Refactor to use domains to hold all request information

ngsi_adapter/src/.gjslintrc

@@ -5,5 +5,5 @@
 --nomultiprocess
 --debug_indentation
 --time
---disable=110,212,217
+--disable=1,110,212,217
 --custom_jsdoc_tags=module,function,callback,abstract,constant,augments,memberof,returns

ngsi_adapter/src/lib/adapter.js

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 Telefónica I+D
+ * Copyright 2013-2015 Telefónica I+D
  * All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -19,7 +19,7 @@
 /**
  * Module that implements a HTTP asynchronous server processing requests for
  * adaptation from raw monitoring data into NGSI format, then using the results
- * to invoke Context Broker.
+ * to invoke ContextBroker.
  *
  * @module adapter
  */
@@ -40,46 +40,46 @@ var http = require('http'),
 
 
 /**
- * Asynchronously process POST requests and then invoke updateContext() on ContextBroker.
+ * Asynchronously process incoming requests and then invoke updateContext() on ContextBroker.
  *
- * @param {http.IncomingMessage} request    The request to this server.
- * @param {RequestCallback}      callback   The callback that handles the response.
+ * @param {Domain}          reqdomain  Domain handling request (includes context, timestamp, id, type, body & parser).
+ * @param {RequestCallback} callback   The callback for responses from ContextBroker.
  */
-function doPost(request, callback) {
+function updateContext(reqdomain, callback) {
     try {
-        domain.active.context.op = 'Parse';
-        logger.debug('Probe data "%s"', request.body);
-        var remoteUrl = url.parse(opts.brokerUrl);
-        var dataParser = request.parser;
-        var updateReqType = dataParser.getContentType();
-        var updateReqBody = dataParser.updateContextRequest(request);
-        var updateReqOpts = {
-            hostname: remoteUrl.hostname,
-            port: remoteUrl.port,
-            path: '/NGSI10/updateContext',
-            method: 'POST',
-            headers: {
-               'Accept': updateReqType,
-               'Content-Type': updateReqType,
-               'Content-Length': updateReqBody.length
-            }
-        };
-        updateReqOpts.headers[common.txIdHttpHeader] = domain.active.context.trans;
+        reqdomain.context.op = 'Parse';
+        logger.debug('Probe data "%s"', reqdomain.body);
+        var parser = reqdomain.parser,
+            remoteUrl = url.parse(opts.brokerUrl),
+            updateReqType = parser.getContentType(),
+            updateReqBody = parser.updateContextRequest(reqdomain),
+            updateReqOpts = {
+                hostname: remoteUrl.hostname,
+                port: remoteUrl.port,
+                path: '/NGSI10/updateContext',
+                method: 'POST',
+                headers: {
+                   'Accept': updateReqType,
+                   'Content-Type': updateReqType,
+                   'Content-Length': updateReqBody.length
+                }
+            };
+        updateReqOpts.headers[common.txIdHttpHeader] = reqdomain.context.trans;
         /* jshint unused: false */
         var operation = retry.operation({ retries: opts.retries });
         operation.attempt(function(currentAttempt) {
-            domain.active.context.op = 'UpdateContext';
+            reqdomain.context.op = 'UpdateContext';
             logger.info('Request to ContextBroker at %s...', opts.brokerUrl);
-            logger.debug('%s', { toString: function() {
-                return updateReqBody.split('\n').map(function(line) {return line.trim();}).join('');
+            logger.debug('%s', { toString: function () {
+                return updateReqBody.split('\n').map(function (line) {return line.trim();}).join('');
             }});
-            var updateReq = http.request(updateReqOpts, function(response) {
+            var updateReq = http.request(updateReqOpts, function (response) {
                 var responseBody = '';
                 response.setEncoding('utf8');
                 response.on('data', function(chunk) {
                     responseBody += chunk;
                 });
-                response.on('end', function() {
+                response.on('end', function () {
                     callback(null, response.statusCode, responseBody);
                 });
             });
@@ -102,70 +102,74 @@ function doPost(request, callback) {
  * Callback for requests to updateContext().
  *
  * @callback RequestCallback
- * @param {Error}   err                     The error ocurred in request, or null.
- * @param {Number} [responseStatus]         The response status code.
- * @param {String} [responseBody]           The response body contents.
+ * @param {Error}   err                The error occurred in request, or null.
+ * @param {Number} [responseStatus]    The response status code.
+ * @param {String} [responseBody]      The response body contents.
  */
-function callback(err, responseStatus, responseBody) {
+function updateContextCallback(err, responseStatus, responseBody) {
     if (err) {
         logger.error(err.message);
     } else {
         logger.info('Response status %d %s', responseStatus, http.STATUS_CODES[responseStatus]);
-        logger.debug('%s', { toString: function() {
-            return responseBody.split('\n').map(function(line) {return line.trim();}).join('');
-        }});
+        logger.debug('%s', {
+            toString: function () {
+                return responseBody.split('\n').map(function (line) {
+                    return line.trim();
+                }).join('');
+            }
+        });
     }
 }
 
