The Tor Browser: services/common/modules-testing/storageserver.js@6474c204b198 (annotated)

services/common/modules-testing/storageserver.js@6474c204b198 (annotated)

services/common/modules-testing/storageserver.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* 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/. */
 /**
  * This file contains an implementation of the Storage Server in JavaScript.
  *
  * The server should not be used for any production purposes.
  */
 const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
 this.EXPORTED_SYMBOLS = [
   "ServerBSO",
   "StorageServerCallback",
   "StorageServerCollection",
   "StorageServer",
   "storageServerForUsers",
 ];
 Cu.import("resource://testing-common/httpd.js");
 Cu.import("resource://services-common/async.js");
 Cu.import("resource://gre/modules/Log.jsm");
 Cu.import("resource://services-common/utils.js");
 const STORAGE_HTTP_LOGGER = "Services.Common.Test.Server";
 const STORAGE_API_VERSION = "2.0";
 // Use the same method that record.js does, which mirrors the server.
 function new_timestamp() {
   return Math.round(Date.now());
 }
 function isInteger(s) {
   let re = /^[0-9]+$/;
   return re.test(s);
 }
 function writeHttpBody(response, body) {
   if (!body) {
     return;
   }
   response.bodyOutputStream.write(body, body.length);
 }
 function sendMozSvcError(request, response, code) {
   response.setStatusLine(request.httpVersion, 400, "Bad Request");
   response.setHeader("Content-Type", "text/plain", false);
   response.bodyOutputStream.write(code, code.length);
 }
 /**
  * Represent a BSO on the server.
  *
  * A BSO is constructed from an ID, content, and a modified time.
  *
  * @param id
  *        (string) ID of the BSO being created.
  * @param payload
  *        (strong|object) Payload for the BSO. Should ideally be a string. If
  *        an object is passed, it will be fed into JSON.stringify and that
  *        output will be set as the payload.
  * @param modified
  *        (number) Milliseconds since UNIX epoch that the BSO was last
  *        modified. If not defined or null, the current time will be used.
  */
 this.ServerBSO = function ServerBSO(id, payload, modified) {
   if (!id) {
     throw new Error("No ID for ServerBSO!");
   }
   if (!id.match(/^[a-zA-Z0-9_-]{1,64}$/)) {
     throw new Error("BSO ID is invalid: " + id);
   }
   this._log = Log.repository.getLogger(STORAGE_HTTP_LOGGER);
   this.id = id;
   if (!payload) {
     return;
   }
   CommonUtils.ensureMillisecondsTimestamp(modified);
   if (typeof payload == "object") {
     payload = JSON.stringify(payload);
   }
   this.payload = payload;
   this.modified = modified || new_timestamp();
 }
 ServerBSO.prototype = {
   FIELDS: [
     "id",
     "modified",
     "payload",
     "ttl",
     "sortindex",
   ],
   toJSON: function toJSON() {
     let obj = {};
     for each (let key in this.FIELDS) {
       if (this[key] !== undefined) {
         obj[key] = this[key];
       }
     }
     return obj;
   },
   delete: function delete_() {
     this.deleted = true;
     delete this.payload;
     delete this.modified;
   },
   /**
    * Handler for GET requests for this BSO.
    */
   getHandler: function getHandler(request, response) {
     let code = 200;
     let status = "OK";
     let body;
     function sendResponse() {
       response.setStatusLine(request.httpVersion, code, status);
       writeHttpBody(response, body);
     }
     if (request.hasHeader("x-if-modified-since")) {
       let headerModified = parseInt(request.getHeader("x-if-modified-since"),
 );
       CommonUtils.ensureMillisecondsTimestamp(headerModified);
       if (headerModified >= this.modified) {
         code = 304;
         status = "Not Modified";
         sendResponse();
         return;
       }
     } else if (request.hasHeader("x-if-unmodified-since")) {
       let requestModified = parseInt(request.getHeader("x-if-unmodified-since"),
 );
       let serverModified = this.modified;
       if (serverModified > requestModified) {
         code = 412;
         status = "Precondition Failed";
         sendResponse();
         return;
       }
     }
     if (!this.deleted) {
       body = JSON.stringify(this.toJSON());
       response.setHeader("Content-Type", "application/json", false);
       response.setHeader("X-Last-Modified", "" + this.modified, false);
     } else {
       code = 404;
       status = "Not Found";
     }
     sendResponse();
   },
   /**
    * Handler for PUT requests for this BSO.
    */
   putHandler: function putHandler(request, response) {
     if (request.hasHeader("Content-Type")) {
       let ct = request.getHeader("Content-Type");
       if (ct != "application/json") {
         throw HTTP_415;
       }
     }
     let input = CommonUtils.readBytesFromInputStream(request.bodyInputStream);
     let parsed;
     try {
       parsed = JSON.parse(input);
     } catch (ex) {
       return sendMozSvcError(request, response, "8");
     }
     if (typeof(parsed) != "object") {
       return sendMozSvcError(request, response, "8");
     }
     // Don't update if a conditional request fails preconditions.
     if (request.hasHeader("x-if-unmodified-since")) {
       let reqModified = parseInt(request.getHeader("x-if-unmodified-since"));
       if (reqModified < this.modified) {
         response.setStatusLine(request.httpVersion, 412, "Precondition Failed");
         return;
       }
     }
     let code, status;
     if (this.payload) {
       code = 204;
       status = "No Content";
     } else {
       code = 201;
       status = "Created";
     }
     // Alert when we see unrecognized fields.
