Files
async-http-client/Sources/AsyncHTTPClient/ConnectionPool/HTTPConnectionPool.swift
T
Rick Newton-Rogers c621142327 Adopt GitHub actions (#780)
Migrate CI to use GitHub Actions.

### Motivation:

To migrate to GitHub actions and centralised infrastructure.

### Modifications:

Changes of note:
* Adopt swift-format using rules from SwiftNIO.
* Remove scripts and docker files which are no longer needed.
* Disabled warnings-as-errors on Swift 6.0 CI pipelines for now.

### Result:

Feature parity with old CI.
2024-10-29 15:01:46 +00:00

783 lines
28 KiB
Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the AsyncHTTPClient open source project
//
// Copyright (c) 2021 Apple Inc. and the AsyncHTTPClient project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of AsyncHTTPClient project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
import Logging
import NIOConcurrencyHelpers
import NIOCore
import NIOSSL
protocol HTTPConnectionPoolDelegate {
func connectionPoolDidShutdown(_ pool: HTTPConnectionPool, unclean: Bool)
}
final class HTTPConnectionPool {
private let stateLock = NIOLock()
private var _state: StateMachine
/// The connection idle timeout timers. Protected by the stateLock
private var _idleTimer = [Connection.ID: Scheduled<Void>]()
/// The connection backoff timeout timers. Protected by the stateLock
private var _backoffTimer = [Connection.ID: Scheduled<Void>]()
/// The request connection timeout timers. Protected by the stateLock
private var _requestTimer = [Request.ID: Scheduled<Void>]()
private static let fallbackConnectTimeout: TimeAmount = .seconds(30)
let key: ConnectionPool.Key
private var logger: Logger
private let eventLoopGroup: EventLoopGroup
private let connectionFactory: ConnectionFactory
private let clientConfiguration: HTTPClient.Configuration
private let idleConnectionTimeout: TimeAmount
let delegate: HTTPConnectionPoolDelegate
init(
eventLoopGroup: EventLoopGroup,
sslContextCache: SSLContextCache,
tlsConfiguration: TLSConfiguration?,
clientConfiguration: HTTPClient.Configuration,
key: ConnectionPool.Key,
delegate: HTTPConnectionPoolDelegate,
idGenerator: Connection.ID.Generator,
backgroundActivityLogger logger: Logger
) {
self.eventLoopGroup = eventLoopGroup
self.connectionFactory = ConnectionFactory(
key: key,
tlsConfiguration: tlsConfiguration,
clientConfiguration: clientConfiguration,
sslContextCache: sslContextCache
)
self.clientConfiguration = clientConfiguration
self.key = key
self.delegate = delegate
var logger = logger
logger[metadataKey: "ahc-pool-key"] = "\(key)"
self.logger = logger
self.idleConnectionTimeout = clientConfiguration.connectionPool.idleTimeout
self._state = StateMachine(
idGenerator: idGenerator,
maximumConcurrentHTTP1Connections: clientConfiguration.connectionPool
.concurrentHTTP1ConnectionsPerHostSoftLimit,
retryConnectionEstablishment: clientConfiguration.connectionPool.retryConnectionEstablishment,
preferHTTP1: clientConfiguration.httpVersion == .http1Only,
maximumConnectionUses: clientConfiguration.maximumUsesPerConnection
)
}
func executeRequest(_ request: HTTPSchedulableRequest) {
self.modifyStateAndRunActions { $0.executeRequest(.init(request)) }
}
func shutdown() {
self.logger.debug("Shutting down connection pool")
self.modifyStateAndRunActions { $0.shutdown() }
}
// MARK: - Private Methods -
// MARK: Actions
/// An `HTTPConnectionPool` internal action type that matches the `StateMachine`'s action.
