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/*
* Copyright (C) 2011 The Android Open Source Project
*
* 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 okhttp3.internal.EMPTY_BYTE_ARRAY
import okhttp3.internal.EMPTY_HEADERS
import okhttp3.internal.assertThreadDoesntHoldLock
import okhttp3.internal.closeQuietly
import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.http2.ErrorCode.REFUSED_STREAM
import okhttp3.internal.http2.Settings.Companion.DEFAULT_INITIAL_WINDOW_SIZE
import okhttp3.internal.ignoreIoExceptions
import okhttp3.internal.notifyAll
import okhttp3.internal.peerName
import okhttp3.internal.platform.Platform
import okhttp3.internal.platform.Platform.Companion.INFO
import okhttp3.internal.toHeaders
import okhttp3.internal.wait
import okio.Buffer
import okio.BufferedSink
import okio.BufferedSource
import okio.ByteString
import okio.buffer
import okio.sink
import okio.source
import java.io.Closeable
import java.io.IOException
import java.io.InterruptedIOException
import java.net.Socket
import java.util.concurrent.TimeUnit
/**
* A socket connection to a remote peer. A connection hosts streams which can send and receive
* data.
*
* Many methods in this API are **synchronous:** the call is completed before the method returns.
* This is typical for Java but atypical for HTTP/2. This is motivated by exception transparency:
* an [IOException] that was triggered by a certain caller can be caught and handled by that caller.
*/
@Suppress("NAME_SHADOWING")
class Http2Connection internal constructor(builder: Builder) : Closeable {
// Internal state of this connection is guarded by 'this'. No blocking operations may be
// performed while holding this lock!
//
// Socket writes are guarded by frameWriter.
//
// Socket reads are unguarded but are only made by the reader thread.
//
// Certain operations (like SYN_STREAM) need to synchronize on both the frameWriter (to do
// blocking I/O) and this (to create streams). Such operations must synchronize on 'this' last.
// This ensures that we never wait for a blocking operation while holding 'this'.
/** True if this peer initiated the connection. */
internal val client: Boolean = builder.client
/** User code to run in response to incoming streams or settings. */
internal val listener: Listener = builder.listener
internal val streams = mutableMapOf()
internal val connectionName: String = builder.connectionName
internal var lastGoodStreamId = 0
/** http://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-5.1.1 */
internal var nextStreamId = if (builder.client) 3 else 2
private var isShutdown = false
/** For scheduling everything asynchronous. */
private val taskRunner = builder.taskRunner
/** Asynchronously writes frames to the outgoing socket. */
private val writerQueue = taskRunner.newQueue()
/** Ensures push promise callbacks events are sent in order per stream. */
private val pushQueue = taskRunner.newQueue()
/** Notifies the listener of settings changes. */
private val settingsListenerQueue = taskRunner.newQueue()
/** User code to run in response to push promise events. */
private val pushObserver: PushObserver = builder.pushObserver
// Total number of pings send and received of the corresponding types. All guarded by this.
private var intervalPingsSent = 0L
private var intervalPongsReceived = 0L
private var degradedPingsSent = 0L
private var degradedPongsReceived = 0L
private var awaitPingsSent = 0L
private var awaitPongsReceived = 0L
/** Consider this connection to be unhealthy if a degraded pong isn't received by this time. */
private var degradedPongDeadlineNs = 0L
/** Settings we communicate to the peer. */
val okHttpSettings = Settings().apply {
// Flow control was designed more for servers, or proxies than edge clients. If we are a client,
// set the flow control window to 16MiB. This avoids thrashing window updates every 64KiB, yet
// small enough to avoid blowing up the heap.
if (builder.client) {
set(Settings.INITIAL_WINDOW_SIZE, OKHTTP_CLIENT_WINDOW_SIZE)
}
}
/**
* Settings we receive from the peer. Changes to the field are guarded by this. The instance is
* never mutated once it has been assigned.
