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//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
import Dispatch
import LSPLogging
import LanguageServerProtocol
/// A connection between two message handlers in the same process.
///
/// You must call `start(handler:)` before sending any messages, and must call `close()` when finished to avoid a memory leak.
///
/// ```
/// let client: MessageHandler = ...
/// let server: MessageHandler = ...
/// let conn = LocalConnection()
/// conn.start(handler: server)
/// conn.send(...) // handled by server
/// conn.close()
/// ```
public final class LocalConnection: Connection, Sendable {
private enum State {
case ready, started, closed
}
/// A name of the endpoint for this connection, used for logging, e.g. `clangd`.
private let name: String
/// The queue guarding `_nextRequestID`.
private let queue: DispatchQueue = DispatchQueue(label: "local-connection-queue")
/// - Important: Must only be accessed from `queue`
nonisolated(unsafe) private var _nextRequestID: Int = 0
/// - Important: Must only be accessed from `queue`
nonisolated(unsafe) private var state: State = .ready
/// - Important: Must only be accessed from `queue`
nonisolated(unsafe) private var handler: MessageHandler? = nil
public init(name: String) {
self.name = name
}
deinit {
queue.sync {
if state != .closed {
closeAssumingOnQueue()
}
}
}
public func start(handler: MessageHandler) {
queue.sync {
precondition(state == .ready)
state = .started
self.handler = handler
}
}
/// - Important: Must only be called from `queue`
private func closeAssumingOnQueue() {
dispatchPrecondition(condition: .onQueue(queue))
precondition(state != .closed)
handler = nil
state = .closed
}
public func close() {
queue.sync {
closeAssumingOnQueue()
}
}
func nextRequestID() -> RequestID {
return queue.sync {
_nextRequestID += 1
return .number(_nextRequestID)
}
}
public func send<Notification: NotificationType>(_ notification: Notification) {
logger.info(
"""
Sending notification to \(self.name, privacy: .public)
\(notification.forLogging)
"""
)
guard let handler = queue.sync(execute: { handler }) else {
return
}
handler.handle(notification)
}
public func send<Request: RequestType>(
_ request: Request,
reply: @Sendable @escaping (LSPResult<Request.Response>) -> Void
) -> RequestID {
let id = nextRequestID()
logger.info(
"""
Sending request to \(self.name, privacy: .public) (id: \(id, privacy: .public)):
\(request.forLogging)
"""
)
guard let handler = queue.sync(execute: { handler }) else {
logger.info(
"""
Replying to request \(id, privacy: .public) with .serverCancelled because no handler is specified in \(self.name, privacy: .public)
"""
)
reply(.failure(.serverCancelled))
return id
}
precondition(self.state == .started)
handler.handle(request, id: id) { result in
switch result {
case .success(let response):
logger.info(
"""
Received reply for request \(id, privacy: .public) from \(self.name, privacy: .public)
\(response.forLogging)
"""
)
case .failure(let error):
logger.error(
"""
Received error for request \(id, privacy: .public) from \(self.name, privacy: .public)
\(error.forLogging)
"""
)
}
reply(result)
}
return id
}
}
|
