@ExperimentalApi(value="https://github.com/grpc/grpc-java/issues/1788") public abstract class ServerCallStreamObserver<V> extends CallStreamObserver<V>
CallStreamObserver
to allows for interaction with call
cancellation events on the server side.
Like StreamObserver
, implementations are not required to be thread-safe; if multiple
threads will be writing to an instance concurrently, the application must synchronize its calls.
DO NOT MOCK: The API is too complex to reliably mock. Use InProcessChannelBuilder to create "real" RPCs suitable for testing and interact with the server using a normal client stub.
Constructor and Description |
---|
ServerCallStreamObserver() |
Modifier and Type | Method and Description |
---|---|
void |
disableAutoRequest()
Swaps to manual flow control where no message will be delivered to
StreamObserver.onNext(Object) unless it is request() ed. |
abstract boolean |
isCancelled()
Returns
true when the call is cancelled and the server is encouraged to abort
processing to save resources, since the client will not be processing any further methods. |
abstract void |
setCompression(java.lang.String compression)
Sets the compression algorithm to use for the call.
|
abstract void |
setOnCancelHandler(java.lang.Runnable onCancelHandler)
Sets a
Runnable to be called if the call is cancelled and the server is encouraged to
abort processing to save resources, since the client will not process any further messages. |
disableAutoInboundFlowControl, isReady, request, setMessageCompression, setOnReadyHandler
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
onCompleted, onError, onNext
public abstract boolean isCancelled()
true
when the call is cancelled and the server is encouraged to abort
processing to save resources, since the client will not be processing any further methods.
Cancellations can be caused by timeouts, explicit cancellation by client, network errors, and
similar.
This method may safely be called concurrently from multiple threads.
public abstract void setOnCancelHandler(java.lang.Runnable onCancelHandler)
Runnable
to be called if the call is cancelled and the server is encouraged to
abort processing to save resources, since the client will not process any further messages.
Cancellations can be caused by timeouts, explicit cancellation by the client, network errors,
etc.
It is guaranteed that execution of the Runnable
is serialized with calls to the
'inbound' StreamObserver
. That also means that the callback will be delayed if other
callbacks are running; if one of those other callbacks runs for a significant amount of time
it can poll isCancelled()
, which is not delayed.
This method may only be called during the initial call to the application, before the
service returns its StreamObserver
.
Setting the onCancelHandler will suppress the on-cancel exception thrown by
StreamObserver.onNext(V)
.
onCancelHandler
- to call when client has cancelled the call.public abstract void setCompression(java.lang.String compression)
It is safe to call this even if the client does not support the compression format chosen. The implementation will handle negotiation with the client and may fall back to no compression.
compression
- the compression algorithm to use.java.lang.IllegalArgumentException
- if the compressor name can not be found.public void disableAutoRequest()
StreamObserver.onNext(Object)
unless it is request()
ed.
It may only be called during the initial call to the application, before the service returns
its StreamObserver
.
Note that for cases where the message is received before the service handler is invoked, this method will have no effect. This is true for:
MethodDescriptor.MethodType.UNARY
operations.MethodDescriptor.MethodType.SERVER_STREAMING
operations.This API is still a work in-progress and may change in the future.