time-to-botec

Benchmark sampling in different programming languages
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cast_buffer.js (1708B)

      1 /**
      2 * @license Apache-2.0
      3 *
      4 * Copyright (c) 2018 The Stdlib Authors.
      5 *
      6 * Licensed under the Apache License, Version 2.0 (the "License");
      7 * you may not use this file except in compliance with the License.
      8 * You may obtain a copy of the License at
      9 *
     10 *    http://www.apache.org/licenses/LICENSE-2.0
     11 *
     12 * Unless required by applicable law or agreed to in writing, software
     13 * distributed under the License is distributed on an "AS IS" BASIS,
     14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15 * See the License for the specific language governing permissions and
     16 * limitations under the License.
     17 */
     18 
     19 'use strict';
     20 
     21 // MODULES //
     22 
     23 var bufferCtors = require( './../../base/buffer-ctors' );
     24 var allocUnsafe = require( '@stdlib/buffer/alloc-unsafe' );
     25 
     26 
     27 // MAIN //
     28 
     29 /**
     30 * Casts buffer elements by copying those elements to a buffer of another data type.
     31 *
     32 * @private
     33 * @param {(Array|TypedArray|Buffer)} buffer - input buffer
     34 * @param {NonNegativeInteger} len - number of elements to cast
     35 * @param {string} dtype - data type
     36 * @returns {(Array|TypedArray|Buffer)} output buffer
     37 *
     38 * @example
     39 * var b = castBuffer( [ 1.0, 2.0, 3.0 ], 3, 'float64' );
     40 * // returns <Float64Array>[ 1.0, 2.0, 3.0 ]
     41 */
     42 function castBuffer( buffer, len, dtype ) {
     43 	var ctor;
     44 	var out;
     45 	var i;
     46 
     47 	ctor = bufferCtors( dtype );
     48 	if ( dtype === 'generic') {
     49 		out = [];
     50 		for ( i = 0; i < len; i++ ) {
     51 			out.push( buffer[ i ] );
     52 		}
     53 	} else if ( dtype === 'binary' ) {
     54 		out = allocUnsafe( len );
     55 		for ( i = 0; i < len; i++ ) {
     56 			out[ i ] = buffer[ i ];
     57 		}
     58 	} else {
     59 		out = new ctor( len );
     60 		for ( i = 0; i < len; i++ ) {
     61 			out[ i ] = buffer[ i ];
     62 		}
     63 	}
     64 	return out;
     65 }
     66 
     67 
     68 // EXPORTS //
     69 
     70 module.exports = castBuffer;