nsITransport

IID:cbb0baeb-5fcb-408b-a2be-9f8fc98d0af1
Inherits From:nsISupports

This interface provides a common way of accessing i/o streams connected to some resource. This interface does not in any way specify the resource. It provides methods to open blocking or non-blocking, buffered or unbuffered streams to the resource. The name "transport" is meant to connote the inherent data transfer implied by this interface (i.e., data is being transfered in some fashion via the streams exposed by this interface).

A transport can have an event sink associated with it. The event sink receives transport-specific events as the transfer is occuring. For a socket transport, these events can include status about the connection. See nsISocketTransport for more info about socket transport specifics.


Constants

Open flags.
PRUint32 OPEN_BLOCKING = 1
PRUint32 OPEN_UNBUFFERED = 2
Generic nsITransportEventSink status codes. nsITransport implementations may override these status codes with their own more specific status codes (e.g., see nsISocketTransport).
PRUint32 STATUS_READING = -2142568440
PRUint32 STATUS_WRITING = -2142568439

Methods

void close ( nsresult reason ) nsIInputStream openInputStream ( PRUint32 flags , PRUint32 segmentSize , PRUint32 segmentCount ) nsIOutputStream openOutputStream ( PRUint32 flags , PRUint32 segmentSize , PRUint32 segmentCount ) void setEventSink ( nsITransportEventSink sink , nsIEventTarget eventTarget )

void close ( nsresult reason )

Close the transport and any open streams.

Arguments:
reason: the reason for closing the stream.

nsIInputStream openInputStream ( PRUint32 flags , PRUint32 segmentSize , PRUint32 segmentCount )

Open an input stream on this transport.

Flags have the following meaning:

OPEN_BLOCKING If specified, then the resulting stream will have blocking stream semantics. This means that if the stream has no data and is not closed, then reading from it will block the calling thread until at least one byte is available or until the stream is closed. If this flag is NOT specified, then the stream has non-blocking stream semantics. This means that if the stream has no data and is not closed, then reading from it returns NS_BASE_STREAM_WOULD_BLOCK. In addition, in non-blocking mode, the stream is guaranteed to support nsIAsyncInputStream. This interface allows the consumer of the stream to be notified when the stream can again be read.

OPEN_UNBUFFERED If specified, the resulting stream may not support ReadSegments. ReadSegments is only gauranteed to be implemented when this flag is NOT specified.

Arguments:
flags: optional transport specific flags.
segmentSize: if OPEN_UNBUFFERED is not set, then this parameter specifies the size of each buffer segment (pass 0 to use default value).
segmentCount: if OPEN_UNBUFFERED is not set, then this parameter specifies the maximum number of buffer segments (pass 0 to use default value).

nsIOutputStream openOutputStream ( PRUint32 flags , PRUint32 segmentSize , PRUint32 segmentCount )

Open an output stream on this transport.

Flags have the following meaning:

OPEN_BLOCKING If specified, then the resulting stream will have blocking stream semantics. This means that if the stream is full and is not closed, then writing to it will block the calling thread until ALL of the data can be written or until the stream is closed. If this flag is NOT specified, then the stream has non-blocking stream semantics. This means that if the stream is full and is not closed, then writing to it returns NS_BASE_STREAM_WOULD_BLOCK. In addition, in non- blocking mode, the stream is guaranteed to support nsIAsyncOutputStream. This interface allows the consumer of the stream to be notified when the stream can again accept more data.

OPEN_UNBUFFERED If specified, the resulting stream may not support WriteSegments and WriteFrom. WriteSegments and WriteFrom are only gauranteed to be implemented when this flag is NOT specified.

Arguments:
flags: optional transport specific flags.
segmentSize: if OPEN_UNBUFFERED is not set, then this parameter specifies the size of each buffer segment (pass 0 to use default value).
segmentCount: if OPEN_UNBUFFERED is not set, then this parameter specifies the maximum number of buffer segments (pass 0 to use default value).

void setEventSink ( nsITransportEventSink sink , nsIEventTarget eventTarget )

Set the transport event sink.

Arguments:
sink: receives transport layer notifications
eventTarget: indicates the event target to which the notifications should be delivered. if NULL, then the notifications may occur on any thread.

References

This interface is passed as an argument to the following methods:

nsITransportEventSink.onTransportStatus

This interface is returned from the following methods:

nsIStreamTransportService.createInputTransport, nsIStreamTransportService.createOutputTransport

Reference documentation is generated from Mozilla's source.

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