front_end/heap_snapshot_worker/HeapSnapshotLoader.js - devtools/devtools-frontend - Git at Google

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 import * as TextUtils from '../text_utils/text_utils.js';

 import {HeapSnapshotHeader, HeapSnapshotProgress, JSHeapSnapshot} from './HeapSnapshot.js';  // eslint-disable-line no-unused-vars
 import {HeapSnapshotWorkerDispatcher} from './HeapSnapshotWorkerDispatcher.js';  // eslint-disable-line no-unused-vars

 /**
  * @unrestricted
  */
 export class HeapSnapshotLoader {
   /**
    * @param {!HeapSnapshotWorkerDispatcher} dispatcher
    */
   constructor(dispatcher) {
     this._reset();
     this._progress = new HeapSnapshotProgress(dispatcher);
     this._buffer = '';
     this._dataCallback = null;
     this._done = false;
     this._parseInput();
   }

   dispose() {
     this._reset();
   }

   _reset() {
     this._json = '';
     this._snapshot = {};
   }

   close() {
     this._done = true;
     if (this._dataCallback) {
       this._dataCallback('');
     }
   }

   /**
    * @return {!JSHeapSnapshot}
    */
   buildSnapshot() {
     this._progress.updateStatus(ls`Processing snapshot…`);
     const result = new JSHeapSnapshot(this._snapshot, this._progress);
     this._reset();
     return result;
   }

   _parseUintArray() {
     let index = 0;
     const char0 = '0'.charCodeAt(0);
     const char9 = '9'.charCodeAt(0);
     const closingBracket = ']'.charCodeAt(0);
     const length = this._json.length;
     while (true) {
       while (index < length) {
         const code = this._json.charCodeAt(index);
         if (char0 <= code && code <= char9) {
           break;
         } else if (code === closingBracket) {
           this._json = this._json.slice(index + 1);
           return false;
         }
         ++index;
       }
       if (index === length) {
         this._json = '';
         return true;
       }
       let nextNumber = 0;
       const startIndex = index;
       while (index < length) {
         const code = this._json.charCodeAt(index);
         if (char0 > code || code > char9) {
           break;
         }
         nextNumber *= 10;
         nextNumber += (code - char0);
         ++index;
       }
       if (index === length) {
         this._json = this._json.slice(startIndex);
         return true;
       }
       this._array[this._arrayIndex++] = nextNumber;
     }
   }

   _parseStringsArray() {
     this._progress.updateStatus(ls`Parsing strings…`);
     const closingBracketIndex = this._json.lastIndexOf(']');
     if (closingBracketIndex === -1) {
       throw new Error('Incomplete JSON');
     }
     this._json = this._json.slice(0, closingBracketIndex + 1);
     this._snapshot.strings = JSON.parse(this._json);
   }

   /**
    * @param {string} chunk
    */
   write(chunk) {
     this._buffer += chunk;
     if (!this._dataCallback) {
       return;
     }
     this._dataCallback(this._buffer);
     this._dataCallback = null;
     this._buffer = '';
   }

   /**
    * @return {!Promise<string>}
    */
   _fetchChunk() {
     return this._done ? Promise.resolve(this._buffer) : new Promise(r => this._dataCallback = r);
   }

   /**
    * @param {string} token
    * @param {number=} startIndex
    * @return {!Promise<number>}
    */
   async _findToken(token, startIndex) {
     while (true) {
       const pos = this._json.indexOf(token, startIndex || 0);
       if (pos !== -1) {
         return pos;
       }
       startIndex = this._json.length - token.length + 1;
       this._json += await this._fetchChunk();
     }
   }

   /**
    * @param {string} name
    * @param {string} title
    * @param {number=} length
    * @return {!Promise<!Uint32Array|!Array<number>>}
    */
   async _parseArray(name, title, length) {
     const nameIndex = await this._findToken(name);
     const bracketIndex = await this._findToken('[', nameIndex);
     this._json = this._json.slice(bracketIndex + 1);
     this._array = length ? new Uint32Array(length) : [];
     this._arrayIndex = 0;
     while (this._parseUintArray()) {
       this._progress.updateProgress(title, this._arrayIndex, this._array.length);
       this._json += await this._fetchChunk();
     }
     const result = this._array;
     this._array = null;
     return result;
   }

   async _parseInput() {
     const snapshotToken = '"snapshot"';
     const snapshotTokenIndex = await this._findToken(snapshotToken);
     if (snapshotTokenIndex === -1) {
       throw new Error('Snapshot token not found');
     }

