Files

99 lines
3.2 KiB
Swift

// Copyright (c) 2021 Spotify AB.
//
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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.
@testable import XCRemoteCache
import XCTest
class ExclusiveFileTests: FileXCTestCase {
private var url: URL!
private var file: ExclusiveFile!
@Atomic
private var i = 0
override func setUpWithError() throws {
try super.setUpWithError()
url = try prepareTempDir().appendingPathComponent("file")
file = ExclusiveFile(url, mode: .override)
}
func testExclusiveAccessIsBlocking() throws {
// Expected flow:
// 1) Queue2 acquires a lock
// 2) Queue2 sets i = 1 and waits 100ms
// 3) Queue1 asks for accessing a file, but waits to acquire a log (locked by queue2)
// 4) Queue2 increments i = 2 and releases a lock
// 5) Queue1 accesses a file and verifies that i == 2
// 6) The full scenario has to finish within 0.3s
let exclusiveScope = expectation(description: "exclusiveScope")
let finished = expectation(description: "finished")
// Queue 1
DispatchQueue.global(qos: .userInitiated).async {
self.wait(for: [exclusiveScope], timeout: 0.3)
try? self.file.exclusiveAccess { _ in
XCTAssertEqual(self.i, 2)
finished.fulfill()
}
}
// Queue 2
DispatchQueue.global(qos: .userInitiated).async {
try? self.file.exclusiveAccess { _ in
defer {
self.i = 2
}
self.i = 1
exclusiveScope.fulfill()
Thread.sleep(forTimeInterval: 0.1)
}
}
wait(for: [finished], timeout: 0.3)
}
func testOverrideModeOverrideExistingFile() throws {
let data = Data([1])
file = ExclusiveFile(url, mode: .override)
try file.exclusiveAccess { file in
file.write(data)
}
try file.exclusiveAccess { file in
file.write(data)
}
XCTAssertEqual(fileManager.contents(atPath: url.path), data)
}
func testAppendModeAddsAtTheEndOfFile() throws {
let data = Data([1])
file = ExclusiveFile(url, mode: .append)
try file.exclusiveAccess { file in
file.write(data)
}
try file.exclusiveAccess { file in
file.write(data)
}
XCTAssertEqual(fileManager.contents(atPath: url.path), data + data)
}
}