pymsql example

examples/mysql.py

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+"""PyMySQL example"""
+import tulip
+import socket
+from pymysql import connections
+from greentulip import socket as greensocket
+
+
+class GreenConnection(connections.Connection):
+
+    def _connect(self):
+        try:
+            if self.unix_socket:
+                raise NotImplementedError()
+            else:
+                sock = greensocket.socket(socket.AF_INET, socket.SOCK_STREAM)
+                sock.connect((self.host, self.port))
+                self.host_info = "socket %s:%d" % (self.host, self.port)
+            if self.no_delay:
+                sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
+            self.socket = sock
+            self.rfile = self.socket.makefile("rb")
+            self.wfile = self.socket.makefile("wb")
+            self._get_server_information()
+            self._request_authentication()
+            self._send_autocommit_mode()
+        except socket.error as e:
+            raise Exception(
+                2003, "Can't connect to MySQL server on %r (%s)" % (
+                    self.host, e.args[0]))
+
+
+if __name__ == '__main__':
+    import greentulip
+    import time
+    import tulip
+
+    @tulip.task
+    def sleeper():
+        # show that we're not blocked
+        while True:
+            yield from tulip.sleep(0.2)
+            print('.')
+
+    @greentulip.task
+    def db():
+        conn = GreenConnection(host='localhost')
+
+        try:
+            with conn as cur:
+                print('>> sleeping')
+                st = time.monotonic()
+                cur.execute('SELECT SLEEP(2)')
+                en = time.monotonic() - st
+                assert en >= 2
+                print('<< sleeping {:.3f}s'.format(en))
+
+                cur.execute('SELECT 42')
+                print('"SELECT 42" -> {!r}'.format(cur.fetchone()))
+
+                print('>> sleeping')
+                st = time.monotonic()
+                cur.execute('SELECT SLEEP(1)')
+                en = time.monotonic() - st
+                assert en >= 1
+                print('<< sleeping {:.3f}s'.format(en))
+        finally:
+            conn.close()
+
+    @tulip.task
+    def run():
+        yield from tulip.wait([db(), sleeper()],
+                              return_when=tulip.FIRST_COMPLETED)
+
+    tulip.set_event_loop_policy(greentulip.GreenEventLoopPolicy())
+    tulip.get_event_loop().run_until_complete(run())