-
Notifications
You must be signed in to change notification settings - Fork 156
/
NumericBuffers.ts
152 lines (146 loc) · 4.97 KB
/
NumericBuffers.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
import { DeveloperError } from "../base/DeveloperError";
import { ArrayBuffers } from "./ArrayBuffers";
import { MetadataComponentTypes } from "../metadata/MetadataComponentTypes";
/**
* Methods for extracting `number`- or `bigint` values or arrays thereof
* from `Buffer` objects
*
* @internal
*/
export class NumericBuffers {
/**
* Obtains a single number or bigint from the given buffer,
* at the given index, based on the given component type.
*
* @param buffer - The buffer
* @param index - The index
* @param componentType - The component type
* @returns The number or bigint
* @throws DeveloperError If the given `componentType` is not valid
*/
static getNumericFromBuffer(
buffer: Buffer,
index: number,
componentType: string
): any {
const byteSize =
MetadataComponentTypes.byteSizeForComponentType(componentType);
const byteOffset = index * byteSize;
switch (componentType) {
case "INT8":
return buffer.readInt8(byteOffset);
case "UINT8":
return buffer.readUint8(byteOffset);
case "INT16":
return buffer.readInt16LE(byteOffset);
case "UINT16":
return buffer.readUInt16LE(byteOffset);
case "INT32":
return buffer.readInt32LE(byteOffset);
case "UINT32":
return buffer.readUInt32LE(byteOffset);
case "INT64":
return buffer.readBigInt64LE(byteOffset);
case "UINT64":
return buffer.readBigUInt64LE(byteOffset);
case "FLOAT32":
return buffer.readFloatLE(byteOffset);
case "FLOAT64":
return buffer.readDoubleLE(byteOffset);
}
throw new DeveloperError(`Unknown component type: ${componentType}`);
}
/**
* Obtains an array of number or bigint values from the given buffer,
* starting at the given index, based on the given component type.
*
* @param buffer - The buffer
* @param index - The index
* @param arrayLength - The length of the array, in number of elements
* @param componentType - The component type
* @returns The number or bigint array
* @throws DeveloperError If the given `componentType` is not valid
*/
static getNumericArrayFromBuffer(
buffer: Buffer,
index: number,
arrayLength: number,
componentType: string
): any {
const typedArray = NumericBuffers.getTypedArrayFromBuffer(
buffer,
index,
arrayLength,
componentType
);
const array = [...typedArray];
return array;
}
/**
* Obtains a typed array of number or bigint values from the given buffer,
* starting at the given index, based on the given component type.
*
* @param buffer - The buffer
* @param index - The index
* @param arrayLength - The length of the array, in number of elements
* @param componentType - The component type
* @returns The number or bigint typed array
* @throws DeveloperError If the given `componentType` is not valid
*/
private static getTypedArrayFromBuffer(
buffer: Buffer,
index: number,
arrayLength: number,
componentType: string
) {
const componentSize =
MetadataComponentTypes.byteSizeForComponentType(componentType);
const elementSize = arrayLength * componentSize;
const byteOffset = index * elementSize;
const arrayBuffer = ArrayBuffers.fromBuffer(buffer);
switch (componentType) {
case "INT8":
return new Int8Array(arrayBuffer, byteOffset, arrayLength);
case "UINT8":
return new Uint8Array(arrayBuffer, byteOffset, arrayLength);
case "INT16":
return new Int16Array(arrayBuffer, byteOffset, arrayLength);
case "UINT16":
return new Uint16Array(arrayBuffer, byteOffset, arrayLength);
case "INT32":
return new Int32Array(arrayBuffer, byteOffset, arrayLength);
case "UINT32":
return new Uint32Array(arrayBuffer, byteOffset, arrayLength);
case "INT64":
return new BigInt64Array(arrayBuffer, byteOffset, arrayLength);
case "UINT64":
return new BigUint64Array(arrayBuffer, byteOffset, arrayLength);
case "FLOAT32":
return new Float32Array(arrayBuffer, byteOffset, arrayLength);
case "FLOAT64":
return new Float64Array(arrayBuffer, byteOffset, arrayLength);
}
throw new DeveloperError(`Unknown component type: ${componentType}`);
}
/**
* Returns an array that contains the `number`- or `bigint` values
* that are stored in the given buffer
*
* @param buffer - The buffer
* @param componentType - The component type
* @returns The number or bigint array
* @throws DeveloperError If the given `componentType` is not valid
*/
static getNumericBufferAsArray(buffer: Buffer, componentType: string): any {
const size = MetadataComponentTypes.byteSizeForComponentType(componentType);
const arrayLength = buffer.length / size;
const typedArray = NumericBuffers.getTypedArrayFromBuffer(
buffer,
0,
arrayLength,
componentType
);
const array = [...typedArray];
return array;
}
}