 
 /**
- * Server requests listener.
+ * HTTP requests listener.
  *
  * Request URL looks like `http://host:port/path?query`:
  *
  * - Request query string MUST include arguments `id` and `type`
  * - Request path will denote the name of the originating probe
  * - Request headers may include a transaction identifier ({@link common#txIdHttpHeader})
  *
- * @param {http.IncomingMessage} request    The request to this server.
- * @param {http.ServerResponse}  response   The response from this server.
+ * @param {http.IncomingMessage} request    The HTTP request to this server.
+ * @param {http.ServerResponse}  response   The HTTP response from this server.
  */
 function asyncRequestListener(request, response) {
-    var reqd = domain.create();
-    reqd.add(request);
-    reqd.add(response);
-    reqd.context = {
+    var reqdomain = domain.create();
+    reqdomain.add(request);
+    reqdomain.add(response);
+    reqdomain.context = {
         trans: request.headers[common.txIdHttpHeader.toLowerCase()] || cuid(),
         op: request.method
     };
-    reqd.on('error', function(err) {
+    reqdomain.on('error', function (err) {
         logger.error(err.message);
         response.writeHead(500);  // server error
         response.end();
     });
-    reqd.run(function() {
+    reqdomain.run(function () {
         logger.info('Request on resource %s', request.url.split('?').join(' with params '));
         var status = 405;  // not allowed
         if (request.method === 'POST') {
             var query = url.parse(request.url, true).query;
-            var entityId = query.id;
-            var entityType = query.type;
+            reqdomain.entityId = query.id;
+            reqdomain.entityType = query.type;
             try {
                 status = 400;  // bad request
-                if (!entityId || !entityType) {
+                if (!reqdomain.entityId || !reqdomain.entityType) {
                     throw new Error('Missing entityId and/or entityType');
                 }
                 status = 404;  // not found
-                request.parser = parser.getParser(request);
+                reqdomain.parser = parser.getParser(request);
                 status = 200;  // ok
-                request.timestamp = Date.now();
-                request.body = '';
-                request.on('data', function(chunk) {
-                    request.body += chunk;
+                reqdomain.timestamp = Date.now();
+                reqdomain.body = '';
+                request.on('data', function (chunk) {
+                    reqdomain.body += chunk;
                 });
-                request.on('end', function() {
-                    process.nextTick(function() {
-                        doPost(request, exports.requestCallback);
+                request.on('end', function () {
+                    process.nextTick(function () {
+                        updateContext(reqdomain, exports.updateContextCallback);
                     });
                 });
             } catch (err) {
@@ -183,20 +187,20 @@ function asyncRequestListener(request, response) {
  * Server main.
  */
 function main() {
-    process.on('uncaughtException', function(err) {
+    process.on('uncaughtException', function (err) {
         logger.error({op: 'Exit'}, err.message);
         process.exit(1);
     });
-    process.on('exit', function() {
+    process.on('exit', function () {
         logger.info({op: 'Exit'}, 'Server stopped');
     });
-    process.on('SIGINT', function() {
+    process.on('SIGINT', function () {
         process.exit();
     });
-    process.on('SIGTERM', function() {
+    process.on('SIGTERM', function () {
         process.exit();
     });
-    http.createServer(asyncRequestListener).listen(opts.listenPort, opts.listenHost, function() {
+    http.createServer(asyncRequestListener).listen(opts.listenPort, opts.listenHost, function () {
         logger.info({op: 'Init'}, 'Server listening at http://%s:%d/', this.address().address, this.address().port);
     });
 }
@@ -206,7 +210,7 @@ function main() {
 exports.main = main;
 
 /** @export */
-exports.requestCallback = callback;
+exports.updateContextCallback = updateContextCallback;
 
 
 if (require.main === module) {

ngsi_adapter/src/lib/parsers/common/base.js

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 Telefónica I+D
+ * Copyright 2013-2015 Telefónica I+D
  * All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -52,31 +52,33 @@ baseParser.timestampAttrName = '_timestamp';
  * @memberof baseParser
  * @returns {String} The content type (the format) for Context Broker requests.
  */
-baseParser.getContentType = function() {
+baseParser.getContentType = function () {
     return 'application/xml';
 };
 
