File: watchdog_reader_test.go

package info (click to toggle)
golang-github-ncw-swift 0.0~git20180327.b2a7479-2
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 384 kB
  • sloc: sh: 18; makefile: 4
file content (137 lines) | stat: -rw-r--r-- 3,923 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
// This tests WatchdogReader

package swift

import (
	"bytes"
	"io"
	"io/ioutil"
	"testing"
	"time"
)

// Uses testReader from timeout_reader_test.go

func testWatchdogReaderTimeout(t *testing.T, initialTimeout, watchdogTimeout time.Duration, expectedTimeout bool) {
	test := newTestReader(3, 10*time.Millisecond)
	timer, firedChan := setupTimer(initialTimeout)
	wr := newWatchdogReader(test, watchdogTimeout, timer)
	b, err := ioutil.ReadAll(wr)
	if err != nil || string(b) != "AAA" {
		t.Fatalf("Bad read %s %s", err, b)
	}
	checkTimer(t, firedChan, expectedTimeout)
}

func setupTimer(initialTimeout time.Duration) (timer *time.Timer, fired <-chan bool) {
	timer = time.NewTimer(initialTimeout)
	firedChan := make(chan bool)
	started := make(chan bool)
	go func() {
		started <- true
		select {
		case <-timer.C:
			firedChan <- true
		}
	}()
	<-started
	return timer, firedChan
}

func checkTimer(t *testing.T, firedChan <-chan bool, expectedTimeout bool) {
	fired := false
	select {
	case fired = <-firedChan:
	default:
	}
	if expectedTimeout {
		if !fired {
			t.Fatal("Timer should have fired")
		}
	} else {
		if fired {
			t.Fatal("Timer should not have fired")
		}
	}
}

func TestWatchdogReaderNoTimeout(t *testing.T) {
	testWatchdogReaderTimeout(t, 100*time.Millisecond, 100*time.Millisecond, false)
}

func TestWatchdogReaderTimeout(t *testing.T) {
	testWatchdogReaderTimeout(t, 5*time.Millisecond, 5*time.Millisecond, true)
}

func TestWatchdogReaderNoTimeoutShortInitial(t *testing.T) {
	testWatchdogReaderTimeout(t, 5*time.Millisecond, 100*time.Millisecond, false)
}

func TestWatchdogReaderTimeoutLongInitial(t *testing.T) {
	testWatchdogReaderTimeout(t, 100*time.Millisecond, 5*time.Millisecond, true)
}

//slowReader simulates reading from a slow network connection by introducing a delay
//in each Read() proportional to the amount of bytes read.
type slowReader struct {
	reader       io.Reader
	delayPerByte time.Duration
}

func (r *slowReader) Read(p []byte) (n int, err error) {
	n, err = r.reader.Read(p)
	if n > 0 {
		time.Sleep(time.Duration(n) * r.delayPerByte)
	}
	return
}

//This test verifies that the watchdogReader's timeout is not triggered by data
//that comes in very slowly. (It should only be triggered if no data arrives at
//all.)
func TestWatchdogReaderOnSlowNetwork(t *testing.T) {
	byteString := make([]byte, 8*watchdogChunkSize)
	reader := &slowReader{
		reader: bytes.NewReader(byteString),
		//reading everything at once would take 100 ms, which is longer than the
		//watchdog timeout below
		delayPerByte: 200 * time.Millisecond / time.Duration(len(byteString)),
	}

	timer, firedChan := setupTimer(100 * time.Millisecond)
	wr := newWatchdogReader(reader, 190*time.Millisecond, timer)

	//use io.ReadFull instead of ioutil.ReadAll here because ReadAll already does
	//some chunking that would keep this testcase from failing
	b := make([]byte, len(byteString))
	n, err := io.ReadFull(wr, b)
	if err != nil || n != len(b) || !bytes.Equal(b, byteString) {
		t.Fatalf("Bad read %s %d", err, n)
	}

	checkTimer(t, firedChan, false)
}

//This test verifies that the watchdogReader's chunking logic does not mess up
//the byte strings that are read.
func TestWatchdogReaderValidity(t *testing.T) {
	byteString := []byte("abcdefghij")
	//make a reader with a non-standard chunk size (1 MiB would be much too huge
	//to comfortably look at the bytestring that comes out of the reader)
	wr := &watchdogReader{
		reader:    bytes.NewReader(byteString),
		chunkSize: 3, //len(byteString) % chunkSize != 0 to be extra rude :)
		//don't care about the timeout stuff here
		timeout: 5 * time.Minute,
		timer:   time.NewTimer(5 * time.Minute),
	}

	b := make([]byte, len(byteString))
	n, err := io.ReadFull(wr, b)
	if err != nil || n != len(b) {
		t.Fatalf("Read error: %s", err)
	}
	if !bytes.Equal(b, byteString) {
		t.Fatalf("Bad read: %#v != %#v", string(b), string(byteString))
	}
}