如何在Golang中实现Benchmark子测试_Golang Benchmark子测试方法汇总

func BenchmarkCopySlice(b *testing.B) {
    sizes := []int{10, 100, 1000}
    for _, n := range sizes {
        b.Run(fmt.Sprintf("Size_%d", n), func(b *testing.B) {
            src := make([]int, n)
            dst := make([]int, n)
            for i := 0; i < b.N; i++ {
                copy(dst, src)
            }
        })
    }
}

BenchmarkCopySlice/Size_10
BenchmarkCopySlice/Size_10-8          100000000            10.5 ns/op
BenchmarkCopySlice/Size_100
BenchmarkCopySlice/Size_100-8         10000000           125 ns/op
BenchmarkCopySlice/Size_1000
BenchmarkCopySlice/Size_1000-8         1000000          1250 ns/op

func BenchmarkLookup_Map(b *testing.B) {
    m := map[string]int{"a": 1, "b": 2, "c": 3}
    b.Run("MapLookup", func(b *testing.B) {
        for i := 0; i < b.N; i++ {
            _ = m["b"]
        }
    })
}

func BenchmarkLookup_Switch(b *testing.B) {
    key := "b"
    b.Run("SwitchLookup", func(b *testing.B) {
        var val int
        for i := 0; i < b.N; i++ {
            switch key {
            case "a":
                val = 1
            case "b":
                val = 2
            case "c":
                val = 3
            }
        }
        _ = val
    })
}

func BenchmarkConcurrentMapAccess(b *testing.B) {
    m := sync.Map{}
    b.Run("Concurrent_Write_Read", func(b *testing.B) {
        b.RunParallel(func(pb *testing.PB) {
            i := 0
            for pb.Next() {
                key := fmt.Sprintf("key_%d", i%100)
                m.Store(key, i)
                _, _ = m.Load(key)
                i++
            }
        })
    })
}

// 错误：i 被所有子测试共享
for i := range tests {
    b.Run(fmt.Sprintf("Test%d", i), func(b *testing.B) {
        // 使用了外部 i，值可能错乱
    })
}

for i := range tests {
    i := i // 创建局部副本
    b.Run(fmt.Sprintf("Test%d", i), func(b *testing.B) {
        // 使用局部 i
    })
}