Python psycopg2.extensions.POLL_WRITE Examples

The following are 4 code examples of psycopg2.extensions.POLL_WRITE(). You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may also want to check out all available functions/classes of the module psycopg2.extensions , or try the search function .
Example #1
Source File: redshift_psql.py    From mycroft with MIT License 6 votes vote down vote up 
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
Example #2
Source File: extras.py    From syntheticmass with Apache License 2.0 6 votes vote down vote up 
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)
Example #3
Source File: pgexecute.py    From pgcli with BSD 3-Clause "New" or "Revised" License 5 votes vote down vote up 
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
Example #4
Source File: extras.py    From aws-workshop with MIT License 5 votes vote down vote up 
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