Thread: Vehicle Maintenence Plugin

Originally Posted by Sonicxtacy02

one thing i did have to do is scale the mile reading back to once ever 2 seconds because my timer that handles the calculation took more than a second the calculate and save to file.

What I like to do in this situation is queue the actual write to the file in a separate thread, so that the updates to the UI are pretty fast. Then on the background thread do bulk-writes to the file instead of one at a time. File access is much slower than in-memory access, but once you have a handle open for a file, you should be able to write lots of data to it quickly.

Not sure what you're programming this in though.

Great job, and good luck!

I'm writing in vb.net.. and i'm a noob (still) dont know much about multi-threading. Spose now's a good time to read up lol.

Originally Posted by Sonicxtacy02

I'm writing in vb.net.. and i'm a noob (still) dont know much about multi-threading. Spose now's a good time to read up lol.

I'd help ya out, but I'm a C# developer, so the syntax issues will cause issues.
But basically I create a separate class to handle writes to the file. If you're using .NET 2.0 or higher, use a generic Queue to Enqueue the item you want to write to the file system. Have a private method in your class that does a loop over the queue, dequeing each item and write it to the file system.

Your class should have one System.Threading.Thread members in it, and have it point to the method with the write loop.
Then just call the Start Abort method on your thread to start your looping method.

Here's a really quick and dirty example written in C#, that has not been tested. But you should be able to get the idea.
But yes, do some reading.

Code:

public class QueuedWriter:IDisposable
    {
        StreamWriter writer; // writer use to actually write to the file
        Thread workerThread; // background thread used to perform the writes to the file
        Queue<string> itemsToWrite = new Queue<string>(); // queue of items that will be written to the file
        public QueuedWriter(string fileName)
        {
            writer = new StreamWriter(fileName);
            workerThread = new Thread(mainLoop); // notice, we're specifying the mainLoop method in the constructor of the Thread
            workerThread.Priority = ThreadPriority.BelowNormal;
            workerThread.Start();
        }

        public void WriteItem(string item)
        {
            itemsToWrite.Enqueue(item);
        }

        private void mainLoop()
        {
            bool abort = false;
            while (!abort)
            {
                try
                {
                    /// Write everything that has been queued
                    while (itemsToWrite.Count > 0)
                    {
                        writer.WriteLine(itemsToWrite.Dequeue());
                    }
                    //Nothing to write, sleep a while
                    Thread.Sleep(1000);
                    writer.Flush();
                }
                catch (ThreadAbortException)
                {
                    abort = true;
                }
            }
        }

        #region IDisposable Members

        public void Dispose()
        {
            if (workerThread != null)
            {
                workerThread.Abort();
            }
            workerThread = null;
            if (writer != null)
            {
                writer.Flush();
                writer.Close();
                writer.Dispose();
            }
        }

        #endregion
    }

i've got a c# to vb.net converter.. so that will help. Thanks!

Originally Posted by Sonicxtacy02

... one thing i did have to do is scale the mile reading back to once ever 2 seconds because my timer that handles the calculation took more than a second the calculate and save to file.

Maybe scale it back to 5 seconds for those of us with slow CPUs.

This is looking good Sonic! One thing I would consider is to input the odometer reading when the plugin is installed and setup, and have that updated on the screen as well. This way you have a real world comparison to see how accurate it is keeping track of the millage. Also making the value clickable, and correcting / syncing it with the actual odometer would be a major plus.

For a quick trip to the store, many of us do not have the computer come on, but would like to keep the "system odometer" in sync with those lost tracked miles ect. Also the "floating" of the lat and lon can add up pretty fast. Back when I was trying to get Festy's gas mileage thing to work, I noticed this. With the USB GPS puck here on the desk, I left it running for a day when I left in the middle of working on it and noticed that I had traveled a few miles hahah.

As far as frequency of updates, personally I think once ever minute, 5 minutes or so is more than enough. Oil changes are the most frequent thing to change for example, & I doubt having to know within 2 seconds that's its time for an oil change is really going to matter that much

This would decrease the overall CPU usage, as well as not constantly thrashing / writing to the hard drive every 2 seconds.

As for the cost per mile for items, that should be fairly simple to do. In your example its $17.50 for an oil change that is done every 3,000 miles:

$17.50 divided by 3000 = .006 cents per mile.

I also completely agree, and would love to see a fuel log wrapped into this! Fill er' up, enter the number of gallons, price per gallon and the odometer reading. At the next fill up do the same, and you can then have it calculate many miles per gallon you are getting.

subcribe::

Originally Posted by GizmoQ

Maybe scale it back to 5 seconds for those of us with slow CPUs.

I'll have it user settable... IF the threading idea falls through for whatever reason. If i can have the file IO done separate from the actual distance calculation it should work out great. Only problem would be if RR is closed between writes. RR really needs a way to let plugins know its terminating.

Originally Posted by JohnWPB

This is looking good Sonic! One thing I would consider is to input the odometer reading when the plugin is installed and setup, and have that updated on the screen as well. This way you have a real world comparison to see how accurate it is keeping track of the millage. Also making the value clickable, and correcting / syncing it with the actual odometer would be a major plus.

Can do

For a quick trip to the store, many of us do not have the computer come on, but would like to keep the "system odometer" in sync with those lost tracked miles ect. Also the "floating" of the lat and lon can add up pretty fast. Back when I was trying to get Festy's gas mileage thing to work, I noticed this. With the USB GPS puck here on the desk, I left it running for a day when I left in the middle of working on it and noticed that I had traveled a few miles hahah.

I've got a kick out for floating coordinates that monitors the heading value. This should work really well... unless you guys are out doing high speed donuts lol.

As far as frequency of updates, personally I think once ever minute, 5 minutes or so is more than enough. Oil changes are the most frequent thing to change for example, & I doubt having to know within 2 seconds that's its time for an oil change is really going to matter that much

This would decrease the overall CPU usage, as well as not constantly thrashing / writing to the hard drive every 2 seconds.

when i say the timer runs too fast at once per second only real issue is getting the lat and lon from RR before the CalculateDistance function is run. If RR hasnt reported back to the plugin before the function runs the result of the function is Nan and it crashes the system. I can probably easily write prevention for this.. but for now once every 2 seconds has been absolutely no issue on my 1.2ghz celeron i'm developing on.

As for the cost per mile for items, that should be fairly simple to do. In your example its $17.50 for an oil change that is done every 3,000 miles:

$17.50 divided by 3000 = .006 cents per mile.

I will definitely add it in some capacity as it is pretty easy to do. i was thinking more along the lines of having to calculate each time the oil change is done.

I also completely agree, and would love to see a fuel log wrapped into this! Fill er' up, enter the number of gallons, price per gallon and the odometer reading. At the next fill up do the same, and you can then have it calculate many miles per gallon you are getting.

Will also incorporate this.

One more thing i incorporated before leavin work on friday is a slider that gives you yet another visual indication of how close you are to exceeding your maintenance limit.

I've been plugging away at this for the last few days and i have more progress. I've completed the setup and adding maintenance screens... and also optimized the calculatedistance function a little bit so that a Nan return isnt possible. I've also incorporated a concept similar to what eigenVector suggested to keep I/O overhead down.

Next step is to work on the fueling information. Then adding a cost calculator.