Merge branch 'ext-work'FF_Checkpoint_1

1 files changed, 1481 insertions, 0 deletions

diff --git a/toolkit/mozapps/extensions/internal/XPIProviderUtils.js b/toolkit/mozapps/extensions/internal/XPIProviderUtils.js
new file mode 100644
index 000000000..d4798b726
--- /dev/null
+++ b/toolkit/mozapps/extensions/internal/XPIProviderUtils.js
@@ -0,0 +1,1481 @@
+/* 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/. */
+
+"use strict";
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cr = Components.results;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/AddonManager.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "AddonRepository",
+                                  "resource://gre/modules/addons/AddonRepository.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
+                                  "resource://gre/modules/FileUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "DeferredSave",
+                                  "resource://gre/modules/DeferredSave.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Promise",
+                                  "resource://gre/modules/Promise.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "OS",
+                                  "resource://gre/modules/osfile.jsm");
+
+Cu.import("resource://gre/modules/Log.jsm");
+const LOGGER_ID = "addons.xpi-utils";
+
+// Create a new logger for use by the Addons XPI Provider Utils
+// (Requires AddonManager.jsm)
+let logger = Log.repository.getLogger(LOGGER_ID);
+
+const KEY_PROFILEDIR                  = "ProfD";
+const FILE_DATABASE                   = "extensions.sqlite";
+const FILE_JSON_DB                    = "extensions.json";
+const FILE_OLD_DATABASE               = "extensions.rdf";
+const FILE_XPI_ADDONS_LIST            = "extensions.ini";
+
+// The value for this is in Makefile.in
+#expand const DB_SCHEMA               = __MOZ_EXTENSIONS_DB_SCHEMA__;
+
+// The last version of DB_SCHEMA implemented in SQLITE
+const LAST_SQLITE_DB_SCHEMA           = 14;
+const PREF_DB_SCHEMA                  = "extensions.databaseSchema";
+const PREF_PENDING_OPERATIONS         = "extensions.pendingOperations";
+const PREF_EM_ENABLED_ADDONS          = "extensions.enabledAddons";
+const PREF_EM_DSS_ENABLED             = "extensions.dss.enabled";
+
+// Properties that only exist in the database
+const DB_METADATA        = ["syncGUID",
+                            "installDate",
+                            "updateDate",
+                            "size",
+                            "sourceURI",
+                            "releaseNotesURI",
+                            "applyBackgroundUpdates"];
+const DB_BOOL_METADATA   = ["visible", "active", "userDisabled", "appDisabled",
+                            "pendingUninstall", "bootstrap", "skinnable",
+                            "softDisabled", "isForeignInstall",
+                            "hasBinaryComponents", "strictCompatibility"];
+
+// Properties to save in JSON file
+const PROP_JSON_FIELDS = ["id", "syncGUID", "location", "version", "type",
+                          "internalName", "updateURL", "updateKey", "optionsURL",
+                          "optionsType", "aboutURL", "iconURL", "icon64URL",
+                          "defaultLocale", "visible", "active", "userDisabled",
+                          "appDisabled", "pendingUninstall", "descriptor", "installDate",
+                          "updateDate", "applyBackgroundUpdates", "bootstrap",
+                          "skinnable", "size", "sourceURI", "releaseNotesURI",
+                          "softDisabled", "foreignInstall", "hasBinaryComponents",
+                          "strictCompatibility", "locales", "targetApplications",
+                          "targetPlatforms", "multiprocessCompatible", "jetsdk", "native"];
+
+// Time to wait before async save of XPI JSON database, in milliseconds
+const ASYNC_SAVE_DELAY_MS = 20;
+
+const PREFIX_ITEM_URI                 = "urn:mozilla:item:";
+const RDFURI_ITEM_ROOT                = "urn:mozilla:item:root"
+const PREFIX_NS_EM                    = "http://www.mozilla.org/2004/em-rdf#";
+
+XPCOMUtils.defineLazyServiceGetter(this, "gRDF", "@mozilla.org/rdf/rdf-service;1",
+                                   Ci.nsIRDFService);
+
+function EM_R(aProperty) {
+  return gRDF.GetResource(PREFIX_NS_EM + aProperty);
+}
+
+/**
+ * Converts an RDF literal, resource or integer into a string.
+ *
+ * @param  aLiteral
+ *         The RDF object to convert
+ * @return a string if the object could be converted or null
+ */
+function getRDFValue(aLiteral) {
+  if (aLiteral instanceof Ci.nsIRDFLiteral)
+    return aLiteral.Value;
+  if (aLiteral instanceof Ci.nsIRDFResource)
+    return aLiteral.Value;
+  if (aLiteral instanceof Ci.nsIRDFInt)
+    return aLiteral.Value;
+  return null;
+}
+
+/**
+ * Gets an RDF property as a string
+ *
+ * @param  aDs
+ *         The RDF datasource to read the property from
+ * @param  aResource
+ *         The RDF resource to read the property from
+ * @param  aProperty
+ *         The property to read
+ * @return a string if the property existed or null
+ */
+function getRDFProperty(aDs, aResource, aProperty) {
+  return getRDFValue(aDs.GetTarget(aResource, EM_R(aProperty), true));
+}
+
+/**
+ * Asynchronously fill in the _repositoryAddon field for one addon
+ */
+function getRepositoryAddon(aAddon, aCallback) {
+  if (!aAddon) {
+    aCallback(aAddon);
+    return;
+  }
+  function completeAddon(aRepositoryAddon) {
+    aAddon._repositoryAddon = aRepositoryAddon;
+    aAddon.compatibilityOverrides = aRepositoryAddon ?
+                                      aRepositoryAddon.compatibilityOverrides :
+                                      null;
+    aCallback(aAddon);
+  }
+  AddonRepository.getCachedAddonByID(aAddon.id, completeAddon);
+}
+
+/**
+ * Wrap an API-supplied function in an exception handler to make it safe to call
+ */
+function makeSafe(aCallback) {
+  return function(...aArgs) {
+    try {
+      aCallback(...aArgs);
+    }
+    catch(ex) {
+      logger.warn("XPI Database callback failed", ex);
+    }
+  }
+}
+
+/**
+ * A helper method to asynchronously call a function on an array
+ * of objects, calling a callback when function(x) has been gathered
+ * for every element of the array.
+ * WARNING: not currently error-safe; if the async function does not call
+ * our internal callback for any of the array elements, asyncMap will not
+ * call the callback parameter.
