Request Timeout for web.client.Agent

[oberstet]

Agent should have an option to set the request timeout.

Currently, the old getPage has

• option to set request timeout
• no option to set connectionTimeout
• no persistent connection pool

and Agent has

• no option to set request timeout
• option to set connectionTimeout
• persistent connection pool

So Agent is lacking behind getPage wrt to request timeout.

The attached patch adds a request timeout option. When the timeout hits, the request fails with twisted.web._newclient.ResponseNeverReceived.

The request timeout is for the whole request, that is setup as soon as the request has been started to write to the transport. It is not a response-only timeout that would only be started when the producer has finished producing and then timeout for receiving the response.

[itamar]

I would prefer this be done via a generic timeout mechanism added to Deferreds (utilizing Deferred cancellation). However, if that feature doesn't happen soon having built-in timeouts is certainly much better than nothing.

[exarkun]

I would prefer this be done via a generic timeout mechanism added to Deferreds (utilizing Deferred cancellation).

Me too, strongly.