Merge pull request #1 from juicedata/meta_cache

Add entry cache to speed up lookup

Author: davies

go.mod

@@ -0,0 +1,5 @@
+module github.com/vmware/go-nfs-client
+
+go 1.15
+
+require github.com/rasky/go-xdr v0.0.0-20170124162913-1a41d1a06c93

go.sum

@@ -0,0 +1,2 @@
+github.com/rasky/go-xdr v0.0.0-20170124162913-1a41d1a06c93 h1:UVArwN/wkKjMVhh2EQGC0tEc1+FqiLlvYXY5mQ2f8Wg=
+github.com/rasky/go-xdr v0.0.0-20170124162913-1a41d1a06c93/go.mod h1:Nfe4efndBz4TibWycNE+lqyJZiMX4ycx+QKV8Ta0f/o=

nfs/example/test/main.go

@@ -12,6 +12,7 @@ import (
 	"log"
 	"os"
 	"strings"
+	"time"
 
 	"github.com/vmware/go-nfs-client/nfs"
 	"github.com/vmware/go-nfs-client/nfs/rpc"
@@ -33,7 +34,7 @@ func main() {
 
 	util.Infof("host=%s target=%s dir=%s\n", host, target, dir)
 
-	mount, err := nfs.DialMount(host)
+	mount, err := nfs.DialMount(host, time.Second)
 	if err != nil {
 		log.Fatalf("unable to dial MOUNT service: %v", err)
 	}

nfs/mount.go

@@ -6,6 +6,7 @@ package nfs
 import (
 	"errors"
 	"fmt"
+	"time"
 
 	"github.com/vmware/go-nfs-client/nfs/rpc"
 	"github.com/vmware/go-nfs-client/nfs/xdr"
@@ -34,9 +35,10 @@ const (
 
 type Mount struct {
 	*rpc.Client
-	auth    rpc.Auth
-	dirPath string
-	Addr    string
+	auth         rpc.Auth
+	dirPath      string
+	Addr         string
+	entryTimeout time.Duration
 }
 
 func (m *Mount) Unmount() error {
@@ -104,7 +106,7 @@ func (m *Mount) Mount(dirpath string, auth rpc.Auth) (*Target, error) {
 		m.dirPath = dirpath
 		m.auth = auth
 
-		vol, err := NewTarget(m.Addr, auth, fh, dirpath)
+		vol, err := NewTarget(m.Addr, auth, fh, dirpath, m.entryTimeout)
 		if err != nil {
 			return nil, err
 		}
@@ -127,7 +129,7 @@ func (m *Mount) Mount(dirpath string, auth rpc.Auth) (*Target, error) {
 	return nil, fmt.Errorf("unknown mount stat: %d", mountstat3)
 }
 
-func DialMount(addr string) (*Mount, error) {
+func DialMount(addr string, entryTimeout time.Duration) (*Mount, error) {
 	// get MOUNT port
 	m := rpc.Mapping{
 		Prog: MountProg,
@@ -142,7 +144,8 @@ func DialMount(addr string) (*Mount, error) {
 	}
 
 	return &Mount{
-		Client: client,
-		Addr:   addr,
+		Client:       client,
+		Addr:         addr,
+		entryTimeout: entryTimeout,
 	}, nil
 }

nfs/target.go

@@ -9,22 +9,33 @@ import (
 	"path"
 	"path/filepath"
 	"strings"
+	"sync"
+	"time"
 
 	"github.com/vmware/go-nfs-client/nfs/rpc"
 	"github.com/vmware/go-nfs-client/nfs/util"
 	"github.com/vmware/go-nfs-client/nfs/xdr"
 )
 
+type cacheEntry struct {
+	fh     []byte
+	attr   *Fattr
+	expire time.Time
+}
 type Target struct {
 	*rpc.Client
 
 	auth    rpc.Auth
 	fh      []byte
 	dirPath string
 	fsinfo  *FSInfo
+
+	entryTimeout time.Duration
+	cacheM       sync.Mutex
+	entries      map[string]map[string]*cacheEntry
 }
 
