/// <summary>
/// This method is called whenever the module is sent a message from the EdgeHub.
/// It just pipe the messages without any change.
/// It prints all the incoming messages.
/// </summary>
static async Task <MessageResponse> DecompressMessage(Message message, object userContext)
{
var moduleClient = userContext as ModuleClient;
if (moduleClient == null)
{
throw new InvalidOperationException("UserContext doesn't contain " + "expected values");
}
await moduleClient.CompleteAsync(message);
byte[] messageBytes = message.GetBytes();
if (message.Properties.Contains(new System.Collections.Generic.KeyValuePair <string, string>("compression", "gzip")))
{
Console.WriteLine($"Received compressed message with body size: {messageBytes.Length}");
if (messageBytes.Length > 0)
{
var decompressedMessageData = CompressionClass.Decompress(messageBytes);
var outMessage = new Message(decompressedMessageData);
foreach (var prop in message.Properties)
{
outMessage.Properties.Add(prop.Key, prop.Value);
}
await moduleClient.SendEventAsync("decompressMessageOutput", outMessage);
Console.WriteLine($"Sent decompressed message sent with body size: {decompressedMessageData.Length}");
}
else
{
//If message body is 0 then pass through with no changes
var outMessage = new Message(messageBytes);
foreach (var prop in message.Properties)
{
outMessage.Properties.Add(prop.Key, prop.Value);
}
await moduleClient.SendEventAsync("compressMessageOutput", outMessage);
Console.WriteLine("Message had no body and was passed as-is.");
}
}
else
{
var outMessage = new Message(messageBytes);
foreach (var prop in message.Properties)
{
outMessage.Properties.Add(prop.Key, prop.Value);
}
await moduleClient.SendEventAsync("decompressMessageOutput", outMessage);
Console.WriteLine("Message was not compressed and was passed as-is.");
}
return(MessageResponse.None);
}
/// <summary>
/// This Compress message method is called whenever the module is sent a message from the EdgeHub.
/// It just pipe the messages without any change.
/// It prints all the incoming messages.
/// </summary>
static async Task <MessageResponse> CompressMessage(Message message, object userContext)
{
var moduleClient = userContext as ModuleClient;
if (moduleClient == null)
{
throw new InvalidOperationException("UserContext doesn't contain expected values");
}
await moduleClient.CompleteAsync(message);
byte[] messageBytes = message.GetBytes(); //returns the BodyStream of the message as bytes
Console.WriteLine($"Received message with body size: {messageBytes.Length}");
if (messageBytes.Length > 0)
{
var compressedMessageData = CompressionClass.Compress(messageBytes);
var outMessage = new Message(compressedMessageData);
// copy properties from original message to new message
foreach (var prop in message.Properties)
{
outMessage.Properties.Add(prop.Key, prop.Value);
}
// add a new property indicating the message is compressed with gzip so the backend can handle compressed and non-compressed messages
outMessage.Properties.Add("compression", "gzip");
await moduleClient.SendEventAsync("compressMessageOutput", outMessage);
Console.WriteLine($"Sent compressed message with body size: {compressedMessageData.Length}");
}
else
{
var outMessage = new Message(messageBytes);
foreach (var prop in message.Properties)
{
outMessage.Properties.Add(prop.Key, prop.Value);
}
await moduleClient.SendEventAsync("compressMessageOutput", outMessage);
Console.WriteLine("Message had no body and was passed as-is.");
}
return(MessageResponse.None);
}
public static async Task Run(
[IoTHubTrigger("messages/events", ConsumerGroup = "$Default", Connection = "IoTHubEventHubEndpoint")] EventData message,
[Blob("test-out/{sys.randguid}.xml", FileAccess.Write, Connection = "OutputBlobConnectionString")] Stream output,
ILogger log)
{
if (message.Properties.Contains(new System.Collections.Generic.KeyValuePair <string, object>("compression", "gzip")))
{
var fncResult = CompressionClass.Decompress(message.Body.ToArray());
log.LogInformation($"Decompressed message: {Encoding.UTF8.GetString(fncResult)}");
try
{
await output.WriteAsync(fncResult, 0, fncResult.Length);
}
catch (Exception e)
{
log.LogError(e.Message);
}
}
else
{
log.LogInformation($"Received uncompressed message: {Encoding.UTF8.GetString(message.Body.ToArray())}");
await output.WriteAsync(message.Body.ToArray(), 0, message.Body.Count);
}
}
public void Decompress_External_GZip_Data_Returns_Original_Data()
{
Assert.Equal(decompressedContentData, CompressionClass.Decompress(compressedContentData));
}
public void Decompress_Empty_Data_Returns_Empty_Data()
{
Assert.Equal(emptyMsgData, CompressionClass.Decompress(emptyMsgData));
}
public void Compress_Decompress_Returns_Original_Data()
{
var compressedData = CompressionClass.Compress(decompressedContentData);
Assert.Equal(decompressedContentData, CompressionClass.Decompress(compressedData));
}
public void Compress_Empty_Buffer_Returns_Empty_Buffer()
{
Assert.Equal(emptyMsgData, CompressionClass.Compress(emptyMsgData));
}
