Writing to MemoryStream with foreach

Question

As you can see here:

enter image description here

20% CPU in a 3 minutes and 20 seconds excessive 40 executions async/await at a time for 9700 times caused quite a bit of CPU usage.

Code:

public MemoryStream getMessageBody()
{
 #region Get MessageBody
 IEnumerable<BytesWraper> MessageBody = GetMessageBodySource();
 if (MessageBody == null) {
 return null;
 }
 #endregion
 #region Write MessageBody's Data to a MemoryStream so we can convert it later to a String
 MemoryStream memoryStream = new MemoryStream(ContentLength == -1 ? 0 : ContentLength);
 try {
 foreach (BytesWraper bytes in MessageBody) {
 memoryStream.Write(bytes.Value, 0, bytes.Length);
 }
 } catch (Exception) {
 return null;
 }
 #endregion
 if (ConnectionClosed()) {
 _request.Dispose();
 }
 MessageBodyLoaded = true;
 return memoryStream;
}

Is there a way here to reduce the amount of usage by this foreach call? Perhaps not need to do it at all?

All im then doing with the result is as follows:

return MessageBody != null ? CharacterSet.GetString(MessageBody.GetBuffer(), 0, (int)MessageBody.Length) : null

(where MessageBody is getMessageBody())

• t3chb0t: Could you explain what BytesWrapper is and what you are actually doing here? Saying this code is slow, need help isn't very clear. Help us help you and explain what you're doing in more detail.
• Peter Taylor: I can't work out how to parse "20% CPU in a 3 minutes and 20 seconds excessive 40 executions async/await at a time for 9700 times caused quite a bit of CPU usage." I understand that the total execution time of your test is 200 seconds and that this loop is responsible for 20% of this and potentially a bottleneck, but I can't see how to fit the middle of the line into the sentence.
• Ma Dude: BytesWrapper simply a get; set of .Value (byte[]) and .Length (int of byte[].length) @t3chb0t
• Ma Dude: Basically its grabbing bytes from a TCP response and then I simply convert it to a string.

Answer 1

Have you tried something like this (?):

MemoryStream memoryStream = new MemoryStream(MessageBody.SelectMany(mb => mb.Value).ToArray());

• Ma Dude: Edit: So I actually went with your one as it actually essentially did the same as mine, and if there was any performance impact then it wouldnt have been much like at all. Just edit it to the following: Encoding.UTF8.GetString(MessageBody.SelectMany(mb => mb.Value).ToArray()); as this returns as a string which is essentially what I was wanting.
• t3chb0t: @ImPRAGMA mhmm... but the foreach should be faster here anyway so it's not necessarily an improvement if your goal is better performance. Did you measure it?