add tests for fswatcher

2025-12-21 03:34:50 +00:00 · 2018-02-28 10:17:19 +01:00
parent a2dfb51d51
commit 26c67a6e5c
5 changed files with 283 additions and 216 deletions
--- a/internal/fswatcher/fswatcher.go
+++ b/internal/fswatcher/fswatcher.go
@@ -24,6 +24,7 @@ type FSWatcher struct {
 	i           Inotify
 	w           Walker
 	maxWatchers int
+	eventSize   int
 }

 func NewFSWatcher() (*FSWatcher, error) {
@@ -31,11 +32,12 @@ func NewFSWatcher() (*FSWatcher, error) {
 		i:           inotify.NewInotify(),
 		w:           walker.NewWalker(),
 		maxWatchers: inotify.MaxWatchers,
+		eventSize:   inotify.EventSize,
 	}, nil
 }

-func (iw *FSWatcher) Close() {
-	iw.i.Close()
+func (fs *FSWatcher) Close() {
+	fs.i.Close()
 }

 func (fs *FSWatcher) Init(rdirs, dirs []string) (chan error, chan struct{}) {
@@ -48,10 +50,10 @@ func (fs *FSWatcher) Init(rdirs, dirs []string) (chan error, chan struct{}) {
 			errCh <- fmt.Errorf("setting up inotify: %v", err)
 		}
 		for _, dir := range rdirs {
-			addWatchers(dir, -1, fs.i, fs.maxWatchers, fs.w, errCh)
+			fs.addWatchers(dir, -1, errCh)
 		}
 		for _, dir := range dirs {
-			addWatchers(dir, 0, fs.i, fs.maxWatchers, fs.w, errCh)
+			fs.addWatchers(dir, 0, errCh)
 		}
 		close(doneCh)
 	}()
@@ -59,47 +61,65 @@ func (fs *FSWatcher) Init(rdirs, dirs []string) (chan error, chan struct{}) {
 	return errCh, doneCh
 }

-func addWatchers(dir string, depth int, i Inotify, maxWatchers int, w Walker, errCh chan error) {
-	dirCh, walkErrCh, doneCh := w.Walk(dir, depth)
-loop:
+func (fs *FSWatcher) addWatchers(dir string, depth int, errCh chan error) {
+	dirCh, walkErrCh, doneCh := fs.w.Walk(dir, depth)
+
 	for {
-		if maxWatchers > 0 && i.NumWatchers() >= maxWatchers {
+		if fs.maxWatchers > 0 && fs.i.NumWatchers() >= fs.maxWatchers {
 			close(doneCh)
-			break loop
+			return
 		}
+
 		select {
 		case err := <-walkErrCh:
 			errCh <- fmt.Errorf("adding inotift watchers: %v", err)
 		case dir, ok := <-dirCh:
 			if !ok {
-				break loop
+				return
 			}
-			if err := i.Watch(dir); err != nil {
+			if err := fs.i.Watch(dir); err != nil {
 				errCh <- fmt.Errorf("Can't create watcher: %v", err)
 			}
 		}
 	}
 }

-func (fs *FSWatcher) Start(rdirs, dirs []string, errCh chan error) (chan struct{}, chan string, error) {
-	err := fs.i.Init()
-	if err != nil {
-		return nil, nil, fmt.Errorf("setting up inotify: %v", err)
-	}
+func (fs *FSWatcher) Run() (chan struct{}, chan string, chan error) {
+	triggerCh, dataCh, eventCh, errCh := make(chan struct{}), make(chan []byte), make(chan string), make(chan error)

-	for _, dir := range rdirs {
-		addWatchers(dir, -1, fs.i, fs.maxWatchers, fs.w, errCh)
-	}
-	for _, dir := range dirs {
-		addWatchers(dir, 0, fs.i, fs.maxWatchers, fs.w, errCh)
-	}
+	go fs.observe(triggerCh, dataCh, errCh)
+	go fs.parseEvents(dataCh, eventCh, errCh)