     for (let [key, value] in Iterator(parsed)) {
       switch (key) {
         case "payload":
           if (typeof(value) != "string") {
             sendMozSvcError(request, response, "8");
             return true;
           }
           this.payload = value;
           break;
         case "ttl":
           if (!isInteger(value)) {
             sendMozSvcError(request, response, "8");
             return true;
           }
           this.ttl = parseInt(value, 10);
           break;
         case "sortindex":
           if (!isInteger(value) || value.length > 9) {
             sendMozSvcError(request, response, "8");
             return true;
           }
           this.sortindex = parseInt(value, 10);
           break;
         case "id":
           break;
         default:
           this._log.warn("Unexpected field in BSO record: " + key);
           sendMozSvcError(request, response, "8");
           return true;
       }
     }
     this.modified = request.timestamp;
     this.deleted = false;
     response.setHeader("X-Last-Modified", "" + this.modified, false);
     response.setStatusLine(request.httpVersion, code, status);
   },
 };
 /**
  * Represent a collection on the server.
  *
  * The '_bsos' attribute is a mapping of id -> ServerBSO objects.
  *
  * Note that if you want these records to be accessible individually,
  * you need to register their handlers with the server separately, or use a
  * containing HTTP server that will do so on your behalf.
  *
  * @param bsos
  *        An object mapping BSO IDs to ServerBSOs.
  * @param acceptNew
  *        If true, POSTs to this collection URI will result in new BSOs being
  *        created and wired in on the fly.
  * @param timestamp
  *        An optional timestamp value to initialize the modified time of the
  *        collection. This should be in the format returned by new_timestamp().
  */
 this.StorageServerCollection =
  function StorageServerCollection(bsos, acceptNew, timestamp=new_timestamp()) {
   this._bsos = bsos || {};
   this.acceptNew = acceptNew || false;
   /*
    * Track modified timestamp.
    * We can't just use the timestamps of contained BSOs: an empty collection
    * has a modified time.
    */
   CommonUtils.ensureMillisecondsTimestamp(timestamp);
   this._timestamp = timestamp;
   this._log = Log.repository.getLogger(STORAGE_HTTP_LOGGER);
 }
 StorageServerCollection.prototype = {
   BATCH_MAX_COUNT: 100,         // # of records.
   BATCH_MAX_SIZE: 1024 * 1024,  // # bytes.
   _timestamp: null,
   get timestamp() {
     return this._timestamp;
   },
   set timestamp(timestamp) {
     CommonUtils.ensureMillisecondsTimestamp(timestamp);
     this._timestamp = timestamp;
   },
   get totalPayloadSize() {
     let size = 0;
     for each (let bso in this.bsos()) {
       size += bso.payload.length;
     }
     return size;
   },
   /**
    * Convenience accessor for our BSO keys.
    * Excludes deleted items, of course.
    *
    * @param filter
    *        A predicate function (applied to the ID and BSO) which dictates
    *        whether to include the BSO's ID in the output.
    *
    * @return an array of IDs.
    */
   keys: function keys(filter) {
     return [id for ([id, bso] in Iterator(this._bsos))
                if (!bso.deleted && (!filter || filter(id, bso)))];
   },
   /**
    * Convenience method to get an array of BSOs.
    * Optionally provide a filter function.
    *
    * @param filter
    *        A predicate function, applied to the BSO, which dictates whether to
    *        include the BSO in the output.
    *
    * @return an array of ServerBSOs.
    */
   bsos: function bsos(filter) {
     let os = [bso for ([id, bso] in Iterator(this._bsos))
               if (!bso.deleted)];
     if (!filter) {
       return os;
     }
     return os.filter(filter);
   },
   /**
    * Obtain a BSO by ID.
    */
   bso: function bso(id) {
     return this._bsos[id];
   },
   /**
    * Obtain the payload of a specific BSO.
    *
    * Raises if the specified BSO does not exist.
    */
   payload: function payload(id) {
     return this.bso(id).payload;
   },
   /**
    * Insert the provided BSO under its ID.
    *
    * @return the provided BSO.
    */
   insertBSO: function insertBSO(bso) {
     return this._bsos[bso.id] = bso;
   },
   /**
    * Insert the provided payload as part of a new ServerBSO with the provided
    * ID.
    *
    * @param id
    *        The GUID for the BSO.
    * @param payload
    *        The payload, as provided to the ServerBSO constructor.
    * @param modified
    *        An optional modified time for the ServerBSO. If not specified, the
    *        current time will be used.
    *
    * @return the inserted BSO.
    */
   insert: function insert(id, payload, modified) {
     return this.insertBSO(new ServerBSO(id, payload, modified));
   },
   /**
    * Removes an object entirely from the collection.
    *
    * @param id
    *        (string) ID to remove.
