v8/tools/logreader.js

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// Copyright 2009 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.
*/
// Initlialize namespaces
var devtools = devtools || {};
devtools.profiler = devtools.profiler || {};
/**
* Base class for processing log files.
*
* @param {Array.<Object>} dispatchTable A table used for parsing and processing
* log records.
* @constructor
*/
devtools.profiler.LogReader = function(dispatchTable) {
/**
* @type {Array.<Object>}
*/
this.dispatchTable_ = dispatchTable;
this.dispatchTable_['alias'] =
{ parsers: [null, null], processor: this.processAlias_ };
this.dispatchTable_['repeat'] =
{ parsers: [parseInt, 'var-args'], processor: this.processRepeat_,
backrefs: true };
/**
* A key-value map for aliases. Translates short name -> full name.
* @type {Object}
*/
this.aliases_ = {};
/**
* A key-value map for previous address values.
* @type {Object}
*/
this.prevAddresses_ = {};
/**
* A key-value map for events than can be backreference-compressed.
* @type {Object}
*/
this.backRefsCommands_ = {};
this.initBackRefsCommands_();
/**
* Back references for decompression.
* @type {Array.<string>}
*/
this.backRefs_ = [];
};
/**
* Creates a parser for an address entry.
*
* @param {string} addressTag Address tag to perform offset decoding.
* @return {function(string):number} Address parser.
*/
devtools.profiler.LogReader.prototype.createAddressParser = function(
addressTag) {
var self = this;
return (function (str) {
var value = parseInt(str, 16);
var firstChar = str.charAt(0);
if (firstChar == '+' || firstChar == '-') {
var addr = self.prevAddresses_[addressTag];
addr += value;
self.prevAddresses_[addressTag] = addr;
return addr;
} else if (firstChar != '0' || str.charAt(1) != 'x') {
self.prevAddresses_[addressTag] = value;
}
return value;
});
};
/**
* Expands an alias symbol, if applicable.
*
* @param {string} symbol Symbol to expand.
* @return {string} Expanded symbol, or the input symbol itself.
*/
devtools.profiler.LogReader.prototype.expandAlias = function(symbol) {
return symbol in this.aliases_ ? this.aliases_[symbol] : symbol;
};
/**
* Used for printing error messages.
*
* @param {string} str Error message.
*/
devtools.profiler.LogReader.prototype.printError = function(str) {
// Do nothing.
};
/**
* Processes a portion of V8 profiler event log.
*
* @param {string} chunk A portion of log.
*/
devtools.profiler.LogReader.prototype.processLogChunk = function(chunk) {
this.processLog_(chunk.split('\n'));
};
/**
* Processes stack record.
*
* @param {number} pc Program counter.
* @param {Array.<string>} stack String representation of a stack.
* @return {Array.<number>} Processed stack.
*/
devtools.profiler.LogReader.prototype.processStack = function(pc, stack) {
var fullStack = [pc];
var prevFrame = pc;
for (var i = 0, n = stack.length; i < n; ++i) {
var frame = stack[i];
var firstChar = frame.charAt(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));
}
}
return fullStack;
};
/**
* Returns whether a particular dispatch must be skipped.
*
* @param {!Object} dispatch Dispatch record.
* @return {boolean} True if dispatch must be skipped.
*/
devtools.profiler.LogReader.prototype.skipDispatch = function(dispatch) {
return false;
};
/**
* Does a dispatch of a log record.
*
* @param {Array.<string>} fields Log record.
* @private
*/
devtools.profiler.LogReader.prototype.dispatchLogRow_ = function(fields) {
// Obtain the dispatch.
var command = fields[0];
if (!(command in this.dispatchTable_)) {
throw new Error('unknown command: ' + command);
}
var dispatch = this.dispatchTable_[command];
if (dispatch === null || this.skipDispatch(dispatch)) {
return;
}
// Parse fields.
var parsedFields = [];
for (var i = 0; i < dispatch.parsers.length; ++i) {
var parser = dispatch.parsers[i];
if (parser === null) {
parsedFields.push(fields[1 + i]);
} else if (typeof parser == 'function') {
parsedFields.push(parser(fields[1 + i]));
} else {
// var-args
parsedFields.push(fields.slice(1 + i));
break;
}
}
// Run the processor.
dispatch.processor.apply(this, parsedFields);
};
/**
* Decompresses a line if it was backreference-compressed.
*
* @param {string} line Possibly compressed line.
* @return {string} Decompressed line.
* @private
*/
devtools.profiler.LogReader.prototype.expandBackRef_ = function(line) {
var backRefPos;
// Filter out case when a regexp is created containing '#'.
if (line.charAt(line.length - 1) != '"'
&& (backRefPos = line.lastIndexOf('#')) != -1) {
var backRef = line.substr(backRefPos + 1);
var backRefIdx = parseInt(backRef, 10) - 1;
var colonPos = backRef.indexOf(':');
var backRefStart =
colonPos != -1 ? parseInt(backRef.substr(colonPos + 1), 10) : 0;
line = line.substr(0, backRefPos) +
this.backRefs_[backRefIdx].substr(backRefStart);
}
this.backRefs_.unshift(line);
if (this.backRefs_.length > 10) {
this.backRefs_.length = 10;
}
return line;
};
/**
* Initializes the map of backward reference compressible commands.
* @private
*/
devtools.profiler.LogReader.prototype.initBackRefsCommands_ = function() {
for (var event in this.dispatchTable_) {
var dispatch = this.dispatchTable_[event];
if (dispatch && dispatch.backrefs) {
this.backRefsCommands_[event] = true;
}
}
};
/**
* Processes alias log record. Adds an alias to a corresponding map.
*
* @param {string} symbol Short name.
* @param {string} expansion Long name.
* @private
*/
devtools.profiler.LogReader.prototype.processAlias_ = function(
symbol, expansion) {
if (expansion in this.dispatchTable_) {
this.dispatchTable_[symbol] = this.dispatchTable_[expansion];
if (expansion in this.backRefsCommands_) {
this.backRefsCommands_[symbol] = true;
}
} else {
this.aliases_[symbol] = expansion;
}
};
/**
* Processes log lines.
*
* @param {Array.<string>} lines Log lines.
* @private
*/
devtools.profiler.LogReader.prototype.processLog_ = function(lines) {
var csvParser = new devtools.profiler.CsvParser();
try {
for (var i = 0, n = lines.length; i < n; ++i) {
var line = lines[i];
if (!line) {
continue;
}
if (line.charAt(0) == '#' ||
line.substr(0, line.indexOf(',')) in this.backRefsCommands_) {
line = this.expandBackRef_(line);
}
var fields = csvParser.parseLine(line);
this.dispatchLogRow_(fields);
}
} catch (e) {
this.printError('line ' + (i + 1) + ': ' + (e.message || e));
throw e;
}
};
/**
* Processes repeat log record. Expands it according to calls count and
* invokes processing.
*
* @param {number} count Count.
* @param {Array.<string>} cmd Parsed command.
* @private
*/
devtools.profiler.LogReader.prototype.processRepeat_ = function(count, cmd) {
// Replace the repeat-prefixed command from backrefs list with a non-prefixed.
this.backRefs_[0] = cmd.join(',');
for (var i = 0; i < count; ++i) {
this.dispatchLogRow_(cmd);
}
};