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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SkReader32_DEFINED
#define SkReader32_DEFINED
#include "SkTypes.h"
#include "SkScalar.h"
#include "SkPoint.h"
#include "SkRect.h"
class SkReader32 : SkNoncopyable {
public:
SkReader32() : fCurr(NULL), fStop(NULL), fBase(NULL) {}
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;
}
uint32_t size() const { return fStop - fBase; }
uint32_t offset() const { return fCurr - fBase; }
bool eof() const { return fCurr >= fStop; }
const void* base() const { return fBase; }
const void* peek() const { return fCurr; }
uint32_t available() const { return fStop - fCurr; }
bool isAvailable(uint32_t size) const { return fCurr + size <= fStop; }
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;
}
SkScalar readScalar() {
SkASSERT(ptr_align_4(fCurr));
SkScalar value = *(const SkScalar*)fCurr;
fCurr += sizeof(value);
SkASSERT(fCurr <= fStop);
return value;
}
const SkPoint* skipPoint() {
return (const SkPoint*)this->skip(sizeof(SkPoint));
}
const SkRect* skipRect() {
return (const SkRect*)this->skip(sizeof(SkRect));
}
const void* skip(size_t size) {
SkASSERT(ptr_align_4(fCurr));
const void* addr = fCurr;
fCurr += SkAlign4(size);
SkASSERT(fCurr <= fStop);
return addr;
}
void read(void* dst, size_t size) {
SkASSERT(0 == size || dst != NULL);
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(); }
/**
* Read the length of a string written by SkWriter32::writeString()
* (if len is not NULL) and return the null-ternimated address of the
* string.
*/
const char* readString(size_t* len = NULL);
private:
// 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*)NULL) & 3) == 0;
}
#endif
};
#endif
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