golang 関数キャッシュのテストとベンチマーク分析

import (
    "testing"
    "time"
)

// fibonacci 计算斐波那契数
func fibonacci(n int) int {
    if n <= 1 {
        return n
    }
    return fibonacci(n-1) + fibonacci(n-2)
}

// fibonacciWithCache 使用缓存的斐波那契函数
var fibonacciWithCache = cache.Memoize(fibonacci)

func TestFibonacciCache(t *testing.T) {
    tests := []struct {
        input, expected int
    }{
        {1, 1},
        {2, 1},
        {5, 5},
        {10, 55},
    }

    for _, test := range tests {
        start := time.Now()
        actual := fibonacciWithCache(test.input)
        elapsed := time.Since(start)

        if actual != test.expected {
            t.Errorf("Expected %d but got %d", test.expected, actual)
        }

        // 检查缓存命中率
        if elapsed > 50*time.Microsecond {
            t.Errorf("Expected cache hit but got cache miss")
        }
    }
}

func BenchmarkFibonacci(b *testing.B) {
    for i := 0; i < b.N; i++ {
        fibonacci(20)
    }
}

func BenchmarkFibonacciWithCache(b *testing.B) {
    for i := 0; i < b.N; i++ {
        fibonacciWithCache(20)
    }
}

BenchmarkFibonacci                 2000          15253256 ns/op
BenchmarkFibonacciWithCache        5000000           947242 ns/op