+ *
+ * @param  aObjects
+ *         The array of objects to process asynchronously
+ * @param  aMethod
+ *         Function with signature function(object, function aCallback(f_of_object))
+ * @param  aCallback
+ *         Function with signature f([aMethod(object)]), called when all values
+ *         are available
+ */
+function asyncMap(aObjects, aMethod, aCallback) {
+  var resultsPending = aObjects.length;
+  var results = []
+  if (resultsPending == 0) {
+    aCallback(results);
+    return;
+  }
+
+  function asyncMap_gotValue(aIndex, aValue) {
+    results[aIndex] = aValue;
+    if (--resultsPending == 0) {
+      aCallback(results);
+    }
+  }
+
+  aObjects.map(function asyncMap_each(aObject, aIndex, aArray) {
+    try {
+      aMethod(aObject, function asyncMap_callback(aResult) {
+        asyncMap_gotValue(aIndex, aResult);
+      });
+    }
+    catch (e) {
+      logger.warn("Async map function failed", e);
+      asyncMap_gotValue(aIndex, undefined);
+    }
+  });
+}
+
+/**
+ * A generator to synchronously return result rows from an mozIStorageStatement.
+ *
+ * @param  aStatement
+ *         The statement to execute
+ */
+function resultRows(aStatement) {
+  try {
+    while (stepStatement(aStatement))
+      yield aStatement.row;
+  }
+  finally {
+    aStatement.reset();
+  }
+}
+
+/**
+ * A helper function to log an SQL error.
+ *
+ * @param  aError
+ *         The storage error code associated with the error
+ * @param  aErrorString
+ *         An error message
+ */
+function logSQLError(aError, aErrorString) {
+  logger.error("SQL error " + aError + ": " + aErrorString);
+}
+
+/**
+ * A helper function to log any errors that occur during async statements.
+ *
+ * @param  aError
+ *         A mozIStorageError to log
+ */
+function asyncErrorLogger(aError) {
+  logSQLError(aError.result, aError.message);
+}
+
+/**
+ * A helper function to step a statement synchronously and log any error that
+ * occurs.
+ *
+ * @param  aStatement
+ *         A mozIStorageStatement to execute
+ */
+function stepStatement(aStatement) {
+  try {
+    return aStatement.executeStep();
+  }
+  catch (e) {
+    logSQLError(XPIDatabase.connection.lastError,
+                XPIDatabase.connection.lastErrorString);
+    throw e;
+  }
+}
+
+/**
+ * Copies properties from one object to another. If no target object is passed
+ * a new object will be created and returned.
+ *
+ * @param  aObject
+ *         An object to copy from
+ * @param  aProperties
+ *         An array of properties to be copied
+ * @param  aTarget
+ *         An optional target object to copy the properties to
+ * @return the object that the properties were copied onto
+ */
+function copyProperties(aObject, aProperties, aTarget) {
+  if (!aTarget)
+    aTarget = {};
+  aProperties.forEach(function(aProp) {
+    aTarget[aProp] = aObject[aProp];
+  });
+  return aTarget;
+}
+
+/**
+ * Copies properties from a mozIStorageRow to an object. If no target object is
+ * passed a new object will be created and returned.
+ *
+ * @param  aRow
+ *         A mozIStorageRow to copy from
+ * @param  aProperties
+ *         An array of properties to be copied
+ * @param  aTarget
+ *         An optional target object to copy the properties to
+ * @return the object that the properties were copied onto
+ */
+function copyRowProperties(aRow, aProperties, aTarget) {
+  if (!aTarget)
+    aTarget = {};
+  aProperties.forEach(function(aProp) {
+    aTarget[aProp] = aRow.getResultByName(aProp);
+  });
+  return aTarget;
+}
+
+/**
+ * The DBAddonInternal is a special AddonInternal that has been retrieved from
+ * the database. The constructor will initialize the DBAddonInternal with a set
+ * of fields, which could come from either the JSON store or as an
+ * XPIProvider.AddonInternal created from an addon's manifest
+ * @constructor
+ * @param aLoaded
+ *        Addon data fields loaded from JSON or the addon manifest.
+ */
+function DBAddonInternal(aLoaded) {
+  copyProperties(aLoaded, PROP_JSON_FIELDS, this);
+
+  if (aLoaded._installLocation) {
+    this._installLocation = aLoaded._installLocation;
+    this.location = aLoaded._installLocation._name;
+  }
+  else if (aLoaded.location) {
+    this._installLocation = XPIProvider.installLocationsByName[this.location];
+  }
+
+  this._key = this.location + ":" + this.id;
+
+  try {
+    this._sourceBundle = this._installLocation.getLocationForID(this.id);
+  }
+  catch (e) {
+    // An exception will be thrown if the add-on appears in the database but
+    // not on disk. In general this should only happen during startup as
+    // this change is being detected.
+  }
+
+  XPCOMUtils.defineLazyGetter(this, "pendingUpgrade",
+    function DBA_pendingUpgradeGetter() {
+      for (let install of XPIProvider.installs) {
+        if (install.state == AddonManager.STATE_INSTALLED &&
+            !(install.addon.inDatabase) &&
+            install.addon.id == this.id &&
+            install.installLocation == this._installLocation) {
+          delete this.pendingUpgrade;
+          return this.pendingUpgrade = install.addon;
+        }
+      };
+      return null;
+    });
+}
+
+function DBAddonInternalPrototype()
+{
+  this.applyCompatibilityUpdate =
+    function(aUpdate, aSyncCompatibility) {
+      this.targetApplications.forEach(function(aTargetApp) {
+        aUpdate.targetApplications.forEach(function(aUpdateTarget) {
+          if (aTargetApp.id == aUpdateTarget.id && (aSyncCompatibility ||
+              Services.vc.compare(aTargetApp.maxVersion, aUpdateTarget.maxVersion) < 0)) {
+            aTargetApp.minVersion = aUpdateTarget.minVersion;
+            aTargetApp.maxVersion = aUpdateTarget.maxVersion;
+            XPIDatabase.saveChanges();
+          }
+        });
+      });
+      if (aUpdate.multiprocessCompatible !== undefined &&
+          aUpdate.multiprocessCompatible != this.multiprocessCompatible) {
+        this.multiprocessCompatible = aUpdate.multiprocessCompatible;
+        XPIDatabase.saveChanges();
+      }
+      XPIProvider.updateAddonDisabledState(this);
+    };
+
+  this.toJSON =
+    function() {
+      return copyProperties(this, PROP_JSON_FIELDS);
+    };
+
+  Object.defineProperty(this, "inDatabase",
+                        { get: function() { return true; },
+                          enumerable: true,
+                          configurable: true });
+}
+DBAddonInternalPrototype.prototype = AddonInternal.prototype;
+
+DBAddonInternal.prototype = new DBAddonInternalPrototype();
+
+/**
+ * Internal interface: find an addon from an already loaded addonDB
+ */
+function _findAddon(addonDB, aFilter) {
+  for (let addon of addonDB.values()) {
+    if (aFilter(addon)) {
+      return addon;
+    }
+  }
+  return null;
+}
+
+/**
+ * Internal interface to get a filtered list of addons from a loaded addonDB
+ */
+function _filterDB(addonDB, aFilter) {
+  return [for (addon of addonDB.values()) if (aFilter(addon)) addon];
+}
+
+this.XPIDatabase = {
+  // true if the database connection has been opened
+  initialized: false,
+  // The database file
+  jsonFile: FileUtils.getFile(KEY_PROFILEDIR, [FILE_JSON_DB], true),
+  // Migration data loaded from an old version of the database.
