Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling
 
PerlMonks  

Re: How can I determine the server is waiting for input in POE::Wheel::ReadWrite?

by Joost (Canon)
on Nov 15, 2009 at 21:27 UTC ( #807309=note: print w/ replies, xml ) Need Help??


in reply to How can I determine the server is waiting for input in POE::Wheel::ReadWrite?

As a simplification, you may want to think of the processing of network data the same way as reading a file while some other process is writing to it.

You cannot determine without some protocol when a "block" of data is complete. The common solutions to this problem are:

a) the above mentioned "end of block" marker. In the case of a line-based protocol, the newline character serves as an end-of-block marker. This is especially useful if its inefficient to know the length of a block in advance (usually, because the block is large and takes a long time to compute). And line-based protocols are just nice to read for humans, which can also be a big help in analyzing any problems.

b) prefix the block with its length. HTTP for instance provides a mechanism for this using the content-length header. Many binary protocols work the same way. When possible, this gives a few advantages over end-of-block markers; the client will know how much memory to allocate for the incoming data, and it can make it easier to pass the data on without any additional processing.


Comment on Re: How can I determine the server is waiting for input in POE::Wheel::ReadWrite?

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://807309]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others scrutinizing the Monastery: (13)
As of 2014-07-22 10:28 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    My favorite superfluous repetitious redundant duplicative phrase is:









    Results (109 votes), past polls