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// Copyright 2014 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Performance test for different implementations of
* byteArrayToString.
*/
goog.provide('goog.crypt.byteArrayToStringPerf');
goog.require('goog.array');
goog.require('goog.dom');
goog.require('goog.testing.PerformanceTable');
goog.setTestOnly('goog.crypt.byteArrayToStringPerf');
var table = new goog.testing.PerformanceTable(goog.dom.getElement('perfTable'));
var BYTES_LENGTH = Math.pow(2, 20);
var CHUNK_SIZE = 8192;
function getBytes() {
var bytes = [];
for (var i = 0; i < BYTES_LENGTH; i++) {
bytes.push('A'.charCodeAt(0));
}
return bytes;
}
function copyAndSpliceByteArray(bytes) {
// Copy the passed byte array since we're going to destroy it.
var remainingBytes = goog.array.clone(bytes);
var strings = [];
// Convert each chunk to a string.
while (remainingBytes.length) {
var chunk = goog.array.splice(remainingBytes, 0, CHUNK_SIZE);
strings.push(String.fromCharCode.apply(null, chunk));
}
return strings.join('');
}
function sliceByteArrayConcat(bytes) {
var str = '';
for (var i = 0; i < bytes.length; i += CHUNK_SIZE) {
var chunk = goog.array.slice(bytes, i, i + CHUNK_SIZE);
str += String.fromCharCode.apply(null, chunk);
}
return str;
}
function sliceByteArrayJoin(bytes) {
var strings = [];
for (var i = 0; i < bytes.length; i += CHUNK_SIZE) {
var chunk = goog.array.slice(bytes, i, i + CHUNK_SIZE);
strings.push(String.fromCharCode.apply(null, chunk));
}
return strings.join('');
}
function mapByteArray(bytes) {
var strings = goog.array.map(bytes, String.fromCharCode);
return strings.join('');
}
function forLoopByteArrayConcat(bytes) {
var str = '';
for (var i = 0; i < bytes.length; i++) {
str += String.fromCharCode(bytes[i]);
}
return str;
}
function forLoopByteArrayJoin(bytes) {
var strs = [];
for (var i = 0; i < bytes.length; i++) {
strs.push(String.fromCharCode(bytes[i]));
}
return strs.join('');
}
function run() {
var bytes = getBytes();
table.run(
goog.partial(copyAndSpliceByteArray, getBytes()),
'Copy array and splice out chunks.');
table.run(
goog.partial(sliceByteArrayConcat, getBytes()),
'Slice out copies of the byte array, concatenating results');
table.run(
goog.partial(sliceByteArrayJoin, getBytes()),
'Slice out copies of the byte array, joining results');
table.run(
goog.partial(forLoopByteArrayConcat, getBytes()),
'Use for loop with concat.');
table.run(
goog.partial(forLoopByteArrayJoin, getBytes()),
'Use for loop with join.');
// Purposefully commented out. This ends up being tremendously expensive.
// table.run(goog.partial(mapByteArray, getBytes()),
// 'Use goog.array.map and fromCharCode.');
}
run();
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