/// However it splits up the actions into actions that need to be executed inside the `stateLock`
/// and outside the `stateLock`.
private struct Actions {
enum ConnectionAction {
enum Unlocked {
case createConnection(Connection.ID, on: EventLoop)
case closeConnection(Connection, isShutdown: StateMachine.ConnectionAction.IsShutdown)
case cleanupConnections(CleanupContext, isShutdown: StateMachine.ConnectionAction.IsShutdown)
case migration(
createConnections: [(Connection.ID, EventLoop)],
closeConnections: [Connection]
)
case none
}
enum Locked {
case scheduleBackoffTimer(Connection.ID, backoff: TimeAmount, on: EventLoop)
case cancelBackoffTimers([Connection.ID])
case scheduleTimeoutTimer(Connection.ID, on: EventLoop)
case cancelTimeoutTimer(Connection.ID)
case none
}
}
enum RequestAction {
enum Unlocked {
case executeRequest(Request, Connection)
case executeRequests([Request], Connection)
case failRequest(Request, Error)
case failRequests([Request], Error)
case none
}
enum Locked {
case scheduleRequestTimeout(for: Request, on: EventLoop)
case cancelRequestTimeout(Request.ID)
case cancelRequestTimeouts([Request])
case none
}
}
struct Locked {
var connection: ConnectionAction.Locked
var request: RequestAction.Locked
}
struct Unlocked {
var connection: ConnectionAction.Unlocked
var request: RequestAction.Unlocked
}
var locked: Locked
var unlocked: Unlocked
init(from stateMachineAction: StateMachine.Action) {
self.locked = Locked(connection: .none, request: .none)
self.unlocked = Unlocked(connection: .none, request: .none)
switch stateMachineAction.request {
case .executeRequest(let request, let connection, let cancelTimeout):
if cancelTimeout {
self.locked.request = .cancelRequestTimeout(request.id)
}
self.unlocked.request = .executeRequest(request, connection)
case .executeRequestsAndCancelTimeouts(let requests, let connection):
self.locked.request = .cancelRequestTimeouts(requests)
self.unlocked.request = .executeRequests(requests, connection)
case .failRequest(let request, let error, let cancelTimeout):
if cancelTimeout {
self.locked.request = .cancelRequestTimeout(request.id)
}
self.unlocked.request = .failRequest(request, error)
case .failRequestsAndCancelTimeouts(let requests, let error):
self.locked.request = .cancelRequestTimeouts(requests)
self.unlocked.request = .failRequests(requests, error)
case .scheduleRequestTimeout(for: let request, on: let eventLoop):
self.locked.request = .scheduleRequestTimeout(for: request, on: eventLoop)
case .none:
break
}
switch stateMachineAction.connection {
case .createConnection(let connectionID, on: let eventLoop):
self.unlocked.connection = .createConnection(connectionID, on: eventLoop)
case .scheduleBackoffTimer(let connectionID, let backoff, on: let eventLoop):
self.locked.connection = .scheduleBackoffTimer(connectionID, backoff: backoff, on: eventLoop)
case .scheduleTimeoutTimer(let connectionID, on: let eventLoop):
self.locked.connection = .scheduleTimeoutTimer(connectionID, on: eventLoop)
case .cancelTimeoutTimer(let connectionID):
self.locked.connection = .cancelTimeoutTimer(connectionID)
case .closeConnection(let connection, let isShutdown):
self.unlocked.connection = .closeConnection(connection, isShutdown: isShutdown)
case .cleanupConnections(var cleanupContext, let isShutdown):
//
self.locked.connection = .cancelBackoffTimers(cleanupContext.connectBackoff)
cleanupContext.connectBackoff = []
self.unlocked.connection = .cleanupConnections(cleanupContext, isShutdown: isShutdown)
case .migration(
let createConnections,
let closeConnections,
let scheduleTimeout
):
if let (connectionID, eventLoop) = scheduleTimeout {
self.locked.connection = .scheduleTimeoutTimer(connectionID, on: eventLoop)
}
self.unlocked.connection = .migration(
createConnections: createConnections,
