73 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			73 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| /* eslint-disable node/no-deprecated-api */
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| 
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| var toString = Object.prototype.toString
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| 
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| var isModern = (
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|   typeof Buffer !== 'undefined' &&
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|   typeof Buffer.alloc === 'function' &&
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|   typeof Buffer.allocUnsafe === 'function' &&
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|   typeof Buffer.from === 'function'
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| )
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| 
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| function isArrayBuffer (input) {
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|   return toString.call(input).slice(8, -1) === 'ArrayBuffer'
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| }
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| 
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| function fromArrayBuffer (obj, byteOffset, length) {
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|   byteOffset >>>= 0
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| 
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|   var maxLength = obj.byteLength - byteOffset
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| 
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|   if (maxLength < 0) {
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|     throw new RangeError("'offset' is out of bounds")
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|   }
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| 
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|   if (length === undefined) {
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|     length = maxLength
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|   } else {
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|     length >>>= 0
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| 
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|     if (length > maxLength) {
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|       throw new RangeError("'length' is out of bounds")
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|     }
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|   }
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| 
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|   return isModern
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|     ? Buffer.from(obj.slice(byteOffset, byteOffset + length))
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|     : new Buffer(new Uint8Array(obj.slice(byteOffset, byteOffset + length)))
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| }
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| 
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| function fromString (string, encoding) {
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|   if (typeof encoding !== 'string' || encoding === '') {
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|     encoding = 'utf8'
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|   }
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| 
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|   if (!Buffer.isEncoding(encoding)) {
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|     throw new TypeError('"encoding" must be a valid string encoding')
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|   }
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| 
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|   return isModern
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|     ? Buffer.from(string, encoding)
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|     : new Buffer(string, encoding)
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| }
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| 
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| function bufferFrom (value, encodingOrOffset, length) {
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|   if (typeof value === 'number') {
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|     throw new TypeError('"value" argument must not be a number')
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|   }
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| 
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|   if (isArrayBuffer(value)) {
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|     return fromArrayBuffer(value, encodingOrOffset, length)
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|   }
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| 
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|   if (typeof value === 'string') {
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|     return fromString(value, encodingOrOffset)
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|   }
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| 
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|   return isModern
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|     ? Buffer.from(value)
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|     : new Buffer(value)
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| }
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| 
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| module.exports = bufferFrom
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