Renamed necessary components for ABP integration

lib/rules.js

-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this file,
- * You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-Cu.import("resource://gre/modules/Services.jsm");
-Cu.import("resource://gre/modules/FileUtils.jsm");
-
-let {Prefs} = require("prefs");
-
-let RULES_VERSION = 2;
-
-let CUSTOM_RULE_PRIORITY = 0x7FFFFFFF;
-
-let rules = {expressions: []};
-
-loadRules();
-
-// Make first attempt to update rules after five minutes
-let updateTimer = null;
-updateTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
-updateTimer.initWithCallback(onTimer, 1000 * 60 * 5, Ci.nsITimer.TYPE_REPEATING_SLACK);
-onShutdown.add(function() updateTimer.cancel());
-
-function loadRules()
-{
-  loadRulesFrom(Services.io.newFileURI(getRuleFile()).spec, false, function(success)
-  {
-    if (!success)
-      loadRulesFrom(require("info").addonRoot + "defaults/rules.json", true);
-  });
-}
-
-function loadRulesFrom(url, ignoreVersion, callback)
-{
-  if (typeof callback != "function")
-    callback = function() {};
-
-  let request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"].createInstance(Ci.nsIXMLHttpRequest);
-  request.open("GET", url);
-  request.overrideMimeType("text/plain");
-  request.addEventListener("load", function()
-  {
-    try
-    {
-      // Remove comments from the file if any
-      let data = JSON.parse(request.responseText.replace(/^\s*\/\/.*/mg, ""));
-      if (ignoreVersion || data.version == RULES_VERSION)
-      {
-        rules = data;
-        callback(true);
-
-        // Add user-defined rules after calling the callback - if the callback
-        // saves the rules then the custom rules won't be included.
-        addCustomRules();
-      }
-      else
-        callback(false);
-    }
-    catch (e)
-    {
-      Cu.reportError(e);
-      callback(false);
-    }
-  }, false);
-  request.addEventListener("error", function()
-  {
-    callback(false);
-  }, false);
-
-  try
-  {
-    request.send(null);
-  }
-  catch (e)
-  {
-    if (e.result != Cr.NS_ERROR_FILE_NOT_FOUND)
-      Cu.reportError(e);
-    callback(false);
-  }
-}
-
-function getRuleFile()
-{
-  let result = FileUtils.getFile("ProfD", ["url-fixer-rules.json"]);
-
-  getRuleFile = function() result;
-  return getRuleFile();
-}
-
-function addCustomRules()
-{
-  for (let domain in Prefs.whitelist)
-    onWhitelistEntryAdded(domain);
-}
-
-function onWhitelistEntryAdded(domain)
-{
-  let reverse = domain.split("").reverse().join("");
-  addSuffix(rules.domain, reverse, CUSTOM_RULE_PRIORITY);
-}
-exports.onWhitelistEntryAdded = onWhitelistEntryAdded;
-
-function onWhitelistEntryRemoved(domain)
-{
-  let reverse = domain.split("").reverse().join("");
-  removeSuffix(rules.domain, reverse, CUSTOM_RULE_PRIORITY);
-}
-exports.onWhitelistEntryRemoved = onWhitelistEntryRemoved;
-
-function addSuffix(tree, suffix, priority)
-{
-  if (suffix.length == 0)
-  {
-    // We are at the last character, just put our priority here
-    tree[""] = " " + priority;
-    return;
-  }
-
-  let c = suffix[0];
-  if (c in tree)
-  {
-    let existing = tree[c];
-    if (typeof existing == "string")
-    {
-      // Single choice for this suffix, maybe the same entry?