closeConnections: closeConnections
)
case .none:
break
}
}
}
// MARK: Run actions
private func modifyStateAndRunActions(_ closure: (inout StateMachine) -> StateMachine.Action) {
let unlockedActions = self.stateLock.withLock { () -> Actions.Unlocked in
let stateMachineAction = closure(&self._state)
let poolAction = Actions(from: stateMachineAction)
self.runLockedConnectionAction(poolAction.locked.connection)
self.runLockedRequestAction(poolAction.locked.request)
return poolAction.unlocked
}
self.runUnlockedActions(unlockedActions)
}
private func runLockedConnectionAction(_ action: Actions.ConnectionAction.Locked) {
switch action {
case .scheduleBackoffTimer(let connectionID, let backoff, on: let eventLoop):
self.scheduleConnectionStartBackoffTimer(connectionID, backoff, on: eventLoop)
case .scheduleTimeoutTimer(let connectionID, on: let eventLoop):
self.scheduleIdleTimerForConnection(connectionID, on: eventLoop)
case .cancelTimeoutTimer(let connectionID):
self.cancelIdleTimerForConnection(connectionID)
case .cancelBackoffTimers(let connectionIDs):
for connectionID in connectionIDs {
self.cancelConnectionStartBackoffTimer(connectionID)
}
case .none:
break
}
}
private func runLockedRequestAction(_ action: Actions.RequestAction.Locked) {
switch action {
case .scheduleRequestTimeout(for: let request, on: let eventLoop):
self.scheduleRequestTimeout(request, on: eventLoop)
case .cancelRequestTimeout(let requestID):
self.cancelRequestTimeout(requestID)
case .cancelRequestTimeouts(let requests):
for request in requests { self.cancelRequestTimeout(request.id) }
case .none:
break
}
}
private func runUnlockedActions(_ actions: Actions.Unlocked) {
self.runUnlockedConnectionAction(actions.connection)
self.runUnlockedRequestAction(actions.request)
}
private func runUnlockedConnectionAction(_ action: Actions.ConnectionAction.Unlocked) {
switch action {
case .createConnection(let connectionID, let eventLoop):
self.createConnection(connectionID, on: eventLoop)
case .closeConnection(let connection, let isShutdown):
self.logger.trace(
"close connection",
metadata: [
"ahc-connection-id": "\(connection.id)"
]
)
// we are not interested in the close promise...
connection.close(promise: nil)
if case .yes(let unclean) = isShutdown {
self.delegate.connectionPoolDidShutdown(self, unclean: unclean)
}
case .cleanupConnections(let cleanupContext, let isShutdown):
for connection in cleanupContext.close {
connection.close(promise: nil)
}
for connection in cleanupContext.cancel {
connection.shutdown()
}
for connectionID in cleanupContext.connectBackoff {
self.cancelConnectionStartBackoffTimer(connectionID)
}
if case .yes(let unclean) = isShutdown {
self.delegate.connectionPoolDidShutdown(self, unclean: unclean)
}
case .migration(let createConnections, let closeConnections):
for connection in closeConnections {
connection.close(promise: nil)
}
for (connectionID, eventLoop) in createConnections {
self.createConnection(connectionID, on: eventLoop)
}
case .none:
break
}
}
private func runUnlockedRequestAction(_ action: Actions.RequestAction.Unlocked) {
switch action {
case .executeRequest(let request, let connection):
connection.executeRequest(request.req)
case .executeRequests(let requests, let connection):
for request in requests { connection.executeRequest(request.req) }
case .failRequest(let request, let error):
request.req.fail(error)
case .failRequests(let requests, let error):
for request in requests { request.req.fail(error) }
case .none:
break
}
}
private func createConnection(_ connectionID: Connection.ID, on eventLoop: EventLoop) {
self.logger.trace(
"Opening fresh connection",
metadata: [
"ahc-connection-id": "\(connectionID)"
]
)
// Even though this function is called make it actually creates/establishes a connection.