-	triggerCh := make(chan struct{})
-	dataCh := make(chan []byte)
-	go Observe(fs.i, triggerCh, dataCh, errCh)
-
-	eventCh := make(chan string)
-	go parseEvents(fs.i, dataCh, eventCh, errCh)
-
-	return triggerCh, eventCh, nil
+	return triggerCh, eventCh, errCh
+}
+
+func (fs *FSWatcher) observe(triggerCh chan struct{}, dataCh chan []byte, errCh chan error) {
+	buf := make([]byte, 5*fs.eventSize)
+
+	for {
+		n, err := fs.i.Read(buf)
+		triggerCh <- struct{}{}
+		if err != nil {
+			errCh <- fmt.Errorf("reading inotify buffer: %v", err)
+			continue
+		}
+		bufCopy := make([]byte, n)
+		copy(bufCopy, buf)
+		dataCh <- bufCopy
+	}
+}
+
+func (fs *FSWatcher) parseEvents(dataCh chan []byte, eventCh chan string, errCh chan error) {
+	for buf := range dataCh {
+		var ptr uint32
+		for len(buf[ptr:]) > 0 {
+			event, size, err := fs.i.ParseNextEvent(buf[ptr:])
+			ptr += size
+			if err != nil {
+				errCh <- fmt.Errorf("parsing events: %v", err)
+				continue
+			}
+			eventCh <- fmt.Sprintf("%20s | %s", event.Op, event.Name)
+		}
+	}
 }
--- a/internal/fswatcher/fswatcher_test.go
+++ b/internal/fswatcher/fswatcher_test.go
@@ -2,14 +2,16 @@ package fswatcher

 import (
 	"errors"
+	"fmt"
 	"reflect"
+	"strings"
 	"testing"
 	"time"

 	"github.com/dominicbreuker/pspy/internal/fswatcher/inotify"
 )

-func TestInit(t *testing.T) {
+func initObjs() (*MockInotify, *MockWalker, *FSWatcher) {
 	i := NewMockInotify()
 	w := &MockWalker{
 		subdirs: map[string][]string{
@@ -22,7 +24,13 @@ func TestInit(t *testing.T) {
 		i:           i,
 		w:           w,
 		maxWatchers: 999,
+		eventSize:   11,
 	}
+	return i, w, fs
+}
+
+func TestInit(t *testing.T) {
+	i, _, fs := initObjs()
 	rdirs := []string{"mydir1"}
 	dirs := []string{"mydir2"}

@@ -45,6 +53,76 @@ loop:
 	}
 }

+func TestRun(t *testing.T) {
+	i, _, fs := initObjs()
+	triggerCh, eventCh, errCh := fs.Run()
+
+	// send data (len=11)
+	go func() {
+		sendInotifyData(t, i.bufReads, "name:type__")            // single event
+		sendInotifyData(t, i.bufReads, "error:read_")            // read error
+		sendInotifyData(t, i.bufReads, "error:parse")            // parse error
+		sendInotifyData(t, i.bufReads, "name1:type1name2:type2") // 2 events
+	}()
+
+	// parse first datum
+	expectTrigger(t, triggerCh)
+	expectEvent(t, eventCh, "type__ | name")
+
+	// parse second datum
+	expectTrigger(t, triggerCh)
+	expectError(t, errCh, "reading inotify buffer: error-inotify-read")
+
+	// parse third datum
+	expectTrigger(t, triggerCh)
+	expectError(t, errCh, "parsing events: parse-event-error")
+
+	// parse fourth datum
+	expectTrigger(t, triggerCh)
+	expectEvent(t, eventCh, "type1 | name1")
+	expectEvent(t, eventCh, "type2 | name2")
+}
+
+const timeout = 500 * time.Millisecond
+
+func sendInotifyData(t *testing.T, dataCh chan []byte, s string) {
+	select {
+	case dataCh <- []byte(s):
+	case <-time.After(timeout):
+		t.Fatalf("Could not send data in time: %s", s)
+	}
+}
+
+func expectTrigger(t *testing.T, triggerCh chan struct{}) {
+	select {
+	case <-triggerCh:
+	case <-time.After(timeout):
+		t.Fatalf("Timeout: did not receive trigger in time")
+	}
+}
+
+func expectEvent(t *testing.T, eventCh chan string, exp string) {
+	select {
+	case e := <-eventCh:
+		if strings.TrimSpace(e) != exp {
+			t.Errorf("Wrong event: %+v", e)
+		}
+	case <-time.After(timeout):
+		t.Fatalf("Timeout: did not receive event in time")
+	}
+}
+
+func expectError(t *testing.T, errCh chan error, exp string) {
+	select {
+	case err := <-errCh:
+		if err.Error() != exp {
+			t.Errorf("Wrong error: %v", err)
+		}
+	case <-time.After(timeout):
+		t.Fatalf("Timeout: did not receive error in time")
+	}
+}
+
 // mocks