+  migrateData: null,
+  // Active add-on directories loaded from extensions.ini and prefs at startup.
+  activeBundles: null,
+
+  // Saved error object if we fail to read an existing database
+  _loadError: null,
+
+  // Error reported by our most recent attempt to read or write the database, if any
+  get lastError() {
+    if (this._loadError)
+      return this._loadError;
+    if (this._deferredSave)
+      return this._deferredSave.lastError;
+    return null;
+  },
+
+  /**
+   * Mark the current stored data dirty, and schedule a flush to disk
+   */
+  saveChanges: function() {
+    if (!this.initialized) {
+      throw new Error("Attempt to use XPI database when it is not initialized");
+    }
+
+    if (XPIProvider._closing) {
+      // use an Error here so we get a stack trace.
+      let err = new Error("XPI database modified after shutdown began");
+      logger.warn(err);
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_late_stack", Log.stackTrace(err));
+    }
+
+    if (!this._deferredSave) {
+      this._deferredSave = new DeferredSave(this.jsonFile.path,
+                                            () => JSON.stringify(this),
+                                            ASYNC_SAVE_DELAY_MS);
+    }
+
+    let promise = this._deferredSave.saveChanges();
+    if (!this._schemaVersionSet) {
+      this._schemaVersionSet = true;
+      promise.then(
+        count => {
+          // Update the XPIDB schema version preference the first time we successfully
+          // save the database.
+          logger.debug("XPI Database saved, setting schema version preference to " + DB_SCHEMA);
+          Services.prefs.setIntPref(PREF_DB_SCHEMA, DB_SCHEMA);
+          // Reading the DB worked once, so we don't need the load error
+          this._loadError = null;
+        },
+        error => {
+          // Need to try setting the schema version again later
+          this._schemaVersionSet = false;
+          logger.warn("Failed to save XPI database", error);
+          // this._deferredSave.lastError has the most recent error so we don't
+          // need this any more
+          this._loadError = null;
+        });
+    }
+  },
+
+  flush: function() {
+    // handle the "in memory only" and "saveChanges never called" cases
+    if (!this._deferredSave) {
+      return Promise.resolve(0);
+    }
+
+    return this._deferredSave.flush();
+  },
+
+  /**
+   * Converts the current internal state of the XPI addon database to
+   * a JSON.stringify()-ready structure
+   */
+  toJSON: function() {
+    if (!this.addonDB) {
+      // We never loaded the database?
+      throw new Error("Attempt to save database without loading it first");
+    }
+
+    let toSave = {
+      schemaVersion: DB_SCHEMA,
+      addons: [...this.addonDB.values()]
+    };
+    return toSave;
+  },
+
+  /**
+   * Pull upgrade information from an existing SQLITE database
+   *
+   * @return false if there is no SQLITE database
+   *         true and sets this.migrateData to null if the SQLITE DB exists
+   *              but does not contain useful information
+   *         true and sets this.migrateData to
+   *              {location: {id1:{addon1}, id2:{addon2}}, location2:{...}, ...}
+   *              if there is useful information
+   */
+  getMigrateDataFromSQLITE: function XPIDB_getMigrateDataFromSQLITE() {
+    let connection = null;
+    let dbfile = FileUtils.getFile(KEY_PROFILEDIR, [FILE_DATABASE], true);
+    // Attempt to open the database
+    try {
+      connection = Services.storage.openUnsharedDatabase(dbfile);
+    }
+    catch (e) {
+      logger.warn("Failed to open sqlite database " + dbfile.path + " for upgrade", e);
+      return null;
+    }
+    logger.debug("Migrating data from sqlite");
+    let migrateData = this.getMigrateDataFromDatabase(connection);
+    connection.close();
+    return migrateData;
+  },
+
+  /**
+   * Synchronously opens and reads the database file, upgrading from old
+   * databases or making a new DB if needed.
+   *
+   * The possibilities, in order of priority, are:
+   * 1) Perfectly good, up to date database
+   * 2) Out of date JSON database needs to be upgraded => upgrade
+   * 3) JSON database exists but is mangled somehow => build new JSON
+   * 4) no JSON DB, but a useable SQLITE db we can upgrade from => upgrade
+   * 5) useless SQLITE DB => build new JSON
+   * 6) useable RDF DB => upgrade
+   * 7) useless RDF DB => build new JSON
+   * 8) Nothing at all => build new JSON
+   * @param  aRebuildOnError
+   *         A boolean indicating whether add-on information should be loaded
+   *         from the install locations if the database needs to be rebuilt.
+   *         (if false, caller is XPIProvider.checkForChanges() which will rebuild)
+   */
+  syncLoadDB: function XPIDB_syncLoadDB(aRebuildOnError) {
+    this.migrateData = null;
+    let fstream = null;
+    let data = "";
+    try {
+      let readTimer = AddonManagerPrivate.simpleTimer("XPIDB_syncRead_MS");
+      logger.debug("Opening XPI database " + this.jsonFile.path);
+      fstream = Components.classes["@mozilla.org/network/file-input-stream;1"].
+              createInstance(Components.interfaces.nsIFileInputStream);
+      fstream.init(this.jsonFile, -1, 0, 0);
+      let cstream = null;
+      try {
+        cstream = Components.classes["@mozilla.org/intl/converter-input-stream;1"].