*/
var peerSettings = DEFAULT_SETTINGS
/** The total number of bytes consumed by the application. */
var readBytesTotal = 0L
private set
/** The total number of bytes acknowledged by outgoing `WINDOW_UPDATE` frames. */
var readBytesAcknowledged = 0L
private set
/** The total number of bytes produced by the application. */
var writeBytesTotal = 0L
private set
/** The total number of bytes permitted to be produced according to `WINDOW_UPDATE` frames. */
var writeBytesMaximum: Long = peerSettings.initialWindowSize.toLong()
private set
internal val socket: Socket = builder.socket
val writer = Http2Writer(builder.sink, client)
// Visible for testing
val readerRunnable = ReaderRunnable(Http2Reader(builder.source, client))
// Guarded by this.
private val currentPushRequests = mutableSetOf()
init {
if (builder.pingIntervalMillis != 0) {
val pingIntervalNanos = TimeUnit.MILLISECONDS.toNanos(builder.pingIntervalMillis.toLong())
writerQueue.schedule("$connectionName ping", pingIntervalNanos) {
val failDueToMissingPong = synchronized(this@Http2Connection) {
if (intervalPongsReceived < intervalPingsSent) {
return@synchronized true
} else {
intervalPingsSent++
return@synchronized false
}
}
if (failDueToMissingPong) {
failConnection(null)
return@schedule -1L
} else {
writePing(false, INTERVAL_PING, 0)
return@schedule pingIntervalNanos
}
}
}
}
/**
* Returns the number of [open streams][Http2Stream.isOpen] on this connection.
*/
@Synchronized fun openStreamCount(): Int = streams.size
@Synchronized fun getStream(id: Int): Http2Stream? = streams[id]
@Synchronized internal fun removeStream(streamId: Int): Http2Stream? {
val stream = streams.remove(streamId)
// The removed stream may be blocked on a connection-wide window update.
notifyAll()
return stream
}
@Synchronized internal fun updateConnectionFlowControl(read: Long) {
readBytesTotal += read
val readBytesToAcknowledge = readBytesTotal - readBytesAcknowledged
if (readBytesToAcknowledge >= okHttpSettings.initialWindowSize / 2) {
writeWindowUpdateLater(0, readBytesToAcknowledge)
readBytesAcknowledged += readBytesToAcknowledge
}
}
/**
* Returns a new server-initiated stream.
*
* @param associatedStreamId the stream that triggered the sender to create this stream.
* @param out true to create an output stream that we can use to send data to the remote peer.
* Corresponds to `FLAG_FIN`.
*/
@Throws(IOException::class)
fun pushStream(
associatedStreamId: Int,
requestHeaders: List,
out: Boolean
): Http2Stream {
check(!client) { "Client cannot push requests." }
return newStream(associatedStreamId, requestHeaders, out)
}
/**
* Returns a new locally-initiated stream.
*
* @param out true to create an output stream that we can use to send data to the remote peer.
* Corresponds to `FLAG_FIN`.
*/
@Throws(IOException::class)
fun newStream(
requestHeaders: List,
out: Boolean
): Http2Stream {
return newStream(0, requestHeaders, out)
}
@Throws(IOException::class)
private fun newStream(
associatedStreamId: Int,
requestHeaders: List,
out: Boolean
): Http2Stream {
val outFinished = !out
val inFinished = false
val flushHeaders: Boolean
val stream: Http2Stream
val streamId: Int
synchronized(writer) {
synchronized(this) {
if (nextStreamId > Int.MAX_VALUE / 2) {
shutdown(REFUSED_STREAM)
}
if (isShutdown) {
throw ConnectionShutdownException()
}
streamId = nextStreamId
nextStreamId += 2
stream = Http2Stream(streamId, this, outFinished, inFinished, null)
flushHeaders = !out ||
writeBytesTotal >= writeBytesMaximum ||
stream.writeBytesTotal >= stream.writeBytesMaximum
if (stream.isOpen) {
streams[streamId] = stream
}
}
if (associatedStreamId == 0) {
writer.headers(outFinished, streamId, requestHeaders)
} else {
require(!client) { "client streams shouldn't have associated stream IDs" }
// HTTP/2 has a PUSH_PROMISE frame.
writer.pushPromise(associatedStreamId, streamId, requestHeaders)
}
}
if (flushHeaders) {
writer.flush()
}
return stream
}
@Throws(IOException::class)
internal fun writeHeaders(
streamId: Int,
outFinished: Boolean,
alternating: List
) {
writer.headers(outFinished, streamId, alternating)
}
/**
* Callers of this method are not thread safe, and sometimes on application threads. Most often,
* this method will be called to send a buffer worth of data to the peer.
