io.netty.handler.codec.http2.Http2Connection Maven / Gradle / Ivy
/*
* Copyright 2014 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License, version 2.0 (the
* "License"); you may not use this file except in compliance with the License. You may obtain a
* copy of the License at:
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package io.netty.handler.codec.http2;
import io.netty.buffer.ByteBuf;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.Promise;
/**
* Manager for the state of an HTTP/2 connection with the remote end-point.
*/
public interface Http2Connection {
/**
* Listener for life-cycle events for streams in this connection.
*/
interface Listener {
/**
* Notifies the listener that the given stream was added to the connection. This stream may
* not yet be active (i.e. {@code OPEN} or {@code HALF CLOSED}).
*
* If a {@link RuntimeException} is thrown it will be logged and not propagated.
* Throwing from this method is not supported and is considered a programming error.
*/
void onStreamAdded(Http2Stream stream);
/**
* Notifies the listener that the given stream was made active (i.e. {@code OPEN} or {@code HALF CLOSED}).
*
* If a {@link RuntimeException} is thrown it will be logged and not propagated.
* Throwing from this method is not supported and is considered a programming error.
*/
void onStreamActive(Http2Stream stream);
/**
* Notifies the listener that the given stream has transitioned from {@code OPEN} to {@code HALF CLOSED}.
* This method will not be called until a state transition occurs from when
* {@link #onStreamActive(Http2Stream)} was called.
* The stream can be inspected to determine which side is {@code HALF CLOSED}.
*
* If a {@link RuntimeException} is thrown it will be logged and not propagated.
* Throwing from this method is not supported and is considered a programming error.
*/
void onStreamHalfClosed(Http2Stream stream);
/**
* Notifies the listener that the given stream is now {@code CLOSED} in both directions and will no longer
* be accessible via {@link #forEachActiveStream(Http2StreamVisitor)}.
*
* If a {@link RuntimeException} is thrown it will be logged and not propagated.
* Throwing from this method is not supported and is considered a programming error.
*/
void onStreamClosed(Http2Stream stream);
/**
* Notifies the listener that the given stream has now been removed from the connection and
* will no longer be returned via {@link Http2Connection#stream(int)}. The connection may
* maintain inactive streams for some time before removing them.
*
* If a {@link RuntimeException} is thrown it will be logged and not propagated.
* Throwing from this method is not supported and is considered a programming error.
*/
void onStreamRemoved(Http2Stream stream);
/**
* Called when a {@code GOAWAY} frame was sent for the connection.
*
* If a {@link RuntimeException} is thrown it will be logged and not propagated.
* Throwing from this method is not supported and is considered a programming error.
* @param lastStreamId the last known stream of the remote endpoint.
* @param errorCode the error code, if abnormal closure.
* @param debugData application-defined debug data.
*/
void onGoAwaySent(int lastStreamId, long errorCode, ByteBuf debugData);
/**
* Called when a {@code GOAWAY} was received from the remote endpoint. This event handler duplicates {@link
* Http2FrameListener#onGoAwayRead(io.netty.channel.ChannelHandlerContext, int, long, ByteBuf)}
* but is added here in order to simplify application logic for handling {@code GOAWAY} in a uniform way. An
* application should generally not handle both events, but if it does this method is called second, after
* notifying the {@link Http2FrameListener}.
*
* If a {@link RuntimeException} is thrown it will be logged and not propagated.
* Throwing from this method is not supported and is considered a programming error.
* @param lastStreamId the last known stream of the remote endpoint.
* @param errorCode the error code, if abnormal closure.
* @param debugData application-defined debug data.
*/
void onGoAwayReceived(int lastStreamId, long errorCode, ByteBuf debugData);
}
/**
* A view of the connection from one endpoint (local or remote).
*/
interface Endpoint {
/**
* Increment and get the next generated stream id this endpoint. If negative, the stream IDs are
* exhausted for this endpoint an no further streams may be created.
*/
int incrementAndGetNextStreamId();
/**
* Indicates whether the given streamId is from the set of IDs used by this endpoint to
* create new streams.
*/
boolean isValidStreamId(int streamId);
/**
* Indicates whether or not this endpoint may have created the given stream. This is {@code true} if
* {@link #isValidStreamId(int)} and {@code streamId} <= {@link #lastStreamCreated()}.
*/
boolean mayHaveCreatedStream(int streamId);
/**
* Indicates whether or not this endpoint created the given stream.
*/
boolean created(Http2Stream stream);
/**
* Indicates whether or a stream created by this endpoint can be opened without violating
* {@link #maxActiveStreams()}.
*/
boolean canOpenStream();
/**
* Creates a stream initiated by this endpoint. This could fail for the following reasons:
*
* - The requested stream ID is not the next sequential ID for this endpoint.
* - The stream already exists.
* - {@link #canOpenStream()} is {@code false}.
* - The connection is marked as going away.
*
*
* The initial state of the stream will be immediately set before notifying {@link Listener}s. The state
* transition is sensitive to {@code halfClosed} and is defined by {@link Http2Stream#open(boolean)}.
* @param streamId The ID of the stream
* @param halfClosed see {@link Http2Stream#open(boolean)}.
* @see Http2Stream#open(boolean)
*/
Http2Stream createStream(int streamId, boolean halfClosed) throws Http2Exception;
/**
* Creates a push stream in the reserved state for this endpoint and notifies all listeners.
* This could fail for the following reasons:
*
* - Server push is not allowed to the opposite endpoint.
* - The requested stream ID is not the next sequential stream ID for this endpoint.
* - The number of concurrent streams is above the allowed threshold for this endpoint.
* - The connection is marked as going away.
* - The parent stream ID does not exist or is not {@code OPEN} from the side sending the push
* promise.
