that->fCurrentOffset = this->fCurrentOffset; |
| return that; |
| } |
| |
| size_t getLength() const override { |
| return fSize; |
| } |
| |
| const void* getMemoryBase() override { |
| if (fBlockMemory->fHead && !fBlockMemory->fHead->fNext) { |
| return fBlockMemory->fHead->start(); |
| } |
| return nullptr; |
| } |
| |
| private: |
| sk_sp<SkBlockMemoryRefCnt> const fBlockMemory; |
| SkDynamicMemoryWStream::Block const * fCurrent; |
| size_t const fSize; |
| size_t fOffset; |
| size_t fCurrentOffset; |
| }; |
| |
| std::unique_ptr<SkStreamAsset> SkDynamicMemoryWStream::detachAsStream() { |
| if (nullptr == fHead) { |
| // no need to reset. |
| return SkMemoryStream::Make(nullptr); |
| } |
| if (fHead == fTail) { // one block, may be worth shrinking. |
| ptrdiff_t used = fTail->fCurr - (char*)fTail; |
| fHead = fTail = (SkDynamicMemoryWStream::Block*)sk_realloc_throw(fTail, SkToSizeT(used)); |
| fTail->fStop = fTail->fCurr = (char*)fTail + used; // Update pointers. |
| SkASSERT(nullptr == fTail->fNext); |
| SkASSERT(0 == fBytesWrittenBeforeTail); |
| } |
| std::unique_ptr<SkStreamAsset> stream |
| = skstd::make_unique<SkBlockMemoryStream>(sk_make_sp<SkBlockMemoryRefCnt>(fHead), |
| this->bytesWritten()); |
| fHead = nullptr; // signal reset() to not free anything |
| this->reset(); |
| return stream; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| static sk_sp<SkData> mmap_filename(const char path[]) { |
| SkFile* file = sk_fopen(path, kRead_SkFILE_Flag); |
| if (nullptr == file) { |
| return nullptr; |
| } |
| |
| auto data = SkData::MakeFromFILE(file); |
| sk_fclose(file); |
| return data; |
| } |
| |
| std::unique_ptr<SkStreamAsset> SkStream::MakeFromFile(const char path[]) { |
| auto data(mmap_filename(path)); |
| if (data) { |
| return skstd::make_unique<SkMemoryStream>(std::move(data)); |
| } |
| |
| // If we get here, then our attempt at using mmap failed, so try normal file access. |
| auto stream = skstd::make_unique<SkFILEStream>(path); |
| if (!stream->isValid()) { |
| return nullptr; |
| } |
| return stream; |
| } |
| |
| // Declared in SkStreamPriv.h: |
| sk_sp<SkData> SkCopyStreamToData(SkStream* stream) { |
| SkASSERT(stream != nullptr); |
| |
| if (stream->hasLength()) { |
| return SkData::MakeFromStream(stream, stream->getLength()); |
| } |
| |
| SkDynamicMemoryWStream tempStream; |
| const size_t bufferSize = 4096; |
| char buffer[bufferSize]; |
| do { |
| size_t bytesRead = stream->read(buffer, bufferSize); |
| tempStream.write(buffer, bytesRead); |
| } while (!stream->isAtEnd()); |
| return tempStream.detachAsData(); |
| } |
| |
| bool SkStreamCopy(SkWStream* out, SkStream* input) { |
| const char* base = static_cast<const char*>(input->getMemoryBase()); |
| if (base && input->hasPosition() && input->hasLength()) { |
| // Shortcut that avoids the while loop. |
| size_t position = input->getPosition(); |
| size_t length = input->getLength(); |
| SkASSERT(length >= position); |
| return out->write(&base[position], length - position); |
| } |
| char scratch[4096]; |
| size_t count; |
| while (true) { |
| count = input->read(scratch, sizeof(scratch)); |
| if (0 == count) { |
| return true; |
| } |
| if (!out->write(scratch, count)) { |
| return false; |
| } |
| } |
| } |