-      if (existing.substr(0, suffix.length - 1) == suffix.substr(1) && existing[suffix.length - 1] == " ")
-      {
-        // Same entry, simply replace it by new priority
-        tree[c] = suffix.substr(1) + " " + priority;
-      }
-      else
-      {
-        // Different entry, need to add a new branching point and go deeper
-        if (existing[0] == " ")
-          tree[c] = {"": existing};
-        else
-        {
-          tree[c] = {};
-          tree[c][existing[0]] = existing.substr(1);
-        }
-        addSuffix(tree[c], suffix.substr(1), priority);
-      }
-    }
-    else
-    {
-      // Multiple choices for this suffix - go deeper
-      addSuffix(existing, suffix.substr(1), priority);
-    }
-  }
-  else
-  {
-    // No existing entry yet, just add ours
-    tree[c] = suffix.substr(1) + " " + priority;
-  }
-}
-
-function removeSuffix(tree, suffix, priority)
-{
-  if (suffix.length == 0)
-  {
-    // We are at the last character, check whether there is an entry with
-    // matching priority
-    if ("" in tree && tree[""] == " " + priority)
-      delete tree[""];
-    return;
-  }
-
-  let c = suffix[0];
-  if (!(c in tree))
-    return;
-
-  if (typeof tree[c] == "string")
-  {
-    // Single entry - check whether it is the right one
-    if (tree[c] == suffix.substr(1) + " " + priority)
-      delete tree[c];
-  }
-  else
-  {
-    // Multiple entries, need to go deeper
-    removeSuffix(tree[c], suffix.substr(1), priority);
-  }
-}
-
-function onTimer()
-{
-  // Next check in 1 hour
-  updateTimer.delay = 1000 * 60 * 60;
-
-  // Only download rules every three days
-  let nextUpdate = Prefs.lastRuleUpdate + 60 * 60 * 24 * 3;
-  if (nextUpdate > Date.now() / 1000)
-    return;
-
-  loadRulesFrom("http://urlfixer.org/download/rules.json?version=" + RULES_VERSION, false, function(success)
-  {
-    if (success)
-    {
-      rules.timestamp = Date.now();
-
-      try
-      {
-        // Save the rules to file.
-        let rulesText = JSON.stringify(rules);
-        let fileStream = FileUtils.openSafeFileOutputStream(getRuleFile());
-        let stream = Cc["@mozilla.org/intl/converter-output-stream;1"].createInstance(Ci.nsIConverterOutputStream);
-        stream.init(fileStream, "UTF-8", 16384, Ci.nsIConverterInputStream.DEFAULT_REPLACEMENT_CHARACTER);
-        stream.writeString(rulesText);
-        stream.flush();
-        FileUtils.closeSafeFileOutputStream(fileStream);
-      }
-      catch(e)
-      {
-        Cu.reportError(e);
-      }
-    }
-  });
-
-  Prefs.lastRuleUpdate = Date.now() / 1000;
-}
-
-exports.getSchemeCorrection = getSchemeCorrection;
-function getSchemeCorrection(scheme)
-{
-  return getBestMatch(scheme, rules.scheme, 1, null);
-}
-
-exports.isKnownScheme = isKnownScheme;
-function isKnownScheme(scheme)
-{
-  return (getSimilarStrings(scheme, rules.scheme, 0, null).length > 0);
-}
-
-exports.getDomainCorrection = getDomainCorrection;
-function getDomainCorrection(domain)
-{
-  // Apply user's custom changes first
-  let customRules = Prefs.custom_replace;
-  for (let searchString in customRules)
-  {
-    let replacement = customRules[searchString];
-    searchString = searchString.toLowerCase();
-    if (/^re:+/.test(searchString))
-      domain = domain.replace(new RegExp(RegExp.rightContext, "g"), replacement);
-    else
-      domain = domain.replace(searchString, replacement);
-  }
-
-  // Now apply our rules on the domain name
-  for (let i = 0, l = rules.expressions.length; i < l; i++)
-    domain = applyExpression(domain, rules.expressions[i]);
-
-  // Find similar known domains, test domains without the www. prefix
-  if (domain.substr(0, 4) == "www.")
-    domain = "www." + getBestMatch(domain.substr(4), rules.domain, 1, ".");
-  else
-    domain = getBestMatch(domain, rules.domain, 1, ".");
-
-  return domain;
-}
-
-exports.getDomainReferral = getDomainReferral;
-function getDomainReferral(domain)
-{
-  if ("domainReferrals" in rules && domain in rules.domainReferrals)
-    return rules.domainReferrals[domain];
-  else
-    return null;
-}
-
-function applyExpression(string, expression)
-{
-  if (expression.nomatch && new RegExp(expression.nomatch).test(string))
-    return string;
-
-  return string.replace(new RegExp(expression.find, "g"), expression.replace);
-}
-
-function getSimilarStrings(input, dictionary, maxDistance, separator)
-{
-  // We use a non-deterministic final automaton to perform a search on all
-  // strings in the dictionary simultaneously (see
-  // http://blog.notdot.net/2010/07/Damn-Cool-Algorithms-Levenshtein-Automata
-  // for the basic algorithm). However, we use Damerau-Levenshtein distance
-  // (transposition of two adjacent letters counts as one operation), meaning
-  // one additional transition for the automaton. The number of automaton states
-  // can theoretically be extremely large, the maxDistance parameter limits the
-  // number of states we need to process however. We process the input string
-  // backwards to allow matching domain names for a longer host name.
