okhttp3.internal.http2.PushObserver.kt 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 okhttp3.Protocol
import okio.BufferedSource
/**
* [HTTP/2][Protocol.HTTP_2] only. Processes server-initiated HTTP requests on the client.
* Implementations must quickly dispatch callbacks to avoid creating a bottleneck.
*
* While [onReset] may occur at any time, the following callbacks are expected in order,
* correlated by stream ID.
*
* * [onRequest]
* * [onHeaders] (unless canceled)
* * [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.
*/
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 `:method`, `:scheme`, `:authority`,
* and `:path`.
*/
fun onRequest(streamId: Int, requestHeaders: List): Boolean
/**
* The response headers corresponding to a pushed request. When [last] is true, there are
* no data frames to follow.
*
* @param streamId server-initiated stream ID: an even number.
* @param responseHeaders minimally includes `:status`.
* @param last when true, there is no response data.
*/
fun onHeaders(streamId: Int, responseHeaders: List, last: Boolean): Boolean
/**
* 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.
*/
@Throws(IOException::class)
fun onData(streamId: Int, source: BufferedSource, byteCount: Int, last: Boolean): Boolean
/** Indicates the reason why this stream was canceled. */
fun onReset(streamId: Int, errorCode: ErrorCode)
companion object {
@JvmField val CANCEL: PushObserver = object : PushObserver {
override fun onRequest(streamId: Int, requestHeaders: List): Boolean {
return true
}
override fun onHeaders(streamId: Int, responseHeaders: List, last: Boolean): Boolean {
return true
}
@Throws(IOException::class)
override fun onData(streamId: Int, source: BufferedSource, byteCount: Int, last: Boolean): Boolean {
source.skip(byteCount.toLong())
return true
}
override fun onReset(streamId: Int, errorCode: ErrorCode) {
}
}
}
}