+                createInstance(Components.interfaces.nsIConverterInputStream);
+        cstream.init(fstream, "UTF-8", 0, 0);
+
+        let str = {};
+        let read = 0;
+        do {
+          read = cstream.readString(0xffffffff, str); // read as much as we can and put it in str.value
+          data += str.value;
+        } while (read != 0);
+
+        readTimer.done();
+        this.parseDB(data, aRebuildOnError);
+      }
+      catch(e) {
+        logger.error("Failed to load XPI JSON data from profile", e);
+        let rebuildTimer = AddonManagerPrivate.simpleTimer("XPIDB_rebuildReadFailed_MS");
+        this.rebuildDatabase(aRebuildOnError);
+        rebuildTimer.done();
+      }
+      finally {
+        if (cstream)
+          cstream.close();
+      }
+    }
+    catch (e) {
+      if (e.result === Cr.NS_ERROR_FILE_NOT_FOUND) {
+        this.upgradeDB(aRebuildOnError);
+      }
+      else {
+        this.rebuildUnreadableDB(e, aRebuildOnError);
+      }
+    }
+    finally {
+      if (fstream)
+        fstream.close();
+    }
+    // If an async load was also in progress, resolve that promise with our DB;
+    // otherwise create a resolved promise
+    if (this._dbPromise) {
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_overlapped_load", 1);
+      this._dbPromise.resolve(this.addonDB);
+    }
+    else
+      this._dbPromise = Promise.resolve(this.addonDB);
+  },
+
+  /**
+   * Parse loaded data, reconstructing the database if the loaded data is not valid
+   * @param aRebuildOnError
+   *        If true, synchronously reconstruct the database from installed add-ons
+   */
+  parseDB: function(aData, aRebuildOnError) {
+    let parseTimer = AddonManagerPrivate.simpleTimer("XPIDB_parseDB_MS");
+    try {
+      // dump("Loaded JSON:\n" + aData + "\n");
+      let inputAddons = JSON.parse(aData);
+      // Now do some sanity checks on our JSON db
+      if (!("schemaVersion" in inputAddons) || !("addons" in inputAddons)) {
+        parseTimer.done();
+        // Content of JSON file is bad, need to rebuild from scratch
+        logger.error("bad JSON file contents");
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "badJSON");
+        let rebuildTimer = AddonManagerPrivate.simpleTimer("XPIDB_rebuildBadJSON_MS");
+        this.rebuildDatabase(aRebuildOnError);
+        rebuildTimer.done();
+        return;
+      }
+      if (inputAddons.schemaVersion != DB_SCHEMA) {
+        // Handle mismatched JSON schema version. For now, we assume
+        // compatibility for JSON data, though we throw away any fields we
+        // don't know about (bug 902956)
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError",
+                                                "schemaMismatch-" + inputAddons.schemaVersion);
+        logger.debug("JSON schema mismatch: expected " + DB_SCHEMA +
+            ", actual " + inputAddons.schemaVersion);
+        // When we rev the schema of the JSON database, we need to make sure we
+        // force the DB to save so that the DB_SCHEMA value in the JSON file and
+        // the preference are updated.
+      }
+      // If we got here, we probably have good data
+      // Make AddonInternal instances from the loaded data and save them
+      let addonDB = new Map();
+      for (let loadedAddon of inputAddons.addons) {
+        let newAddon = new DBAddonInternal(loadedAddon);
+        addonDB.set(newAddon._key, newAddon);
+      };
+      parseTimer.done();
+      this.addonDB = addonDB;
+      logger.debug("Successfully read XPI database");
+      this.initialized = true;
+    }
+    catch(e) {
+      // If we catch and log a SyntaxError from the JSON
+      // parser, the xpcshell test harness fails the test for us: bug 870828
+      parseTimer.done();
+      if (e.name == "SyntaxError") {
+        logger.error("Syntax error parsing saved XPI JSON data");
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "syntax");
+      }
+      else {
+        logger.error("Failed to load XPI JSON data from profile", e);
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "other");
+      }
+      let rebuildTimer = AddonManagerPrivate.simpleTimer("XPIDB_rebuildReadFailed_MS");
+      this.rebuildDatabase(aRebuildOnError);
+      rebuildTimer.done();
+    }
+  },
+
+  /**
+   * Upgrade database from earlier (sqlite or RDF) version if available
+   */
+  upgradeDB: function(aRebuildOnError) {
+    let upgradeTimer = AddonManagerPrivate.simpleTimer("XPIDB_upgradeDB_MS");
+    try {
+      let schemaVersion = Services.prefs.getIntPref(PREF_DB_SCHEMA);
+      if (schemaVersion <= LAST_SQLITE_DB_SCHEMA) {
+        // we should have an older SQLITE database
+        logger.debug("Attempting to upgrade from SQLITE database");
+        this.migrateData = this.getMigrateDataFromSQLITE();
+      }
+      else {
+        // we've upgraded before but the JSON file is gone, fall through
+        // and rebuild from scratch
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "dbMissing");
+      }
+    }
+    catch(e) {
+      // No schema version pref means either a really old upgrade (RDF) or
+      // a new profile
+      this.migrateData = this.getMigrateDataFromRDF();
+    }
+
+    this.rebuildDatabase(aRebuildOnError);
+    upgradeTimer.done();
+  },
+
+  /**
+   * Reconstruct when the DB file exists but is unreadable
+   * (for example because read permission is denied)
+   */
+  rebuildUnreadableDB: function(aError, aRebuildOnError) {
+    let rebuildTimer = AddonManagerPrivate.simpleTimer("XPIDB_rebuildUnreadableDB_MS");
+    logger.warn("Extensions database " + this.jsonFile.path +
+        " exists but is not readable; rebuilding", aError);
+    // Remember the error message until we try and write at least once, so
+    // we know at shutdown time that there was a problem
+    this._loadError = aError;
+    AddonManagerPrivate.recordSimpleMeasure("XPIDB_startupError", "unreadable");
+    this.rebuildDatabase(aRebuildOnError);
+    rebuildTimer.done();
+  },
+
+  /**
+   * Open and read the XPI database asynchronously, upgrading if
+   * necessary. If any DB load operation fails, we need to
+   * synchronously rebuild the DB from the installed extensions.
+   *
+   * @return Promise<Map> resolves to the Map of loaded JSON data stored
+   *         in this.addonDB; never rejects.
