TierFS enhancements

go.mod

@@ -70,6 +70,7 @@ require (
 	github.com/spf13/cobra v1.0.0
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.7.1
+	github.com/streadway/handy v0.0.0-20190108123426-d5acb3125c2a
 	github.com/stretchr/testify v1.6.1
 	github.com/thanhpk/randstr v1.0.4
 	github.com/tidwall/pretty v1.0.1 // indirect

go.sum

@@ -1063,6 +1063,7 @@ github.com/ssgreg/nlreturn/v2 v2.0.1 h1:+lm6xFjVuNw/9t/Fh5sIwfNWefiD5bddzc6vwJ1T
 github.com/ssgreg/nlreturn/v2 v2.0.1/go.mod h1:E/iiPB78hV7Szg2YfRgyIrk1AD6JVMTRkkxBiELzh2I=
 github.com/streadway/amqp v0.0.0-20190404075320-75d898a42a94/go.mod h1:AZpEONHx3DKn8O/DFsRAY58/XVQiIPMTMB1SddzLXVw=
 github.com/streadway/amqp v0.0.0-20190827072141-edfb9018d271/go.mod h1:AZpEONHx3DKn8O/DFsRAY58/XVQiIPMTMB1SddzLXVw=
+github.com/streadway/handy v0.0.0-20190108123426-d5acb3125c2a h1:AhmOdSHeswKHBjhsLs/7+1voOxT+LLrSk/Nxvk35fug=
 github.com/streadway/handy v0.0.0-20190108123426-d5acb3125c2a/go.mod h1:qNTQ5P5JnDBl6z3cMAg/SywNDC5ABu5ApDIw6lUbRmI=
 github.com/streadway/quantile v0.0.0-20150917103942-b0c588724d25 h1:7z3LSn867ex6VSaahyKadf4WtSsJIgne6A1WLOAGM8A=
 github.com/streadway/quantile v0.0.0-20150917103942-b0c588724d25/go.mod h1:lbP8tGiBjZ5YWIc2fzuRpTaz0b/53vT6PEs3QuAWzuU=

pyramid/directory.go

@@ -0,0 +1,86 @@
+package pyramid
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"sync"
+)
+
+// directory synchronizes between file operations that might change (create/delete) directories
+type directory struct {
+	// ceilingDir is the root directory of the FS - shouldn't never be deleted
+	ceilingDir string
+	mu         sync.Mutex
+}
+
+// deleteDirRecIfEmpty deletes the given directory if it is empty.
+// It will continue to delete all parents directory if they are empty, until the ceilingDir.
+// Passed dir path isn't checked for malicious referencing (e.g. "../../../usr") and should never be
+// controlled by any user input.
+func (d *directory) deleteDirRecIfEmpty(dir string) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	for dir != d.ceilingDir {
+		empty, err := isDirEmpty(dir)
+		if err != nil {
+			if errors.Is(err, os.ErrNotExist) {
+				return nil
+			}
+			return err
+		}
+		if !empty {
+			return nil
+		}
+
+		parentDir := path.Dir(dir)
+		if err := os.Remove(dir); err != nil {
+			return err
+		}
+		dir = parentDir
+	}
+
+	return nil
+}
+
+func isDirEmpty(name string) (bool, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	_, err = f.Readdirnames(1)
+	if errors.Is(err, io.EOF) {
+		return true, nil
+	}
+	return false, err
+}
+
+// createFile creates the file under the path and creates all parent dirs if missing.
+func (d *directory) createFile(path string) (*os.File, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if err := os.MkdirAll(filepath.Dir(path), os.ModePerm); err != nil {
+		return nil, fmt.Errorf("creating dir: %w", err)
+	}
+
+	return os.Create(path)
+}
+
+// renameFile will move the src file to dst location and creates all parent dirs if missing.
+func (d *directory) renameFile(src, dst string) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if err := os.MkdirAll(filepath.Dir(dst), os.ModePerm); err != nil {
+		return fmt.Errorf("creating dir: %w", err)
+	}
+
+	return os.Rename(src, dst)
+}

