1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/*
* 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);
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
|