    */
   remove: function remove(id) {
     delete this._bsos[id];
   },
   _inResultSet: function _inResultSet(bso, options) {
     if (!bso.payload) {
       return false;
     }
     if (options.ids) {
       if (options.ids.indexOf(bso.id) == -1) {
         return false;
       }
     }
     if (options.newer) {
       if (bso.modified <= options.newer) {
         return false;
       }
     }
     if (options.older) {
       if (bso.modified >= options.older) {
         return false;
       }
     }
     return true;
   },
   count: function count(options) {
     options = options || {};
     let c = 0;
     for (let [id, bso] in Iterator(this._bsos)) {
       if (bso.modified && this._inResultSet(bso, options)) {
         c++;
       }
     }
     return c;
   },
   get: function get(options) {
     let data = [];
     for each (let bso in this._bsos) {
       if (!bso.modified) {
         continue;
       }
       if (!this._inResultSet(bso, options)) {
         continue;
       }
       data.push(bso);
     }
     if (options.sort) {
       if (options.sort == "oldest") {
         data.sort(function sortOldest(a, b) {
           if (a.modified == b.modified) {
             return 0;
           }
           return a.modified < b.modified ? -1 : 1;
         });
       } else if (options.sort == "newest") {
         data.sort(function sortNewest(a, b) {
           if (a.modified == b.modified) {
             return 0;
           }
           return a.modified > b.modified ? -1 : 1;
         });
       } else if (options.sort == "index") {
         data.sort(function sortIndex(a, b) {
           if (a.sortindex == b.sortindex) {
             return 0;
           }
           if (a.sortindex !== undefined && b.sortindex == undefined) {
             return 1;
           }
           if (a.sortindex === undefined && b.sortindex !== undefined) {
             return -1;
           }
           return a.sortindex > b.sortindex ? -1 : 1;
         });
       }
     }
     if (options.limit) {
       data = data.slice(0, options.limit);
     }
     return data;
   },
   post: function post(input, timestamp) {
     let success = [];
     let failed = {};
     let count = 0;
     let size = 0;
     // This will count records where we have an existing ServerBSO
     // registered with us as successful and all other records as failed.
     for each (let record in input) {
       count += 1;
       if (count > this.BATCH_MAX_COUNT) {
         failed[record.id] = "Max record count exceeded.";
         continue;
       }
       if (typeof(record.payload) != "string") {
         failed[record.id] = "Payload is not a string!";
         continue;
       }
       size += record.payload.length;
       if (size > this.BATCH_MAX_SIZE) {
         failed[record.id] = "Payload max size exceeded!";
         continue;
       }
       if (record.sortindex) {
         if (!isInteger(record.sortindex)) {
           failed[record.id] = "sortindex is not an integer.";
           continue;
         }
         if (record.sortindex.length > 9) {
           failed[record.id] = "sortindex is too long.";
           continue;
         }
       }
       if ("ttl" in record) {
         if (!isInteger(record.ttl)) {
           failed[record.id] = "ttl is not an integer.";
           continue;
         }
       }
       try {
         let bso = this.bso(record.id);
         if (!bso && this.acceptNew) {
           this._log.debug("Creating BSO " + JSON.stringify(record.id) +
                           " on the fly.");
           bso = new ServerBSO(record.id);
           this.insertBSO(bso);
         }
         if (bso) {
           bso.payload = record.payload;
           bso.modified = timestamp;
           bso.deleted = false;
           success.push(record.id);
           if (record.sortindex) {
             bso.sortindex = parseInt(record.sortindex, 10);
           }
         } else {
           failed[record.id] = "no bso configured";
         }
       } catch (ex) {
         this._log.info("Exception when processing BSO: " +
                        CommonUtils.exceptionStr(ex));
         failed[record.id] = "Exception when processing.";
       }
     }
     return {success: success, failed: failed};
   },
   delete: function delete_(options) {
     options = options || {};
     // Protocol 2.0 only allows the "ids" query string argument.
     let keys = Object.keys(options).filter(function(k) {
       return k != "ids";
     });
     if (keys.length) {
       this._log.warn("Invalid query string parameter to collection delete: " +
                      keys.join(", "));
       throw new Error("Malformed client request.");
     }
     if (options.ids && options.ids.length > this.BATCH_MAX_COUNT) {
       throw HTTP_400;
     }
     let deleted = [];
     for (let [id, bso] in Iterator(this._bsos)) {
       if (this._inResultSet(bso, options)) {
         this._log.debug("Deleting " + JSON.stringify(bso));
         deleted.push(bso.id);
         bso.delete();
       }
     }
     return deleted;
   },
   parseOptions: function parseOptions(request) {
     let options = {};
     for each (let chunk in request.queryString.split("&")) {
       if (!chunk) {
         continue;
       }
       chunk = chunk.split("=");
       let key = decodeURIComponent(chunk[0]);
       if (chunk.length == 1) {
         options[key] = "";
       } else {
         options[key] = decodeURIComponent(chunk[1]);
       }
     }
     if (options.ids) {
       options.ids = options.ids.split(",");
     }
     if (options.newer) {
       if (!isInteger(options.newer)) {
         throw HTTP_400;
       }
       CommonUtils.ensureMillisecondsTimestamp(options.newer);
       options.newer = parseInt(options.newer, 10);
     }
     if (options.older) {
       if (!isInteger(options.older)) {
         throw HTTP_400;
       }
       CommonUtils.ensureMillisecondsTimestamp(options.older);
       options.older = parseInt(options.older, 10);
     }
     if (options.limit) {
       if (!isInteger(options.limit)) {
         throw HTTP_400;
       }
       options.limit = parseInt(options.limit, 10);
     }
     return options;
   },
   getHandler: function getHandler(request, response) {
     let options = this.parseOptions(request);
     let data = this.get(options);
     if (request.hasHeader("x-if-modified-since")) {
       let requestModified = parseInt(request.getHeader("x-if-modified-since"),
 );
       let newestBSO = 0;
       for each (let bso in data) {
         if (bso.modified > newestBSO) {
           newestBSO = bso.modified;
         }
       }
       if (requestModified >= newestBSO) {
         response.setHeader("X-Last-Modified", "" + newestBSO);
         response.setStatusLine(request.httpVersion, 304, "Not Modified");
         return;
       }
     } else if (request.hasHeader("x-if-unmodified-since")) {
       let requestModified = parseInt(request.getHeader("x-if-unmodified-since"),
 );
       let serverModified = this.timestamp;
       if (serverModified > requestModified) {
         response.setHeader("X-Last-Modified", "" + serverModified);
         response.setStatusLine(request.httpVersion, 412, "Precondition Failed");
         return;
       }
     }
     if (options.full) {
       data = data.map(function map(bso) {
         return bso.toJSON();
       });
     } else {
       data = data.map(function map(bso) {
         return bso.id;
       });
     }
     // application/json is default media type.