pyramid/directory_test.go

@@ -0,0 +1,80 @@
+package pyramid
+
+import (
+	"io/ioutil"
+	"os"
+	"path"
+	"strconv"
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestConcurrentCreateDeleteDir(t *testing.T) {
+	name, err := ioutil.TempDir("", "test-dir-")
+	require.NoError(t, err)
+	sut := directory{ceilingDir: name}
+
+	var wg sync.WaitGroup
+	concurrency := 1000
+	pathDir := path.Join(name, "a/b/c/")
+
+	for i := 0; i < concurrency; i++ {
+		// create and delete
+		filepath := path.Join(pathDir, strconv.Itoa(i))
+		wg.Add(2)
+		go func() {
+			f, err := sut.createFile(filepath)
+			require.NoError(t, err)
+			require.NoError(t, f.Close())
+			require.NoError(t, os.Remove(filepath))
+
+			wg.Done()
+		}()
+		// delete folder - this will sometime succeed if the folder is empty
+		go func() {
+			require.NoError(t, sut.deleteDirRecIfEmpty(pathDir))
+
+			wg.Done()
+		}()
+	}
+	// It doesn't really matter if the dir exists and its content.
+	// It's more about not panicking thru all of this
+	wg.Wait()
+}
+
+func TestConcurrentRenameDeleteDir(t *testing.T) {
+	name, err := ioutil.TempDir("", "test-dir-")
+	require.NoError(t, err)
+	sut := directory{ceilingDir: name}
+
+	var wg sync.WaitGroup
+	concurrency := 1000
+	pathDir := path.Join(name, "a/b/c/")
+
+	for i := 0; i < concurrency; i++ {
+		// create and delete
+		originalPath := path.Join(name, strconv.Itoa(i))
+		require.NoError(t, ioutil.WriteFile(originalPath, []byte("some data"), os.ModePerm))
+
+		filepath := path.Join(pathDir, strconv.Itoa(i))
+		wg.Add(2)
+		go func() {
+			err := sut.renameFile(originalPath, filepath)
+			require.NoError(t, err)
+			require.NoError(t, os.Remove(filepath))
+
+			wg.Done()
+		}()
+		// delete folder - this will sometime succeed if the folder is empty
+		go func() {
+			require.NoError(t, sut.deleteDirRecIfEmpty(pathDir))
+
+			wg.Done()
+		}()
+	}
+	// It doesn't really matter if the dir exists and its content.
+	// It's more about not panicking thru all of this
+	wg.Wait()
+}

pyramid/eviction.go

@@ -17,9 +17,9 @@ type lruSizeEviction struct {
 	cache simplelru.LRUCache
 }
 
-func newLRUSizeEviction(capacity int64, evict func(rPath relativePath)) (eviction, error) {
-	cache, err := lru.NewWithEvict(capacity, func(key interface{}, _ interface{}, _ int64) {
-		evict(key.(relativePath))
+func newLRUSizeEviction(capacity int64, evict func(rPath relativePath, cost int64)) (eviction, error) {
+	cache, err := lru.NewWithEvict(capacity, func(key interface{}, _ interface{}, cost int64) {
+		evict(key.(relativePath), cost)
 	})
 	if err != nil {
 		return nil, fmt.Errorf("creating cache: %w", err)

pyramid/file.go

@@ -1,47 +1,21 @@
 package pyramid
 
 import (
+	"errors"
 	"fmt"
 	"os"
 )
 
 // File is pyramid wrapper for os.file that triggers pyramid hooks for file actions.
 type File struct {
-	fh *os.File
+	*os.File
 
-	closed    bool
 	persisted bool
 	store     func(string) error
 }
 
-func (f *File) Read(p []byte) (n int, err error) {
-	return f.fh.Read(p)
-}
-
-func (f *File) ReadAt(p []byte, off int64) (n int, err error) {
-	return f.fh.ReadAt(p, off)
-}
-
-func (f *File) Write(p []byte) (n int, err error) {
-	return f.fh.Write(p)
-}
-
-func (f *File) Stat() (os.FileInfo, error) {
-	return f.fh.Stat()
-}
-
-func (f *File) Sync() error {
-	return f.fh.Sync()
-}
-
-func (f *File) Close() error {
-	f.closed = true
-	return f.fh.Close()
-}
-
 var (
 	errAlreadyPersisted = fmt.Errorf("file is already persisted")
-	errFileNotClosed    = fmt.Errorf("file isn't closed")
 )
 