+   */
+  asyncLoadDB: function XPIDB_asyncLoadDB() {
+    // Already started (and possibly finished) loading
+    if (this._dbPromise) {
+      return this._dbPromise;
+    }
+
+    logger.debug("Starting async load of XPI database " + this.jsonFile.path);
+    AddonManagerPrivate.recordSimpleMeasure("XPIDB_async_load", XPIProvider.runPhase);
+    let readOptions = {
+      outExecutionDuration: 0
+    };
+    return this._dbPromise = OS.File.read(this.jsonFile.path, null, readOptions).then(
+      byteArray => {
+        logger.debug("Async JSON file read took " + readOptions.outExecutionDuration + " MS");
+        AddonManagerPrivate.recordSimpleMeasure("XPIDB_asyncRead_MS",
+          readOptions.outExecutionDuration);
+        if (this._addonDB) {
+          logger.debug("Synchronous load completed while waiting for async load");
+          return this.addonDB;
+        }
+        logger.debug("Finished async read of XPI database, parsing...");
+        let decodeTimer = AddonManagerPrivate.simpleTimer("XPIDB_decode_MS");
+        let decoder = new TextDecoder();
+        let data = decoder.decode(byteArray);
+        decodeTimer.done();
+        this.parseDB(data, true);
+        return this.addonDB;
+      })
+    .then(null,
+      error => {
+        if (this._addonDB) {
+          logger.debug("Synchronous load completed while waiting for async load");
+          return this.addonDB;
+        }
+        if (error.becauseNoSuchFile) {
+          this.upgradeDB(true);
+        }
+        else {
+          // it's there but unreadable
+          this.rebuildUnreadableDB(error, true);
+        }
+        return this.addonDB;
+      });
+  },
+
+  /**
+   * Rebuild the database from addon install directories. If this.migrateData
+   * is available, uses migrated information for settings on the addons found
+   * during rebuild
+   * @param aRebuildOnError
+   *         A boolean indicating whether add-on information should be loaded
+   *         from the install locations if the database needs to be rebuilt.
+   *         (if false, caller is XPIProvider.checkForChanges() which will rebuild)
+   */
+  rebuildDatabase: function XIPDB_rebuildDatabase(aRebuildOnError) {
+    this.addonDB = new Map();
+    this.initialized = true;
+
+    if (XPIStates.size == 0) {
+      // No extensions installed, so we're done
+      logger.debug("Rebuilding XPI database with no extensions");
+      return;
+    }
+
+    // If there is no migration data then load the list of add-on directories
+    // that were active during the last run
+    if (!this.migrateData)
+      this.activeBundles = this.getActiveBundles();
+
+    if (aRebuildOnError) {
+      logger.warn("Rebuilding add-ons database from installed extensions.");
+      try {
+        XPIProvider.processFileChanges({}, false);
+      }
+      catch (e) {
+        logger.error("Failed to rebuild XPI database from installed extensions", e);
+      }
+      // Make sure to update the active add-ons and add-ons list on shutdown
+      Services.prefs.setBoolPref(PREF_PENDING_OPERATIONS, true);
+    }
+  },
+
+  /**
+   * Gets the list of file descriptors of active extension directories or XPI
+   * files from the add-ons list. This must be loaded from disk since the
+   * directory service gives no easy way to get both directly. This list doesn't
+   * include themes as preferences already say which theme is currently active
+   *
+   * @return an array of persistent descriptors for the directories
+   */
+  getActiveBundles: function XPIDB_getActiveBundles() {
+    let bundles = [];
+
+    // non-bootstrapped extensions
+    let addonsList = FileUtils.getFile(KEY_PROFILEDIR, [FILE_XPI_ADDONS_LIST],
+                                       true);
+
+    if (!addonsList.exists())
+      // XXX Irving believes this is broken in the case where there is no
+      // extensions.ini but there are bootstrap extensions (e.g. Android)
+      return null;
+
+    try {
+      let iniFactory = Cc["@mozilla.org/xpcom/ini-parser-factory;1"]
+                         .getService(Ci.nsIINIParserFactory);
+      let parser = iniFactory.createINIParser(addonsList);
+      let keys = parser.getKeys("ExtensionDirs");
+
+      while (keys.hasMore())
+        bundles.push(parser.getString("ExtensionDirs", keys.getNext()));
+    }
+    catch (e) {
+      logger.warn("Failed to parse extensions.ini", e);
+      return null;
+    }
+
+    // Also include the list of active bootstrapped extensions
+    for (let id in XPIProvider.bootstrappedAddons)
+      bundles.push(XPIProvider.bootstrappedAddons[id].descriptor);
+
+    return bundles;
+  },
+
+  /**
+   * Retrieves migration data from the old extensions.rdf database.
+   *
+   * @return an object holding information about what add-ons were previously
+   *         userDisabled and any updated compatibility information
+   */
+  getMigrateDataFromRDF: function XPIDB_getMigrateDataFromRDF(aDbWasMissing) {
+
+    // Migrate data from extensions.rdf
+    let rdffile = FileUtils.getFile(KEY_PROFILEDIR, [FILE_OLD_DATABASE], true);
+    if (!rdffile.exists())
+      return null;
+
+    logger.debug("Migrating data from " + FILE_OLD_DATABASE);
+    let migrateData = {};
+
+    try {
+      let ds = gRDF.GetDataSourceBlocking(Services.io.newFileURI(rdffile).spec);
+      let root = Cc["@mozilla.org/rdf/container;1"].
+                 createInstance(Ci.nsIRDFContainer);
+      root.Init(ds, gRDF.GetResource(RDFURI_ITEM_ROOT));
+      let elements = root.GetElements();
+
+      while (elements.hasMoreElements()) {
+        let source = elements.getNext().QueryInterface(Ci.nsIRDFResource);
+
+        let location = getRDFProperty(ds, source, "installLocation");
+        if (location) {
+          if (!(location in migrateData))
+            migrateData[location] = {};
+          let id = source.ValueUTF8.substring(PREFIX_ITEM_URI.length);
+          migrateData[location][id] = {
+            version: getRDFProperty(ds, source, "version"),
+            userDisabled: false,
+            targetApplications: []
+          }
+
+          let disabled = getRDFProperty(ds, source, "userDisabled");
+          if (disabled == "true" || disabled == "needs-disable")
+            migrateData[location][id].userDisabled = true;
+
+          let targetApps = ds.GetTargets(source, EM_R("targetApplication"),
+                                         true);
+          while (targetApps.hasMoreElements()) {
+            let targetApp = targetApps.getNext()
+                                      .QueryInterface(Ci.nsIRDFResource);
+            let appInfo = {
+              id: getRDFProperty(ds, targetApp, "id")
+            };
+
+            let minVersion = getRDFProperty(ds, targetApp, "updatedMinVersion");
+            if (minVersion) {
+              appInfo.minVersion = minVersion;
+              appInfo.maxVersion = getRDFProperty(ds, targetApp, "updatedMaxVersion");
+            }
+            else {
+              appInfo.minVersion = getRDFProperty(ds, targetApp, "minVersion");
+              appInfo.maxVersion = getRDFProperty(ds, targetApp, "maxVersion");
+            }
+            migrateData[location][id].targetApplications.push(appInfo);
+          }
+        }
+      }
+    }
+    catch (e) {
+      logger.warn("Error reading " + FILE_OLD_DATABASE, e);
+      migrateData = null;
+    }
+
+    return migrateData;
+  },
+
+  /**
+   * Retrieves migration data from a database that has an older or newer schema.
