fix performance regression. Do not escape request path in echo.ServeH…

[aldas]

fix #1777 performance regression. Do not escape request path in echo.ServeHTTP. Make sure that path is not double escaped in rewrite/proxy middleware.

did 3 benchmarks

# before problem was introduced
go test -run="-" -bench="BenchmarkEcho.*" -count 10 > before_problem.out
# on current master
go test -run="-" -bench="BenchmarkEcho.*" -count 10 > before_fix.out
# on fix branch
go test -run="-" -bench="BenchmarkEcho.*" -count 10 > after_fix.out  

Results:

before versus after performance problem was commited

x@x:~/code/echo$ benchstat before_problem.out before_fix.out 
name                      old time/op    new time/op    delta
EchoStaticRoutes-6          19.9µs ± 2%    28.2µs ± 1%  +41.84%  (p=0.000 n=8+9)
EchoStaticRoutesMisses-6    22.6µs ±13%    28.4µs ± 1%  +25.61%  (p=0.000 n=10+8)
EchoGitHubAPI-6             32.7µs ± 2%    56.7µs ± 1%  +73.19%  (p=0.000 n=8+8)
EchoGitHubAPIMisses-6       33.1µs ± 1%    56.7µs ± 1%  +71.52%  (p=0.000 n=8+9)
EchoParseAPI-6              2.52µs ± 5%    3.89µs ± 2%  +54.44%  (p=0.000 n=10+10)

commit on master before problem was fixed versus after fix branch

x@x:~/code/echo$ benchstat before_fix.out after_fix.out 
name                      old time/op    new time/op    delta
EchoStaticRoutes-6          28.2µs ± 1%    17.7µs ± 9%   -37.14%  (p=0.000 n=9+10)
EchoStaticRoutesMisses-6    28.4µs ± 1%    17.3µs ± 2%   -39.04%  (p=0.000 n=8+9)
EchoGitHubAPI-6             56.7µs ± 1%    32.2µs ± 2%   -43.23%  (p=0.000 n=8+10)
EchoGitHubAPIMisses-6       56.7µs ± 1%    32.8µs ± 2%   -42.22%  (p=0.000 n=9+8)
EchoParseAPI-6              3.89µs ± 2%    2.14µs ± 3%   -44.99%  (p=0.000 n=10+9)

before problem was commits versus after fix
NB: these numbers include also other changes we have done to router in master

x@x:~/code/echo$ benchstat before_problem.out after_fix.out 
name                      old time/op    new time/op    delta
EchoStaticRoutes-6          19.9µs ± 2%    17.7µs ± 9%  -10.83%  (p=0.000 n=8+10)
EchoStaticRoutesMisses-6    22.6µs ±13%    17.3µs ± 2%  -23.43%  (p=0.000 n=10+9)
EchoGitHubAPI-6             32.7µs ± 2%    32.2µs ± 2%   -1.67%  (p=0.008 n=8+10)
EchoGitHubAPIMisses-6       33.1µs ± 1%    32.8µs ± 2%   -0.90%  (p=0.021 n=8+8)
EchoParseAPI-6              2.52µs ± 5%    2.14µs ± 3%  -15.04%  (p=0.000 n=10+9)

I added similar benchmark tests as router has but this time we use full echo stack e.ServeHTTP

func benchmarkEchoRoutes(b *testing.B, routes []*Route) {
	e := New()
	req := httptest.NewRequest("GET", "/", nil)
	u := req.URL
	w := httptest.NewRecorder()

	b.ReportAllocs()

	// Add routes
	for _, route := range routes {
		e.Add(route.Method, route.Path, func(c Context) error {
			return nil
		})
	}

	// Find routes
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		for _, route := range routes {
			req.Method = route.Method
			u.Path = route.Path
			e.ServeHTTP(w, req)
		}
	}
}

func BenchmarkEchoStaticRoutes(b *testing.B) {
	benchmarkEchoRoutes(b, staticRoutes)
}

func BenchmarkEchoStaticRoutesMisses(b *testing.B) {
	benchmarkEchoRoutes(b, staticRoutes)
}

func BenchmarkEchoGitHubAPI(b *testing.B) {
	benchmarkEchoRoutes(b, gitHubAPI)
}

func BenchmarkEchoGitHubAPIMisses(b *testing.B) {
	benchmarkEchoRoutes(b, gitHubAPI)
}

func BenchmarkEchoParseAPI(b *testing.B) {
	benchmarkEchoRoutes(b, parseAPI)
}

NB: I think Rewrite and Proxy has somewhat fundamental flaw by using map for rewrite rules. Map does not have guaranteed iteration order so overlapping rules are not executed in expected order

[codecov]

Codecov Report

Merging #1799 (16e13ca) into master (6f9b71c) will increase coverage by 0.10%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1799      +/-   ##
==========================================
+ Coverage   89.56%   89.67%   +0.10%     
==========================================
  Files          32       32              
  Lines        2646     2674      +28     
==========================================
+ Hits         2370     2398      +28     
  Misses        178      178              
  Partials       98       98              

Impacted Files	Coverage Δ
echo.go	91.64% <100.00%> (+0.10%)	⬆️
middleware/middleware.go	100.00% <100.00%> (ø)
middleware/proxy_1_11.go	100.00% <0.00%> (ø)
router.go	96.04% <0.00%> (+0.16%)	⬆️

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[lammel]

Added a test case to verify behaviour for #1798.
Approved, great work @aldas