// TBD: Should we rename it? To what?
self.connectionFactory.makeConnection(
for: self,
connectionID: connectionID,
http1ConnectionDelegate: self,
http2ConnectionDelegate: self,
deadline: .now() + (self.clientConfiguration.timeout.connect ?? Self.fallbackConnectTimeout),
eventLoop: eventLoop,
logger: self.logger
)
}
private func scheduleRequestTimeout(_ request: Request, on eventLoop: EventLoop) {
let requestID = request.id
let scheduled = eventLoop.scheduleTask(deadline: request.connectionDeadline) {
// there might be a race between a the timeout timer and the pool scheduling the
// request on another thread.
self.modifyStateAndRunActions { stateMachine in
if self._requestTimer.removeValue(forKey: requestID) != nil {
// The timer still exists. State Machines assumes it is alive. Inform state
// machine.
return stateMachine.timeoutRequest(requestID)
}
return .none
}
}
assert(self._requestTimer[requestID] == nil)
self._requestTimer[requestID] = scheduled
request.req.requestWasQueued(self)
}
private func cancelRequestTimeout(_ id: Request.ID) {
guard let cancelTimer = self._requestTimer.removeValue(forKey: id) else {
preconditionFailure("Expected to have a timer for request \(id) at this point.")
}
cancelTimer.cancel()
}
private func scheduleIdleTimerForConnection(_ connectionID: Connection.ID, on eventLoop: EventLoop) {
self.logger.trace(
"Schedule idle connection timeout timer",
metadata: [
"ahc-connection-id": "\(connectionID)"
]
)
let scheduled = eventLoop.scheduleTask(in: self.idleConnectionTimeout) {
// there might be a race between a cancelTimer call and the triggering
// of this scheduled task. both want to acquire the lock
self.modifyStateAndRunActions { stateMachine in
if self._idleTimer.removeValue(forKey: connectionID) != nil {
// The timer still exists. State Machines assumes it is alive
return stateMachine.connectionIdleTimeout(connectionID)
}
return .none
}
}
assert(self._idleTimer[connectionID] == nil)
self._idleTimer[connectionID] = scheduled
}
private func cancelIdleTimerForConnection(_ connectionID: Connection.ID) {
self.logger.trace(
"Cancel idle connection timeout timer",
metadata: [
"ahc-connection-id": "\(connectionID)"
]
)
guard let cancelTimer = self._idleTimer.removeValue(forKey: connectionID) else {
preconditionFailure("Expected to have an idle timer for connection \(connectionID) at this point.")
}
cancelTimer.cancel()
}
private func scheduleConnectionStartBackoffTimer(
_ connectionID: Connection.ID,
_ timeAmount: TimeAmount,
on eventLoop: EventLoop
) {
self.logger.trace(
"Schedule connection creation backoff timer",
metadata: [
"ahc-connection-id": "\(connectionID)"
]
)
let scheduled = eventLoop.scheduleTask(in: timeAmount) {
// there might be a race between a backoffTimer and the pool shutting down.
self.modifyStateAndRunActions { stateMachine in
if self._backoffTimer.removeValue(forKey: connectionID) != nil {
// The timer still exists. State Machines assumes it is alive
return stateMachine.connectionCreationBackoffDone(connectionID)
}
return .none
}
}
assert(self._backoffTimer[connectionID] == nil)
self._backoffTimer[connectionID] = scheduled
}
private func cancelConnectionStartBackoffTimer(_ connectionID: Connection.ID) {
guard let backoffTimer = self._backoffTimer.removeValue(forKey: connectionID) else {
preconditionFailure("Expected to have a backoff timer for connection \(connectionID) at this point.")
