| /* |
| * Copyright (C) 2006 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 SkBuffer_DEFINED |
| #define SkBuffer_DEFINED |
| |
| #include "SkScalar.h" |
| |
| /** \class SkRBuffer |
| |
| Light weight class for reading data from a memory block. |
| The RBuffer is given the buffer to read from, with either a specified size |
| or no size (in which case no range checking is performed). It is iillegal |
| to attempt to read a value from an empty RBuffer (data == null). |
| */ |
| class SkRBuffer : SkNoncopyable { |
| public: |
| SkRBuffer() : fData(0), fPos(0), fStop(0) {} |
| /** Initialize RBuffer with a data pointer, but no specified length. |
| This signals the RBuffer to not perform range checks during reading. |
| */ |
| SkRBuffer(const void* data) |
| { |
| fData = (const char*)data; |
| fPos = (const char*)data; |
| fStop = 0; // no bounds checking |
| } |
| /** Initialize RBuffer with a data point and length. |
| */ |
| SkRBuffer(const void* data, size_t size) |
| { |
| SkASSERT(data != 0 || size == 0); |
| fData = (const char*)data; |
| fPos = (const char*)data; |
| fStop = (const char*)data + size; |
| } |
| |
| /** Return the number of bytes that have been read from the beginning |
| of the data pointer. |
| */ |
| size_t pos() const { return fPos - fData; } |
| /** Return the total size of the data pointer. Only defined if the length was |
| specified in the constructor or in a call to reset(). |
| */ |
| size_t size() const { return fStop - fData; } |
| /** Return true if the buffer has read to the end of the data pointer. |
| Only defined if the length was specified in the constructor or in a call |
| to reset(). Always returns true if the length was not specified. |
| */ |
| bool eof() const { return fPos >= fStop; } |
| |
| /** Read the specified number of bytes from the data pointer. If buffer is not |
| null, copy those bytes into buffer. |
| */ |
| void read(void* buffer, size_t size) { if (size) this->readNoSizeCheck(buffer, size); } |
| const void* skip(size_t size); // return start of skipped data |
| size_t skipToAlign4(); |
| |
| void* readPtr() { void* ptr; read(&ptr, sizeof(ptr)); return ptr; } |
| SkScalar readScalar() { SkScalar x; read(&x, 4); return x; } |
| uint32_t readU32() { uint32_t x; read(&x, 4); return x; } |
| int32_t readS32() { int32_t x; read(&x, 4); return x; } |
| uint16_t readU16() { uint16_t x; read(&x, 2); return x; } |
| int16_t readS16() { int16_t x; read(&x, 2); return x; } |
| uint8_t readU8() { uint8_t x; read(&x, 1); return x; } |
| bool readBool() { return this->readU8() != 0; } |
| |
| protected: |
| void readNoSizeCheck(void* buffer, size_t size); |
| |
| const char* fData; |
| const char* fPos; |
| const char* fStop; |
| }; |
| |
| /** \class SkWBuffer |
| |
| Light weight class for writing data to a memory block. |
| The WBuffer is given the buffer to write into, with either a specified size |
| or no size, in which case no range checking is performed. An empty WBuffer |
| is legal, in which case no data is ever written, but the relative pos() |
| is updated. |
| */ |
| class SkWBuffer : SkNoncopyable { |
| public: |
| SkWBuffer() : fData(0), fPos(0), fStop(0) {} |
| SkWBuffer(void* data) { reset(data); } |
| SkWBuffer(void* data, size_t size) { reset(data, size); } |
| |
| void reset(void* data) |
| { |
| fData = (char*)data; |
| fPos = (char*)data; |
| fStop = 0; // no bounds checking |
| } |
| void reset(void* data, size_t size) |
| { |
| SkASSERT(data != 0 || size == 0); |
| fData = (char*)data; |
| fPos = (char*)data; |
| fStop = (char*)data + size; |
| } |
| |
| void* data() const { return fData; } |
| size_t pos() const { return fPos - fData; } |
| size_t size() const { return fStop - fData; } |
| bool eof() const { return fPos >= fStop; } |
| void* skip(size_t size); // return start of skipped data |
| void write(const void* buffer, size_t size) { if (size) this->writeNoSizeCheck(buffer, size); } |
| size_t padToAlign4(); |
| |
| void writePtr(const void* x) { this->writeNoSizeCheck(&x, sizeof(x)); } |
| void writeScalar(SkScalar x) { this->writeNoSizeCheck(&x, 4); } |
| void write32(int32_t x) { this->writeNoSizeCheck(&x, 4); } |
| void write16(int16_t x) { this->writeNoSizeCheck(&x, 2); } |
| void write8(int8_t x) { this->writeNoSizeCheck(&x, 1); } |
| void writeBool(bool x) { this->write8(x); } |
| |
| protected: |
| void writeNoSizeCheck(const void* buffer, size_t size); |
| |
| char* fData; |
| char* fPos; |
| char* fStop; |
| }; |
| |
| #endif |
| |