48 lines
1.8 KiB
Swift
48 lines
1.8 KiB
Swift
//
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// JXTransitionDefine.swift
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// Test
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//
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// Created by 曾觉新 on 2022/10/11.
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//
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import UIKit
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public func jx_swizzled_instanceMethod(_ prefix: String, oldClass: Swift.AnyClass!, oldSelector: String, newClass: Swift.AnyClass) {
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let newSelector = prefix + "_" + oldSelector;
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let originalSelector = NSSelectorFromString(oldSelector)
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let swizzledSelector = NSSelectorFromString(newSelector)
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let originalMethod = class_getInstanceMethod(oldClass, originalSelector)
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let swizzledMethod = class_getInstanceMethod(newClass, swizzledSelector)
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let isAdd = class_addMethod(oldClass, originalSelector, method_getImplementation(swizzledMethod!), method_getTypeEncoding(swizzledMethod!))
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if isAdd {
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class_replaceMethod(newClass, swizzledSelector, method_getImplementation(originalMethod!), method_getTypeEncoding(originalMethod!))
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}else {
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method_exchangeImplementations(originalMethod!, swizzledMethod!)
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}
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}
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// MARK: - Swizzling会改变全局状态，所以用DispatchQueue.once来确保无论多少线程都只会被执行一次
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extension DispatchQueue {
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private static var onceTracker = [String]()
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// Executes a block of code, associated with a unique token, only once. The code is thread safe and will only execute the code once even in the presence of multithreaded calls.
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public class func once(token: String, block: () -> Void) {
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// 保证被 objc_sync_enter 和 objc_sync_exit 包裹的代码可以有序同步地执行
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objc_sync_enter(self)
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defer { // 作用域结束后执行defer中的代码
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objc_sync_exit(self)
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}
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if onceTracker.contains(token) {
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return
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}
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onceTracker.append(token)
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block()
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}
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}
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