     let newlines = false;
     if (request.hasHeader("accept")) {
       let accept = request.getHeader("accept");
       if (accept == "application/newlines") {
         newlines = true;
       } else if (accept != "application/json") {
         throw HTTP_406;
       }
     }
     let body;
     if (newlines) {
       response.setHeader("Content-Type", "application/newlines", false);
       let normalized = data.map(function map(d) {
         return JSON.stringify(d);
       });
       body = normalized.join("\n") + "\n";
     } else {
       response.setHeader("Content-Type", "application/json", false);
       body = JSON.stringify({items: data});
     }
     this._log.info("Records: " + data.length);
     response.setHeader("X-Num-Records", "" + data.length, false);
     response.setHeader("X-Last-Modified", "" + this.timestamp, false);
     response.setStatusLine(request.httpVersion, 200, "OK");
     response.bodyOutputStream.write(body, body.length);
   },
   postHandler: function postHandler(request, response) {
     let options = this.parseOptions(request);
     if (!request.hasHeader("content-type")) {
       this._log.info("No Content-Type request header!");
       throw HTTP_400;
     }
     let inputStream = request.bodyInputStream;
     let inputBody = CommonUtils.readBytesFromInputStream(inputStream);
     let input = [];
     let inputMediaType = request.getHeader("content-type");
     if (inputMediaType == "application/json") {
       try {
         input = JSON.parse(inputBody);
       } catch (ex) {
         this._log.info("JSON parse error on input body!");
         throw HTTP_400;
       }
       if (!Array.isArray(input)) {
         this._log.info("Input JSON type not an array!");
         return sendMozSvcError(request, response, "8");
       }
     } else if (inputMediaType == "application/newlines") {
       for each (let line in inputBody.split("\n")) {
         let record;
         try {
           record = JSON.parse(line);
         } catch (ex) {
           this._log.info("JSON parse error on line!");
           return sendMozSvcError(request, response, "8");
         }
         input.push(record);
       }
     } else {
       this._log.info("Unknown media type: " + inputMediaType);
       throw HTTP_415;
     }
     if (this._ensureUnmodifiedSince(request, response)) {
       return;
     }
     let res = this.post(input, request.timestamp);
     let body = JSON.stringify(res);
     response.setHeader("Content-Type", "application/json", false);
     this.timestamp = request.timestamp;
     response.setHeader("X-Last-Modified", "" + this.timestamp, false);
     response.setStatusLine(request.httpVersion, "200", "OK");
     response.bodyOutputStream.write(body, body.length);
   },
   deleteHandler: function deleteHandler(request, response) {
     this._log.debug("Invoking StorageServerCollection.DELETE.");
     let options = this.parseOptions(request);
     if (this._ensureUnmodifiedSince(request, response)) {
       return;
     }
     let deleted = this.delete(options);
     response.deleted = deleted;
     this.timestamp = request.timestamp;
     response.setStatusLine(request.httpVersion, 204, "No Content");
   },
   handler: function handler() {
     let self = this;
     return function(request, response) {
       switch(request.method) {
         case "GET":
           return self.getHandler(request, response);
         case "POST":
           return self.postHandler(request, response);
         case "DELETE":
           return self.deleteHandler(request, response);
       }
       request.setHeader("Allow", "GET,POST,DELETE");
       response.setStatusLine(request.httpVersion, 405, "Method Not Allowed");
     };
   },
   _ensureUnmodifiedSince: function _ensureUnmodifiedSince(request, response) {
     if (!request.hasHeader("x-if-unmodified-since")) {
       return false;
     }
     let requestModified = parseInt(request.getHeader("x-if-unmodified-since"),
 );
     let serverModified = this.timestamp;
     this._log.debug("Request modified time: " + requestModified +
                     "; Server modified time: " + serverModified);
     if (serverModified <= requestModified) {
       return false;
     }
     this._log.info("Conditional request rejected because client time older " +
                    "than collection timestamp.");
     response.setStatusLine(request.httpVersion, 412, "Precondition Failed");
     return true;
   },
 };
 //===========================================================================//
 // httpd.js-based Storage server.                                            //
 //===========================================================================//
 /**
  * In general, the preferred way of using StorageServer is to directly
  * introspect it. Callbacks are available for operations which are hard to
  * verify through introspection, such as deletions.
  *
  * One of the goals of this server is to provide enough hooks for test code to
  * find out what it needs without monkeypatching. Use this object as your
  * prototype, and override as appropriate.