 // Mock Inotify
@@ -52,12 +130,14 @@ loop:
 type MockInotify struct {
 	initialized bool
 	watching    []string
+	bufReads    chan []byte
 }

 func NewMockInotify() *MockInotify {
 	return &MockInotify{
 		initialized: false,
 		watching:    make([]string, 0),
+		bufReads:    make(chan []byte),
 	}
 }

@@ -79,11 +159,22 @@ func (i *MockInotify) NumWatchers() int {
 }

 func (i *MockInotify) Read(buf []byte) (int, error) {
-	return 32, nil
+	b := <-i.bufReads
+	t := strings.Split(string(b), ":")
+	if t[0] == "error" && t[1] == "read_" {
+		return -1, fmt.Errorf("error-inotify-read")
+	}
+	copy(buf, b)
+	return len(b), nil
 }

 func (i *MockInotify) ParseNextEvent(buf []byte) (*inotify.Event, uint32, error) {
-	return &inotify.Event{Name: "name", Op: "CREATE"}, 32, nil
+	s := string(buf[:11])
+	t := strings.Split(s, ":")
+	if t[0] == "error" && t[1] == "parse" {
+		return nil, uint32(len(buf)), fmt.Errorf("parse-event-error")
+	}
+	return &inotify.Event{Name: t[0], Op: t[1]}, 11, nil
 }

 func (i *MockInotify) Close() error {
--- a/internal/fswatcher/inotify/inotify.go
+++ b/internal/fswatcher/inotify/inotify.go
@@ -17,6 +17,8 @@ const maximumWatchersFile = "/proc/sys/fs/inotify/max_user_watches"
 // set to -1 if the number cannot be determined
 var MaxWatchers int = -1

+const EventSize int = unix.SizeofInotifyEvent
+
 func init() {
 	mw, err := getMaxWatchers()
 	if err == nil {
@@ -83,6 +85,13 @@ func (i *Inotify) ParseNextEvent(buf []byte) (*Event, uint32, error) {
 	sys := (*unix.InotifyEvent)(unsafe.Pointer(&buf[0]))
 	offset := unix.SizeofInotifyEvent + sys.Len

+	if sys.Wd == -1 {
+		// watch descriptors should never be negative, yet there appears to be an unfixed bug causing them to be:
+		// https://rachelbythebay.com/w/2014/11/24/touch/
+		// https://code.launchpad.net/~jamesodhunt/libnih/libnih-inotify-overflow-fix-for-777093/+merge/65372
+		return nil, offset, fmt.Errorf("possible inotify event overflow")
+	}
+
 	watcher, ok := i.Watchers[int(sys.Wd)]
 	if !ok {
 		return nil, offset, fmt.Errorf("unknown watcher ID: %d", sys.Wd)
--- a/internal/pspy/pspy.go
+++ b/internal/pspy/pspy.go
@@ -15,7 +15,8 @@ type Logger interface {
 }

 type FSWatcher interface {
-	Start(rdirs, dirs []string, errCh chan error) (chan struct{}, chan string, error)
+	Init(rdirs, dirs []string) (chan error, chan struct{})
+	Run() (chan struct{}, chan string, chan error)
 }

 type ProcfsScanner interface {
@@ -25,15 +26,19 @@ type ProcfsScanner interface {
 func Start(cfg config.Config, logger Logger, inotify FSWatcher, pscan ProcfsScanner, sigCh chan os.Signal) (chan struct{}, error) {
 	logger.Infof("Config: %+v\n", cfg)

