DragonFly On-Line Manual Pages

cl_queue_srv(1)        DragonFly General Commands Manual       cl_queue_srv(1)

       Authors: Enrique Marcote (enrique.marcote@erlang-consulting.com) Miguel
       Rodriguez (miguel@erlang-consulting.com)

MODULE
       cl_queue_srv

DESCRIPTION
       The queue controller manages the access to a priority queue.  The queue
       can be a disk or memory queue.

START/STOP EXPORTS
       Start/stop functions.

   start_link() -> Result
   start_link(Filename) -> Result
       Types

       Filename = string()

       Result = {ok, Pid} | {error, Reason}

       Pid = pid()

       Reason = term()

       Starts the queue controller.  If the Filename is given the queue will
       be stored on disk, if not a memory queue will be used instead.  If an
       error ocurrs while opening the queue, the controller cannot be started
       and an error is returned.

QUEUE EXPORTS
       Queue related functions.

   in(Pid, Item, Priority) -> ok
       Types

       Pid = pid()

       Item = term()

       Priority = int()

       Inserts an Item in the rear of the queue with priority Priority.

   len(Pid) -> Len
       Types

       Pid = pid()

       Len = int()

       Returns the number of items in the queue.

   out(Pid) -> Result
   out(Pid, Num) -> Result
       Types

       Pid = pid()

       Result = Items

       Items = [Item]

       Item = term()

       Removes Num items from the front of queue.  Returns  the  list of Items
       removed.  If there are no enough items on the queue, Items may contain
       less elements than Num.  If the queue is empty an empty list is
       returned.

       If Num is not specified, 1 item will be removed.

       The item in the front is the first item among those with the highest
       priority.

   out_r(Pid) -> Result
   out_r(Pid, Num) -> Result
       Types

       Pid = pid()

       Result = Items

       Items = [Item]

       Item = term()

       Removes Num items from the rear of queue.  Returns  the  list of Items
       removed.  If there are no enough items on the queue, Items may contain
       less elements than Num.  If the queue is empty an empty list is
       returned.

       If Num is not specified, 1 item will be removed.

       The item at the rear is the last item among those with the lowest
       priority.

COUNT EXPORTS
       Count functions.

   count_in(Pid) -> Count
       Types

       Pid = pid()

       Count = int()

       Returns the number of inserted items since the last reset/1 call ar
       since the server was started.

   count_out(Pid) -> Count
       Types

       Pid = pid()

       Count = int()

       Returns the number of extracted items since the last reset/1 call ar
       since the server was started (items extracted from the rear and front).

   count_reset(Pid) -> ok
       Types

       Pid = pid()

       Resets the in and out counters back to 0.

RPS EXPORTS
       RPS (Request Per Second) functions.

   rps(Pid) -> Rps
       Types

       Pid = pid()

       Rps = int()

       Returns the actual number of requests per second.  This function counts
       the out requests during one second and returns the calculated value.

   rps_avg(Pid) -> Rps
       Types

       Pid = pid()

       Rps = int()

       Returns the average number of requests per second since the last count
       reset (see count_reset/1).

SEE ALSO
       common_lib(1)

common_lib                      Version: 3.3.4                 cl_queue_srv(1)