v8/tools/logreader.mjs

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// Copyright 2011 the V8 project authors. 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.
/**
* @fileoverview Log Reader is used to process log file produced by V8.
*/
import { CsvParser } from "./csvparser.mjs";
// Parses dummy variable for readability;
export function parseString(field) { return field };
export const parseVarArgs = 'parse-var-args';
/**
* Base class for processing log files.
*
* @param {boolean} timedRange Ignore ticks outside timed range.
* @param {boolean} pairwiseTimedRange Ignore ticks outside pairs of timer
* markers.
* @constructor
*/
export class LogReader {
constructor(timedRange=false, pairwiseTimedRange=false) {
this.dispatchTable_ = new Map();
this.timedRange_ = timedRange;
this.pairwiseTimedRange_ = pairwiseTimedRange;
if (pairwiseTimedRange) this.timedRange_ = true;
this.lineNum_ = 0;
this.csvParser_ = new CsvParser();
// Variables for tracking of 'current-time' log entries:
this.hasSeenTimerMarker_ = false;
this.logLinesSinceLastTimerMarker_ = [];
}
/**
* @param {Object} table A table used for parsing and processing
* log records.
* exampleDispatchTable = {
* "log-entry-XXX": {
* parser: [parseString, parseInt, ..., parseVarArgs],
* processor: this.processXXX.bind(this)
* },
* ...
* }
*/
setDispatchTable(table) {
if (Object.getPrototypeOf(table) !== null) {
throw new Error("Dispatch expected table.__proto__=null for speedup");
}
for (let name in table) {
const parser = table[name];
if (parser === undefined) continue;
if (!parser.isAsync) parser.isAsync = false;
if (!Array.isArray(parser.parsers)) {
throw new Error(`Invalid parsers: dispatchTable['${
name}'].parsers should be an Array.`);
}
let type = typeof parser.processor;
if (type !== 'function') {
throw new Error(`Invalid processor: typeof dispatchTable['${
name}'].processor is '${type}' instead of 'function'`);
}
if (!parser.processor.name.startsWith('bound ')) {
parser.processor = parser.processor.bind(this);
}
this.dispatchTable_.set(name, parser);
}
}
/**
* A thin wrapper around shell's 'read' function showing a file name on error.
*/
readFile(fileName) {
try {
return read(fileName);
} catch (e) {
printErr(`file="${fileName}": ${e.message || e}`);
throw e;
}
}
/**
* Used for printing error messages.
*
* @param {string} str Error message.
*/
printError(str) {
// Do nothing.
}
/**
* Processes a portion of V8 profiler event log.
*
* @param {string} chunk A portion of log.
*/
async processLogChunk(chunk) {
let end = chunk.length;
let current = 0;
// Kept for debugging in case of parsing errors.
let lineNumber = 0;
while (current < end) {
const next = chunk.indexOf("\n", current);
if (next === -1) break;
lineNumber++;
const line = chunk.substring(current, next);
current = next + 1;
await this.processLogLine(line);
}
}
/**
* Processes a line of V8 profiler event log.
*
* @param {string} line A line of log.
*/
async processLogLine(line) {
if (!this.timedRange_) {
await this.processLogLine_(line);
return;
}
if (line.startsWith("current-time")) {
if (this.hasSeenTimerMarker_) {
await this.processLog_(this.logLinesSinceLastTimerMarker_);
this.logLinesSinceLastTimerMarker_ = [];
// In pairwise mode, a "current-time" line ends the timed range.
if (this.pairwiseTimedRange_) {
this.hasSeenTimerMarker_ = false;
}
} else {
this.hasSeenTimerMarker_ = true;
}
} else {
if (this.hasSeenTimerMarker_) {
this.logLinesSinceLastTimerMarker_.push(line);
} else if (!line.startsWith("tick")) {
await this.processLogLine_(line);
}
}
}
/**
* Processes stack record.
*
* @param {number} pc Program counter.
* @param {number} func JS Function.
* @param {Array.<string>} stack String representation of a stack.
* @return {Array.<number>} Processed stack.
*/
processStack(pc, func, stack) {
const fullStack = func ? [pc, func] : [pc];
let prevFrame = pc;
const length = stack.length;
for (let i = 0, n = length; i < n; ++i) {
const frame = stack[i];
const firstChar = frame[0];
if (firstChar === '+' || firstChar === '-') {
// An offset from the previous frame.
prevFrame += parseInt(frame, 16);
fullStack.push(prevFrame);
// Filter out possible 'overflow' string.
} else if (firstChar !== 'o') {
fullStack.push(parseInt(frame, 16));
} else {
console.error(`Dropping unknown tick frame: ${frame}`);
}
}
return fullStack;
}
/**
* Does a dispatch of a log record.
*
* @param {Array.<string>} fields Log record.
* @private
*/
async dispatchLogRow_(fields) {
// Obtain the dispatch.
const command = fields[0];
const dispatch = this.dispatchTable_.get(command);
if (dispatch === undefined) return;
const parsers = dispatch.parsers;
const length = parsers.length;
// Parse fields.
const parsedFields = new Array(length);
for (let i = 0; i < length; ++i) {
const parser = parsers[i];
if (parser === parseVarArgs) {
parsedFields[i] = fields.slice(1 + i);
break;
} else {
parsedFields[i] = parser(fields[1 + i]);
}
}
// Run the processor.
await dispatch.processor(...parsedFields);
}
/**
* Processes log lines.
*
* @param {Array.<string>} lines Log lines.
* @private
*/
async processLog_(lines) {
for (let i = 0, n = lines.length; i < n; ++i) {
await this.processLogLine_(lines[i]);
}
}
/**
* Processes a single log line.
*
* @param {String} a log line
* @private
*/
async processLogLine_(line) {
if (line.length > 0) {
try {
const fields = this.csvParser_.parseLine(line);
await this.dispatchLogRow_(fields);
} catch (e) {
this.printError(`line ${this.lineNum_ + 1}: ${e.message || e}\n${e.stack}`);
}
}
this.lineNum_++;
}
}