*
* Writes are subject to the write window of the stream and the connection. Until there is a
* window sufficient to send [byteCount], the caller will block. For example, a user of
* `HttpURLConnection` who flushes more bytes to the output stream than the connection's write
* window will block.
*
* Zero [byteCount] writes are not subject to flow control and will not block. The only use case
* for zero [byteCount] is closing a flushed output stream.
*/
@Throws(IOException::class)
fun writeData(
streamId: Int,
outFinished: Boolean,
buffer: Buffer?,
byteCount: Long
) {
// Empty data frames are not flow-controlled.
if (byteCount == 0L) {
writer.data(outFinished, streamId, buffer, 0)
return
}
var byteCount = byteCount
while (byteCount > 0L) {
var toWrite: Int
synchronized(this@Http2Connection) {
try {
while (writeBytesTotal >= writeBytesMaximum) {
// Before blocking, confirm that the stream we're writing is still open. It's possible
// that the stream has since been closed (such as if this write timed out.)
if (!streams.containsKey(streamId)) {
throw IOException("stream closed")
}
[email protected]() // Wait until we receive a WINDOW_UPDATE.
}
} catch (e: InterruptedException) {
Thread.currentThread().interrupt() // Retain interrupted status.
throw InterruptedIOException()
}
toWrite = minOf(byteCount, writeBytesMaximum - writeBytesTotal).toInt()
toWrite = minOf(toWrite, writer.maxDataLength())
writeBytesTotal += toWrite.toLong()
}
byteCount -= toWrite.toLong()
writer.data(outFinished && byteCount == 0L, streamId, buffer, toWrite)
}
}
internal fun writeSynResetLater(
streamId: Int,
errorCode: ErrorCode
) {
writerQueue.execute("$connectionName[$streamId] writeSynReset") {
try {
writeSynReset(streamId, errorCode)
} catch (e: IOException) {
failConnection(e)
}
}
}
@Throws(IOException::class)
internal fun writeSynReset(
streamId: Int,
statusCode: ErrorCode
) {
writer.rstStream(streamId, statusCode)
}
internal fun writeWindowUpdateLater(
streamId: Int,
unacknowledgedBytesRead: Long
) {
writerQueue.execute("$connectionName[$streamId] windowUpdate") {
try {
writer.windowUpdate(streamId, unacknowledgedBytesRead)
} catch (e: IOException) {
failConnection(e)
}
}
}
fun writePing(
reply: Boolean,
payload1: Int,
payload2: Int
) {
try {
writer.ping(reply, payload1, payload2)
} catch (e: IOException) {
failConnection(e)
}
}
/** For testing: sends a ping and waits for a pong. */
@Throws(InterruptedException::class)
fun writePingAndAwaitPong() {
writePing()
awaitPong()
}
/** For testing: sends a ping to be awaited with [awaitPong]. */
@Throws(InterruptedException::class)
fun writePing() {
synchronized(this) {
awaitPingsSent++
}
writePing(false, AWAIT_PING, 0x4f4b6f6b /* "OKok" */)
}
/** For testing: awaits a pong. */
@Synchronized @Throws(InterruptedException::class)
fun awaitPong() {
while (awaitPongsReceived < awaitPingsSent) {
wait()
}
}
@Throws(IOException::class)
fun flush() {
writer.flush()
}
/**
* Degrades this connection such that new streams can neither be created locally, nor accepted
* from the remote peer. Existing streams are not impacted. This is intended to permit an endpoint
* to gracefully stop accepting new requests without harming previously established streams.
*/
@Throws(IOException::class)
fun shutdown(statusCode: ErrorCode) {
synchronized(writer) {
val lastGoodStreamId: Int
synchronized(this) {
if (isShutdown) {
return
}
isShutdown = true
lastGoodStreamId = this.lastGoodStreamId
}
// TODO: propagate exception message into debugData.
