All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.apache.coyote.http2.StreamStateMachine Maven / Gradle / Ivy

There is a newer version: 11.0.1
Show newest version
/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF 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
 *
 *      http://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 org.apache.coyote.http2;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.res.StringManager;

/**
 * See state diagram in RFC 7540. 
* The following additions are supported by this state machine: *
    *
  • differentiate between closed (normal) and closed caused by reset
  • *
*/ class StreamStateMachine { private static final Log log = LogFactory.getLog(StreamStateMachine.class); private static final StringManager sm = StringManager.getManager(StreamStateMachine.class); private final String connectionId; private final String streamId; private State state; StreamStateMachine(String connectionId, String streamId) { this.connectionId = connectionId; this.streamId = streamId; stateChange(null, State.IDLE); } final synchronized void sentHeaders() { // No change if currently OPEN stateChange(State.RESERVED_LOCAL, State.HALF_CLOSED_REMOTE); } final synchronized void receivedStartOfHeaders() { stateChange(State.IDLE, State.OPEN); stateChange(State.RESERVED_REMOTE, State.HALF_CLOSED_LOCAL); } final synchronized void sentEndOfStream() { stateChange(State.OPEN, State.HALF_CLOSED_LOCAL); stateChange(State.HALF_CLOSED_REMOTE, State.CLOSED_TX); } final synchronized void receivedEndOfStream() { stateChange(State.OPEN, State.HALF_CLOSED_REMOTE); stateChange(State.HALF_CLOSED_LOCAL, State.CLOSED_RX); } /** * Marks the stream as reset. This method will not change the stream state if: *
    *
  • The stream is already reset
  • *
  • The stream is already closed
  • *
* * @throws IllegalStateException If the stream is in a state that does not permit resets */ public synchronized void sendReset() { if (state == State.IDLE) { throw new IllegalStateException(sm.getString("streamStateMachine.invalidReset", connectionId, streamId)); } if (state.canReset()) { stateChange(state, State.CLOSED_RST_TX); } } final synchronized void receivedReset() { stateChange(state, State.CLOSED_RST_RX); } private void stateChange(State oldState, State newState) { if (state == oldState) { state = newState; if (log.isTraceEnabled()) { log.trace(sm.getString("streamStateMachine.debug.change", connectionId, streamId, oldState, newState)); } } } final synchronized void checkFrameType(FrameType frameType) throws Http2Exception { // No state change. Checks that receiving the frame type is valid for // the current state of this stream. if (!isFrameTypePermitted(frameType)) { if (state.connectionErrorForInvalidFrame) { throw new ConnectionException( sm.getString("streamStateMachine.invalidFrame", connectionId, streamId, state, frameType), state.errorCodeForInvalidFrame); } else { throw new StreamException( sm.getString("streamStateMachine.invalidFrame", connectionId, streamId, state, frameType), state.errorCodeForInvalidFrame, Integer.parseInt(streamId)); } } } final synchronized boolean isFrameTypePermitted(FrameType frameType) { return state.isFrameTypePermitted(frameType); } final synchronized boolean isActive() { return state.isActive(); } final synchronized boolean canRead() { return state.canRead(); } final synchronized boolean canWrite() { return state.canWrite(); } final synchronized boolean isClosedFinal() { return state == State.CLOSED_FINAL; } final synchronized void closeIfIdle() { stateChange(State.IDLE, State.CLOSED_FINAL); } final synchronized String getCurrentStateName() { return state.name(); } private enum State { // @formatter:off IDLE (false, false, false, true, Http2Error.PROTOCOL_ERROR, FrameType.HEADERS, FrameType.PRIORITY), OPEN (true, true, true, true, Http2Error.PROTOCOL_ERROR, FrameType.DATA, FrameType.HEADERS, FrameType.PRIORITY, FrameType.RST, FrameType.PUSH_PROMISE, FrameType.WINDOW_UPDATE), RESERVED_LOCAL (false, false, true, true, Http2Error.PROTOCOL_ERROR, FrameType.PRIORITY, FrameType.RST, FrameType.WINDOW_UPDATE), RESERVED_REMOTE (false, true, true, true, Http2Error.PROTOCOL_ERROR, FrameType.HEADERS, FrameType.PRIORITY, FrameType.RST), HALF_CLOSED_LOCAL (true, false, true, true, Http2Error.PROTOCOL_ERROR, FrameType.DATA, FrameType.HEADERS, FrameType.PRIORITY, FrameType.RST, FrameType.PUSH_PROMISE, FrameType.WINDOW_UPDATE), HALF_CLOSED_REMOTE (false, true, true, true, Http2Error.STREAM_CLOSED, FrameType.PRIORITY, FrameType.RST, FrameType.WINDOW_UPDATE), CLOSED_RX (false, false, false, true, Http2Error.STREAM_CLOSED, FrameType.PRIORITY), CLOSED_TX (false, false, false, true, Http2Error.STREAM_CLOSED, FrameType.PRIORITY, FrameType.RST, FrameType.WINDOW_UPDATE), CLOSED_RST_RX (false, false, false, false, Http2Error.STREAM_CLOSED, FrameType.PRIORITY), CLOSED_RST_TX (false, false, false, false, Http2Error.STREAM_CLOSED, FrameType.DATA, FrameType.HEADERS, FrameType.PRIORITY, FrameType.RST, FrameType.PUSH_PROMISE, FrameType.WINDOW_UPDATE), CLOSED_FINAL (false, false, false, true, Http2Error.PROTOCOL_ERROR, FrameType.PRIORITY); // @formatter:on private final boolean canRead; private final boolean canWrite; private final boolean canReset; private final boolean connectionErrorForInvalidFrame; private final Http2Error errorCodeForInvalidFrame; private final Set frameTypesPermitted; State(boolean canRead, boolean canWrite, boolean canReset, boolean connectionErrorForInvalidFrame, Http2Error errorCode, FrameType... frameTypes) { this.canRead = canRead; this.canWrite = canWrite; this.canReset = canReset; this.connectionErrorForInvalidFrame = connectionErrorForInvalidFrame; this.errorCodeForInvalidFrame = errorCode; frameTypesPermitted = new HashSet<>(Arrays.asList(frameTypes)); } public boolean isActive() { return canWrite || canRead; } public boolean canRead() { return canRead; } public boolean canWrite() { return canWrite; } public boolean canReset() { return canReset; } public boolean isFrameTypePermitted(FrameType frameType) { return frameTypesPermitted.contains(frameType); } } }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy