gin/cleanpath_benchmark_test.go

136 lines
2.6 KiB
Go

package gin
import "testing"
func oldCleanPath(p string) string {
// Turn empty string into "/"
if p == "" {
return "/"
}
n := len(p)
var buf []byte
// Invariants:
// reading from path; r is index of next byte to process.
// writing to buf; w is index of next byte to write.
// path must start with '/'
r := 1
w := 1
if p[0] != '/' {
r = 0
buf = make([]byte, n+1)
buf[0] = '/'
}
trailing := n > 1 && p[n-1] == '/'
// A bit more clunky without a 'lazybuf' like the path package, but the loop
// gets completely inlined (bufApp). So in contrast to the path package this
// loop has no expensive function calls (except 1x make)
for r < n {
switch {
case p[r] == '/':
// empty path element, trailing slash is added after the end
r++
case p[r] == '.' && r+1 == n:
trailing = true
r++
case p[r] == '.' && p[r+1] == '/':
// . element
r += 2
case p[r] == '.' && p[r+1] == '.' && (r+2 == n || p[r+2] == '/'):
// .. element: remove to last /
r += 3
if w > 1 {
// can backtrack
w--
if buf == nil {
for w > 1 && p[w] != '/' {
w--
}
} else {
for w > 1 && buf[w] != '/' {
w--
}
}
}
default:
// real path element.
// add slash if needed
if w > 1 {
bufApp(&buf, p, w, '/')
w++
}
// copy element
for r < n && p[r] != '/' {
bufApp(&buf, p, w, p[r])
w++
r++
}
}
}
// re-append trailing slash
if trailing && w > 1 {
bufApp(&buf, p, w, '/')
w++
}
if buf == nil {
return p[:w]
}
return string(buf[:w])
}
var result string
func BenchmarkCleanPath(b *testing.B) {
functions := []struct {
test string
fun func(string) string
}{
{"OldCleanPath", oldCleanPath},
{"NewCleanPath", cleanPath},
}
paths := []string{
"/", "/abc", "/a/b/c", "/abc/", "/a/b/c/",
"", "a/", "abc", "abc/def", "a/b/c",
"//", "/abc//", "/abc/def//", "/a/b/c//",
"/abc//def//ghi", "//abc", "///abc",
"//abc//", ".", "./", "/abc/./def",
"/./abc/def", "/abc/.", "..", "../",
"../../", "../..", "../../abc",
"/abc/def/ghi/../jkl", "/abc/def/../ghi/../jkl",
"/abc/def/..", "/abc/def/../..",
"/abc/def/../../..", "/abc/def/../../..",
"/abc/def/../../../ghi/jkl/../../../mno",
"abc/..def", "abc/./...", "abc/a../...", "abc/a..z",
"abc/./../def", "abc//./../def", "abc/../../././../def",
"abc/./../..def", "abc/../.../..def", "abc/.//../..def",
}
for _, function := range functions {
b.Run(function.test, func(b *testing.B) {
for n := 0; n < b.N; n++ {
var r string
for _, path := range paths {
r = function.fun(path)
}
result = r
}
})
}
}