  */
 this.StorageServerCallback = {
   onCollectionDeleted: function onCollectionDeleted(user, collection) {},
   onItemDeleted: function onItemDeleted(user, collection, bsoID) {},
   /**
    * Called at the top of every request.
    *
    * Allows the test to inspect the request. Hooks should be careful not to
    * modify or change state of the request or they may impact future processing.
    */
   onRequest: function onRequest(request) {},
 };
 /**
  * Construct a new test Storage server. Takes a callback object (e.g.,
  * StorageServerCallback) as input.
  */
 this.StorageServer = function StorageServer(callback) {
   this.callback     = callback || {__proto__: StorageServerCallback};
   this.server       = new HttpServer();
   this.started      = false;
   this.users        = {};
   this.requestCount = 0;
   this._log         = Log.repository.getLogger(STORAGE_HTTP_LOGGER);
   // Install our own default handler. This allows us to mess around with the
   // whole URL space.
   let handler = this.server._handler;
   handler._handleDefault = this.handleDefault.bind(this, handler);
 }
 StorageServer.prototype = {
   DEFAULT_QUOTA: 1024 * 1024, // # bytes.
   server: null,    // HttpServer.
   users:  null,    // Map of username => {collections, password}.
   /**
    * If true, the server will allow any arbitrary user to be used.
    *
    * No authentication will be performed. Whatever user is detected from the
    * URL or auth headers will be created (if needed) and used.
    */
   allowAllUsers: false,
   /**
    * Start the StorageServer's underlying HTTP server.
    *
    * @param port
    *        The numeric port on which to start. A falsy value implies to
    *        select any available port.
    * @param cb
    *        A callback function (of no arguments) which is invoked after
    *        startup.
    */
   start: function start(port, cb) {
     if (this.started) {
       this._log.warn("Warning: server already started on " + this.port);
       return;
     }
     if (!port) {
       port = -1;
     }
     this.port = port;
     try {
       this.server.start(this.port);
       this.port = this.server.identity.primaryPort;
       this.started = true;
       if (cb) {
         cb();
       }
     } catch (ex) {
       _("==========================================");
       _("Got exception starting Storage HTTP server on port " + this.port);
       _("Error: " + CommonUtils.exceptionStr(ex));
       _("Is there a process already listening on port " + this.port + "?");
       _("==========================================");
       do_throw(ex);
     }
   },
   /**
    * Start the server synchronously.
    *
    * @param port
    *        The numeric port on which to start. The default is to choose
    *        any available port.
    */
   startSynchronous: function startSynchronous(port=-1) {
     let cb = Async.makeSpinningCallback();
     this.start(port, cb);
     cb.wait();
   },
   /**
    * Stop the StorageServer's HTTP server.
    *
    * @param cb
    *        A callback function. Invoked after the server has been stopped.
    *
    */
   stop: function stop(cb) {
     if (!this.started) {
       this._log.warn("StorageServer: Warning: server not running. Can't stop " +
                      "me now!");
       return;
     }
     this.server.stop(cb);
     this.started = false;
   },
   serverTime: function serverTime() {
     return new_timestamp();
   },
   /**
    * Create a new user, complete with an empty set of collections.
    *
    * @param username
    *        The username to use. An Error will be thrown if a user by that name
    *        already exists.
    * @param password
    *        A password string.
    *
    * @return a user object, as would be returned by server.user(username).
    */
   registerUser: function registerUser(username, password) {
     if (username in this.users) {
       throw new Error("User already exists.");
     }
     if (!isFinite(parseInt(username))) {
       throw new Error("Usernames must be numeric: " + username);
     }
     this._log.info("Registering new user with server: " + username);
     this.users[username] = {
       password: password,
       collections: {},
       quota: this.DEFAULT_QUOTA,
     };
     return this.user(username);
   },
   userExists: function userExists(username) {
     return username in this.users;
   },
   getCollection: function getCollection(username, collection) {
     return this.users[username].collections[collection];
   },
   _insertCollection: function _insertCollection(collections, collection, bsos) {
     let coll = new StorageServerCollection(bsos, true);
     coll.collectionHandler = coll.handler();
     collections[collection] = coll;
     return coll;
   },
   createCollection: function createCollection(username, collection, bsos) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     let collections = this.users[username].collections;
     if (collection in collections) {
       throw new Error("Collection already exists.");
     }
     return this._insertCollection(collections, collection, bsos);
   },
   deleteCollection: function deleteCollection(username, collection) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     delete this.users[username].collections[collection];
   },
   /**
    * Accept a map like the following:
    * {
    *   meta: {global: {version: 1, ...}},
    *   crypto: {"keys": {}, foo: {bar: 2}},
    *   bookmarks: {}
    * }
    * to cause collections and BSOs to be created.
    * If a collection already exists, no error is raised.
    * If a BSO already exists, it will be updated to the new contents.
    */
   createContents: function createContents(username, collections) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     let userCollections = this.users[username].collections;
     for (let [id, contents] in Iterator(collections)) {
       let coll = userCollections[id] ||
                  this._insertCollection(userCollections, id);
       for (let [bsoID, payload] in Iterator(contents)) {
         coll.insert(bsoID, payload);
       }
     }
   },
   /**
    * Insert a BSO in an existing collection.
    */
   insertBSO: function insertBSO(username, collection, bso) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     let userCollections = this.users[username].collections;
     if (!(collection in userCollections)) {
       throw new Error("Unknown collection.");
     }
     userCollections[collection].insertBSO(bso);
     return bso;
   },
   /**
    * Delete all of the collections for the named user.
