/*
* Static Methods
*/
public static TME_CVData_Input GenerateCvDataFromBsmMessage(BsmMessage bsm)
{
TME_CVData_Input results = new TME_CVData_Input();
byte[] rawBsm;
try
{
//Converted payload to raw bsm byte[] (ASN.1)
rawBsm = Enumerable.Range(0, bsm.payload.Length)
.Where(i => i % 2 == 0)
.Select(i => Convert.ToByte(bsm.payload.Substring(i, 2), 16))
.ToArray();
}
catch (Exception e)
{
throw new Exception(string.Format("Unable to parse bsm.payload to byte[]: {0}", bsm.payload), e);
}
ExtractedBSM rExtractedBsm = new ExtractedBSM();
//Try to extract the BSM from the raw ASN.1 byte[]
if (!rExtractedBsm.loadFromASN(rawBsm))
{
throw new Exception(string.Format("Error deserializing BSM from ASN.1: {0}",
string.Concat(Array.ConvertAll(rawBsm, b => b.ToString("X2")))));
}
results.NomadicDeviceID = rExtractedBsm.getNomadicId();
results.DateGenerated = DateTime.Parse(bsm.time);
results.Speed = (short)rExtractedBsm.getSpeed() * 2.236936292054402;
results.Heading = (short)rExtractedBsm.getHeading();
results.Latitude = rExtractedBsm.getLatitude();
results.Longitude = rExtractedBsm.getLongitude();
results.MMLocation = rExtractedBsm.getMileMarker();
results.CVQueuedState = rExtractedBsm.getQueuedState();
results.CoefficientOfFriction = rExtractedBsm.getCoefOfFriction();
results.Temperature = (short)rExtractedBsm.getAirTemp();
results.RoadwayId = rExtractedBsm.getRoadwayId();
results.LateralAcceleration = rExtractedBsm.getLatAccel();
results.LongitudinalAcceleration = rExtractedBsm.getLongAccel();
return(results);
}
public override void Run()
{
Trace.TraceInformation("[TRACE] Entering BsmWorkerRole::Run()...");
if (srBsmQueue == null)
{
Trace.TraceError("ERROR: Unable to run BsmWorkerRole-- Inbound BSM queue does not exist");
Trace.TraceInformation("[TRACE] Exiting BsmWorkerRole::Run()...");
return;
}
const int minPollWaitPeriod_ms = 10;
const int maxPollWaitPeriod_ms = 1000;
const int maxQueueMessagePollCount = 32; //32 is the MAX allowed
const int messageLeaseTime = 30;
int currPollWaitPeriod_ms = maxPollWaitPeriod_ms;
while (true)
{
var rMessages = srBsmQueue.GetMessages(maxQueueMessagePollCount, new TimeSpan(0, 0, 0, messageLeaseTime * maxQueueMessagePollCount));
if (rMessages.Count() > 0)
{
List <TME_CVData_Input> rCvDataEntriesToAdd = new List <TME_CVData_Input>();
if (currPollWaitPeriod_ms > minPollWaitPeriod_ms)
{
// Get the queue message count
srBsmQueue.FetchAttributes();
int?messageCount = srBsmQueue.ApproximateMessageCount;
Trace.WriteLine(String.Format("Processing {0} new queue messages...",
messageCount));
}
BsmTimeTableLogger.StartNewLogEntry(srBsmQueue, rMessages);
foreach (var rMessage in rMessages)
{
string strMessageJSON = rMessage.AsString;
try
{
/*
* Extract raw bsm data from queue message
*/
BsmBundle rBsmBundle = Newtonsoft.Json.JsonConvert.DeserializeObject <BsmBundle>(strMessageJSON);
foreach (var bsm in rBsmBundle.payload)
{
TME_CVData_Input rCvData = null;
try
{
DateTimeOffset extractStartTime = DateTimeOffset.Now;
//Validate conversion and BSM inside 'GenerateFromBsmMessage'. Throw exception with errors.
rCvData = GenerateCvDataFromBsmMessage(bsm);
if ((DateTimeOffset.Now - extractStartTime).TotalSeconds > 0.5)
{
Trace.TraceWarning("Took {0} seconds to extract BSM Data", (DateTimeOffset.Now - extractStartTime).TotalSeconds);
}
}
catch (Exception e)
{
Trace.TraceWarning("Exception occurred when extracting CV Data from BSM Payload\n{0}",
e.Message);
}
//If conversion was good, add to DbSet.
if (rCvData != null)
{
rCvDataEntriesToAdd.Add(rCvData);
}
}
}
catch (Newtonsoft.Json.JsonSerializationException e)
{
Trace.TraceError("Exception when deserializing queue item. Message: '{0}'",
e.Message);
}
finally
{
currPollWaitPeriod_ms = minPollWaitPeriod_ms;
}
}
BsmTimeTableLogger.SetDeserializationComplete();
foreach (var rMessage in rMessages)
{
try
{
srBsmQueue.DeleteMessage(rMessage);
}
catch (Exception e)
{
Trace.TraceError("Exception occurred when deleting message from queue. Did the processing of the BSM take longer then the message's lease time?\n{0}",
e.Message);
}
}
BsmTimeTableLogger.SetQueueDeleteComplete();
//Save changes to DB.
if (rCvDataEntriesToAdd.Count() > 0)
{
foreach (var rCvData in rCvDataEntriesToAdd)
{
try
{
DateTimeOffset dbSetAddStartTime = DateTimeOffset.Now;
/*
* This use to take forever when the dbSet got large.
* This was fixed by adding "base.Configuration.AutoDetectChangesEnabled = false;"
* to the dbContext constructor.
*/
srDbContext.TME_CVData_Input.Add(rCvData);
if ((DateTimeOffset.Now - dbSetAddStartTime).TotalSeconds > 0.5)
{
Trace.TraceWarning("Took {0} seconds to add CvData to DbSet", (DateTimeOffset.Now - dbSetAddStartTime).TotalSeconds);
}
}
catch (Exception e)
{
Trace.TraceError("Exception occurred when adding CV Data to DbSet\n{0}",
e.Message);
}
}
try
{
srDbContext.SaveChanges();
}
catch (Exception e)
{
Trace.TraceError("Exception occurred when saving changes to Db\n{0}", e);
}
rCvDataEntriesToAdd.ForEach(x => srDbContext.Entry <TME_CVData_Input>(x).State = System.Data.Entity.EntityState.Detached);
}
BsmTimeTableLogger.SubmitLogEntry(rCvDataEntriesToAdd.Count());
}
else //if(rMessages.Count() == 0)
{
Trace.WriteLine(String.Format("Waiting {0}ms for new {1} queue items...",
currPollWaitPeriod_ms, srBsmQueueName));
Thread.Sleep(currPollWaitPeriod_ms);
// Gradually scale up the poll wait period until we reach the max (10,20,40,80,160,...1000)
currPollWaitPeriod_ms *= 2;
currPollWaitPeriod_ms = Math.Min(currPollWaitPeriod_ms, maxPollWaitPeriod_ms);
}
}
}
