psycopg2 async example

tests/psycopg2_green.py

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+import uwsgi
+import psycopg2
+
+def async_wait(conn):
+	# conn can be a connection or a cursor
+	if not hasattr(conn, 'poll'):
+		conn = conn.connection
+	
+	# interesting part: suspend until ready
+	while True:
+		state = conn.poll()
+		if state == psycopg2.extensions.POLL_OK:
+			break
+		elif state == psycopg2.extensions.POLL_READ:
+			uwsgi.green_wait_fdread(conn.fileno())
+		elif state == psycopg2.extensions.POLL_WRITE:
+			uwsgi.green_wait_fdwrite(conn.fileno())
+		else:
+			raise Exception("Unexpected result from poll: %r", state)
+
+			
+
+
+
+def application(env, start_response):
+
+	start_response('200 Ok', [('Content-type', 'text/html')])
+
+	conn = psycopg2.connect("dbname=prova user=postgres", async=True)
+
+	# suspend until connection
+	async_wait(conn)
+
+	curs = conn.cursor()
+
+	yield "<table>"
+
+	curs.execute("SELECT * FROM tests")
+
+	# suspend until result
+	async_wait(curs)
+
+	while True:
+		row = curs.fetchone()
+		if not row: break
+		yield "<tr><td>%s</td></tr>" % str(row)
+
+	yield "</table>"
+
+	conn.close()