     this._progress.updateStatus(ls`Loading snapshot info…`);
     const json = this._json.slice(snapshotTokenIndex + snapshotToken.length + 1);
     this._jsonTokenizer = new TextUtils.TextUtils.BalancedJSONTokenizer(metaJSON => {
       this._json = this._jsonTokenizer.remainder();
       this._jsonTokenizer = null;
       this._snapshot.snapshot = /** @type {!HeapSnapshotHeader} */ (JSON.parse(metaJSON));
     });
     this._jsonTokenizer.write(json);
     while (this._jsonTokenizer) {
       this._jsonTokenizer.write(await this._fetchChunk());
     }

     this._snapshot.nodes = await this._parseArray(
         '"nodes"', ls`Loading nodes… %d%%`,
         this._snapshot.snapshot.meta.node_fields.length * this._snapshot.snapshot.node_count);

     this._snapshot.edges = await this._parseArray(
         '"edges"', ls`Loading edges… %d%%`,
         this._snapshot.snapshot.meta.edge_fields.length * this._snapshot.snapshot.edge_count);

     if (this._snapshot.snapshot.trace_function_count) {
       this._snapshot.trace_function_infos = await this._parseArray(
           '"trace_function_infos"', ls`Loading allocation traces… %d%%`,
           this._snapshot.snapshot.meta.trace_function_info_fields.length *
               this._snapshot.snapshot.trace_function_count);

       const thisTokenEndIndex = await this._findToken(':');
       const nextTokenIndex = await this._findToken('"', thisTokenEndIndex);
       const openBracketIndex = this._json.indexOf('[');
       const closeBracketIndex = this._json.lastIndexOf(']', nextTokenIndex);
       this._snapshot.trace_tree = JSON.parse(this._json.substring(openBracketIndex, closeBracketIndex + 1));
       this._json = this._json.slice(closeBracketIndex + 1);
     }

     if (this._snapshot.snapshot.meta.sample_fields) {
       this._snapshot.samples = await this._parseArray('"samples"', ls`Loading samples…`);
     }

     if (this._snapshot.snapshot.meta['location_fields']) {
       this._snapshot.locations = await this._parseArray('"locations"', ls`Loading locations…`);
     } else {
       this._snapshot.locations = [];
     }

     this._progress.updateStatus(ls`Loading strings…`);
     const stringsTokenIndex = await this._findToken('"strings"');
     const bracketIndex = await this._findToken('[', stringsTokenIndex);
     this._json = this._json.slice(bracketIndex);
     while (!this._done) {
       this._json += await this._fetchChunk();
     }
     this._parseStringsArray();
   }
 }
	/*
	* Copyright (C) 2012 Google Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	*
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following disclaimer
	* in the documentation and/or other materials provided with the
	* distribution.
	* * Neither the name of Google Inc. nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	import * as TextUtils from '../text_utils/text_utils.js';

	import {HeapSnapshotHeader, HeapSnapshotProgress, JSHeapSnapshot} from './HeapSnapshot.js'; // eslint-disable-line no-unused-vars
	import {HeapSnapshotWorkerDispatcher} from './HeapSnapshotWorkerDispatcher.js'; // eslint-disable-line no-unused-vars

	/**
	* @unrestricted
	*/
	export class HeapSnapshotLoader {
	/**
	* @param {!HeapSnapshotWorkerDispatcher} dispatcher
	*/
	constructor(dispatcher) {
	this._reset();
	this._progress = new HeapSnapshotProgress(dispatcher);
	this._buffer = '';
	this._dataCallback = null;
	this._done = false;
	this._parseInput();
	}

	dispose() {
	this._reset();
	}

	_reset() {
	this._json = '';
	this._snapshot = {};
	}

	close() {
	this._done = true;
	if (this._dataCallback) {
	this._dataCallback('');
	}
	}

	/**
	* @return {!JSHeapSnapshot}
	*/
	buildSnapshot() {
	this._progress.updateStatus(ls`Processing snapshot…`);
	const result = new JSHeapSnapshot(this._snapshot, this._progress);
	this._reset();
	return result;
	}

	_parseUintArray() {
	let index = 0;
	const char0 = '0'.charCodeAt(0);
	const char9 = '9'.charCodeAt(0);
	const closingBracket = ']'.charCodeAt(0);
	const length = this._json.length;
	while (true) {
	while (index < length) {
	const code = this._json.charCodeAt(index);
	if (char0 <= code && code <= char9) {
	break;
	} else if (code === closingBracket) {
	this._json = this._json.slice(index + 1);
	return false;
	}
	++index;
	}
	if (index === length) {
	this._json = '';
	return true;
	}
	let nextNumber = 0;
	const startIndex = index;
	while (index < length) {
	const code = this._json.charCodeAt(index);
	if (char0 > code \|\| code > char9) {
	break;
	}
	nextNumber *= 10;
	nextNumber += (code - char0);
	++index;
	}
	if (index === length) {
	this._json = this._json.slice(startIndex);
	return true;
	}
	this._array[this._arrayIndex++] = nextNumber;
	}
	}