// TODO: configure a timeout on the reader so that it doesn’t block forever.
writer.goAway(lastGoodStreamId, statusCode, EMPTY_BYTE_ARRAY)
}
}
/**
* Closes this connection. This cancels all open streams and unanswered pings. It closes the
* underlying input and output streams and shuts down internal task queues.
*/
override fun close() {
close(ErrorCode.NO_ERROR, ErrorCode.CANCEL, null)
}
internal fun close(
connectionCode: ErrorCode,
streamCode: ErrorCode,
cause: IOException?
) {
this.assertThreadDoesntHoldLock()
ignoreIoExceptions {
shutdown(connectionCode)
}
var streamsToClose: Array? = null
synchronized(this) {
if (streams.isNotEmpty()) {
streamsToClose = streams.values.toTypedArray()
streams.clear()
}
}
streamsToClose?.forEach { stream ->
ignoreIoExceptions {
stream.close(streamCode, cause)
}
}
// Close the writer to release its resources (such as deflaters).
ignoreIoExceptions {
writer.close()
}
// Close the socket to break out the reader thread, which will clean up after itself.
ignoreIoExceptions {
socket.close()
}
// Release the threads.
writerQueue.shutdown()
pushQueue.shutdown()
settingsListenerQueue.shutdown()
}
private fun failConnection(e: IOException?) {
close(ErrorCode.PROTOCOL_ERROR, ErrorCode.PROTOCOL_ERROR, e)
}
/**
* Sends any initial frames and starts reading frames from the remote peer. This should be called
* after [Builder.build] for all new connections.
*
* @param sendConnectionPreface true to send connection preface frames. This should always be true
* except for in tests that don't check for a connection preface.
*/
@Throws(IOException::class) @JvmOverloads
fun start(sendConnectionPreface: Boolean = true) {
if (sendConnectionPreface) {
writer.connectionPreface()
writer.settings(okHttpSettings)
val windowSize = okHttpSettings.initialWindowSize
if (windowSize != DEFAULT_INITIAL_WINDOW_SIZE) {
writer.windowUpdate(0, (windowSize - DEFAULT_INITIAL_WINDOW_SIZE).toLong())
}
}
Thread(readerRunnable, connectionName).start() // Not a daemon thread.
}
/** Merges [settings] into this peer's settings and sends them to the remote peer. */
@Throws(IOException::class)
fun setSettings(settings: Settings) {
synchronized(writer) {
synchronized(this) {
if (isShutdown) {
throw ConnectionShutdownException()
}
okHttpSettings.merge(settings)
}
writer.settings(settings)
}
}
@Synchronized
fun isHealthy(nowNs: Long): Boolean {
if (isShutdown) return false
// A degraded pong is overdue.
if (degradedPongsReceived < degradedPingsSent && nowNs >= degradedPongDeadlineNs) return false
return true
}
/**
* HTTP/2 can have both stream timeouts (due to a problem with a single stream) and connection
* timeouts (due to a problem with the transport). When a stream times out we don't know whether
* the problem impacts just one stream or the entire connection.
*
* To differentiate the two cases we ping the server when a stream times out. If the overall
* connection is fine the ping will receive a pong; otherwise it won't.
*
* The deadline to respond to this ping attempts to limit the cost of being wrong. If it is too
* long, streams created while we await the pong will reuse broken connections and inevitably
* fail. If it is too short, slow connections will be marked as failed and extra TCP and TLS
* handshakes will be required.
*
* The deadline is currently hardcoded. We may make this configurable in the future!
*/
internal fun sendDegradedPingLater() {
synchronized(this) {
if (degradedPongsReceived < degradedPingsSent) return // Already awaiting a degraded pong.