+   *
+   * @return an object holding information about what add-ons were previously
+   *         userDisabled and any updated compatibility information
+   */
+  getMigrateDataFromDatabase: function XPIDB_getMigrateDataFromDatabase(aConnection) {
+    let migrateData = {};
+
+    // Attempt to migrate data from a different (even future!) version of the
+    // database
+    try {
+      var stmt = aConnection.createStatement("PRAGMA table_info(addon)");
+
+      const REQUIRED = ["internal_id", "id", "location", "userDisabled",
+                        "installDate", "version"];
+
+      let reqCount = 0;
+      let props = [];
+      for (let row in resultRows(stmt)) {
+        if (REQUIRED.indexOf(row.name) != -1) {
+          reqCount++;
+          props.push(row.name);
+        }
+        else if (DB_METADATA.indexOf(row.name) != -1) {
+          props.push(row.name);
+        }
+        else if (DB_BOOL_METADATA.indexOf(row.name) != -1) {
+          props.push(row.name);
+        }
+      }
+
+      if (reqCount < REQUIRED.length) {
+        logger.error("Unable to read anything useful from the database");
+        return null;
+      }
+      stmt.finalize();
+
+      stmt = aConnection.createStatement("SELECT " + props.join(",") + " FROM addon");
+      for (let row in resultRows(stmt)) {
+        if (!(row.location in migrateData))
+          migrateData[row.location] = {};
+        let addonData = {
+          targetApplications: []
+        }
+        migrateData[row.location][row.id] = addonData;
+
+        props.forEach(function(aProp) {
+          if (aProp == "isForeignInstall")
+            addonData.foreignInstall = (row[aProp] == 1);
+          if (DB_BOOL_METADATA.indexOf(aProp) != -1)
+            addonData[aProp] = row[aProp] == 1;
+          else
+            addonData[aProp] = row[aProp];
+        })
+      }
+
+      var taStmt = aConnection.createStatement("SELECT id, minVersion, " +
+                                                   "maxVersion FROM " +
+                                                   "targetApplication WHERE " +
+                                                   "addon_internal_id=:internal_id");
+
+      for (let location in migrateData) {
+        for (let id in migrateData[location]) {
+          taStmt.params.internal_id = migrateData[location][id].internal_id;
+          delete migrateData[location][id].internal_id;
+          for (let row in resultRows(taStmt)) {
+            migrateData[location][id].targetApplications.push({
+              id: row.id,
+              minVersion: row.minVersion,
+              maxVersion: row.maxVersion
+            });
+          }
+        }
+      }
+    }
+    catch (e) {
+      // An error here means the schema is too different to read
+      logger.error("Error migrating data", e);
+      return null;
+    }
+    finally {
+      if (taStmt)
+        taStmt.finalize();
+      if (stmt)
+        stmt.finalize();
+    }
+
+    return migrateData;
+  },
+
+  /**
+   * Shuts down the database connection and releases all cached objects.
+   * Return: Promise{integer} resolves / rejects with the result of the DB
+   *                          flush after the database is flushed and
+   *                          all cleanup is done
+   */
+  shutdown: function XPIDB_shutdown() {
+    logger.debug("shutdown");
+    if (this.initialized) {
+      // If our last database I/O had an error, try one last time to save.
+      if (this.lastError)
+        this.saveChanges();
+
+      this.initialized = false;
+
+      if (this._deferredSave) {
+        AddonManagerPrivate.recordSimpleMeasure(
+            "XPIDB_saves_total", this._deferredSave.totalSaves);
+        AddonManagerPrivate.recordSimpleMeasure(
+            "XPIDB_saves_overlapped", this._deferredSave.overlappedSaves);
+        AddonManagerPrivate.recordSimpleMeasure(
+            "XPIDB_saves_late", this._deferredSave.dirty ? 1 : 0);
+      }
+
+      // Return a promise that any pending writes of the DB are complete and we
+      // are finished cleaning up
+      let flushPromise = this.flush();
+      flushPromise.then(null, error => {
+          logger.error("Flush of XPI database failed", error);
+          AddonManagerPrivate.recordSimpleMeasure("XPIDB_shutdownFlush_failed", 1);
+          // If our last attempt to read or write the DB failed, force a new
+          // extensions.ini to be written to disk on the next startup
+          Services.prefs.setBoolPref(PREF_PENDING_OPERATIONS, true);
+        })
+        .then(count => {
+          // Clear out the cached addons data loaded from JSON
+          delete this.addonDB;
+          delete this._dbPromise;
+          // same for the deferred save
+          delete this._deferredSave;
+          // re-enable the schema version setter
+          delete this._schemaVersionSet;
+        });
+      return flushPromise;
+    }
+    return Promise.resolve(0);
+  },
+
+  /**
+   * Asynchronously list all addons that match the filter function
+   * @param  aFilter
+   *         Function that takes an addon instance and returns
+   *         true if that addon should be included in the selected array
+   * @param  aCallback
+   *         Called back with an array of addons matching aFilter
+   *         or an empty array if none match
+   */
+  getAddonList: function(aFilter, aCallback) {
+    this.asyncLoadDB().then(
+      addonDB => {
+        let addonList = _filterDB(addonDB, aFilter);
+        asyncMap(addonList, getRepositoryAddon, makeSafe(aCallback));
+      })
+    .then(null,
+        error => {
+          logger.error("getAddonList failed", error);
+          makeSafe(aCallback)([]);
+        });
+  },
+
+  /**
+   * (Possibly asynchronously) get the first addon that matches the filter function
+   * @param  aFilter
+   *         Function that takes an addon instance and returns
+   *         true if that addon should be selected
+   * @param  aCallback
+   *         Called back with the addon, or null if no matching addon is found
+   */
+  getAddon: function(aFilter, aCallback) {
+    return this.asyncLoadDB().then(
+      addonDB => {
+        getRepositoryAddon(_findAddon(addonDB, aFilter), makeSafe(aCallback));
+      })
+    .then(null,
+        error => {
+          logger.error("getAddon failed", e);
+          makeSafe(aCallback)(null);
+        });
+  },
+
+  /**
+   * Asynchronously gets an add-on with a particular ID in a particular
+   * install location.
+   *
+   * @param  aId
+   *         The ID of the add-on to retrieve
+   * @param  aLocation
+   *         The name of the install location
+   * @param  aCallback
+   *         A callback to pass the DBAddonInternal to
+   */
+  getAddonInLocation: function XPIDB_getAddonInLocation(aId, aLocation, aCallback) {
+    this.asyncLoadDB().then(
+        addonDB => getRepositoryAddon(addonDB.get(aLocation + ":" + aId),
+                                      makeSafe(aCallback)));
+  },
+
+  /**
+   * Asynchronously gets the add-on with the specified ID that is visible.
