Kamaelia.Experimental.Chassis

• prefab Carousel
• prefab Graphline
• prefab InboxControlledCarousel
• prefab Pipeline

• Inbox size limiting Pipelines, Graphlines and Carousels
  • Example Usages
  • More details

Inbox size limiting Pipelines, Graphlines and Carousels

Extended versions of Kamaelia.Chassis.Pipeline, Kamaelia.Chassis.Graphline and Kamaelia.Chassis.Carousel that add the ability to specify size limits for inboxes of components.

Example Usages

A pipeline with inbox size limits on 3 of the components' "inbox" inboxes:

Pipeline( 5,  MyComponent(),      # 'inbox' inbox limited to 5 items
          2,  MyComponent(),      # 'inbox' inbox limited to 2 items
              MyComponent(),      # 'inbox' inbox unlimited
          28, MyComponent()       # 'inbox' inbox limited to 28 items
        )

A graphline where component 'A' has a size limit of 5 on its "inbox" inbox; and component 'C' has a size limit of 17 on its "control" inbox:

Graphline( A = MyComponent(),
           B = MyComponent(),
           C = MyComponent(),
           linkages = { ... },
           boxsizes = {
               ("A","inbox") : 5,
               ("C","control") : 17
           }
         )

A Carousel, where the child component will have a size limit of 5 on its "inbox" inbox:

Carousel( MyComponent(), boxsize=5 )

Decoding a Dirac video file and saving each frame in a separate file:

Pipeline(
    RateControlledFileReader("video.dirac", ... ),
    DiracDecoder(),
    TagWithSequenceNumber(),
    InboxControlledCarousel(
        lambda (seqnum, frame) :
            Pipeline( OneShot(frame),
                      FrameToYUV4MPEG(),
                      SimpleFileWriter("%08d.yuv4mpeg" % seqnum),
                    )
        ),
    )

More details

The behaviour of these three components/prefabs is identical to their original counterparts (Kamaelia.Chassis.Pipeline, Kamaelia.Chassis.Graphline and Kamaelia.Chassis.Carousel).

For Pipelines, if you want to size limit the "inbox" inbox of a particular component in the pipeline, then put the size limit as an integer before it. Any component without an integer before it is left with the default of an unlimited "inbox" inbox.

The behaviour therefore reduces back to be identical to that of the normal Pipeline component.

For Graphlines, if you want to size limit particular inboxes, supply the "boxsizes" argument with a dictionary that maps (componentName, boxName) keys to the size limit for that box.

Again, if you don't specify a "boxsizes" argument, then behaviour is identical to that of the normal Graphline component.

For Carousels, if you want a size limit on the "inbox" inbox of the child component (created by the factory function), then specify it using the "boxsizes" argument.

Again, if you don't specify a "boxsizes" argument, then behaviour is identical to that of the normal Carousel component.

InboxControlledCarousel behaves identically to Carousel.

The "inbox" inbox is equivalent to the "next" inbox of Carousel. The "data_inbox" inbox is equivalent to the "inbox" inbox of Carousel.

---

Kamaelia.Experimental.Chassis.Carousel

prefab: Carousel

Carousel(componentFactory[,make1stRequest][,boxSize]) -> new Carousel component

Create a Carousel component that makes child components one at a time (in carousel fashion) using the supplied factory function.

Keyword arguments:

• componentFactory -- function that takes a single argument and returns a component
• make1stRequest -- if True, Carousel will send an initial "NEXT" request. (default=False)
• boxsize -- size limit for "inbox" inbox of the created child component

Kamaelia.Experimental.Chassis.Graphline

prefab: Graphline

Graphline([linkages][,boxsizes],**components) -> new Graphline component

Encapsulates the specified set of components and wires them up with the specified linkages.

Keyword arguments:

• linkages -- dictionary mapping ("componentname","boxname") to ("componentname","boxname")
• boxsizes -- dictionary mapping ("componentname","boxname") to size limit for inbox
• components -- dictionary mapping names to component instances (default is nothing)

Kamaelia.Experimental.Chassis.InboxControlledCarousel

prefab: InboxControlledCarousel

InboxControlledCarousel(componentFactory[,make1stRequest][,boxSize]) -> new Carousel component

Create an InboxControlledCarousel component that makes child components one at a time (in carousel fashion) using the supplied factory function.

Keyword arguments:

• componentFactory -- function that takes a single argument and returns a component
• make1stRequest -- if True, Carousel will send an initial "NEXT" request. (default=False)
• boxsize -- size limit for "inbox" inbox of the created child component

Kamaelia.Experimental.Chassis.Pipeline

prefab: Pipeline

Pipeline(*components) -> new Pipeline component.

Encapsulates the specified set of components and wires them up in a chain (a Pipeline) in the order you provided them.

Keyword arguments:

• components -- the components you want, in the order you want them wired up. Any Integers set the "inbox" inbox size limit for the component that follows them.