    *
    * @param username
    *        The name of the affected user.
    */
   deleteCollections: function deleteCollections(username) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     let userCollections = this.users[username].collections;
     for each (let [name, coll] in Iterator(userCollections)) {
       this._log.trace("Bulk deleting " + name + " for " + username + "...");
       coll.delete({});
     }
     this.users[username].collections = {};
   },
   getQuota: function getQuota(username) {
     if (!(username in this.users)) {
       throw new Error("Unknown user.");
     }
     return this.users[username].quota;
   },
   /**
    * Obtain the newest timestamp of all collections for a user.
    */
   newestCollectionTimestamp: function newestCollectionTimestamp(username) {
     let collections = this.users[username].collections;
     let newest = 0;
     for each (let collection in collections) {
       if (collection.timestamp > newest) {
         newest = collection.timestamp;
       }
     }
     return newest;
   },
   /**
    * Compute the object that is returned for an info/collections request.
    */
   infoCollections: function infoCollections(username) {
     let responseObject = {};
     let colls = this.users[username].collections;
     for (let coll in colls) {
       responseObject[coll] = colls[coll].timestamp;
     }
     this._log.trace("StorageServer: info/collections returning " +
                     JSON.stringify(responseObject));
     return responseObject;
   },
   infoCounts: function infoCounts(username) {
     let data = {};
     let collections = this.users[username].collections;
     for (let [k, v] in Iterator(collections)) {
       let count = v.count();
       if (!count) {
         continue;
       }
       data[k] = count;
     }
     return data;
   },
   infoUsage: function infoUsage(username) {
     let data = {};
     let collections = this.users[username].collections;
     for (let [k, v] in Iterator(collections)) {
       data[k] = v.totalPayloadSize;
     }
     return data;
   },
   infoQuota: function infoQuota(username) {
     let total = 0;
     for each (let value in this.infoUsage(username)) {
       total += value;
     }
     return {
       quota: this.getQuota(username),
       usage: total
     };
   },
   /**
    * Simple accessor to allow collective binding and abbreviation of a bunch of
    * methods. Yay!
    * Use like this:
    *
    *   let u = server.user("john");
    *   u.collection("bookmarks").bso("abcdefg").payload;  // Etc.
    *
    * @return a proxy for the user data stored in this server.
    */
   user: function user(username) {
     let collection       = this.getCollection.bind(this, username);
     let createCollection = this.createCollection.bind(this, username);
     let createContents   = this.createContents.bind(this, username);
     let modified         = function (collectionName) {
       return collection(collectionName).timestamp;
     }
     let deleteCollections = this.deleteCollections.bind(this, username);
     let quota             = this.getQuota.bind(this, username);
     return {
       collection:        collection,
       createCollection:  createCollection,
       createContents:    createContents,
       deleteCollections: deleteCollections,
       modified:          modified,
       quota:             quota,
     };
   },
   _pruneExpired: function _pruneExpired() {
     let now = Date.now();
     for each (let user in this.users) {
       for each (let collection in user.collections) {
         for each (let bso in collection.bsos()) {
           // ttl === 0 is a special case, so we can't simply !ttl.
           if (typeof(bso.ttl) != "number") {
             continue;
           }
           let ttlDate = bso.modified + (bso.ttl * 1000);
           if (ttlDate < now) {
             this._log.info("Deleting BSO because TTL expired: " + bso.id);
             bso.delete();
           }
         }
       }
     }
   },
   /*
    * Regular expressions for splitting up Storage request paths.
    * Storage URLs are of the form:
    *   /$apipath/$version/$userid/$further
    * where $further is usually:
    *   storage/$collection/$bso
    * or
    *   storage/$collection
    * or
    *   info/$op
    *
    * We assume for the sake of simplicity that $apipath is empty.
    *
    * N.B., we don't follow any kind of username spec here, because as far as I
    * can tell there isn't one. See Bug 689671. Instead we follow the Python
    * server code.
    *
    * Path: [all, version, first, rest]
    * Storage: [all, collection?, id?]
    */
   pathRE: /^\/([0-9]+(?:\.[0-9]+)?)(?:\/([0-9]+)\/([^\/]+)(?:\/(.+))?)?$/,
   storageRE: /^([-_a-zA-Z0-9]+)(?:\/([-_a-zA-Z0-9]+)\/?)?$/,
   defaultHeaders: {},
   /**
    * HTTP response utility.
    */
   respond: function respond(req, resp, code, status, body, headers, timestamp) {
     this._log.info("Response: " + code + " " + status);
     resp.setStatusLine(req.httpVersion, code, status);
     for each (let [header, value] in Iterator(headers || this.defaultHeaders)) {
       resp.setHeader(header, value, false);
     }
     if (timestamp) {
       resp.setHeader("X-Timestamp", "" + timestamp, false);
     }
     if (body) {
       resp.bodyOutputStream.write(body, body.length);
     }
   },
   /**
    * This is invoked by the HttpServer. `this` is bound to the StorageServer;
    * `handler` is the HttpServer's handler.
    *
    * TODO: need to use the correct Storage API response codes and errors here.
