参考原文Swift【优化Swift项目编译时间】
借助第三方插件
BuildTimeAnalyzer-for-Xcode

CA689C72-F143-425B-BD12-A30F2A8B8881.png

使用方法

1.下载项目后,运行会弹出一个窗口 303095EE-9603-42B4-8615-594A850ED4B4.png 00BF99B2-0F1C-4D41-BEAA-D8F5317C6882.png

2.按照上面提示,打开自己需要编译的项目,在build setting中，设置Other Swift Flags为-Xfrontend -debug-time-function-bodies
然后clean ,编译,然后就看到最上面第一个示例图

通过参考其他博客,并且亲测各种方法

减少编译时长的方法

1.使用自定义或者第三方组件,建议用framework的方式集成到项目中,会减少编译时长
在网上找了个第三方的下拉刷新,这个第三方没有支持carthage然后自己制作了一个framework进行测试

直接用原代码无framework
先clean 清理DerivedData缓存
1. 21s   2.14s  3. 13s  4. 13s  5. 13s   6. 13s  7. 12s
排除 第一个偏差大的 
78/6 = 13
如果仅仅是clean然后编译 6s  6s  5s 5s  5s 5s 总32 平均 =5.33333

用framework 
先clean 清理DerivedData缓存 
1. 16s  2. 12s   3. 12s  4.12s  5.10s  46/4 = 11.5
仅仅是clean 5s 3s 4s 6s 4s 4s 总26 平均 = 4.33333

2.明确指明类型，不要让编译器去自动推导
这个结论其实不准确,亲测如下

       // 类型声明之后:  48.89ms 47.78ms     clean之后: 50.38ms 49.00ms
       // 自动推导 45.62  47.56ms  49.19ms   clean之后:  50.21ms 49.23ms
       // : Dictionary<String, Any>
        let myCompany = [
            "employees": [
                "employee 1": ["attribute": "value"],
                "employee 2": ["attribute": "value"],
                "employee 3": ["attribute": "value"],
                "employee 4": ["attribute": "value"],
                "employee 5": ["attribute": "value"],
                "employee 6": ["attribute": "value"],
                "employee 7": ["attribute": "value"],
                "employee 8": ["attribute": "value"],
                "employee 9": ["attribute": "value"],
                "employee 10": ["attribute": "value"],
                "employee 11": ["attribute": "value"],
                "employee 12": ["attribute": "value"],
                "employee 13": ["attribute": "value"],
                "employee 14": ["attribute": "value"],
                "employee 15": ["attribute": "value"],
                "employee 16": ["attribute": "value"],
                "employee 17": ["attribute": "value"],
                "employee 18": ["attribute": "value"],
                "employee 19": ["attribute": "value"],
                "employee 20": ["attribute": "value"],

            ]
        ]

3.尽可能将nil判断写成if let方式解包

var num : CGFloat?
num = 44
if num != nil{
   print(num)
}

8AE147D8-5210-4AF5-81AF-3A40668D61E8.png

var num : CGFloat?
num = 44
if let newNum = num {
    print(newNum)
}

6C172988-FFA8-43D9-A1D7-B254F7B5BA4F.png

4.尽量用array.append(data),而不是用array+[data]

// Build time: 246.50ms   243.55ms
let systemOptions = [ 7, 14, 30, -1 ]
let systemNames = (0...2).map{ String(format: "%d", systemOptions[$0]) } + [NSLocalizedString("everything", comment: "")]
        
let count = systemOptions.count
let labelNames = Array(systemNames[0..<count]) + [systemNames.last!]

// Build time: 184.18ms
let systemOptions = [ 7, 14, 30, -1 ]
var systemNames = systemOptions.dropLast().map{ String(format: "%d", $0) }
systemNames.append(NSLocalizedString("everything", comment: ""))

let count = systemOptions.count
var labelNames = Array(systemNames[0..<count])
labelNames.append(systemNames.last!)

5. 尽量不要用三目运算,用if else代替三目运算

// Build time: 76.09ms  74.51ms
let type = 44
let labelNames = type == 0 ? (1...5).map{ type0ToString($0) } : (0...2).map{type0ToString($0)}


// Build time: 71.96ms 72.48ms
var labelNames: [String]
if type == 0 {
    labelNames = (1...5).map{type0ToString($0)}
} else {
    labelNames = (0...2).map{type0ToString($0)}
}

6.尽量不要用一些内置函数例如round/ceil/floor等等

let a: CGFloat = 22
let b: CGFloat = 22
let c: CGFloat = 22
let d: CGFloat = 22
let e: CGFloat = 22
// Build time: 19.51ms 18.66ms
// let expansion = a - b - c + round(d * 0.66) + e

// Build time: 15.07ms  13.68ms
let expansion = a - b - c + d * 0.66 + e

6.尽量使用纯Swift类型,不要和Objective-C混编

尽可能避免混合地使用Swift类型和NSObject子类，会对性能的提高有所帮助

7.尽量避免无意义的log，保持好的编码习惯

参考文章:Swift性能探索和优化分析