v8/tools/codemap.js

// Copyright 2009 the V8 project authors. All rights reserved.
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// Initlialize namespaces
var devtools = devtools || {};
devtools.profiler = devtools.profiler || {};


/**
 * Constructs a mapper that maps addresses into code entries.
 *
 * @constructor
 */
devtools.profiler.CodeMap = function() {
  /**
   * Dynamic code entries. Used for JIT compiled code.
   */
  this.dynamics_ = new goog.structs.SplayTree();

  /**
   * Deleted code entries. Used for code collected by the GC.
   */
  this.deleted_ = [];

  /**
   * Static code entries. Used for libraries code.
   */
  this.statics_ = new goog.structs.SplayTree();

  /**
   * Map of memory pages occupied with static code.
   */
  this.pages_ = [];
};


/**
 * The number of alignment bits in a page address.
 */
devtools.profiler.CodeMap.PAGE_ALIGNMENT = 12;


/**
 * Page size in bytes.
 */
devtools.profiler.CodeMap.PAGE_SIZE =
    1 << devtools.profiler.CodeMap.PAGE_ALIGNMENT;


/**
 * Adds a dynamic (i.e. moveable and discardable) code entry.
 *
 * @param {number} start The starting address.
 * @param {devtools.profiler.CodeMap.CodeEntry} codeEntry Code entry object.
 */
devtools.profiler.CodeMap.prototype.addCode = function(start, codeEntry) {
  this.dynamics_.insert(start, codeEntry);
};


/**
 * Moves a dynamic code entry. Throws an exception if there is no dynamic
 * code entry with the specified starting address.
 *
 * @param {number} from The starting address of the entry being moved.
 * @param {number} to The destination address.
 */
devtools.profiler.CodeMap.prototype.moveCode = function(from, to) {
  var removedNode = this.dynamics_.remove(from);
  this.dynamics_.insert(to, removedNode.value);
};


/**
 * Discards a dynamic code entry. Throws an exception if there is no dynamic
 * code entry with the specified starting address. The entry will still be
 * returned from the 'getAllDynamicEntries' method.
 *
 * @param {number} start The starting address of the entry being deleted.
 */
devtools.profiler.CodeMap.prototype.deleteCode = function(start) {
  var removedNode = this.dynamics_.remove(start);
  this.deleted_.push(removedNode.value);
};


/**
 * Adds a static code entry.
 *
 * @param {number} start The starting address.
 * @param {devtools.profiler.CodeMap.CodeEntry} codeEntry Code entry object.
 */
devtools.profiler.CodeMap.prototype.addStaticCode = function(
    start, codeEntry) {
  this.markPages_(start, start + codeEntry.size);
  this.statics_.insert(start, codeEntry);
};


/**
 * @private
 */
devtools.profiler.CodeMap.prototype.markPages_ = function(start, end) {
  for (var addr = start; addr <= end;
       addr += devtools.profiler.CodeMap.PAGE_SIZE) {
    this.pages_[addr >> devtools.profiler.CodeMap.PAGE_ALIGNMENT] = 1;
  }
};


/**
 * @private
 */
devtools.profiler.CodeMap.prototype.isAddressBelongsTo_ = function(addr, node) {
  return addr >= node.key && addr < (node.key + node.value.size);
};


/**
 * @private
 */
devtools.profiler.CodeMap.prototype.findInTree_ = function(tree, addr) {
  var node = tree.findGreatestLessThan(addr);
  return node && this.isAddressBelongsTo_(addr, node) ? node.value : null;
};


/**
 * Finds a code entry that contains the specified address. Both static and
 * dynamic code entries are considered.
 *
 * @param {number} addr Address.
 */
devtools.profiler.CodeMap.prototype.findEntry = function(addr) {
  var pageAddr = addr >> devtools.profiler.CodeMap.PAGE_ALIGNMENT;
  if (pageAddr in this.pages_) {
    return this.findInTree_(this.statics_, addr);
  }
  var min = this.dynamics_.findMin();
  var max = this.dynamics_.findMax();
  if (max != null && addr < (max.key + max.value.size) && addr >= min.key) {
    return this.findInTree_(this.dynamics_, addr);
  }
  return null;
};


/**
 * Returns an array of all dynamic code entries, including deleted ones.
 */
devtools.profiler.CodeMap.prototype.getAllDynamicEntries = function() {
  var dynamicEntries = this.dynamics_.exportValues();
  return dynamicEntries.concat(this.deleted_);
};


/**
 * Returns an array of all static code entries.
 */
devtools.profiler.CodeMap.prototype.getAllStaticEntries = function() {
  return this.statics_.exportValues();
};


/**
 * Creates a code entry object.
 *
 * @param {number} size Code entry size in bytes.
 * @param {string} opt_name Code entry name.
 * @constructor
 */
devtools.profiler.CodeMap.CodeEntry = function(size, opt_name) {
  this.size = size;
  this.name = opt_name || '';
};


devtools.profiler.CodeMap.CodeEntry.prototype.toString = function() {
  return this.name + ': ' + this.size.toString(16);
};