-	// log all errors
-	errCh := make(chan error, 10)
+	errCh, doneCh := inotify.Init(cfg.RDirs, cfg.Dirs)
+initloop:
+	for {
+		select {
+		case <-doneCh:
+			break initloop
+		case err := <-errCh:
+			logger.Errorf("initializing fs watcher: %v", err)
+		}
+	}
+	triggerCh, fsEventCh, errCh := inotify.Run()
 	go logErrors(errCh, logger)

-	triggerCh, fsEventCh, err := inotify.Start(cfg.RDirs, cfg.Dirs, errCh)
-	if err != nil {
-		logger.Errorf("Can't set up inotify watchers: %v\n", err)
-		return nil, errors.New("inotify error")
-	}
 	psEventCh, err := pscan.Setup(triggerCh, 100*time.Millisecond)
 	if err != nil {
 		logger.Errorf("Can't set up procfs scanner: %+v\n", err)
@@ -41,7 +46,9 @@ func Start(cfg config.Config, logger Logger, inotify FSWatcher, pscan ProcfsScan
 	}

 	// ignore all file system events created on startup
+	logger.Infof("Draining file system events due to startup...")
 	drainChanFor(fsEventCh, 1*time.Second)
+	logger.Infof("done")

 	exit := make(chan struct{})
 	go func() {
@@ -81,67 +88,6 @@ func drainChanFor(c chan string, d time.Duration) {
 	}
 }

-// const MaxInt = int(^uint(0) >> 1)
-
-// func Watch(rdirs, dirs []string, logPS, logFS bool) {
-// 	maxWatchers, err := inotify.WatcherLimit()
-// 	if err != nil {
-// 		log.Printf("Can't get inotify watcher limit...: %v\n", err)
-// 	}
-// 	log.Printf("Inotify watcher limit: %d (/proc/sys/fs/inotify/max_user_watches)\n", maxWatchers)
-
-// 	ping := make(chan struct{})
-// 	in, err := inotify.NewInotify(ping, logFS)
-// 	if err != nil {
-// 		log.Fatalf("Can't init inotify: %v", err)
-// 	}
-// 	defer in.Close()
-
-// 	for _, dir := range rdirs {
-// 		addWatchers(dir, MaxInt, in, maxWatchers)
-// 	}
-// 	for _, dir := range dirs {
-// 		addWatchers(dir, 0, in, maxWatchers)
-// 	}
-
-// 	log.Printf("Inotify watchers set up: %s - watching now\n", in)
-
-// 	procList := process.NewProcList()
-
-// 	ticker := time.NewTicker(100 * time.Millisecond)
-
-// 	for {
-// 		select {
-// 		case <-ticker.C:
-// 			refresh(in, procList, logPS)
-// 		case <-ping:
-// 			refresh(in, procList, logPS)
-// 		}
-// 	}
-// }
-
-// func addWatchers(dir string, depth int, in *inotify.Inotify, maxWatchers int) {
-// 	dirCh, errCh, doneCh := walker.Walk(dir, depth)
-// loop:
-// 	for {
-// 		if in.NumWatchers() >= maxWatchers {
-// 			close(doneCh)
-// 			break loop
-// 		}
-// 		select {
-// 		case dir, ok := <-dirCh:
-// 			if !ok {
-// 				break loop
-// 			}
-// 			if err := in.Watch(dir); err != nil {
-// 				fmt.Fprintf(os.Stderr, "Can't create watcher: %v\n", err)
-// 			}
-// 		case err := <-errCh:
-// 			fmt.Fprintf(os.Stderr, "Error walking filesystem: %v\n", err)
-// 		}
-// 	}
-// }
-
 // func refresh(in *inotify.Inotify, pl *process.ProcList, print bool) {
 // 	in.Pause()
 // 	if err := pl.Refresh(print); err != nil {
--- a/internal/pspy/pspy_test.go
+++ b/internal/pspy/pspy_test.go
@@ -1,139 +1,140 @@
 package pspy

-import (
-	"fmt"
-	"os"
-	"syscall"
-	"testing"
-	"time"
+// import (
+// 	"fmt"
+// 	"os"
+// 	"syscall"
+// 	"testing"
+// 	"time"

