| /* |
| * Copyright 2008 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. |
| */ |
| |
| |
| #ifndef SkReader32_DEFINED |
| #define SkReader32_DEFINED |
| |
| #include "SkData.h" |
| #include "SkMatrix.h" |
| #include "SkPath.h" |
| #include "SkRegion.h" |
| #include "SkRRect.h" |
| #include "SkScalar.h" |
| |
| class SkString; |
| |
| class SkReader32 : SkNoncopyable { |
| public: |
| SkReader32() : fCurr(nullptr), fStop(nullptr), fBase(nullptr) {} |
| SkReader32(const void* data, size_t size) { |
| this->setMemory(data, size); |
| } |
| |
| void setMemory(const void* data, size_t size) { |
| SkASSERT(ptr_align_4(data)); |
| SkASSERT(SkAlign4(size) == size); |
| |
| fBase = fCurr = (const char*)data; |
| fStop = (const char*)data + size; |
| } |
| |
| size_t size() const { return fStop - fBase; } |
| size_t offset() const { return fCurr - fBase; } |
| bool eof() const { return fCurr >= fStop; } |
| const void* base() const { return fBase; } |
| const void* peek() const { return fCurr; } |
| |
| size_t available() const { return fStop - fCurr; } |
| bool isAvailable(size_t size) const { return size <= this->available(); } |
| |
| void rewind() { fCurr = fBase; } |
| |
| void setOffset(size_t offset) { |
| SkASSERT(SkAlign4(offset) == offset); |
| SkASSERT(offset <= this->size()); |
| fCurr = fBase + offset; |
| } |
| |
| bool readBool() { return this->readInt() != 0; } |
| |
| int32_t readInt() { |
| SkASSERT(ptr_align_4(fCurr)); |
| int32_t value = *(const int32_t*)fCurr; |
| fCurr += sizeof(value); |
| SkASSERT(fCurr <= fStop); |
| return value; |
| } |
| |
| void* readPtr() { |
| void* ptr; |
| // we presume this "if" is resolved at compile-time |
| if (4 == sizeof(void*)) { |
| ptr = *(void**)fCurr; |
| } else { |
| memcpy(&ptr, fCurr, sizeof(void*)); |
| } |
| fCurr += sizeof(void*); |
| return ptr; |
| } |
| |
| SkScalar readScalar() { |
| SkASSERT(ptr_align_4(fCurr)); |
| SkScalar value = *(const SkScalar*)fCurr; |
| fCurr += sizeof(value); |
| SkASSERT(fCurr <= fStop); |
| return value; |
| } |
| |
| const void* skip(size_t size) { |
| SkASSERT(ptr_align_4(fCurr)); |
| const void* addr = fCurr; |
| fCurr += SkAlign4(size); |
| SkASSERT(fCurr <= fStop); |
| return addr; |
| } |
| |
| template <typename T> const T& skipT() { |
| SkASSERT(SkAlign4(sizeof(T)) == sizeof(T)); |
| return *(const T*)this->skip(sizeof(T)); |
| } |
| |
| void read(void* dst, size_t size) { |
| SkASSERT(0 == size || dst != nullptr); |
| SkASSERT(ptr_align_4(fCurr)); |
| memcpy(dst, fCurr, size); |
| fCurr += SkAlign4(size); |
| SkASSERT(fCurr <= fStop); |
| } |
| |
| uint8_t readU8() { return (uint8_t)this->readInt(); } |
| uint16_t readU16() { return (uint16_t)this->readInt(); } |
| int32_t readS32() { return this->readInt(); } |
| uint32_t readU32() { return this->readInt(); } |
| |
| bool readPath(SkPath* path) { |
| return this->readObjectFromMemory(path); |
| } |
| |
| bool readMatrix(SkMatrix* matrix) { |
| return this->readObjectFromMemory(matrix); |
| } |
| |
| bool readRRect(SkRRect* rrect) { |
| return this->readObjectFromMemory(rrect); |
| } |
| |
| bool readRegion(SkRegion* rgn) { |
| return this->readObjectFromMemory(rgn); |
| } |
| |
| /** |
| * Read the length of a string (written by SkWriter32::writeString) into |
| * len (if len is not nullptr) and return the null-ternimated address of the |
| * string within the reader's buffer. |
| */ |
| const char* readString(size_t* len = nullptr); |
| |
| /** |
| * Read the string (written by SkWriter32::writeString) and return it in |
| * copy (if copy is not null). Return the length of the string. |
| */ |
| size_t readIntoString(SkString* copy); |
| |
| SkData* readData() { |
| uint32_t byteLength = this->readU32(); |
| if (0 == byteLength) { |
| return SkData::NewEmpty(); |
| } |
| return SkData::NewWithCopy(this->skip(byteLength), byteLength); |
| } |
| |
| private: |
| template <typename T> bool readObjectFromMemory(T* obj) { |
| size_t size = obj->readFromMemory(this->peek(), this->available()); |
| // If readFromMemory() fails (which means that available() was too small), it returns 0 |
| bool success = (size > 0) && (size <= this->available()) && (SkAlign4(size) == size); |
| // In case of failure, we want to skip to the end |
| (void)this->skip(success ? size : this->available()); |
| return success; |
| } |
| |
| // these are always 4-byte aligned |
| const char* fCurr; // current position within buffer |
| const char* fStop; // end of buffer |
| const char* fBase; // beginning of buffer |
| |
| #ifdef SK_DEBUG |
| static bool ptr_align_4(const void* ptr) { |
| return (((const char*)ptr - (const char*)nullptr) & 3) == 0; |
| } |
| #endif |
| }; |
| |
| #endif |