 // Store copies the closed file to all tiers of the pyramid.
@@ -50,14 +24,16 @@ func (f *File) Store(filename string) error {
 		return err
 	}
 
+	err := f.File.Close()
+	if err != nil && !errors.Is(err, os.ErrClosed) {
+		return fmt.Errorf("closing file: %w", err)
+	}
+
 	if f.persisted {
 		return errAlreadyPersisted
 	}
-	if !f.closed {
-		return errFileNotClosed
-	}
 
-	err := f.store(filename)
+	err = f.store(filename)
 	if err == nil {
 		f.persisted = true
 	}

pyramid/file_test.go

@@ -24,7 +24,7 @@ func TestPyramidWriteFile(t *testing.T) {
 
 	storeCalled := false
 	sut := File{
-		fh: fh,
+		File: fh,
 		store: func(string) error {
 			storeCalled = true
 			return nil
@@ -59,7 +59,7 @@ func TestWriteValidate(t *testing.T) {
 	storeCalled := false
 
 	sut := File{
-		fh: fh,
+		File: fh,
 		store: func(string) error {
 			storeCalled = true
 			return nil
@@ -97,7 +97,7 @@ func TestPyramidReadFile(t *testing.T) {
 	}
 
 	sut := ROFile{
-		fh:       fh,
+		File:     fh,
 		eviction: mockEv,
 		rPath:    relativePath(filename),
 	}

pyramid/metrics.go

@@ -0,0 +1,42 @@
+package pyramid
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+// nolint: gomnd
+const (
+	kb                = float64(1024)
+	fsNameLabel       = "fsName"
+	errorTypeLabel    = "type"
+	accessStatusLabel = "status"
+)
+
+var cacheAccess = promauto.NewCounterVec(
+	prometheus.CounterOpts{
+		Name: "tier_fs_cache_hits_total",
+		Help: "TierFS cache hits total count",
+	}, []string{fsNameLabel, accessStatusLabel})
+
+var errorsTotal = promauto.NewCounterVec(
+	prometheus.CounterOpts{
+		Name: "tier_fs_errors_total",
+		Help: "TierFS errors by type",
+	}, []string{fsNameLabel, errorTypeLabel})
+
+var evictionHistograms = promauto.NewHistogramVec(
+	prometheus.HistogramOpts{
+		Name:    "tier_fs_eviction_bytes",
+		Help:    "TierFS evicted object size by bytes",
+		Buckets: prometheus.ExponentialBuckets(kb, 4, 7),
+	},
+	[]string{fsNameLabel})
+
+var downloadHistograms = promauto.NewHistogramVec(
+	prometheus.HistogramOpts{
+		Name:    "tier_fs_download_bytes",
+		Help:    "TierFS download from block-store object size by bytes",
+		Buckets: prometheus.ExponentialBuckets(kb, 4, 7),
+	},
+	[]string{fsNameLabel})

pyramid/ro_file.go

@@ -7,27 +7,23 @@ import (
 // ROFile is pyramid wrapper for os.file that implements io.ReadCloser
 // with hooks for updating evictions.
 type ROFile struct {
-	fh       *os.File
+	*os.File
 	eviction eviction
 
 	rPath relativePath
 }
 
 func (f *ROFile) Read(p []byte) (n int, err error) {
 	f.eviction.touch(f.rPath)
-	return f.fh.Read(p)
+	return f.File.Read(p)
 }
 
 func (f *ROFile) ReadAt(p []byte, off int64) (n int, err error) {
 	f.eviction.touch(f.rPath)
-	return f.fh.ReadAt(p, off)
+	return f.File.ReadAt(p, off)
 }
 
 func (f *ROFile) Stat() (os.FileInfo, error) {
 	f.eviction.touch(f.rPath)
-	return f.fh.Stat()
-}
-
-func (f *ROFile) Close() error {
-	return f.fh.Close()
+	return f.File.Stat()
 }