HTTP/1.1 client library
HTTPConnection go through a number of "states", which defines when a client may legally make another request or fetch the response for a particular request. This diagram details these state transitions:
(null) | | HTTPConnection() v Idle | | putrequest() v Request-started | | ( putheader() ) endheaders() v Request-sent | | response = getresponse() v Unread-response [Response-headers-read] |\____________________ | | | response.read() | putrequest() v v Idle Req-started-unread-response ______/| / | response.read() | | ( putheader() ) endheaders() v v Request-started Req-sent-unread-response | | response.read() v Request-sent
Note: this enforcement is applied by the HTTPConnection class. The HTTPResponse class does not enforce this state machine, which implies sophisticated clients may accelerate the request/response pipeline. Caution should be taken, though: accelerating the states beyond the above pattern may imply knowledge of the server's connection-close behavior for certain requests. For example, it is impossible to tell whether the server will close the connection UNTIL the response headers have been read; this means that further requests cannot be placed into the pipeline until it is known that the server will NOT be closing the connection.
Logical State __state __response
------------- ------- ----------
Idle _CS_IDLE None
Request-started _CS_REQ_STARTED None
Request-sent _CS_REQ_SENT None
Unread-response _CS_IDLE