1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/include/core/SkReader32.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,160 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2008 The Android Open Source Project
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +
1.13 +#ifndef SkReader32_DEFINED
1.14 +#define SkReader32_DEFINED
1.15 +
1.16 +#include "SkMatrix.h"
1.17 +#include "SkPath.h"
1.18 +#include "SkRegion.h"
1.19 +#include "SkRRect.h"
1.20 +#include "SkScalar.h"
1.21 +
1.22 +class SkString;
1.23 +
1.24 +class SkReader32 : SkNoncopyable {
1.25 +public:
1.26 + SkReader32() : fCurr(NULL), fStop(NULL), fBase(NULL) {}
1.27 + SkReader32(const void* data, size_t size) {
1.28 + this->setMemory(data, size);
1.29 + }
1.30 +
1.31 + void setMemory(const void* data, size_t size) {
1.32 + SkASSERT(ptr_align_4(data));
1.33 + SkASSERT(SkAlign4(size) == size);
1.34 +
1.35 + fBase = fCurr = (const char*)data;
1.36 + fStop = (const char*)data + size;
1.37 + }
1.38 +
1.39 + uint32_t size() const { return SkToU32(fStop - fBase); }
1.40 + uint32_t offset() const { return SkToU32(fCurr - fBase); }
1.41 + bool eof() const { return fCurr >= fStop; }
1.42 + const void* base() const { return fBase; }
1.43 + const void* peek() const { return fCurr; }
1.44 +
1.45 + uint32_t available() const { return SkToU32(fStop - fCurr); }
1.46 + bool isAvailable(uint32_t size) const { return fCurr + size <= fStop; }
1.47 +
1.48 + void rewind() { fCurr = fBase; }
1.49 +
1.50 + void setOffset(size_t offset) {
1.51 + SkASSERT(SkAlign4(offset) == offset);
1.52 + SkASSERT(offset <= this->size());
1.53 + fCurr = fBase + offset;
1.54 + }
1.55 +
1.56 + bool readBool() { return this->readInt() != 0; }
1.57 +
1.58 + int32_t readInt() {
1.59 + SkASSERT(ptr_align_4(fCurr));
1.60 + int32_t value = *(const int32_t*)fCurr;
1.61 + fCurr += sizeof(value);
1.62 + SkASSERT(fCurr <= fStop);
1.63 + return value;
1.64 + }
1.65 +
1.66 + void* readPtr() {
1.67 + void* ptr;
1.68 + // we presume this "if" is resolved at compile-time
1.69 + if (4 == sizeof(void*)) {
1.70 + ptr = *(void**)fCurr;
1.71 + } else {
1.72 + memcpy(&ptr, fCurr, sizeof(void*));
1.73 + }
1.74 + fCurr += sizeof(void*);
1.75 + return ptr;
1.76 + }
1.77 +
1.78 + SkScalar readScalar() {
1.79 + SkASSERT(ptr_align_4(fCurr));
1.80 + SkScalar value = *(const SkScalar*)fCurr;
1.81 + fCurr += sizeof(value);
1.82 + SkASSERT(fCurr <= fStop);
1.83 + return value;
1.84 + }
1.85 +
1.86 + const void* skip(size_t size) {
1.87 + SkASSERT(ptr_align_4(fCurr));
1.88 + const void* addr = fCurr;
1.89 + fCurr += SkAlign4(size);
1.90 + SkASSERT(fCurr <= fStop);
1.91 + return addr;
1.92 + }
1.93 +
1.94 + template <typename T> const T& skipT() {
1.95 + SkASSERT(SkAlign4(sizeof(T)) == sizeof(T));
1.96 + return *(const T*)this->skip(sizeof(T));
1.97 + }
1.98 +
1.99 + void read(void* dst, size_t size) {
1.100 + SkASSERT(0 == size || dst != NULL);
1.101 + SkASSERT(ptr_align_4(fCurr));
1.102 + memcpy(dst, fCurr, size);
1.103 + fCurr += SkAlign4(size);
1.104 + SkASSERT(fCurr <= fStop);
1.105 + }
1.106 +
1.107 + uint8_t readU8() { return (uint8_t)this->readInt(); }
1.108 + uint16_t readU16() { return (uint16_t)this->readInt(); }
1.109 + int32_t readS32() { return this->readInt(); }
1.110 + uint32_t readU32() { return this->readInt(); }
1.111 +
1.112 + bool readPath(SkPath* path) {
1.113 + return readObjectFromMemory(path);
1.114 + }
1.115 +
1.116 + bool readMatrix(SkMatrix* matrix) {
1.117 + return readObjectFromMemory(matrix);
1.118 + }
1.119 +
1.120 + bool readRRect(SkRRect* rrect) {
1.121 + return readObjectFromMemory(rrect);
1.122 + }
1.123 +
1.124 + bool readRegion(SkRegion* rgn) {
1.125 + return readObjectFromMemory(rgn);
1.126 + }
1.127 +
1.128 + /**
1.129 + * Read the length of a string (written by SkWriter32::writeString) into
1.130 + * len (if len is not NULL) and return the null-ternimated address of the
1.131 + * string within the reader's buffer.
1.132 + */
1.133 + const char* readString(size_t* len = NULL);
1.134 +
1.135 + /**
1.136 + * Read the string (written by SkWriter32::writeString) and return it in
1.137 + * copy (if copy is not null). Return the length of the string.
1.138 + */
1.139 + size_t readIntoString(SkString* copy);
1.140 +
1.141 +private:
1.142 + template <typename T> bool readObjectFromMemory(T* obj) {
1.143 + size_t size = obj->readFromMemory(this->peek(), this->available());
1.144 + // If readFromMemory() fails (which means that available() was too small), it returns 0
1.145 + bool success = (size > 0) && (size <= this->available()) && (SkAlign4(size) == size);
1.146 + // In case of failure, we want to skip to the end
1.147 + (void)this->skip(success ? size : this->available());
1.148 + return success;
1.149 + }
1.150 +
1.151 + // these are always 4-byte aligned
1.152 + const char* fCurr; // current position within buffer
1.153 + const char* fStop; // end of buffer
1.154 + const char* fBase; // beginning of buffer
1.155 +
1.156 +#ifdef SK_DEBUG
1.157 + static bool ptr_align_4(const void* ptr) {
1.158 + return (((const char*)ptr - (const char*)NULL) & 3) == 0;
1.159 + }
1.160 +#endif
1.161 +};
1.162 +
1.163 +#endif
