biz.source_code.usb

Class UsbIso.Request

java.lang.Object

biz.source_code.usb.UsbIso.Request

Enclosing class:

UsbIso

public class UsbIso.Request
extends java.lang.Object

This class represents an isochronous data transfer request that can be queued with the USB device driver. One request object contains multiple data packets. Multiple request objects may be queued at a time.

The sequence of actions on a Request object is typically:

   UsbIso.getRequest()
   Request.initialize()
   ... For output: Set packet data to be sent to device ...
   Request.submit()
   repeatedly:
      UsbIso.reapRequest()
      ... For input: Check status and process received packet data ...
      ... For output: Check status ...
      Request.initialize()
      ... For output: Set packet data to be sent to device ...
      Request.submit()

Method Summary

Modifier and Type	Method and Description
void	cancel() Cancels a queued request.
int	getEndpointAddr() Returns the endpoint address associated with this request.
int	getPacketActualLength(int packetNo) Returns the amount of data that was actually transferred for the packet.
int	getPacketCount() Returns the packet count of this request.
void	getPacketData(int packetNo, byte[] buf, int len) Used to retrieve data that has been received from the device.
int	getPacketStatus(int packetNo) Returns the completion status code of a packet.
void	initialize(int endpointAddr) Initializes this Request object for the next submit().
void	setPacketCount(int n) May be used to modify the packet count.
void	setPacketData(int packetNo, byte[] buf, int len) Used to provide data to be sent to the device.
void	setPacketLength(int packetNo, int length) May be used to modify the length of data to request for the packet.
void	submit() Submits this request to the USB device driver.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

initialize

public void initialize(int endpointAddr)

Initializes this Request object for the next submit(). For input, an initialized Request object can usually be submitted without change. For output, data has to be copied into the packet data buffers before the Request object is submitted.

Parameters:

endpointAddr - The address of an isochronous USB endpoint. For Android, this is the value returned by UsbEndpoint.getAddress().

submit

public void submit()
            throws java.io.IOException

Submits this request to the USB device driver. The request is added to the queue of active requests.

Throws:

java.io.IOException

cancel

public void cancel()
            throws java.io.IOException

Cancels a queued request. The request remains within the queue amd must be removed from the queue by calling UsbIso.reapRequest(boolean).

Throws:

java.io.IOException

getEndpointAddr

public int getEndpointAddr()

Returns the endpoint address associated with this request.

setPacketCount

public void setPacketCount(int n)

May be used to modify the packet count. The default packet count is maxPacketsPerRequest (see UsbIso constructor).

getPacketCount

public int getPacketCount()

Returns the packet count of this request.

getPacketStatus

public int getPacketStatus(int packetNo)

Returns the completion status code of a packet. For normal completion the status is 0.

setPacketLength

public void setPacketLength(int packetNo,
                            int length)

May be used to modify the length of data to request for the packet. The default packet length is maxPacketSize (see UsbIso constructor).

getPacketActualLength

public int getPacketActualLength(int packetNo)

Returns the amount of data that was actually transferred for the packet. When reading, this is the number of data bytes received from the device.

setPacketData

public void setPacketData(int packetNo,
                          byte[] buf,
                          int len)

Used to provide data to be sent to the device.

getPacketData

public void getPacketData(int packetNo,
                          byte[] buf,
                          int len)

Used to retrieve data that has been received from the device.