}
backoffTimer.cancel()
}
}
// MARK: - Protocol methods -
extension HTTPConnectionPool: HTTPConnectionRequester {
func http1ConnectionCreated(_ connection: HTTP1Connection) {
self.logger.trace(
"successfully created connection",
metadata: [
"ahc-connection-id": "\(connection.id)",
"ahc-http-version": "http/1.1",
]
)
self.modifyStateAndRunActions {
$0.newHTTP1ConnectionCreated(.http1_1(connection))
}
}
func http2ConnectionCreated(_ connection: HTTP2Connection, maximumStreams: Int) {
self.logger.trace(
"successfully created connection",
metadata: [
"ahc-connection-id": "\(connection.id)",
"ahc-http-version": "http/2",
"ahc-max-streams": "\(maximumStreams)",
]
)
self.modifyStateAndRunActions {
$0.newHTTP2ConnectionCreated(.http2(connection), maxConcurrentStreams: maximumStreams)
}
}
func failedToCreateHTTPConnection(_ connectionID: HTTPConnectionPool.Connection.ID, error: Error) {
self.logger.debug(
"connection attempt failed",
metadata: [
"ahc-error": "\(error)",
"ahc-connection-id": "\(connectionID)",
]
)
self.modifyStateAndRunActions {
$0.failedToCreateNewConnection(error, connectionID: connectionID)
}
}
func waitingForConnectivity(_ connectionID: HTTPConnectionPool.Connection.ID, error: Error) {
self.logger.debug(
"waiting for connectivity",
metadata: [
"ahc-error": "\(error)",
"ahc-connection-id": "\(connectionID)",
]
)
self.modifyStateAndRunActions {
$0.waitingForConnectivity(error, connectionID: connectionID)
}
}
}
extension HTTPConnectionPool: HTTP1ConnectionDelegate {
func http1ConnectionClosed(_ connection: HTTP1Connection) {
self.logger.debug(
"connection closed",
metadata: [
"ahc-connection-id": "\(connection.id)",
"ahc-http-version": "http/1.1",
]
)
self.modifyStateAndRunActions {
$0.http1ConnectionClosed(connection.id)
}
}
func http1ConnectionReleased(_ connection: HTTP1Connection) {
self.logger.trace(
"releasing connection",
metadata: [
"ahc-connection-id": "\(connection.id)",
"ahc-http-version": "http/1.1",
]
)
self.modifyStateAndRunActions {
$0.http1ConnectionReleased(connection.id)
}
}
}
extension HTTPConnectionPool: HTTP2ConnectionDelegate {
func http2Connection(_ connection: HTTP2Connection, newMaxStreamSetting: Int) {
self.logger.debug(
"new max stream setting",
metadata: [
"ahc-connection-id": "\(connection.id)",
"ahc-http-version": "http/2",
"ahc-max-streams": "\(newMaxStreamSetting)",
]
)
self.modifyStateAndRunActions {
$0.newHTTP2MaxConcurrentStreamsReceived(connection.id, newMaxStreams: newMaxStreamSetting)
}
}
func http2ConnectionGoAwayReceived(_ connection: HTTP2Connection) {
self.logger.debug(
"connection go away received",
metadata: [
"ahc-connection-id": "\(connection.id)",
"ahc-http-version": "http/2",
]
)
self.modifyStateAndRunActions {
$0.http2ConnectionGoAwayReceived(connection.id)
}
}
func http2ConnectionClosed(_ connection: HTTP2Connection) {
self.logger.debug(
"connection closed",
metadata: [
"ahc-connection-id": "\(connection.id)",
"ahc-http-version": "http/2",
]
)
self.modifyStateAndRunActions {
$0.http2ConnectionClosed(connection.id)
}
}
func http2ConnectionStreamClosed(_ connection: HTTP2Connection, availableStreams: Int) {
self.logger.trace(
"stream closed",
metadata: [
"ahc-connection-id": "\(connection.id)",
"ahc-http-version": "http/2",
]
)
self.modifyStateAndRunActions {
$0.http2ConnectionStreamClosed(connection.id)
}
}
}
extension HTTPConnectionPool: HTTPRequestScheduler {
func cancelRequest(_ request: HTTPSchedulableRequest) {
let requestID = Request(request).id
self.modifyStateAndRunActions {
$0.cancelRequest(requestID)
}
}
}
extension HTTPConnectionPool {
struct Connection: Hashable {
typealias ID = Int
private enum Reference {
case http1_1(HTTP1Connection)
case http2(HTTP2Connection)
case __testOnly_connection(ID, EventLoop)
}
private let _ref: Reference
fileprivate static func http1_1(_ conn: HTTP1Connection) -> Self {
Connection(_ref: .http1_1(conn))
}
fileprivate static func http2(_ conn: HTTP2Connection) -> Self {
Connection(_ref: .http2(conn))
}
static func __testOnly_connection(id: ID, eventLoop: EventLoop) -> Self {
Connection(_ref: .__testOnly_connection(id, eventLoop))
}
var id: ID {
switch self._ref {
case .http1_1(let connection):
return connection.id
case .http2(let connection):
return connection.id
case .__testOnly_connection(let id, _):
return id
}
}
var eventLoop: EventLoop {
switch self._ref {
case .http1_1(let connection):
return connection.channel.eventLoop
case .http2(let connection):
return connection.channel.eventLoop
case .__testOnly_connection(_, let eventLoop):
return eventLoop
}
}
fileprivate func executeRequest(_ request: HTTPExecutableRequest) {
switch self._ref {
case .http1_1(let connection):
return connection.executeRequest(request)
case .http2(let connection):
return connection.executeRequest(request)
case .__testOnly_connection:
break
}
}
/// Shutdown cancels any running requests on the connection and then closes the connection
fileprivate func shutdown() {
switch self._ref {
case .http1_1(let connection):
return connection.shutdown()
case .http2(let connection):
return connection.shutdown()
case .__testOnly_connection:
break
}
}
/// Closes the connection without cancelling running requests. Use this when you are sure, that the
/// connection is currently idle.
