lookup_test.go

     1  // Copyright 2022 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package types_test
     6  
     7  import (
     8  	"go/importer"
     9  	"go/token"
    10  	"path/filepath"
    11  	"runtime"
    12  	"testing"
    13  
    14  	. "go/types"
    15  )
    16  
    17  // BenchmarkLookupFieldOrMethod measures types.LookupFieldOrMethod performance.
    18  // LookupFieldOrMethod is a performance hotspot for both type-checking and
    19  // external API calls.
    20  func BenchmarkLookupFieldOrMethod(b *testing.B) {
    21  	// Choose an arbitrary, large package.
    22  	path := filepath.Join(runtime.GOROOT(), "src", "net", "http")
    23  
    24  	fset := token.NewFileSet()
    25  	files, err := pkgFiles(fset, path)
    26  	if err != nil {
    27  		b.Fatal(err)
    28  	}
    29  
    30  	conf := Config{
    31  		Importer: importer.Default(),
    32  	}
    33  
    34  	pkg, err := conf.Check("http", fset, files, nil)
    35  	if err != nil {
    36  		b.Fatal(err)
    37  	}
    38  
    39  	scope := pkg.Scope()
    40  	names := scope.Names()
    41  
    42  	// Look up an arbitrary name for each type referenced in the package scope.
    43  	lookup := func() {
    44  		for _, name := range names {
    45  			typ := scope.Lookup(name).Type()
    46  			LookupFieldOrMethod(typ, true, pkg, "m")
    47  		}
    48  	}
    49  
    50  	// Perform a lookup once, to ensure that any lazily-evaluated state is
    51  	// complete.
    52  	lookup()
    53  
    54  	b.ResetTimer()
    55  	for i := 0; i < b.N; i++ {
    56  		lookup()
    57  	}
    58  }
    59
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