degradedPingsSent++
degradedPongDeadlineNs = System.nanoTime() + DEGRADED_PONG_TIMEOUT_NS
}
writerQueue.execute("$connectionName ping") {
writePing(false, DEGRADED_PING, 0)
}
}
class Builder(
/** True if this peer initiated the connection; false if this peer accepted the connection. */
internal var client: Boolean,
internal val taskRunner: TaskRunner
) {
internal lateinit var socket: Socket
internal lateinit var connectionName: String
internal lateinit var source: BufferedSource
internal lateinit var sink: BufferedSink
internal var listener = Listener.REFUSE_INCOMING_STREAMS
internal var pushObserver = PushObserver.CANCEL
internal var pingIntervalMillis: Int = 0
@Throws(IOException::class) @JvmOverloads
fun socket(
socket: Socket,
peerName: String = socket.peerName(),
source: BufferedSource = socket.source().buffer(),
sink: BufferedSink = socket.sink().buffer()
) = apply {
this.socket = socket
this.connectionName = when {
client -> "OkHttp $peerName"
else -> "MockWebServer $peerName"
}
this.source = source
this.sink = sink
}
fun listener(listener: Listener) = apply {
this.listener = listener
}
fun pushObserver(pushObserver: PushObserver) = apply {
this.pushObserver = pushObserver
}
fun pingIntervalMillis(pingIntervalMillis: Int) = apply {
this.pingIntervalMillis = pingIntervalMillis
}
fun build(): Http2Connection {
return Http2Connection(this)
}
}
/**
* Methods in this class must not lock FrameWriter. If a method needs to write a frame, create an
* async task to do so.
*/
inner class ReaderRunnable internal constructor(
internal val reader: Http2Reader
) : Runnable, Http2Reader.Handler {
override fun run() {
var connectionErrorCode = ErrorCode.INTERNAL_ERROR
var streamErrorCode = ErrorCode.INTERNAL_ERROR
var errorException: IOException? = null
try {
reader.readConnectionPreface(this)
while (reader.nextFrame(false, this)) {
}
connectionErrorCode = ErrorCode.NO_ERROR
streamErrorCode = ErrorCode.CANCEL
} catch (e: IOException) {
errorException = e
connectionErrorCode = ErrorCode.PROTOCOL_ERROR
streamErrorCode = ErrorCode.PROTOCOL_ERROR
} finally {
close(connectionErrorCode, streamErrorCode, errorException)
reader.closeQuietly()
}
}
@Throws(IOException::class)
override fun data(
inFinished: Boolean,
streamId: Int,
source: BufferedSource,
length: Int
) {
if (pushedStream(streamId)) {
pushDataLater(streamId, source, length, inFinished)
return
}
val dataStream = getStream(streamId)
if (dataStream == null) {
writeSynResetLater(streamId, ErrorCode.PROTOCOL_ERROR)
updateConnectionFlowControl(length.toLong())
source.skip(length.toLong())
return
}
dataStream.receiveData(source, length)
if (inFinished) {
dataStream.receiveHeaders(EMPTY_HEADERS, true)
}
}
override fun headers(
inFinished: Boolean,
streamId: Int,
associatedStreamId: Int,
headerBlock: List
) {
if (pushedStream(streamId)) {
pushHeadersLater(streamId, headerBlock, inFinished)
return
}
val stream: Http2Stream?
synchronized(this@Http2Connection) {
stream = getStream(streamId)
if (stream == null) {
// If we're shutdown, don't bother with this stream.
if (isShutdown) return
// If the stream ID is less than the last created ID, assume it's already closed.
if (streamId <= lastGoodStreamId) return
// If the stream ID is in the client's namespace, assume it's already closed.
if (streamId % 2 == nextStreamId % 2) return
// Create a stream.
val headers = headerBlock.toHeaders()
val newStream = Http2Stream(streamId, this@Http2Connection, false, inFinished, headers)
lastGoodStreamId = streamId
streams[streamId] = newStream
// Use a different task queue for each stream because they should be handled in parallel.
taskRunner.newQueue().execute("$connectionName[$streamId] onStream") {
try {
listener.onStream(newStream)
} catch (e: IOException) {
Platform.get().log("Http2Connection.Listener failure for $connectionName", INFO, e)
ignoreIoExceptions {
newStream.close(ErrorCode.PROTOCOL_ERROR, e)
}
}
}
return
}
}
// Update an existing stream.
stream!!.receiveHeaders(headerBlock.toHeaders(), inFinished)
}
override fun rstStream(streamId: Int, errorCode: ErrorCode) {
if (pushedStream(streamId)) {
pushResetLater(streamId, errorCode)
return
}
val rstStream = removeStream(streamId)
rstStream?.receiveRstStream(errorCode)
}
override fun settings(clearPrevious: Boolean, settings: Settings) {
writerQueue.execute("$connectionName applyAndAckSettings") {
applyAndAckSettings(clearPrevious, settings)
}
}
/**
* Apply inbound settings and send an acknowledgement to the peer that provided them.