 
 /**
- * Gets the updateContext() request body.
+ * Returns the updateContext() request body.
  *
  * @function updateContextRequest
  * @memberof baseParser
  * @this baseParser
- * @param {http.IncomingMessage} request    The HTTP request to this server.
+ * @param {Domain} reqdomain   Domain handling current request (includes context, timestamp, id, type, body & parser).
  * @returns {String} The request body, either in XML or JSON format.
  */
-baseParser.updateContextRequest = function(request) {
-    var query = url.parse(request.url, true).query;
-    var entityId = query.id;
-    var entityType = query.type;
-    var entityData = this.parseRequest(request);
-    var entityAttrs = this.getContextAttrs(entityData);
+baseParser.updateContextRequest = function (reqdomain) {
+    var entityId = reqdomain.entityId,
+        entityType = reqdomain.entityType,
+        entityData = this.parseRequest(reqdomain.body),
+        entityAttrs = this.getContextAttrs(entityData);
+
     if (Object.keys(entityAttrs).length === 0) {
         throw new Error('Missing entity context attributes');
     }
+
     // feature #4: automatically add request timestamp to entity attributes
-    entityAttrs[this.timestampAttrName] = request.timestamp;
+    entityAttrs[this.timestampAttrName] = reqdomain.timestamp;
+
     return (this.getContentType() === 'application/xml') ?
         this.getUpdateContextXML(entityId, entityType, entityAttrs) :
         this.getUpdateContextJSON(entityId, entityType, entityAttrs);
@@ -89,10 +91,10 @@ baseParser.updateContextRequest = function(request) {
  * @abstract
  * @function parseRequest
  * @memberof baseParser
- * @param {http.IncomingMessage} request    The HTTP request to this server.
- * @returns {EntityData} An object holding entity data taken from request body.
+ * @param {String} requestMsg  The data message included in request being processed.
+ * @returns {EntityData} An object holding entity data taken from request message.
  */
-baseParser.parseRequest = function(request) {
+baseParser.parseRequest = function (requestMsg) {
     throw new Error('Must implement');
 };
 
@@ -103,10 +105,10 @@ baseParser.parseRequest = function(request) {
  * @abstract
  * @function getContextAttrs
  * @memberof baseParser
- * @param {EntityData} data                 Object holding raw entity data.
+ * @param {EntityData} data    Object holding raw entity data.
  * @returns {Object} Context attributes.
  */
-baseParser.getContextAttrs = function(data) {
+baseParser.getContextAttrs = function (data) {
     throw new Error('Must implement');
 };
 
@@ -116,12 +118,12 @@ baseParser.getContextAttrs = function(data) {
  *
  * @function getUpdateContextJSON
  * @memberof baseParser
- * @param {String} id                       The entity identifier.
- * @param {String} type                     The entity type.
- * @param {Object} attrs                    The entity context attributes.
+ * @param {String} id          The entity identifier.
+ * @param {String} type        The entity type.
+ * @param {Object} attrs       The entity context attributes.
  * @returns {String} The request body in JSON format.
  */
-baseParser.getUpdateContextJSON = function(id, type, attrs) {
+baseParser.getUpdateContextJSON = function (id, type, attrs) {
     throw new Error('TO-DO');
 };
 
@@ -131,12 +133,12 @@ baseParser.getUpdateContextJSON = function(id, type, attrs) {
  *
  * @function getUpdateContextXML
  * @memberof baseParser
- * @param {String} id                       The entity identifier.
- * @param {String} type                     The entity type.
- * @param {Object} attrs                    The entity context attributes.
+ * @param {String} id          The entity identifier.
+ * @param {String} type        The entity type.
+ * @param {Object} attrs       The entity context attributes.
  * @returns {String} The request body in XML format.
  */
-baseParser.getUpdateContextXML = function(id, type, attrs) {
+baseParser.getUpdateContextXML = function (id, type, attrs) {
     var result = '';
     result += '<?xml version="1.0" encoding="UTF-8"?>\n';
     result += '<updateContextRequest>\n';

ngsi_adapter/src/lib/parsers/common/factory.js

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013 Telefónica I+D
+ * Copyright 2013-2015 Telefónica I+D
  * All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -31,23 +31,37 @@ var url = require('url'),
     path = require('path');
 
 
+/**
+ * Parser factory: returns a dynamically loaded parser object at `lib/parsers/{name}`.
+ *
+ * @param {String} name  The name of the parser.
+ * @returns {Object} The parser been loaded according to given name.
+ */
+function getParserByName(name) {
+    var moduleName = util.format('../%s', name);
+    try {
+        return require(moduleName).parser;
+    } catch (err) {
+        var modulePath = path.normalize(__dirname + path.sep + moduleName + '.js');
+        throw new Error(util.format('Parser from module "%s" could not be loaded', modulePath));
+    }
+}
+
+
 /**
  * Parser factory: given a request URL `http://host:port/path?query`, takes `path` as
  * the name of the probe whose data (request body) will be parsed. Tries to dynamically
- * load a parser object from module at `lib/parsers/` directory named after the probe.
+ * load a parser object from module named after the probe.
  *
- * @param {http.IncomingMessage} request    The request to this server.
+ * @param {http.IncomingMessage} request  The request to this server.
  * @returns {Object} The parser been loaded according to probe mentioned in request.
  */
 function getParser(request) {
-    var probeName = url.parse(request.url).pathname.slice(1),
-        moduleName = util.format('../%s', probeName);
+    var name = url.parse(request.url).pathname.slice(1);
     try {
-        return require(moduleName).parser;
+        return getParserByName(name);
     } catch (err) {
-        var modulePath = path.normalize(__dirname + path.sep + moduleName + '.js');
-        throw new Error((!probeName) ? 'Missing resource in request' :
-            util.format('Unknown probe "%s" (no parser module "%s" loaded)', probeName, modulePath));
+        throw new Error((!name) ? 'Missing resource in request' : util.format('Unknown probe "%s" (%s)', name, err));
     }
 }