    */
   handleDefault: function handleDefault(handler, req, resp) {
     this.requestCount++;
     let timestamp = new_timestamp();
     try {
       this._handleDefault(handler, req, resp, timestamp);
     } catch (e) {
       if (e instanceof HttpError) {
         this.respond(req, resp, e.code, e.description, "", {}, timestamp);
       } else {
         this._log.warn(CommonUtils.exceptionStr(e));
         throw e;
       }
     }
   },
   _handleDefault: function _handleDefault(handler, req, resp, timestamp) {
     let path = req.path;
     if (req.queryString.length) {
       path += "?" + req.queryString;
     }
     this._log.debug("StorageServer: Handling request: " + req.method + " " +
                     path);
     if (this.callback.onRequest) {
       this.callback.onRequest(req);
     }
     // Prune expired records for all users at top of request. This is the
     // easiest way to process TTLs since all requests go through here.
     this._pruneExpired();
     req.timestamp = timestamp;
     resp.setHeader("X-Timestamp", "" + timestamp, false);
     let parts = this.pathRE.exec(req.path);
     if (!parts) {
       this._log.debug("StorageServer: Unexpected request: bad URL " + req.path);
       throw HTTP_404;
     }
     let [all, version, userPath, first, rest] = parts;
     if (version != STORAGE_API_VERSION) {
       this._log.debug("StorageServer: Unknown version.");
       throw HTTP_404;
     }
     let username;
     // By default, the server requires users to be authenticated. When a
     // request arrives, the user must have been previously configured and
     // the request must have authentication. In "allow all users" mode, we
     // take the username from the URL, create the user on the fly, and don't
     // perform any authentication.
     if (!this.allowAllUsers) {
       // Enforce authentication.
       if (!req.hasHeader("authorization")) {
         this.respond(req, resp, 401, "Authorization Required", "{}", {
           "WWW-Authenticate": 'Basic realm="secret"'
         });
         return;
       }
       let ensureUserExists = function ensureUserExists(username) {
         if (this.userExists(username)) {
           return;
         }
         this._log.info("StorageServer: Unknown user: " + username);
         throw HTTP_401;
       }.bind(this);
       let auth = req.getHeader("authorization");
       this._log.debug("Authorization: " + auth);
       if (auth.indexOf("Basic ") == 0) {
         let decoded = CommonUtils.safeAtoB(auth.substr(6));
         this._log.debug("Decoded Basic Auth: " + decoded);
         let [user, password] = decoded.split(":", 2);
         if (!password) {
           this._log.debug("Malformed HTTP Basic Authorization header: " + auth);
           throw HTTP_400;
         }
         this._log.debug("Got HTTP Basic auth for user: " + user);
         ensureUserExists(user);
         username = user;
         if (this.users[user].password != password) {
           this._log.debug("StorageServer: Provided password is not correct.");
           throw HTTP_401;
         }
       // TODO support token auth.
       } else {
         this._log.debug("Unsupported HTTP authorization type: " + auth);
         throw HTTP_500;
       }
     // All users mode.
     } else {
       // Auto create user with dummy password.
       if (!this.userExists(userPath)) {
         this.registerUser(userPath, "DUMMY-PASSWORD-*&%#");
       }
       username = userPath;
     }
     // Hand off to the appropriate handler for this path component.
     if (first in this.toplevelHandlers) {
       let handler = this.toplevelHandlers[first];
       try {
         return handler.call(this, handler, req, resp, version, username, rest);
       } catch (ex) {
         this._log.warn("Got exception during request: " +
                        CommonUtils.exceptionStr(ex));
         throw ex;
       }
     }
     this._log.debug("StorageServer: Unknown top-level " + first);
     throw HTTP_404;
   },
   /**
    * Collection of the handler methods we use for top-level path components.
    */
   toplevelHandlers: {
     "storage": function handleStorage(handler, req, resp, version, username,
                                       rest) {
       let respond = this.respond.bind(this, req, resp);
       if (!rest || !rest.length) {
         this._log.debug("StorageServer: top-level storage " +
                         req.method + " request.");
         if (req.method != "DELETE") {
           respond(405, "Method Not Allowed", null, {"Allow": "DELETE"});
           return;
         }
         this.user(username).deleteCollections();
         respond(204, "No Content");
         return;
       }
       let match = this.storageRE.exec(rest);
       if (!match) {
         this._log.warn("StorageServer: Unknown storage operation " + rest);
         throw HTTP_404;
       }
       let [all, collection, bsoID] = match;
       let coll = this.getCollection(username, collection);
       let collectionExisted = !!coll;
       switch (req.method) {
         case "GET":
           // Tried to GET on a collection that doesn't exist.
           if (!coll) {
             respond(404, "Not Found");
             return;
           }
           // No BSO URL parameter goes to collection handler.
           if (!bsoID) {
             return coll.collectionHandler(req, resp);
           }
           // Handle non-existent BSO.
           let bso = coll.bso(bsoID);
           if (!bso) {
             respond(404, "Not Found");
             return;
           }
           // Proxy to BSO handler.
           return bso.getHandler(req, resp);
         case "DELETE":
           // Collection doesn't exist.
           if (!coll) {
             respond(404, "Not Found");
             return;
           }
           // Deleting a specific BSO.
           if (bsoID) {
             let bso = coll.bso(bsoID);
             // BSO does not exist on the server. Nothing to do.
             if (!bso) {
               respond(404, "Not Found");
               return;
             }
             if (req.hasHeader("x-if-unmodified-since")) {
               let modified = parseInt(req.getHeader("x-if-unmodified-since"));
               CommonUtils.ensureMillisecondsTimestamp(modified);
               if (bso.modified > modified) {
                 respond(412, "Precondition Failed");
                 return;
               }
             }
             bso.delete();
             coll.timestamp = req.timestamp;
             this.callback.onItemDeleted(username, collection, bsoID);
             respond(204, "No Content");
             return;
           }
           // Proxy to collection handler.
           coll.collectionHandler(req, resp);
           // Spot if this is a DELETE for some IDs, and don't blow away the
           // whole collection!
