okhttp3.internal.http2.PushObserver Maven / Gradle / Ivy
/*
* Copyright (C) 2014 Square, Inc.
*
* Licensed 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 okhttp3.internal.http2;
import java.io.IOException;
import java.util.List;
import okhttp3.Protocol;
import okio.BufferedSource;
/**
* {@link Protocol#HTTP_2 HTTP/2} only. Processes server-initiated HTTP requests on the client.
* Implementations must quickly dispatch callbacks to avoid creating a bottleneck.
*
* While {@link #onReset} may occur at any time, the following callbacks are expected in order,
* correlated by stream ID.
*
*
* - {@link #onRequest}
- {@link #onHeaders} (unless canceled)
*
- {@link #onData} (optional sequence of data frames)
*
*
* As a stream ID is scoped to a single HTTP/2 connection, implementations which target multiple
* connections should expect repetition of stream IDs.
*
*
Return true to request cancellation of a pushed stream. Note that this does not guarantee
* future frames won't arrive on the stream ID.
*/
public interface PushObserver {
/**
* Describes the request that the server intends to push a response for.
*
* @param streamId server-initiated stream ID: an even number.
* @param requestHeaders minimally includes {@code :method}, {@code :scheme}, {@code :authority},
* and {@code :path}.
*/
boolean onRequest(int streamId, List requestHeaders);
/**
* The response headers corresponding to a pushed request. When {@code last} is true, there are
* no data frames to follow.
*
* @param streamId server-initiated stream ID: an even number.
* @param responseHeaders minimally includes {@code :status}.
* @param last when true, there is no response data.
*/
boolean onHeaders(int streamId, List responseHeaders, boolean last);
/**
* A chunk of response data corresponding to a pushed request. This data must either be read or
* skipped.
*
* @param streamId server-initiated stream ID: an even number.
* @param source location of data corresponding with this stream ID.
* @param byteCount number of bytes to read or skip from the source.
* @param last when true, there are no data frames to follow.
*/
boolean onData(int streamId, BufferedSource source, int byteCount, boolean last)
throws IOException;
/** Indicates the reason why this stream was canceled. */
void onReset(int streamId, ErrorCode errorCode);
PushObserver CANCEL = new PushObserver() {
@Override public boolean onRequest(int streamId, List requestHeaders) {
return true;
}
@Override public boolean onHeaders(int streamId, List responseHeaders, boolean last) {
return true;
}
@Override public boolean onData(int streamId, BufferedSource source, int byteCount,
boolean last) throws IOException {
source.skip(byteCount);
return true;
}
@Override public void onReset(int streamId, ErrorCode errorCode) {
}
};
}