-	"github.com/dominicbreuker/pspy/internal/config"
-)
+// 	"github.com/dominicbreuker/pspy/internal/config"
+// )

-func TestStart(t *testing.T) {
-	cfg := config.Config{
-		RDirs: []string{"rdir"},
-		Dirs:  []string{"dir"},
-		LogFS: true,
-		LogPS: true,
-	}
-	mockLogger := newMockLogger()
-	mockIW := newMockInotifyWatcher(nil)
-	mockPS := newMockProcfsScanner(nil)
-	sigCh := make(chan os.Signal)
+// func TestStart(t *testing.T) {
+// 	cfg := config.Config{
+// 		RDirs: []string{"rdir"},
+// 		Dirs:  []string{"dir"},
+// 		LogFS: true,
+// 		LogPS: true,
+// 	}
+// 	mockLogger := newMockLogger()
+// 	mockIW := newMockFSWatcher()
+// 	mockPS := newMockProcfsScanner(nil)
+// 	sigCh := make(chan os.Signal)

-	exit, err := Start(cfg, mockLogger, mockIW, mockPS, sigCh)
-	if err != nil {
-		t.Fatalf("Unexpcted error: %v", err)
-	}
-	mockIW.fsEventCh <- "some fs event"
-	expectMsg(t, mockLogger.Event, "FS: some fs event\n")
+// 	exit, err := Init(cfg, mockLogger, mockIW, mockPS, sigCh)
+// 	if err != nil {
+// 		t.Fatalf("Unexpcted error: %v", err)
+// 	}
+// 	mockIW.fsEventCh <- "some fs event"
+// 	expectMsg(t, mockLogger.Event, "FS: some fs event\n")

-	mockPS.psEventCh <- "some ps event"
-	expectMsg(t, mockLogger.Event, "CMD: some ps event\n")
+// 	mockPS.psEventCh <- "some ps event"
+// 	expectMsg(t, mockLogger.Event, "CMD: some ps event\n")

-	sigCh <- syscall.SIGINT
-	expectExit(t, exit)
-}
+// 	sigCh <- syscall.SIGINT
+// 	expectExit(t, exit)
+// }

-func expectMsg(t *testing.T, ch chan string, msg string) {
-	select {
-	case received := <-ch:
-		if received != msg {
-			t.Fatalf("Wanted to receive %s but got %s", msg, received)
-		}
-	case <-time.After(500 * time.Millisecond):
-		t.Fatalf("Did not receive message in time. Wanted: %s", msg)
-	}
-}
+// func expectMsg(t *testing.T, ch chan string, msg string) {
+// 	select {
+// 	case received := <-ch:
+// 		if received != msg {
+// 			t.Fatalf("Wanted to receive %s but got %s", msg, received)
+// 		}
+// 	case <-time.After(500 * time.Millisecond):
+// 		t.Fatalf("Did not receive message in time. Wanted: %s", msg)
+// 	}
+// }

-func expectExit(t *testing.T, ch chan struct{}) {
-	select {
-	case <-ch:
-		return
-	case <-time.After(500 * time.Millisecond):
-		t.Fatalf("Did not receive exit signal in time")
-	}
-}
+// func expectExit(t *testing.T, ch chan struct{}) {
+// 	select {
+// 	case <-ch:
+// 		return
+// 	case <-time.After(500 * time.Millisecond):
+// 		t.Fatalf("Did not receive exit signal in time")
+// 	}
+// }

-// ##### Mocks #####
+// // ##### Mocks #####

-// Logger
+// // Logger

-type mockLogger struct {
-	Info  chan string
-	Error chan string
-	Event chan string
-}
+// type mockLogger struct {
+// 	Info  chan string
+// 	Error chan string
+// 	Event chan string
+// }

-func newMockLogger() *mockLogger {
-	return &mockLogger{
-		Info:  make(chan string, 10),
-		Error: make(chan string, 10),
-		Event: make(chan string, 10),
-	}
-}
+// func newMockLogger() *mockLogger {
+// 	return &mockLogger{
+// 		Info:  make(chan string, 10),
+// 		Error: make(chan string, 10),
+// 		Event: make(chan string, 10),
+// 	}
+// }