* - Could not set a valid priority for the new stream.
*
*
* @param streamId the ID of the push stream
* @param parent the parent stream used to initiate the push stream.
*/
Http2Stream reservePushStream(int streamId, Http2Stream parent) throws Http2Exception;
/**
* Indicates whether or not this endpoint is the server-side of the connection.
*/
boolean isServer();
/**
* This is the SETTINGS_ENABLE_PUSH value sent
* from the opposite endpoint. This method should only be called by Netty (not users) as a result of a
* receiving a {@code SETTINGS} frame.
*/
void allowPushTo(boolean allow);
/**
* This is the SETTINGS_ENABLE_PUSH value sent
* from the opposite endpoint. The initial value must be {@code true} for the client endpoint and always false
* for a server endpoint.
*/
boolean allowPushTo();
/**
* Gets the number of active streams (i.e. {@code OPEN} or {@code HALF CLOSED}) that were created by this
* endpoint.
*/
int numActiveStreams();
/**
* Gets the maximum number of streams (created by this endpoint) that are allowed to be active at
* the same time. This is the
* SETTINGS_MAX_CONCURRENT_STREAMS
* value sent from the opposite endpoint to restrict stream creation by this endpoint.
*
* The default value returned by this method must be "unlimited".
*/
int maxActiveStreams();
/**
* Sets the limit for {@code SETTINGS_MAX_CONCURRENT_STREAMS}.
* @param maxActiveStreams The maximum number of streams (created by this endpoint) that are allowed to be
* active at once. This is the
* SETTINGS_MAX_CONCURRENT_STREAMS value sent
* from the opposite endpoint to restrict stream creation by this endpoint.
*/
void maxActiveStreams(int maxActiveStreams);
/**
* Gets the ID of the stream last successfully created by this endpoint.
*/
int lastStreamCreated();
/**
* If a GOAWAY was received for this endpoint, this will be the last stream ID from the
* GOAWAY frame. Otherwise, this will be {@code -1}.
*/
int lastStreamKnownByPeer();
/**
* Gets the flow controller for this endpoint.
*/
F flowController();
/**
* Sets the flow controller for this endpoint.
*/
void flowController(F flowController);
/**
* Gets the {@link Endpoint} opposite this one.
*/
Endpoint opposite();
}
/**
* A key to be used for associating application-defined properties with streams within this connection.
*/
interface PropertyKey {
}
/**
* Close this connection. No more new streams can be created after this point and
* all streams that exists (active or otherwise) will be closed and removed.
*
Note if iterating active streams via {@link #forEachActiveStream(Http2StreamVisitor)} and an exception is
* thrown it is necessary to call this method again to ensure the close completes.
* @param promise Will be completed when all streams have been removed, and listeners have been notified.
* @return A future that will be completed when all streams have been removed, and listeners have been notified.
*/
Future close(Promise promise);
/**
* Creates a new key that is unique within this {@link Http2Connection}.
*/
PropertyKey newKey();
/**
* Adds a listener of stream life-cycle events.
*/
void addListener(Listener listener);
/**
* Removes a listener of stream life-cycle events. If the same listener was added multiple times
* then only the first occurrence gets removed.
*/
void removeListener(Listener listener);
/**
* Gets the stream if it exists. If not, returns {@code null}.
*/
Http2Stream stream(int streamId);
/**
* Indicates whether or not the given stream may have existed within this connection. This is a short form
* for calling {@link Endpoint#mayHaveCreatedStream(int)} on both endpoints.
*/
boolean streamMayHaveExisted(int streamId);
/**
* Gets the stream object representing the connection, itself (i.e. stream zero). This object
* always exists.
*/
Http2Stream connectionStream();
/**
* Gets the number of streams that are actively in use (i.e. {@code OPEN} or {@code HALF CLOSED}).
*/
int numActiveStreams();
/**
* Provide a means of iterating over the collection of active streams.
*
* @param visitor The visitor which will visit each active stream.
* @return The stream before iteration stopped or {@code null} if iteration went past the end.
*/
Http2Stream forEachActiveStream(Http2StreamVisitor visitor) throws Http2Exception;
/**
* Indicates whether or not the local endpoint for this connection is the server.
*/
boolean isServer();
/**
* Gets a view of this connection from the local {@link Endpoint}.
*/
Endpoint local();
/**
* Gets a view of this connection from the remote {@link Endpoint}.
*/
Endpoint remote();
/**
* Indicates whether or not a {@code GOAWAY} was received from the remote endpoint.
*/
boolean goAwayReceived();
/**
* Indicates that a {@code GOAWAY} was received from the remote endpoint and sets the last known stream.
* @param lastKnownStream The Last-Stream-ID in the
* GOAWAY frame.
* @param errorCode the Error Code in the
* GOAWAY frame.
* @param message The Additional Debug Data in the
* GOAWAY frame. Note that reference count ownership
* belongs to the caller (ownership is not transferred to this method).
*/
void goAwayReceived(int lastKnownStream, long errorCode, ByteBuf message) throws Http2Exception;
/**
* Indicates whether or not a {@code GOAWAY} was sent to the remote endpoint.
*/
boolean goAwaySent();
/**
* Updates the local state of this {@link Http2Connection} as a result of a {@code GOAWAY} to send to the remote
* endpoint.
* @param lastKnownStream The Last-Stream-ID in the
* GOAWAY frame.
* @param errorCode the Error Code in the
* GOAWAY frame.
* GOAWAY frame. Note that reference count ownership
* belongs to the caller (ownership is not transferred to this method).
* @return {@code true} if the corresponding {@code GOAWAY} frame should be sent to the remote endpoint.
*/
boolean goAwaySent(int lastKnownStream, long errorCode, ByteBuf message) throws Http2Exception;
}