chrome-devtools-frontend
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Chrome DevTools UI
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JavaScript
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import * as Common from '../common/common.js';
import {ls} from '../common/common.js'; // eslint-disable-line rulesdir/es_modules_import
import * as Platform from '../platform/platform.js';
import {NameValue} from './NetworkRequest.js'; // eslint-disable-line no-unused-vars
export class ServerTiming {
/**
* @param {string} metric
* @param {?number} value
* @param {?string} description
*/
constructor(metric, value, description) {
this.metric = metric;
this.value = value;
this.description = description;
}
/**
* @param {!Array<!NameValue>} headers
* @return {?Array<!ServerTiming>}
*/
static parseHeaders(headers) {
const rawServerTimingHeaders = headers.filter(item => item.name.toLowerCase() === 'server-timing');
if (!rawServerTimingHeaders.length) {
return null;
}
const serverTimings = rawServerTimingHeaders.reduce((memo, header) => {
const timing = this.createFromHeaderValue(header.value);
memo.push(...timing.map(function(entry) {
return new ServerTiming(
entry.name, entry.hasOwnProperty('dur') ? entry.dur : null, entry.hasOwnProperty('desc') ? entry.desc : '');
}));
return memo;
}, /** @type {!Array<!ServerTiming>} */ ([]));
serverTimings.sort((a, b) => Platform.StringUtilities.compare(a.metric.toLowerCase(), b.metric.toLowerCase()));
return serverTimings;
}
/**
* TODO(crbug.com/1011811): Instead of using !Object<string, *> we should have a proper type
* with name, desc and dur properties.
* @param {string} valueString
* @return {!Array<!Object<string, *>>}
*/
static createFromHeaderValue(valueString) {
function trimLeadingWhiteSpace() {
valueString = valueString.replace(/^\s*/, '');
}
/** @param {string} char */
function consumeDelimiter(char) {
console.assert(char.length === 1);
trimLeadingWhiteSpace();
if (valueString.charAt(0) !== char) {
return false;
}
valueString = valueString.substring(1);
return true;
}
function consumeToken() {
// https://tools.ietf.org/html/rfc7230#appendix-B
const result = /^(?:\s*)([\w!#$%&'*+\-.^`|~]+)(?:\s*)(.*)/.exec(valueString);
if (!result) {
return null;
}
valueString = result[2];
return result[1];
}
function consumeTokenOrQuotedString() {
trimLeadingWhiteSpace();
if (valueString.charAt(0) === '"') {
return consumeQuotedString();
}
return consumeToken();
}
function consumeQuotedString() {
console.assert(valueString.charAt(0) === '"');
valueString = valueString.substring(1); // remove leading DQUOTE
let value = '';
while (valueString.length) {
// split into two parts:
// -everything before the first " or \
// -everything else
const result = /^([^"\\]*)(.*)/.exec(valueString);
if (!result) {
return null; // not a valid quoted-string
}
value += result[1];
if (result[2].charAt(0) === '"') {
// we have found our closing "
valueString = result[2].substring(1); // strip off everything after the closing "
return value; // we are done here
}
console.assert(result[2].charAt(0) === '\\');
// special rules for \ found in quoted-string (https://tools.ietf.org/html/rfc7230#section-3.2.6)
value += result[2].charAt(1); // grab the character AFTER the \ (if there was one)
valueString = result[2].substring(2); // strip off \ and next character
}
return null; // not a valid quoted-string
}
function consumeExtraneous() {
const result = /([,;].*)/.exec(valueString);
if (result) {
valueString = result[1];
}
}
const result = [];
let name;
while ((name = consumeToken()) !== null) {
const entry = {name};
if (valueString.charAt(0) === '=') {
this.showWarning(ls`Deprecated syntax found. Please use: <name>;dur=<duration>;desc=<description>`);
}
while (consumeDelimiter(';')) {
let paramName;
if ((paramName = consumeToken()) === null) {
continue;
}
paramName = paramName.toLowerCase();
const parseParameter = this.getParserForParameter(paramName);
let paramValue = null;
if (consumeDelimiter('=')) {
// always parse the value, even if we don't recognize the parameter name
paramValue = consumeTokenOrQuotedString();
consumeExtraneous();
}
if (parseParameter) {
// paramName is valid
if (entry.hasOwnProperty(paramName)) {
this.showWarning(ls`Duplicate parameter "${paramName}" ignored.`);
continue;
}
if (paramValue === null) {
this.showWarning(ls`No value found for parameter "${paramName}".`);
}
parseParameter.call(this, entry, paramValue);
} else {
// paramName is not valid
this.showWarning(ls`Unrecognized parameter "${paramName}".`);
}
}
result.push(entry);
if (!consumeDelimiter(',')) {
break;
}
}
if (valueString.length) {
this.showWarning(ls`Extraneous trailing characters.`);
}
return result;
}
/**
* @param {string} paramName
* @return {?function(!Object<string, *>, ?string):void}
*/
static getParserForParameter(paramName) {
switch (paramName) {
case 'dur': {
/**
* @param {!Object<string, *>} entry
* @param {*} paramValue
*/
function durParser(entry, paramValue) {
entry.dur = 0;
if (paramValue !== null) {
const duration = parseFloat(paramValue);
if (isNaN(duration)) {
ServerTiming.showWarning(ls`Unable to parse "${paramName}" value "${paramValue}".`);
return;
}
entry.dur = duration;
}
}
return durParser;
}
case 'desc': {
/**
* @param {!Object<string, *>} entry
* @param {?string} paramValue
*/
function descParser(entry, paramValue) {
entry.desc = paramValue || '';
}
return descParser;
}
default: {
return null;
}
}
}
/**
* @param {string} msg
*/
static showWarning(msg) {
Common.Console.Console.instance().warn(Common.UIString.UIString(`ServerTiming: ${msg}`));
}
}