style: changed all simple path concatenation by fmt.Sprintf

[iamamirsalehi]

Related Issue or Design Document

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Further comments

[CLAassistant]

All committers have signed the CLA.

[asahasrabuddhe]

I am not sure if this change is a step in the right direction. fmt.Sprintf is significantly less performant than simple concatenations. By including this change, we would considerably deteriorate the performance of the code.

Consider the following snippet:

package main

import (
	"fmt"
	"testing"
)


func BenchmarkConcatStringByAdd(b *testing.B) {
	id := "123e4567-e89b-12d3-a456-426614174000"
	path := ""
	b.ReportAllocs()
	for b.Loop() {
		path = "/containers/" + id + "/json"
	}
	_ = path
}

func BenchmarkConcatStringBySprintf(b *testing.B) {
	id := "123e4567-e89b-12d3-a456-426614174000"
	path := ""
	b.ReportAllocs()
	for b.Loop() {
		path = fmt.Sprintf("/containers/%s/json", id)
	}
	_ = path
}

Benchmarking the above code yields the following result:

goos: darwin
goarch: arm64
cpu: Apple M1 Pro
BenchmarkConcatStringByAdd
BenchmarkConcatStringByAdd-10        	43265994	        27.32 ns/op	      64 B/op	       1 allocs/op
BenchmarkConcatStringBySprintf
BenchmarkConcatStringBySprintf-10    	18439422	        64.13 ns/op	      80 B/op	       2 allocs/op
PASS

The fmt.Sprintf concatenation is almost 2x slower than simple concatenations. I hope you consider this and change all the fmt.Sprintf to instead be simple concatenations and improve the performance of this library.

[iamamirsalehi]

Thanks @asahasrabuddhe for your tip, I applied what you mentioned

[aeneasr]

Thank you for the contribution, however we generally don’t merge style changes in code that have little added value (we merge bug fixes or feature improvements). This code itself is forked from Docker and we generally don’t accept changes there due to the security nature unless it fixes a known issuey