-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathendian.ts
226 lines (202 loc) · 4.63 KB
/
endian.ts
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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
/**
* @module
*
* Endian related constants, types, and factories.
*/
import type { ArrayBufferReal, BufferPointer } from './native.ts';
import { constant, dataView } from './util.ts';
/**
* Is host big endian.
*/
export const BIG_ENDIAN: boolean = !new Uint8Array(
new Uint16Array([1]).buffer,
)[0];
/**
* Is host little endian.
*/
export const LITTLE_ENDIAN = !BIG_ENDIAN;
/**
* Endian aware.
*/
export interface EndianAware {
/**
* True for little endian, false for big endian.
*/
readonly littleEndian: boolean;
}
let pri: WeakMap<Endian, BufferPointer & EndianAware>;
/**
* Endian aware buffer pointer.
*/
export class Endian implements BufferPointer, EndianAware {
/**
* Endian class.
*/
declare public readonly ['constructor']: EndianClass;
/**
* Type tag.
*/
declare public readonly [Symbol.toStringTag]: string;
/**
* Create instance for buffer.
*
* @param buffer Buffer data.
* @param byteOffset Byte offset into buffer.
* @param littleEndian Host endian, little endian, big endian.
*/
constructor(
buffer: ArrayBufferReal,
byteOffset = 0,
littleEndian: boolean | null = null,
) {
dataView(buffer);
byteOffset = (+byteOffset || 0) - (byteOffset % 1 || 0);
if (!(byteOffset > -Infinity && byteOffset < Infinity)) {
throw new RangeError(`Invalid offset: ${byteOffset}`);
}
(pri ??= new WeakMap()).set(this, {
buffer,
byteOffset,
littleEndian: !!(littleEndian ?? LITTLE_ENDIAN),
});
}
public get buffer(): ArrayBufferLike {
return pri.get(this)!.buffer;
}
public get byteOffset(): number {
return pri.get(this)!.byteOffset;
}
public get littleEndian(): boolean {
return this.constructor.LITTLE_ENDIAN ?? pri.get(this)!.littleEndian;
}
/**
* Type level endian override.
*/
public static readonly LITTLE_ENDIAN: boolean | null = null;
static {
constant(this.prototype, Symbol.toStringTag, 'Endian');
constant(this, 'LITTLE_ENDIAN');
}
}
/**
* Endian class.
*/
export interface EndianClass extends Omit<typeof Endian, 'new'> {}
/**
* Endian constructor.
*/
export interface EndianConstructor extends EndianClass {
/**
* Endian constructor.
*/
new (
buffer: ArrayBufferReal,
byteOffset?: number,
littleEndian?: boolean | null,
): Endian;
}
let dynamicEndians: WeakMap<EndianClass, EndianClass>;
/**
* Extend endian class as default endian.
*
* @param Endian Endian class.
* @returns Extended class.
*/
export function dynamicEndian<T extends EndianClass>(
// deno-lint-ignore ban-types
Endian: T & Function,
): T {
let r = (dynamicEndians ??= new WeakMap()).get(Endian);
if (!r) {
const name = `DynamicEndian<${Endian.name}>`;
dynamicEndians.set(
Endian,
r = {
[name]: class extends (Endian as unknown as EndianConstructor) {
public static override readonly LITTLE_ENDIAN = null;
static {
constant(
this.prototype,
Symbol.toStringTag,
`DynamicEndian<${
Endian.prototype[Symbol.toStringTag]
}>`,
);
constant(this, 'LITTLE_ENDIAN');
}
},
}[name],
);
}
return r as T;
}
let bigEndians: WeakMap<EndianClass, EndianClass>;
/**
* Extend endian class as big endian.
*
* @param Endian Endian class.
* @returns Extended class.
*/
export function bigEndian<T extends EndianClass>(
// deno-lint-ignore ban-types
Endian: T & Function,
): T {
let r = (bigEndians ??= new WeakMap()).get(Endian);
if (!r) {
const name = `BigEndian<${Endian.name}>`;
bigEndians.set(
Endian,
r = {
[name]: class extends (Endian as unknown as EndianConstructor) {
public static override readonly LITTLE_ENDIAN = false;
static {
constant(
this.prototype,
Symbol.toStringTag,
`BigEndian<${
Endian.prototype[Symbol.toStringTag]
}>`,
);
constant(this, 'LITTLE_ENDIAN');
}
},
}[name],
);
}
return r as T;
}
let littleEndians: WeakMap<EndianClass, EndianClass>;
/**
* Extend endian class as little endian.
*
* @param Endian Endian class.
* @returns Extended class.
*/
export function littleEndian<T extends EndianClass>(
// deno-lint-ignore ban-types
Endian: T & Function,
): T {
let r = (littleEndians ??= new WeakMap()).get(Endian);
if (!r) {
const name = `LittleEndian<${Endian.name}>`;
littleEndians.set(
Endian,
r = {
[name]: class extends (Endian as unknown as EndianConstructor) {
public static override readonly LITTLE_ENDIAN = true;
static {
constant(
this.prototype,
Symbol.toStringTag,
`LittleEndian<${
Endian.prototype[Symbol.toStringTag]
}>`,
);
constant(this, 'LITTLE_ENDIAN');
}
},
}[name],
);
}
return r as T;
}