*
* We need to apply the settings and ack them atomically. This is because some HTTP/2
* implementations (nghttp2) forbid peers from taking advantage of settings before they have
* acknowledged! In particular, we shouldn't send frames that assume a new `initialWindowSize`
* until we send the frame that acknowledges this new size.
*
* Since we can't ACK settings on the current reader thread (the reader thread can't write) we
* execute all peer settings logic on the writer thread. This relies on the fact that the
* writer task queue won't reorder tasks; otherwise settings could be applied in the opposite
* order than received.
*/
fun applyAndAckSettings(clearPrevious: Boolean, settings: Settings) {
var delta: Long
var streamsToNotify: Array?
var newPeerSettings: Settings
synchronized(writer) {
synchronized(this@Http2Connection) {
val previousPeerSettings = peerSettings
if (clearPrevious) {
newPeerSettings = settings
} else {
newPeerSettings = Settings().apply {
merge(previousPeerSettings)
merge(settings)
}
}
val peerInitialWindowSize = newPeerSettings.initialWindowSize.toLong()
delta = peerInitialWindowSize - previousPeerSettings.initialWindowSize.toLong()
streamsToNotify = when {
delta == 0L || streams.isEmpty() -> null // No adjustment is necessary.
else -> streams.values.toTypedArray()
}
peerSettings = newPeerSettings
settingsListenerQueue.execute("$connectionName onSettings") {
listener.onSettings(this@Http2Connection, newPeerSettings)
}
}
try {
writer.applyAndAckSettings(newPeerSettings)
} catch (e: IOException) {
failConnection(e)
}
}
if (streamsToNotify != null) {
for (stream in streamsToNotify!!) {
synchronized(stream) {
stream.addBytesToWriteWindow(delta)
}
}
}
}
override fun ackSettings() {
// TODO: If we don't get this callback after sending settings to the peer, SETTINGS_TIMEOUT.
}
override fun ping(
ack: Boolean,
payload1: Int,
payload2: Int
) {
if (ack) {
synchronized(this@Http2Connection) {
when (payload1) {
INTERVAL_PING -> {
intervalPongsReceived++
}
DEGRADED_PING -> {
degradedPongsReceived++
}
AWAIT_PING -> {
awaitPongsReceived++
[email protected]()
}
else -> {
// Ignore an unexpected pong.
}
}
}
} else {
// Send a reply to a client ping if this is a server and vice versa.
writerQueue.execute("$connectionName ping") {
writePing(true, payload1, payload2)
}
}
}
override fun goAway(
lastGoodStreamId: Int,
errorCode: ErrorCode,
debugData: ByteString
) {
if (debugData.size > 0) {
// TODO: log the debugData
}
// Copy the streams first. We don't want to hold a lock when we call receiveRstStream().
val streamsCopy: Array
synchronized(this@Http2Connection) {
streamsCopy = streams.values.toTypedArray()
isShutdown = true
}
// Fail all streams created after the last good stream ID.
for (http2Stream in streamsCopy) {
if (http2Stream.id > lastGoodStreamId && http2Stream.isLocallyInitiated) {
http2Stream.receiveRstStream(REFUSED_STREAM)
removeStream(http2Stream.id)
}
}
}
override fun windowUpdate(streamId: Int, windowSizeIncrement: Long) {
if (streamId == 0) {
synchronized(this@Http2Connection) {
writeBytesMaximum += windowSizeIncrement
[email protected]()
}
} else {
val stream = getStream(streamId)
if (stream != null) {
synchronized(stream) {
stream.addBytesToWriteWindow(windowSizeIncrement)
}
}
}
}
override fun priority(
streamId: Int,
streamDependency: Int,
weight: Int,
exclusive: Boolean
) {
// TODO: honor priority.
}
override fun pushPromise(
streamId: Int,
promisedStreamId: Int,
requestHeaders: List
) {
pushRequestLater(promisedStreamId, requestHeaders)
}
override fun alternateService(
streamId: Int,
origin: String,
protocol: ByteString,
host: String,
port: Int,
maxAge: Long
) {
// TODO: register alternate service.