-
-  let results = [];
-
-  function processState(entry, distance, position, result)
-  {
-    let isString = (typeof entry == "string");
-
-    // Do we have a result?
-    if (position < 0 || input[position] == separator)
-    {
-      if (!isString && "" in entry)
-        results.push([result, input.substr(position + 1), distance, parseInt(entry[""], 10)]);
-      else if (isString && entry[0] == " ")
-        results.push([result, input.substr(position + 1), distance, parseInt(entry, 10)]);
-    }
-
-    // Maybe there is a match
-    if (position >= 0)
-    {
-      let nextChar = input[position];
-      if (!isString && nextChar in entry)
-        processState(entry[nextChar], distance, position - 1, nextChar + result);
-      else if (isString && entry[0] == nextChar)
-        processState(entry.substr(1), distance, position - 1, nextChar + result);
-    }
-
-    // Mistakes
-    if (distance < maxDistance)
-    {
-      // Deletion and substitution
-      if (!isString)
-      {
-        for (let c in entry)
-        {
-          if (c != "")
-            processState(entry[c], distance + 1, position, c + result);
-          if (c != "" && position >= 0)
-            processState(entry[c], distance + 1, position - 1, c + result);
-        }
-      }
-      else if (entry[0] != " ")
-      {
-        processState(entry.substr(1), distance + 1, position, entry[0] + result);
-        if (position >= 0)
-          processState(entry.substr(1), distance + 1, position - 1, entry[0] + result);
-      }
-
-      // Insertion
-      if (position >= 0)
-        processState(entry, distance + 1, position - 1, result);
-
-      // Transposition
-      if (position >= 1)
-      {
-        let nextChar1 = input[position];
-        let nextChar2 = input[position - 1];
-        if (isString)
-        {
-          if (entry[0] == nextChar2 && entry[1] == nextChar1)
-            processState(entry.substr(2), distance + 1, position - 2, nextChar1 + nextChar2 + result);
-        }
-        else if (nextChar2 in entry)
-        {
-          let nextEntry = entry[nextChar2];
-          if (typeof nextEntry != "string")
-          {
-            if (nextChar1 in nextEntry)
-              processState(nextEntry[nextChar1], distance + 1, position - 2, nextChar1 + nextChar2 + result);
-          }
-          else
-          {
-            if (nextEntry[0] == nextChar1)
-              processState(nextEntry.substr(1), distance + 1, position - 2, nextChar1 + nextChar2 + result);
-          }
-        }
-      }
-    }
-  }
-
-  processState(dictionary, 0, input.length - 1, "");
-  return results;
-}
-
-function getBestMatch(input, dictionary, maxDistance, separator)
-{
-  let suggestions = getSimilarStrings(input, dictionary, maxDistance, separator);
-
-  let bestSuggestion = null;
-  let bestSuggestionDistance;
-  let bestSuggestionMatched;
-  let bestSuggestionPriority;
-  for (let i = 0; i < suggestions.length; i++)
-  {
-    let [suggestion, matchedString, distance, priority] = suggestions[i];
-    if (suggestion == input)
-      return suggestion;
-
-    let matchedLen = matchedString.length;
-    if (priority < 0 && matchedLen == input.length)
-    {
-      // TLDs should never be proposed as a replacement for the entire host name
-      continue;
-    }
-
-    if (!bestSuggestion ||
-        bestSuggestionMatched < matchedLen ||
-        (bestSuggestionMatched == matchedLen && bestSuggestionDistance > distance) ||
-        (bestSuggestionMatched == matchedLen && bestSuggestionDistance == distance && bestSuggestionPriority < priority))
-    {
-      bestSuggestion = suggestion;
-      bestSuggestionDistance = distance;
-      bestSuggestionMatched = matchedLen;
-      bestSuggestionPriority = priority;
-    }
-  }
-  if (bestSuggestion)
-    return input.substr(0, input.length - bestSuggestionMatched) + bestSuggestion;
-  else
-    return input;
-}