fileprivate func close(promise: EventLoopPromise<Void>?) {
switch self._ref {
case .http1_1(let connection):
return connection.close(promise: promise)
case .http2(let connection):
return connection.close(promise: promise)
case .__testOnly_connection:
promise?.succeed(())
}
}
static func == (lhs: HTTPConnectionPool.Connection, rhs: HTTPConnectionPool.Connection) -> Bool {
switch (lhs._ref, rhs._ref) {
case (.http1_1(let lhsConn), .http1_1(let rhsConn)):
return lhsConn.id == rhsConn.id
case (.http2(let lhsConn), .http2(let rhsConn)):
return lhsConn.id == rhsConn.id
case (
.__testOnly_connection(let lhsID, let lhsEventLoop), .__testOnly_connection(let rhsID, let rhsEventLoop)
):
return lhsID == rhsID && lhsEventLoop === rhsEventLoop
default:
return false
}
}
func hash(into hasher: inout Hasher) {
switch self._ref {
case .http1_1(let conn):
hasher.combine(conn.id)
case .http2(let conn):
hasher.combine(conn.id)
case .__testOnly_connection(let id, let eventLoop):
hasher.combine(id)
hasher.combine(eventLoop.id)
}
}
}
}
extension HTTPConnectionPool {
/// This is a wrapper that we use inside the connection pool state machine to ensure that
/// the actual request can not be accessed at any time. Further it exposes all that is needed within
/// the state machine. A request ID and the `EventLoop` requirement.
struct Request {
struct ID: Hashable {
let objectIdentifier: ObjectIdentifier
let eventLoopID: EventLoopID?
fileprivate init(_ request: HTTPSchedulableRequest, eventLoopRequirement eventLoopID: EventLoopID?) {
self.objectIdentifier = ObjectIdentifier(request)
self.eventLoopID = eventLoopID
}
}
fileprivate let req: HTTPSchedulableRequest
init(_ request: HTTPSchedulableRequest) {
self.req = request
}
var id: HTTPConnectionPool.Request.ID {
HTTPConnectionPool.Request.ID(self.req, eventLoopRequirement: self.requiredEventLoop?.id)
}
var requiredEventLoop: EventLoop? {
self.req.requiredEventLoop
}
var preferredEventLoop: EventLoop {
self.req.preferredEventLoop
}
var connectionDeadline: NIODeadline {
self.req.connectionDeadline
}
func __testOnly_wrapped_request() -> HTTPSchedulableRequest {
self.req
}
}
}
struct EventLoopID: Hashable {
private var id: Identifier
private enum Identifier: Hashable {
case objectIdentifier(ObjectIdentifier)
case __testOnly_fakeID(Int)
}
init(_ eventLoop: EventLoop) {
self.init(.objectIdentifier(ObjectIdentifier(eventLoop)))
}
private init(_ id: Identifier) {
self.id = id
}
static func __testOnly_fakeID(_ id: Int) -> EventLoopID {
EventLoopID(.__testOnly_fakeID(id))
}
}
extension EventLoop {
var id: EventLoopID { EventLoopID(self) }
}