本文整理匯總了Python中psycopg2.extensions.POLL_READ屬性的典型用法代碼示例。如果您正苦於以下問題：Python extensions.POLL_READ屬性的具體用法？Python extensions.POLL_READ怎麽用？Python extensions.POLL_READ使用的例子？那麽, 這裏精選的屬性代碼示例或許可以為您提供幫助。您也可以進一步了解該屬性所在類psycopg2.extensions的用法示例。
在下文中一共展示了extensions.POLL_READ屬性的4個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的Python代碼示例。
示例1: wait_select_inter
# 需要導入模塊: from psycopg2 import extensions [as 別名]
# 或者: from psycopg2.extensions import POLL_READ [as 別名]
def wait_select_inter(conn):
while True:
try:
state = conn.poll()
if state == POLL_OK:
break
elif state == POLL_READ:
select([conn.fileno()], [], [])
elif state == POLL_WRITE:
select([], [conn.fileno()], [])
else:
raise conn.OperationalError(
"bad state from poll: %s" % state)
except KeyboardInterrupt:
conn.cancel()
# the loop will be broken by a server error
continue 示例2: wait_select
# 需要導入模塊: from psycopg2 import extensions [as 別名]
# 或者: from psycopg2.extensions import POLL_READ [as 別名]
def wait_select(conn):
"""Wait until a connection or cursor has data available.
The function is an example of a wait callback to be registered with
`~psycopg2.extensions.set_wait_callback()`. This function uses
:py:func:`~select.select()` to wait for data available.
"""
import select
from psycopg2.extensions import POLL_OK, POLL_READ, POLL_WRITE
while 1:
state = conn.poll()
if state == POLL_OK:
break
elif state == POLL_READ:
select.select([conn.fileno()], [], [])
elif state == POLL_WRITE:
select.select([], [conn.fileno()], [])
else:
raise conn.OperationalError("bad state from poll: %s" % state) 示例3: _wait_select
# 需要導入模塊: from psycopg2 import extensions [as 別名]
# 或者: from psycopg2.extensions import POLL_READ [as 別名]
def _wait_select(conn):
"""
copy-pasted from psycopg2.extras.wait_select
the default implementation doesn't define a timeout in the select calls
"""
while 1:
try:
state = conn.poll()
if state == POLL_OK:
break
elif state == POLL_READ:
select.select([conn.fileno()], [], [], _WAIT_SELECT_TIMEOUT)
elif state == POLL_WRITE:
select.select([], [conn.fileno()], [], _WAIT_SELECT_TIMEOUT)
else:
raise conn.OperationalError("bad state from poll: %s" % state)
except KeyboardInterrupt:
conn.cancel()
# the loop will be broken by a server error
continue
except select.error as e:
errno = e.args[0]
if errno != 4:
raise
# When running a query, make pressing CTRL+C raise a KeyboardInterrupt
# See http://initd.org/psycopg/articles/2014/07/20/cancelling-postgresql-statements-python/
# See also https://github.com/psycopg/psycopg2/issues/468 示例4: wait_select
# 需要導入模塊: from psycopg2 import extensions [as 別名]
# 或者: from psycopg2.extensions import POLL_READ [as 別名]
def wait_select(conn):
"""Wait until a connection or cursor has data available.
The function is an example of a wait callback to be registered with
`~psycopg2.extensions.set_wait_callback()`. This function uses
:py:func:`~select.select()` to wait for data available.
"""
import select
from psycopg2.extensions import POLL_OK, POLL_READ, POLL_WRITE
while 1:
try:
state = conn.poll()
if state == POLL_OK:
break
elif state == POLL_READ:
select.select([conn.fileno()], [], [])
elif state == POLL_WRITE:
select.select([], [conn.fileno()], [])
else:
raise conn.OperationalError("bad state from poll: %s" % state)
except KeyboardInterrupt:
conn.cancel()
# the loop will be broken by a server error
continue