	_parseStringsArray() {
	this._progress.updateStatus(ls`Parsing strings…`);
	const closingBracketIndex = this._json.lastIndexOf(']');
	if (closingBracketIndex === -1) {
	throw new Error('Incomplete JSON');
	}
	this._json = this._json.slice(0, closingBracketIndex + 1);
	this._snapshot.strings = JSON.parse(this._json);
	}

	/**
	* @param {string} chunk
	*/
	write(chunk) {
	this._buffer += chunk;
	if (!this._dataCallback) {
	return;
	}
	this._dataCallback(this._buffer);
	this._dataCallback = null;
	this._buffer = '';
	}

	/**
	* @return {!Promise<string>}
	*/
	_fetchChunk() {
	return this._done ? Promise.resolve(this._buffer) : new Promise(r => this._dataCallback = r);
	}

	/**
	* @param {string} token
	* @param {number=} startIndex
	* @return {!Promise<number>}
	*/
	async _findToken(token, startIndex) {
	while (true) {
	const pos = this._json.indexOf(token, startIndex \|\| 0);
	if (pos !== -1) {
	return pos;
	}
	startIndex = this._json.length - token.length + 1;
	this._json += await this._fetchChunk();
	}
	}

	/**
	* @param {string} name
	* @param {string} title
	* @param {number=} length
	* @return {!Promise<!Uint32Array\|!Array<number>>}
	*/
	async _parseArray(name, title, length) {
	const nameIndex = await this._findToken(name);
	const bracketIndex = await this._findToken('[', nameIndex);
	this._json = this._json.slice(bracketIndex + 1);
	this._array = length ? new Uint32Array(length) : [];
	this._arrayIndex = 0;
	while (this._parseUintArray()) {
	this._progress.updateProgress(title, this._arrayIndex, this._array.length);
	this._json += await this._fetchChunk();
	}
	const result = this._array;
	this._array = null;
	return result;
	}

	async _parseInput() {
	const snapshotToken = '"snapshot"';
	const snapshotTokenIndex = await this._findToken(snapshotToken);
	if (snapshotTokenIndex === -1) {
	throw new Error('Snapshot token not found');
	}

	this._progress.updateStatus(ls`Loading snapshot info…`);
	const json = this._json.slice(snapshotTokenIndex + snapshotToken.length + 1);
	this._jsonTokenizer = new TextUtils.TextUtils.BalancedJSONTokenizer(metaJSON => {
	this._json = this._jsonTokenizer.remainder();
	this._jsonTokenizer = null;
	this._snapshot.snapshot = /** @type {!HeapSnapshotHeader} */ (JSON.parse(metaJSON));
	});
	this._jsonTokenizer.write(json);
	while (this._jsonTokenizer) {
	this._jsonTokenizer.write(await this._fetchChunk());
	}

	this._snapshot.nodes = await this._parseArray(
	'"nodes"', ls`Loading nodes… %d%%`,
	this._snapshot.snapshot.meta.node_fields.length * this._snapshot.snapshot.node_count);

	this._snapshot.edges = await this._parseArray(
	'"edges"', ls`Loading edges… %d%%`,
	this._snapshot.snapshot.meta.edge_fields.length * this._snapshot.snapshot.edge_count);

	if (this._snapshot.snapshot.trace_function_count) {
	this._snapshot.trace_function_infos = await this._parseArray(
	'"trace_function_infos"', ls`Loading allocation traces… %d%%`,
	this._snapshot.snapshot.meta.trace_function_info_fields.length *
	this._snapshot.snapshot.trace_function_count);

	const thisTokenEndIndex = await this._findToken(':');
	const nextTokenIndex = await this._findToken('"', thisTokenEndIndex);
	const openBracketIndex = this._json.indexOf('[');
	const closeBracketIndex = this._json.lastIndexOf(']', nextTokenIndex);
	this._snapshot.trace_tree = JSON.parse(this._json.substring(openBracketIndex, closeBracketIndex + 1));
	this._json = this._json.slice(closeBracketIndex + 1);
	}

	if (this._snapshot.snapshot.meta.sample_fields) {
	this._snapshot.samples = await this._parseArray('"samples"', ls`Loading samples…`);
	}

	if (this._snapshot.snapshot.meta['location_fields']) {
	this._snapshot.locations = await this._parseArray('"locations"', ls`Loading locations…`);
	} else {
	this._snapshot.locations = [];
	}

	this._progress.updateStatus(ls`Loading strings…`);
	const stringsTokenIndex = await this._findToken('"strings"');
	const bracketIndex = await this._findToken('[', stringsTokenIndex);
	this._json = this._json.slice(bracketIndex);
	while (!this._done) {
	this._json += await this._fetchChunk();
	}
	this._parseStringsArray();
	}
	}