Constructor: Connect to the PostgreSQL back end and return a stream connection.
Switch this stream to using a new socket. Any existing socket is not closed;
it's assumed that we ar
Closes the connection.
Flush any pending output to the backend.
Check for pending backend messages without blocking. Might return false when
there actually are mess
Change the encoding used by this connection.
Reads in a given number of bytes from the backend
Receives a single character from the backend
Consume an expected EOF from the backend
Receives a two byte integer from the backend