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/token"
     9  	"path/filepath"
    10  	"runtime"
    11  	"testing"
    12  
    13  	. "go/types"
    14  )
    15  
    16  // BenchmarkLookupFieldOrMethod measures types.LookupFieldOrMethod performance.
    17  // LookupFieldOrMethod is a performance hotspot for both type-checking and
    18  // external API calls.
    19  func BenchmarkLookupFieldOrMethod(b *testing.B) {
    20  	// Choose an arbitrary, large package.
    21  	path := filepath.Join(runtime.GOROOT(), "src", "net", "http")
    22  
    23  	fset := token.NewFileSet()
    24  	files, err := pkgFiles(fset, path)
    25  	if err != nil {
    26  		b.Fatal(err)
    27  	}
    28  
    29  	conf := Config{
    30  		Importer: defaultImporter(fset),
    31  	}
    32  
    33  	pkg, err := conf.Check("http", fset, files, nil)
    34  	if err != nil {
    35  		b.Fatal(err)
    36  	}
    37  
    38  	scope := pkg.Scope()
    39  	names := scope.Names()
    40  
    41  	// Look up an arbitrary name for each type referenced in the package scope.
    42  	lookup := func() {
    43  		for _, name := range names {
    44  			typ := scope.Lookup(name).Type()
    45  			LookupFieldOrMethod(typ, true, pkg, "m")
    46  		}
    47  	}
    48  
    49  	// Perform a lookup once, to ensure that any lazily-evaluated state is
    50  	// complete.
    51  	lookup()
    52  
    53  	b.ResetTimer()
    54  	for i := 0; i < b.N; i++ {
    55  		lookup()
    56  	}
    57  }
    58
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