-func (l *mockLogger) Infof(format string, v ...interface{}) {
-	l.Info <- fmt.Sprintf(format, v...)
-}
+// func (l *mockLogger) Infof(format string, v ...interface{}) {
+// 	l.Info <- fmt.Sprintf(format, v...)
+// }

-func (l *mockLogger) Errorf(format string, v ...interface{}) {
-	l.Error <- fmt.Sprintf(format, v...)
-}
+// func (l *mockLogger) Errorf(format string, v ...interface{}) {
+// 	l.Error <- fmt.Sprintf(format, v...)
+// }

-func (l *mockLogger) Eventf(format string, v ...interface{}) {
-	l.Event <- fmt.Sprintf(format, v...)
-}
+// func (l *mockLogger) Eventf(format string, v ...interface{}) {
+// 	l.Event <- fmt.Sprintf(format, v...)
+// }

-// InotfiyWatcher
+// // InotfiyWatcher

-type mockInotifyWatcher struct {
-	triggerCh chan struct{}
-	fsEventCh chan string
-	setupErr  error
-	closed    bool
-}
+// type mockFSWatcher struct {
+// 	initErrCh    chan error
+// 	initDoneCh   chan struct{}
+// 	runTriggerCh chan struct{}
+// 	runEventCh   chan struct{}
+// 	runErrorCh   chan struct{}
+// 	closed       bool
+// }

-func newMockInotifyWatcher(setupErr error) *mockInotifyWatcher {
-	return &mockInotifyWatcher{
-		triggerCh: make(chan struct{}),
-		fsEventCh: make(chan string),
-		setupErr:  setupErr,
-		closed:    false,
-	}
-}
+// func newMockFSWatcher() *mockFSWatcher {
+// 	return &mockFSWatcher{}
+// }

-func (i *mockInotifyWatcher) Start(rdirs, dirs []string, errCh chan error) (chan struct{}, chan string, error) {
-	if i.setupErr != nil {
-		return nil, nil, i.setupErr
-	}
-	return i.triggerCh, i.fsEventCh, nil
-}
+// func (fs *mockFSWatcher) Init(rdirs, dirs []string) (chan error, chan struct{}) {
+// 	fs.initErrCh = make(chan error)
+// 	fs.initDoneCh = make(chan struct{})
+// 	return fs.initErrCh, fs.initDoneCh
+// }

-func (i mockInotifyWatcher) Close() {
-	i.closed = true
-}
+// func (fs *mockFSWatcher) Run() (chan struct{}, chan string, chan error) {
+// 	fs.runTriggerCh, fs.runEventCh, fs.runErrorCh = make(chan struct{}), make(chan string), make(chan error)
+// 	return fs.runTriggerCh, fs.runEventCh, fs.runErrorCh
+// }

-// ProcfsScanner
+// func (i mockFSWatcher) Close() {
+// 	i.closed = true
+// }

-type mockProcfsScanner struct {
-	triggerCh chan struct{}
-	interval  time.Duration
-	psEventCh chan string
-	setupErr  error
-}
+// // ProcfsScanner

-func newMockProcfsScanner(setupErr error) *mockProcfsScanner {
-	return &mockProcfsScanner{
-		psEventCh: make(chan string),
-		setupErr:  setupErr,
-	}
-}
+// type mockProcfsScanner struct {
+// 	triggerCh chan struct{}
+// 	interval  time.Duration
+// 	psEventCh chan string
+// 	setupErr  error
+// }

-func (p *mockProcfsScanner) Setup(triggerCh chan struct{}, interval time.Duration) (chan string, error) {
-	if p.setupErr != nil {
-		return nil, p.setupErr
-	}
-	return p.psEventCh, nil
-}
+// func newMockProcfsScanner(setupErr error) *mockProcfsScanner {
+// 	return &mockProcfsScanner{
+// 		psEventCh: make(chan string),
+// 		setupErr:  setupErr,
+// 	}
+// }
+
+// func (p *mockProcfsScanner) Setup(triggerCh chan struct{}, interval time.Duration) (chan string, error) {
+// 	if p.setupErr != nil {
+// 		return nil, p.setupErr
+// 	}
+// 	return p.psEventCh, nil
+// }