-
Notifications
You must be signed in to change notification settings - Fork 1
/
FileAbstraction.hpp
163 lines (131 loc) · 6.48 KB
/
FileAbstraction.hpp
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
/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
*
* Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#ifndef __FILE_ABSTRACTION__
#define __FILE_ABSTRACTION__
#include <stdint.h>
#include <string.h>
#include <libkern/OSByteOrder.h>
#ifdef __OPTIMIZE__
#define INLINE __attribute__((always_inline))
#else
#define INLINE
#endif
//
// This abstraction layer is for use with file formats that have 64-bit/32-bit and Big-Endian/Little-Endian variants
//
// For example: to make a utility that handles 32-bit little enidan files use: Pointer32<LittleEndian>
//
//
// get16() read a 16-bit number from an E endian struct
// set16() write a 16-bit number to an E endian struct
// get32() read a 32-bit number from an E endian struct
// set32() write a 32-bit number to an E endian struct
// get64() read a 64-bit number from an E endian struct
// set64() write a 64-bit number to an E endian struct
//
// getBits() read a bit field from an E endian struct (bitCount=number of bits in field, firstBit=bit index of field)
// setBits() write a bit field to an E endian struct (bitCount=number of bits in field, firstBit=bit index of field)
//
// getBitsRaw() read a bit field from a struct with native endianness
// setBitsRaw() write a bit field from a struct with native endianness
//
class BigEndian
{
public:
static uint16_t get16(const uint16_t& from) INLINE { return OSReadBigInt16(&from, 0); }
static void set16(uint16_t& into, uint16_t value) INLINE { OSWriteBigInt16(&into, 0, value); }
static uint32_t get32(const uint32_t& from) INLINE { return OSReadBigInt32(&from, 0); }
static void set32(uint32_t& into, uint32_t value) INLINE { OSWriteBigInt32(&into, 0, value); }
static int32_t get32(const int32_t& from) INLINE { return OSReadBigInt32(&from, 0); }
static void set32(int32_t& into, int32_t value) INLINE { OSWriteBigInt32(&into, 0, value); }
static uint64_t get64(const uint64_t& from) INLINE { return OSReadBigInt64(&from, 0); }
static void set64(uint64_t& into, uint64_t value) INLINE { OSWriteBigInt64(&into, 0, value); }
static uint32_t getBits(const uint32_t& from,
uint8_t firstBit, uint8_t bitCount) INLINE { return getBitsRaw(get32(from), firstBit, bitCount); }
static void setBits(uint32_t& into, uint32_t value,
uint8_t firstBit, uint8_t bitCount) INLINE { uint32_t temp = get32(into); setBitsRaw(temp, value, firstBit, bitCount); set32(into, temp); }
static uint32_t getBitsRaw(const uint32_t& from,
uint8_t firstBit, uint8_t bitCount) INLINE { return ((from >> (32-firstBit-bitCount)) & ((1<<bitCount)-1)); }
static void setBitsRaw(uint32_t& into, uint32_t value,
uint8_t firstBit, uint8_t bitCount) INLINE { uint32_t temp = into;
const uint32_t mask = ((1<<bitCount)-1);
temp &= ~(mask << (32-firstBit-bitCount));
temp |= ((value & mask) << (32-firstBit-bitCount));
into = temp; }
enum { little_endian = 0 };
};
class LittleEndian
{
public:
static uint16_t get16(const uint16_t& from) INLINE { return OSReadLittleInt16(&from, 0); }
static void set16(uint16_t& into, uint16_t value) INLINE { OSWriteLittleInt16(&into, 0, value); }
static uint32_t get32(const uint32_t& from) INLINE { return OSReadLittleInt32(&from, 0); }
static void set32(uint32_t& into, uint32_t value) INLINE { OSWriteLittleInt32(&into, 0, value); }
static int32_t get32(const int32_t& from) INLINE { return OSReadLittleInt32(&from, 0); }
static void set32(int32_t& into, int32_t value) INLINE { OSWriteLittleInt32(&into, 0, value); }
static uint64_t get64(const uint64_t& from) INLINE { return OSReadLittleInt64(&from, 0); }
static void set64(uint64_t& into, uint64_t value) INLINE { OSWriteLittleInt64(&into, 0, value); }
static uint32_t getBits(const uint32_t& from,
uint8_t firstBit, uint8_t bitCount) INLINE { return getBitsRaw(get32(from), firstBit, bitCount); }
static void setBits(uint32_t& into, uint32_t value,
uint8_t firstBit, uint8_t bitCount) INLINE { uint32_t temp = get32(into); setBitsRaw(temp, value, firstBit, bitCount); set32(into, temp); }
static uint32_t getBitsRaw(const uint32_t& from,
uint8_t firstBit, uint8_t bitCount) INLINE { return ((from >> firstBit) & ((1<<bitCount)-1)); }
static void setBitsRaw(uint32_t& into, uint32_t value,
uint8_t firstBit, uint8_t bitCount) INLINE { uint32_t temp = into;
const uint32_t mask = ((1<<bitCount)-1);
temp &= ~(mask << firstBit);
temp |= ((value & mask) << firstBit);
into = temp; }
enum { little_endian = 1 };
};
template <typename _E>
class Pointer32
{
public:
typedef uint32_t uint_t;
typedef _E E;
static uint64_t getP(const uint_t& from) INLINE { return _E::get32(from); }
static void setP(uint_t& into, uint64_t value) INLINE { _E::set32(into, value); }
// Round to a P-size boundary
template <typename T>
static T round_up(T value) { return (value+3) & ~(T)3; }
template <typename T>
static T round_down(T value) { return value & ~(T)3; }
};
template <typename _E>
class Pointer64
{
public:
typedef uint64_t uint_t;
typedef _E E;
static uint64_t getP(const uint_t& from) INLINE { return _E::get64(from); }
static void setP(uint_t& into, uint64_t value) INLINE { _E::set64(into, value); }
// Round to a P-size boundary
template <typename T>
static T round_up(T value) { return (value+7) & ~(T)7; }
template <typename T>
static T round_down(T value) { return value & ~(T)7; }
};
#endif // __FILE_ABSTRACTION__