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- /*
- * 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 "include/core/SkData.h"
- #include "include/core/SkMatrix.h"
- #include "include/core/SkPath.h"
- #include "include/core/SkRRect.h"
- #include "include/core/SkRegion.h"
- #include "include/core/SkScalar.h"
- #include "include/private/SkNoncopyable.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));
- sk_careful_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);
- sk_sp<SkData> readData() {
- uint32_t byteLength = this->readU32();
- if (0 == byteLength) {
- return SkData::MakeEmpty();
- }
- return SkData::MakeWithCopy(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
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