+   *
+   * @param  aId
+   *         The ID of the add-on to retrieve
+   * @param  aCallback
+   *         A callback to pass the DBAddonInternal to
+   */
+  getVisibleAddonForID: function XPIDB_getVisibleAddonForID(aId, aCallback) {
+    this.getAddon(aAddon => ((aAddon.id == aId) && aAddon.visible),
+                  aCallback);
+  },
+
+  /**
+   * Asynchronously gets the visible add-ons, optionally restricting by type.
+   *
+   * @param  aTypes
+   *         An array of types to include or null to include all types
+   * @param  aCallback
+   *         A callback to pass the array of DBAddonInternals to
+   */
+  getVisibleAddons: function XPIDB_getVisibleAddons(aTypes, aCallback) {
+    this.getAddonList(aAddon => (aAddon.visible &&
+                                 (!aTypes || (aTypes.length == 0) ||
+                                  (aTypes.indexOf(aAddon.type) > -1))),
+                      aCallback);
+  },
+
+  /**
+   * Synchronously gets all add-ons of a particular type.
+   *
+   * @param  aType
+   *         The type of add-on to retrieve
+   * @return an array of DBAddonInternals
+   */
+  getAddonsByType: function XPIDB_getAddonsByType(aType) {
+    if (!this.addonDB) {
+      // jank-tastic! Must synchronously load DB if the theme switches from
+      // an XPI theme to a lightweight theme before the DB has loaded,
+      // because we're called from sync XPIProvider.addonChanged
+      logger.warn("Synchronous load of XPI database due to getAddonsByType(" + aType + ")");
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_byType", XPIProvider.runPhase);
+      this.syncLoadDB(true);
+    }
+    return _filterDB(this.addonDB, aAddon => (aAddon.type == aType));
+  },
+
+  /**
+   * Synchronously gets an add-on with a particular internalName.
+   *
+   * @param  aInternalName
+   *         The internalName of the add-on to retrieve
+   * @return a DBAddonInternal
+   */
+  getVisibleAddonForInternalName: function XPIDB_getVisibleAddonForInternalName(aInternalName) {
+    if (!this.addonDB) {
+      // This may be called when the DB hasn't otherwise been loaded
+      logger.warn("Synchronous load of XPI database due to getVisibleAddonForInternalName");
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_forInternalName",
+          XPIProvider.runPhase);
+      this.syncLoadDB(true);
+    }
+    
+    return _findAddon(this.addonDB,
+                      aAddon => aAddon.visible &&
+                                (aAddon.internalName == aInternalName));
+  },
+
+  /**
+   * Asynchronously gets all add-ons with pending operations.
+   *
+   * @param  aTypes
+   *         The types of add-ons to retrieve or null to get all types
+   * @param  aCallback
+   *         A callback to pass the array of DBAddonInternal to
+   */
+  getVisibleAddonsWithPendingOperations:
+    function XPIDB_getVisibleAddonsWithPendingOperations(aTypes, aCallback) {
+
+    this.getAddonList(
+        aAddon => (aAddon.visible &&
+                   (aAddon.pendingUninstall ||
+                    // Logic here is tricky. If we're active but disabled,
+                    // we're pending disable; !active && !disabled, we're pending enable
+                    (aAddon.active == aAddon.disabled)) &&
+                   (!aTypes || (aTypes.length == 0) || (aTypes.indexOf(aAddon.type) > -1))),
+        aCallback);
+  },
+
+  /**
+   * Asynchronously get an add-on by its Sync GUID.
+   *
+   * @param  aGUID
+   *         Sync GUID of add-on to fetch
+   * @param  aCallback
+   *         A callback to pass the DBAddonInternal record to. Receives null
+   *         if no add-on with that GUID is found.
+   *
+   */
+  getAddonBySyncGUID: function XPIDB_getAddonBySyncGUID(aGUID, aCallback) {
+    this.getAddon(aAddon => aAddon.syncGUID == aGUID,
+                  aCallback);
+  },
+
+  /**
+   * Synchronously gets all add-ons in the database.
+   * This is only called from the preference observer for the default
+   * compatibility version preference, so we can return an empty list if
+   * we haven't loaded the database yet.
+   *
+   * @return  an array of DBAddonInternals
+   */
+  getAddons: function XPIDB_getAddons() {
+    if (!this.addonDB) {
+      return [];
+    }
+    return _filterDB(this.addonDB, aAddon => true);
+  },
+
+  /**
+   * Synchronously adds an AddonInternal's metadata to the database.
+   *
+   * @param  aAddon
+   *         AddonInternal to add
+   * @param  aDescriptor
+   *         The file descriptor of the add-on
+   * @return The DBAddonInternal that was added to the database
+   */
+  addAddonMetadata: function XPIDB_addAddonMetadata(aAddon, aDescriptor) {
+    if (!this.addonDB) {
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_addMetadata",
+          XPIProvider.runPhase);
+      this.syncLoadDB(false);
+    }
+
+    let newAddon = new DBAddonInternal(aAddon);
+    newAddon.descriptor = aDescriptor;
+    this.addonDB.set(newAddon._key, newAddon);
+    if (newAddon.visible) {
+      this.makeAddonVisible(newAddon);
+    }
+
+    this.saveChanges();
+    return newAddon;
+  },
+
+  /**
+   * Synchronously updates an add-on's metadata in the database. Currently just
+   * removes and recreates.
+   *
+   * @param  aOldAddon
+   *         The DBAddonInternal to be replaced
+   * @param  aNewAddon
+   *         The new AddonInternal to add
+   * @param  aDescriptor
+   *         The file descriptor of the add-on
+   * @return The DBAddonInternal that was added to the database
+   */
+  updateAddonMetadata: function XPIDB_updateAddonMetadata(aOldAddon, aNewAddon,
+                                                          aDescriptor) {
+    this.removeAddonMetadata(aOldAddon);
+    aNewAddon.syncGUID = aOldAddon.syncGUID;
+    aNewAddon.installDate = aOldAddon.installDate;
+    aNewAddon.applyBackgroundUpdates = aOldAddon.applyBackgroundUpdates;
+    aNewAddon.foreignInstall = aOldAddon.foreignInstall;
+    aNewAddon.active = (aNewAddon.visible && !aNewAddon.disabled && !aNewAddon.pendingUninstall);
+
+    // addAddonMetadata does a saveChanges()
+    return this.addAddonMetadata(aNewAddon, aDescriptor);
+  },
+
+  /**
+   * Synchronously removes an add-on from the database.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal being removed
+   */
+  removeAddonMetadata: function XPIDB_removeAddonMetadata(aAddon) {
+    this.addonDB.delete(aAddon._key);
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously marks a DBAddonInternal as visible marking all other
+   * instances with the same ID as not visible.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal to make visible
+   */
+  makeAddonVisible: function XPIDB_makeAddonVisible(aAddon) {
+    logger.debug("Make addon " + aAddon._key + " visible");
+    for (let [, otherAddon] of this.addonDB) {
+      if ((otherAddon.id == aAddon.id) && (otherAddon._key != aAddon._key)) {
+        logger.debug("Hide addon " + otherAddon._key);
+        otherAddon.visible = false;
+      }
+    }
+    aAddon.visible = true;
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously sets properties for an add-on.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal being updated
+   * @param  aProperties
+   *         A dictionary of properties to set
+   */
+  setAddonProperties: function XPIDB_setAddonProperties(aAddon, aProperties) {
+    for (let key in aProperties) {
+      aAddon[key] = aProperties[key];
+    }
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously sets the Sync GUID for an add-on.
