/** * Copyright 2017 Bart Butenaers * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. **/ module.exports = function(RED) { "use strict"; var CircularBuffer = require("circular-buffer"); var Math = require("mathjs"); function speed(config) { RED.nodes.createNode(this, config); this.estimationStartup = config.estimation || false; this.ignoreStartup = config.ignore || false; // The buffer size depends on the frequency switch(config.frequency) { case 'sec': this.bufferSize = 1; break; case 'min': this.bufferSize = 60; break; case 'hour': this.bufferSize = 60 * 60; break; default: this.bufferSize = 1; // Default 'sec' } this.circularBuffer = new CircularBuffer(this.bufferSize); this.frequency = config.frequency || 'sec'; this.msgCount = 0; this.prevEstimated = false; this.prevTotalMsgCount = 0; this.totalMsgCount = 0; this.startTime = null; // When the first (unprocessed) message has arrived this.endTime = null; // When the last (unprocessed) message has arrived this.timer = null; var analyse = function() { if (node.startTime == null) { node.startTime = new Date().getTime(); } // Register the time when the last message has arrived (or when the last timer was called, when no message has arrived) node.endTime = new Date().getTime(); // Calculate the time interval (in seconds) since the first (unprocessed) message has arrived var seconds = (node.endTime - node.startTime) / 1000; var remainder = (seconds - Math.floor(seconds)) * 1000; seconds = Math.floor(seconds); // Correct the end time with the remainder, since the time interval since the last message (until now) is skipped in the current calculation. // Otherwise timeslices will get behind, and the curve would have some overshoot (at startup) period before reaching the final speed. node.endTime -= remainder; //console.log(seconds + " seconds between " + new Date(node.startTime).toISOString().slice(11, 23) + " and " + new Date(node.endTime).toISOString().slice(11, 23)); // Store the message count (of the previous second) in the circular buffer. However the timer can be // delayed, so make sure this is done for EVERY second since the last time we got here ... // 10 images/2,5 seconds = 240 images/second for(var i = 0; i < seconds; i++) { var original = node.totalMsgCount; // In the first second we store (the count of) all received messages, except the last one (that has been received in the next second). // In the next second we store that remaining (single) last message. In all later seconds (of this loop) we will store 0. var added = (i == 0) ? Math.max(0, node.msgCount - 1) : Math.max(0, node.msgCount); // Check the content of the tail buffer cell (before it is being removed by inserting a new cell at the head), if available already var removed = (node.circularBuffer.size() >= node.bufferSize) ? node.circularBuffer.get(node.bufferSize-1) : 0; // The total msg count is the sum of all message counts in the circular buffer. Instead of summing all those // buffer cells continiously (over and over again), we will update the sum together with the buffer content. // Sum = previous sum + message count of last second (which is going to be added to the buffer) // - message count of the first second (which is going to be removed from the buffer). node.totalMsgCount = original + added - removed; //console.log(node.totalMsgCount + " = " + original + " + " + added + " - " + removed); // Store the new count in the circular buffer (which will also trigger deletion of the oldest cell at the buffer trail) node.circularBuffer.enq(added); // When startup period exceeded, or startup period should not be ignored ... if (node.ignoreStartup == false || node.circularBuffer.size() == node.circularBuffer.capacity()) { var totalMsgCount = node.totalMsgCount; var estimated = false; // Do a linear interpolation if required (only relevant in the startup period) if (node.estimationStartup == true && node.circularBuffer.size() < node.circularBuffer.capacity()) { if (node.circularBuffer.size() > 0) { totalMsgCount = Math.floor(totalMsgCount * node.circularBuffer.capacity() / node.circularBuffer.size()); } estimated = true; } // Update the status in the editor with the last message count (only if it has changed), or when switching between estimated and real if (node.prevTotalMsgCount != node.totalMsgCount || node.prevEstimated != estimated) { // Show estimations in orange, and real values in green if (estimated == true) { node.status({fill:"yellow",shape:"ring",text:" " + totalMsgCount + "/" + node.frequency }); } else { node.status({fill:"green",shape:"dot",text:" " + totalMsgCount + "/" + node.frequency }); } node.prevTotalMsgCount = totalMsgCount; } // Send a message on the output port node.send({ payload: totalMsgCount, frequency: node.frequency }); node.prevEstimated = estimated; } // The message count that has already been added, shouldn't be added again the next second node.msgCount = Math.max(0, node.msgCount - added); } if (seconds > 0) { // Our new second starts at the end of the previous second node.startTime = node.endTime; } } var node = this; // Initially display a 0 count (except when startup period should be ignored) if (node.ignoreStartup == false) { node.status({fill:"green",shape:"dot",text:" " + node.msgCount + "/" + node.frequency }); } this.on("input", function(msg) { if (node.timer) { // An msg has arrived during the specified (timeout) interval, so remove the (timeout) timer. clearInterval(node.timer); } node.msgCount += 1; //console.log("New msg arrived resulting in a message count of " + node.msgCount ); analyse(); // Register a new timer (with a timeout interval of 1 second), in case no msg should arrive during the next second. node.timer = setInterval(function() { //console.log("Timer called. node.msgCount = " + node.msgCount ); // Seems no msg has arrived during the last second, so register a zero count analyse(); }, 1000); }); this.on("close",function() { if (node.timer) { // Stop the previous timer, to avoid having multiple timers running in parallel after a redeploy. clearInterval(node.timer); } node.status({}); }); } RED.nodes.registerType("msg-speed", speed); };