           //
           // We already handled deleting the BSOs by invoking the deleted
           // collection's handler. However, in the case of
           //
           //   DELETE storage/foobar
           //
           // we also need to remove foobar from the collections map. This
           // clause tries to differentiate the above request from
           //
           //  DELETE storage/foobar?ids=foo,baz
           //
           // and do the right thing.
           // TODO: less hacky method.
           if (-1 == req.queryString.indexOf("ids=")) {
             // When you delete the entire collection, we drop it.
             this._log.debug("Deleting entire collection.");
             delete this.users[username].collections[collection];
             this.callback.onCollectionDeleted(username, collection);
           }
           // Notify of item deletion.
           let deleted = resp.deleted || [];
           for (let i = 0; i < deleted.length; ++i) {
             this.callback.onItemDeleted(username, collection, deleted[i]);
           }
           return;
         case "POST":
         case "PUT":
           // Auto-create collection if it doesn't exist.
           if (!coll) {
             coll = this.createCollection(username, collection);
           }
           try {
             if (bsoID) {
               let bso = coll.bso(bsoID);
               if (!bso) {
                 this._log.trace("StorageServer: creating BSO " + collection +
                                 "/" + bsoID);
                 try {
                   bso = coll.insert(bsoID);
                 } catch (ex) {
                   return sendMozSvcError(req, resp, "8");
                 }
               }
               bso.putHandler(req, resp);
               coll.timestamp = req.timestamp;
               return resp;
             }
             return coll.collectionHandler(req, resp);
           } catch (ex) {
             if (ex instanceof HttpError) {
               if (!collectionExisted) {
                 this.deleteCollection(username, collection);
               }
             }
             throw ex;
           }
         default:
           throw new Error("Request method " + req.method + " not implemented.");
       }
     },
     "info": function handleInfo(handler, req, resp, version, username, rest) {
       switch (rest) {
         case "collections":
           return this.handleInfoCollections(req, resp, username);
         case "collection_counts":
           return this.handleInfoCounts(req, resp, username);
         case "collection_usage":
           return this.handleInfoUsage(req, resp, username);
         case "quota":
           return this.handleInfoQuota(req, resp, username);
         default:
           this._log.warn("StorageServer: Unknown info operation " + rest);
           throw HTTP_404;
       }
     }
   },
   handleInfoConditional: function handleInfoConditional(request, response,
                                                         user) {
     if (!request.hasHeader("x-if-modified-since")) {
       return false;
     }
     let requestModified = request.getHeader("x-if-modified-since");
     requestModified = parseInt(requestModified, 10);
     let serverModified = this.newestCollectionTimestamp(user);
     this._log.info("Server mtime: " + serverModified + "; Client modified: " +
                    requestModified);
     if (serverModified > requestModified) {
       return false;
     }
     this.respond(request, response, 304, "Not Modified", null, {
       "X-Last-Modified": "" + serverModified
     });
     return true;
   },
   handleInfoCollections: function handleInfoCollections(request, response,
                                                         user) {
     if (this.handleInfoConditional(request, response, user)) {
       return;
     }
     let info = this.infoCollections(user);
     let body = JSON.stringify(info);
     this.respond(request, response, 200, "OK", body, {
       "Content-Type":    "application/json",
       "X-Last-Modified": "" + this.newestCollectionTimestamp(user),
     });
   },
   handleInfoCounts: function handleInfoCounts(request, response, user) {
     if (this.handleInfoConditional(request, response, user)) {
       return;
     }
     let counts = this.infoCounts(user);
     let body = JSON.stringify(counts);
     this.respond(request, response, 200, "OK", body, {
       "Content-Type":    "application/json",
       "X-Last-Modified": "" + this.newestCollectionTimestamp(user),
     });
   },
   handleInfoUsage: function handleInfoUsage(request, response, user) {
     if (this.handleInfoConditional(request, response, user)) {
       return;
     }
     let body = JSON.stringify(this.infoUsage(user));
     this.respond(request, response, 200, "OK", body, {
       "Content-Type":    "application/json",
       "X-Last-Modified": "" + this.newestCollectionTimestamp(user),
     });
   },
   handleInfoQuota: function handleInfoQuota(request, response, user) {
     if (this.handleInfoConditional(request, response, user)) {
       return;
     }
     let body = JSON.stringify(this.infoQuota(user));
     this.respond(request, response, 200, "OK", body, {
       "Content-Type":    "application/json",
       "X-Last-Modified": "" + this.newestCollectionTimestamp(user),
     });
   },
 };
 /**
  * Helper to create a storage server for a set of users.
  *
  * Each user is specified by a map of username to password.
  */
 this.storageServerForUsers =
  function storageServerForUsers(users, contents, callback) {
   let server = new StorageServer(callback);
   for (let [user, pass] in Iterator(users)) {
     server.registerUser(user, pass);
     server.createContents(user, contents);
   }
   server.start();
   return server;
 }