67 lines
1.4 KiB
JavaScript
67 lines
1.4 KiB
JavaScript
'use strict'
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// Note: Don't use destructuring assignment for `Buffer`, or we'll hit a
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// browserify bug that makes the statement invalid, throwing an error in
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// sandboxed renderer.
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const Buffer = require('buffer').Buffer
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const typedArrays = {
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Buffer,
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ArrayBuffer,
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Int8Array,
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Uint8Array,
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Uint8ClampedArray,
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Int16Array,
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Uint16Array,
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Int32Array,
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Uint32Array,
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Float32Array,
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Float64Array
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}
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function getType (value) {
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for (const type of Object.keys(typedArrays)) {
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if (value instanceof typedArrays[type]) {
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return type
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}
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}
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return null
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}
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function getBuffer (value) {
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if (value instanceof Buffer) {
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return value
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} else if (value instanceof ArrayBuffer) {
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return Buffer.from(value)
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} else {
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return Buffer.from(value.buffer, value.byteOffset, value.byteLength)
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}
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}
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exports.isBuffer = function (value) {
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return ArrayBuffer.isView(value) || value instanceof ArrayBuffer
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}
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exports.bufferToMeta = function (value) {
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return {
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type: getType(value),
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data: getBuffer(value),
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length: value.length
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}
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}
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exports.metaToBuffer = function (value) {
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const constructor = typedArrays[value.type]
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const data = getBuffer(value.data)
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if (constructor === Buffer) {
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return data
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} else if (constructor === ArrayBuffer) {
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return data.buffer
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} else if (constructor) {
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return new constructor(data.buffer, data.byteOffset, value.length)
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} else {
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return data
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}
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}
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