+   * Only called when the database is already loaded.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal being updated
+   * @param  aGUID
+   *         GUID string to set the value to
+   * @throws if another addon already has the specified GUID
+   */
+  setAddonSyncGUID: function XPIDB_setAddonSyncGUID(aAddon, aGUID) {
+    // Need to make sure no other addon has this GUID
+    function excludeSyncGUID(otherAddon) {
+      return (otherAddon._key != aAddon._key) && (otherAddon.syncGUID == aGUID);
+    }
+    let otherAddon = _findAddon(this.addonDB, excludeSyncGUID);
+    if (otherAddon) {
+      throw new Error("Addon sync GUID conflict for addon " + aAddon._key +
+          ": " + otherAddon._key + " already has GUID " + aGUID);
+    }
+    aAddon.syncGUID = aGUID;
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously updates an add-on's active flag in the database.
+   *
+   * @param  aAddon
+   *         The DBAddonInternal to update
+   */
+  updateAddonActive: function XPIDB_updateAddonActive(aAddon, aActive) {
+    logger.debug("Updating active state for add-on " + aAddon.id + " to " + aActive);
+
+    aAddon.active = aActive;
+    this.saveChanges();
+  },
+
+  /**
+   * Synchronously calculates and updates all the active flags in the database.
+   */
+  updateActiveAddons: function XPIDB_updateActiveAddons() {
+    if (!this.addonDB) {
+      logger.warn("updateActiveAddons called when DB isn't loaded");
+      // force the DB to load
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_updateActive",
+          XPIProvider.runPhase);
+      this.syncLoadDB(true);
+    }
+    logger.debug("Updating add-on states");
+    for (let [, addon] of this.addonDB) {
+      let newActive = (addon.visible && !addon.disabled && !addon.pendingUninstall);
+      if (newActive != addon.active) {
+        addon.active = newActive;
+        this.saveChanges();
+      }
+    }
+  },
+
+  /**
+   * Writes out the XPI add-ons list for the platform to read.
+   * @return true if the file was successfully updated, false otherwise
+   */
+  writeAddonsList: function XPIDB_writeAddonsList() {
+    if (!this.addonDB) {
+      // force the DB to load
+      AddonManagerPrivate.recordSimpleMeasure("XPIDB_lateOpen_writeList",
+          XPIProvider.runPhase);
+      this.syncLoadDB(true);
+    }
+    Services.appinfo.invalidateCachesOnRestart();
+
+    let addonsList = FileUtils.getFile(KEY_PROFILEDIR, [FILE_XPI_ADDONS_LIST],
+                                       true);
+    let enabledAddons = [];
+    let text = "[ExtensionDirs]\r\n";
+    let count = 0;
+    let fullCount = 0;
+
+    let activeAddons = _filterDB(
+      this.addonDB,
+      aAddon => aAddon.active && !aAddon.bootstrap && (aAddon.type != "theme"));
+
+    for (let row of activeAddons) {
+      text += "Extension" + (count++) + "=" + row.descriptor + "\r\n";
+      enabledAddons.push(encodeURIComponent(row.id) + ":" +
+                         encodeURIComponent(row.version));
+    }
+    fullCount += count;
+
+    // The selected skin may come from an inactive theme (the default theme
+    // when a lightweight theme is applied for example)
+    text += "\r\n[ThemeDirs]\r\n";
+
+    let dssEnabled = false;
+    try {
+      dssEnabled = Services.prefs.getBoolPref(PREF_EM_DSS_ENABLED);
+    } catch (e) {}
+
+    let themes = [];
+    if (dssEnabled) {
+      themes = _filterDB(this.addonDB, aAddon => aAddon.type == "theme");
+    }
+    else {
+      let activeTheme = _findAddon(
+        this.addonDB,
+        aAddon => (aAddon.type == "theme") &&
+                  (aAddon.internalName == XPIProvider.selectedSkin));
+      if (activeTheme) {
+        themes.push(activeTheme);
+      }
+    }
+
+    if (themes.length > 0) {
+      count = 0;
+      for (let row of themes) {
+        text += "Extension" + (count++) + "=" + row.descriptor + "\r\n";
+        enabledAddons.push(encodeURIComponent(row.id) + ":" +
+                           encodeURIComponent(row.version));
+      }
+      fullCount += count;
+    }
+
+    text += "\r\n[MultiprocessIncompatibleExtensions]\r\n";
+
+    count = 0;
+    for (let row of activeAddons) {
+      if (!row.multiprocessCompatible) {
+        text += "Extension" + (count++) + "=" + row.id + "\r\n";
+      }
+    }
+
+    if (fullCount > 0) {
+      logger.debug("Writing add-ons list");
+
+      try {
+        let addonsListTmp = FileUtils.getFile(KEY_PROFILEDIR, [FILE_XPI_ADDONS_LIST + ".tmp"],
+                                              true);
+        var fos = FileUtils.openFileOutputStream(addonsListTmp);
+        fos.write(text, text.length);
+        fos.close();
+        addonsListTmp.moveTo(addonsListTmp.parent, FILE_XPI_ADDONS_LIST);
+
+        Services.prefs.setCharPref(PREF_EM_ENABLED_ADDONS, enabledAddons.join(","));
+      }
+      catch (e) {
+        logger.error("Failed to write add-ons list to profile directory", e);
+        return false;
+      }
+    }
+    else {
+      if (addonsList.exists()) {
+        logger.debug("Deleting add-ons list");
+        try {
+          addonsList.remove(false);
+        }
+        catch (e) {
+          logger.error("Failed to remove " + addonsList.path, e);
+          return false;
+        }
+      }
+
+      Services.prefs.clearUserPref(PREF_EM_ENABLED_ADDONS);
+    }
+    return true;
+  }
+};