time_test.go

Documentation: runtime

		 1  // Copyright 2019 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 runtime_test
		 6  
		 7  import (
		 8  	"bytes"
		 9  	"encoding/binary"
		10  	"errors"
		11  	"internal/testenv"
		12  	"os/exec"
		13  	"reflect"
		14  	"runtime"
		15  	"testing"
		16  )
		17  
		18  func TestFakeTime(t *testing.T) {
		19  	if runtime.GOOS == "windows" {
		20  		t.Skip("faketime not supported on windows")
		21  	}
		22  
		23  	// Faketime is advanced in checkdead. External linking brings in cgo,
		24  	// causing checkdead not working.
		25  	testenv.MustInternalLink(t)
		26  
		27  	t.Parallel()
		28  
		29  	exe, err := buildTestProg(t, "testfaketime", "-tags=faketime")
		30  	if err != nil {
		31  		t.Fatal(err)
		32  	}
		33  
		34  	var stdout, stderr bytes.Buffer
		35  	cmd := exec.Command(exe)
		36  	cmd.Stdout = &stdout
		37  	cmd.Stderr = &stderr
		38  
		39  	err = testenv.CleanCmdEnv(cmd).Run()
		40  	if err != nil {
		41  		t.Fatalf("exit status: %v\n%s", err, stderr.String())
		42  	}
		43  
		44  	t.Logf("raw stdout: %q", stdout.String())
		45  	t.Logf("raw stderr: %q", stderr.String())
		46  
		47  	f1, err1 := parseFakeTime(stdout.Bytes())
		48  	if err1 != nil {
		49  		t.Fatal(err1)
		50  	}
		51  	f2, err2 := parseFakeTime(stderr.Bytes())
		52  	if err2 != nil {
		53  		t.Fatal(err2)
		54  	}
		55  
		56  	const time0 = 1257894000000000000
		57  	got := [][]fakeTimeFrame{f1, f2}
		58  	var want = [][]fakeTimeFrame{{
		59  		{time0 + 1, "line 2\n"},
		60  		{time0 + 1, "line 3\n"},
		61  		{time0 + 1e9, "line 5\n"},
		62  		{time0 + 1e9, "2009-11-10T23:00:01Z"},
		63  	}, {
		64  		{time0, "line 1\n"},
		65  		{time0 + 2, "line 4\n"},
		66  	}}
		67  	if !reflect.DeepEqual(want, got) {
		68  		t.Fatalf("want %v, got %v", want, got)
		69  	}
		70  }
		71  
		72  type fakeTimeFrame struct {
		73  	time uint64
		74  	data string
		75  }
		76  
		77  func parseFakeTime(x []byte) ([]fakeTimeFrame, error) {
		78  	var frames []fakeTimeFrame
		79  	for len(x) != 0 {
		80  		if len(x) < 4+8+4 {
		81  			return nil, errors.New("truncated header")
		82  		}
		83  		const magic = "\x00\x00PB"
		84  		if string(x[:len(magic)]) != magic {
		85  			return nil, errors.New("bad magic")
		86  		}
		87  		x = x[len(magic):]
		88  		time := binary.BigEndian.Uint64(x)
		89  		x = x[8:]
		90  		dlen := binary.BigEndian.Uint32(x)
		91  		x = x[4:]
		92  		data := string(x[:dlen])
		93  		x = x[dlen:]
		94  		frames = append(frames, fakeTimeFrame{time, data})
		95  	}
		96  	return frames, nil
		97  }
		98
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