}
}
/** Even, positive numbered streams are pushed streams in HTTP/2. */
internal fun pushedStream(streamId: Int): Boolean = streamId != 0 && streamId and 1 == 0
internal fun pushRequestLater(streamId: Int, requestHeaders: List) {
synchronized(this) {
if (streamId in currentPushRequests) {
writeSynResetLater(streamId, ErrorCode.PROTOCOL_ERROR)
return
}
currentPushRequests.add(streamId)
}
pushQueue.execute("$connectionName[$streamId] onRequest") {
val cancel = pushObserver.onRequest(streamId, requestHeaders)
ignoreIoExceptions {
if (cancel) {
writer.rstStream(streamId, ErrorCode.CANCEL)
synchronized(this@Http2Connection) {
currentPushRequests.remove(streamId)
}
}
}
}
}
internal fun pushHeadersLater(
streamId: Int,
requestHeaders: List,
inFinished: Boolean
) {
pushQueue.execute("$connectionName[$streamId] onHeaders") {
val cancel = pushObserver.onHeaders(streamId, requestHeaders, inFinished)
ignoreIoExceptions {
if (cancel) writer.rstStream(streamId, ErrorCode.CANCEL)
if (cancel || inFinished) {
synchronized(this@Http2Connection) {
currentPushRequests.remove(streamId)
}
}
}
}
}
/**
* Eagerly reads `byteCount` bytes from the source before launching a background task to
* process the data. This avoids corrupting the stream.
*/
@Throws(IOException::class)
internal fun pushDataLater(
streamId: Int,
source: BufferedSource,
byteCount: Int,
inFinished: Boolean
) {
val buffer = Buffer()
source.require(byteCount.toLong()) // Eagerly read the frame before firing client thread.
source.read(buffer, byteCount.toLong())
pushQueue.execute("$connectionName[$streamId] onData") {
ignoreIoExceptions {
val cancel = pushObserver.onData(streamId, buffer, byteCount, inFinished)
if (cancel) writer.rstStream(streamId, ErrorCode.CANCEL)
if (cancel || inFinished) {
synchronized(this@Http2Connection) {
currentPushRequests.remove(streamId)
}
}
}
}
}
internal fun pushResetLater(streamId: Int, errorCode: ErrorCode) {
pushQueue.execute("$connectionName[$streamId] onReset") {
pushObserver.onReset(streamId, errorCode)
synchronized(this@Http2Connection) {
currentPushRequests.remove(streamId)
}
}
}
/** Listener of streams and settings initiated by the peer. */
abstract class Listener {
/**
* Handle a new stream from this connection's peer. Implementations should respond by either
* [replying to the stream][Http2Stream.writeHeaders] or [closing it][Http2Stream.close]. This
* response does not need to be synchronous.
*
* Multiple calls to this method may be made concurrently.
*/
@Throws(IOException::class)
abstract fun onStream(stream: Http2Stream)
/**
* Notification that the connection's peer's settings may have changed to [settings].
* Implementations should take appropriate action to handle the updated settings.
*
* Methods to this method may be made concurrently with [onStream]. But a calls to this method
* are serialized.
*/
open fun onSettings(connection: Http2Connection, settings: Settings) {}
companion object {
@JvmField
val REFUSE_INCOMING_STREAMS: Listener = object : Listener() {
@Throws(IOException::class)
override fun onStream(stream: Http2Stream) {
stream.close(REFUSED_STREAM, null)
}
}
}
}
companion object {
const val OKHTTP_CLIENT_WINDOW_SIZE = 16 * 1024 * 1024
val DEFAULT_SETTINGS = Settings().apply {
set(Settings.INITIAL_WINDOW_SIZE, DEFAULT_INITIAL_WINDOW_SIZE)
set(Settings.MAX_FRAME_SIZE, Http2.INITIAL_MAX_FRAME_SIZE)
}
const val INTERVAL_PING = 1
const val DEGRADED_PING = 2
const val AWAIT_PING = 3
const val DEGRADED_PONG_TIMEOUT_NS = 1_000_000_000 // 1 second.
}
}