add response time procesing header

CHANGES_NEXT_RELEASE

@@ -1 +1 @@
-
+- Add: X-Processing-Time response header with processing time (in milliseconds) expended by current HTTP measure (iotagent-node-lib#1650)

docs/usermanual.md

@@ -118,39 +118,42 @@ It is possible to report as a measure a NGSI-v2 or NGSI-LD payload when related
 `payloadType` `ngsiv2` or `ngsild`. In these cases payload is ingested as measure where entity attributes are measure
 attributes.
 
-Note that the entity ID and type in the measure are also include as attributes `measure_id` and `measure_type` as described 
-[here](https://github.dev/telefonicaid/iotagent-node-lib/doc/api.md#special-measures-and-attributes-names) (both using 
-attribute type `Text`). The ID and type of the entity updated at Context Broker is taken from device/group configuration or provision,
+Note that the entity ID and type in the measure are also include as attributes `measure_id` and `measure_type` as
+described [here](https://github.dev/telefonicaid/iotagent-node-lib/doc/api.md#special-measures-and-attributes-names)
+(both using attribute type `Text`). The ID and type of the entity updated at Context Broker is taken from device/group
+configuration or provision,
 
-However, it is possible to use the same entity ID that the original one by using `entityNameExp` 
-at [device group provision](https://github.com/telefonicaid/iotagent-node-lib/blob/master/doc/api.md#config-group-datamodel), this way:
+However, it is possible to use the same entity ID that the original one by using `entityNameExp` at
+[device group provision](https://github.com/telefonicaid/iotagent-node-lib/blob/master/doc/api.md#config-group-datamodel),
+this way:
 
 ```
 "entityNameExp": "measure_id"
 ```
 
-The `actionType` used in the update sent to Context Broker is taken from the measure in the case that measure corresponds to
-a NGSI-v2 batch update. In other cases (i.e. NGSI-LD or NGSI-v2 non-batch update), the `actionType` is the default one (`append`).
+The `actionType` used in the update sent to Context Broker is taken from the measure in the case that measure
+corresponds to a NGSI-v2 batch update. In other cases (i.e. NGSI-LD or NGSI-v2 non-batch update), the `actionType` is
+the default one (`append`).
 
 For instance, given an incoming **measure** as the follwing one:
 
 ```json
 {
     "id": "MyEntityId1",
     "type": "MyEntityType1",
-    "attr1": { "type": "Text", "value": "MyAttr1Value"}
+    "attr1": { "type": "Text", "value": "MyAttr1Value" }
 }
 ```
 
 It would persist an entity into the Context Broker like the following one:
 
 ```json
 {
-    "id":"MyProvisionID",
-    "type":"MyProvisionType",
-    "attr1": { "type": "Text", "value": "MyAttr1Value"},
-    "measure_id": {"type": "Text","value": "MyEntityId1"},
-    "measure_type":{"type": "Text","value": "MyEntityType1"}
+    "id": "MyProvisionID",
+    "type": "MyProvisionType",
+    "attr1": { "type": "Text", "value": "MyAttr1Value" },
+    "measure_id": { "type": "Text", "value": "MyEntityId1" },
+    "measure_type": { "type": "Text", "value": "MyEntityType1" }
 }
 ```
 
@@ -521,6 +524,14 @@ Content-type: application/json
 }
 ```
 
+#### Time processing
+
+HTTP bindig is returning in a HTTP header named `X-Processing-Time` processing time (in milliseconds) expended by current HTTP measure
+request. For example
+```
+X-Processing-Time: 38 
+```
+
 ### MQTT binding
 
 MQTT binding is based on the existence of a MQTT broker and the usage of different topics to separate the different

lib/bindings/HTTPBinding.js

@@ -454,6 +454,7 @@ function sendConfigurationToDevice(apiKey, group, deviceId, results, callback) {
 
 function handleConfigurationRequest(req, res, next) {
     function replyToDevice(error) {
+        res.set(constants.X_PROCESSING_TIME, Date.now() - req.startTime);
         if (error) {
             res.status(error.code).json(error);
         } else {
@@ -476,6 +477,11 @@ function handleConfigurationRequest(req, res, next) {
     });
 }
 
+function reqTiming(req, res, next) {
+    req.startTime = Date.now();
+    next();
+}
+
 function handleError(error, req, res, next) {
     let code = 500;
 
@@ -484,7 +490,7 @@ function handleError(error, req, res, next) {
     if (error.code && String(error.code).match(/^[2345]\d\d$/)) {
         code = error.code;
     }
-
+    res.set(constants.X_PROCESSING_TIME, Date.now() - req.startTime);
     res.status(code).json({
         name: error.name,
         message: error.message
@@ -623,6 +629,7 @@ function returnCommands(req, res, next) {
     }
     if (req.query && req.query.getCmd === '1') {
         iotAgentLib.commandQueue(req.device.service, req.device.subservice, req.deviceId, function (error, list) {
+            res.set(constants.X_PROCESSING_TIME, Date.now() - req.startTime);
             if (error || !list || list.count === 0) {
                 if (req.accepts('json')) {
                     res.status(200).send({});
@@ -639,8 +646,10 @@ function returnCommands(req, res, next) {
             }
         });
     } else if (req.accepts('json')) {
+        res.set(constants.X_PROCESSING_TIME, Date.now() - req.startTime);
         res.status(200).send({});
     } else {
+        res.set(constants.X_PROCESSING_TIME, Date.now() - req.startTime);
         res.status(200).send('');
     }
 }
@@ -664,6 +673,7 @@ function start(callback) {
 
     httpBindingServer.app.set('port', config.getConfig().http.port);
     httpBindingServer.app.set('host', config.getConfig().http.host || '0.0.0.0');
+    httpBindingServer.app.use(reqTiming);
 
     httpBindingServer.router.get(
         config.getConfig().iota.defaultResource || constants.HTTP_MEASURE_PATH,

lib/constants.js

@@ -58,5 +58,7 @@ module.exports = {
     AMQP_DEFAULT_QUEUE: 'iotaqueue',
     AMQP_DEFAULT_DURABLE: true,
     AMQP_DEFAULT_RETRIES: 5,
-    AMQP_DEFAULT_RETRY_TIME: 5
+    AMQP_DEFAULT_RETRY_TIME: 5,
+
+    X_PROCESSING_TIME: 'X-Processing-Time'
 };