-func NewTarget(addr string, auth rpc.Auth, fh []byte, dirpath string) (*Target, error) {
+func NewTarget(addr string, auth rpc.Auth, fh []byte, dirpath string, entryTimeout time.Duration) (*Target, error) {
 	m := rpc.Mapping{
 		Prog: Nfs3Prog,
 		Vers: Nfs3Vers,
@@ -38,10 +49,12 @@ func NewTarget(addr string, auth rpc.Auth, fh []byte, dirpath string) (*Target,
 	}
 
 	vol := &Target{
-		Client:  client,
-		auth:    auth,
-		fh:      fh,
-		dirPath: dirpath,
+		Client:       client,
+		auth:         auth,
+		fh:           fh,
+		dirPath:      dirpath,
+		entryTimeout: entryTimeout,
+		entries:      make(map[string]map[string]*cacheEntry),
 	}
 
 	fsinfo, err := vol.FSInfo()
@@ -51,7 +64,7 @@ func NewTarget(addr string, auth rpc.Auth, fh []byte, dirpath string) (*Target,
 
 	vol.fsinfo = fsinfo
 	util.Debugf("%s:%s fsinfo=%#v", addr, dirpath, fsinfo)
-
+	go vol.cleanupCache()
 	return vol, nil
 }
 
@@ -105,6 +118,31 @@ func (v *Target) FSInfo() (*FSInfo, error) {
 	return fsinfo, nil
 }
 
+func (v *Target) cleanupCache() {
+	for {
+		v.cacheM.Lock()
+		now := time.Now()
+		var cnt int
+	OUTER:
+		for fh, es := range v.entries {
+			for n, e := range es {
+				if now.After(e.expire) {
+					delete(es, n)
+					if len(es) == 0 {
+						delete(v.entries, fh)
+					}
+				}
+				cnt++
+				if cnt > 1000 {
+					break OUTER
+				}
+			}
+		}
+		v.cacheM.Unlock()
+		time.Sleep(time.Second)
+	}
+}
+
 // Lookup returns attributes and the file handle to a given dirent
 func (v *Target) Lookup(p string) (os.FileInfo, []byte, error) {
 	var (
@@ -117,22 +155,62 @@ func (v *Target) Lookup(p string) (os.FileInfo, []byte, error) {
 	dirents := strings.Split(path.Clean(p), "/")
 	for _, dirent := range dirents {
 		// we're assuming the root is always the root of the mount
-		if dirent == "." || dirent == "" {
+		if dirent == "" {
 			util.Debugf("root -> 0x%x", fh)
-			continue
+			dirent = "."
 		}
 
-		fattr, fh, err = v.lookup(fh, dirent)
+		fattr, fh, err = v.cachedLookup(fh, dirent)
 		if err != nil {
 			return nil, nil, err
 		}
 
 		//util.Debugf("%s -> 0x%x", dirent, fh)
+		// TODO: resolve symlink
 	}
 
 	return fattr, fh, nil
 }
 
+func (v *Target) parsefh(fh []byte) string {
+	return string(fh)
+}
+
+func (v *Target) cachedLookup(fh []byte, name string) (*Fattr, []byte, error) {
+	ino := v.parsefh(fh)
+	v.cacheM.Lock()
+	es := v.entries[ino]
+	if es != nil {
+		e := es[name]
+		if e != nil && time.Since(e.expire) < 0 {
+			v.cacheM.Unlock()
+			return e.attr, e.fh, nil
+		}
+	}
+	v.cacheM.Unlock()
+	attr, fh, err := v.lookup(fh, name)
+	if err == nil && attr.Type == 2 { // only cache directories
+		if es == nil {
+			es = make(map[string]*cacheEntry)
+			v.entries[ino] = es
+		}
+		v.cacheM.Lock()
+		es[name] = &cacheEntry{fh, attr, time.Now().Add(v.entryTimeout)}
+		v.cacheM.Unlock()
+	}
+	return attr, fh, err
+}
+
+func (v *Target) invalidateEntryCache(fh []byte, name string) {
+	ino := v.parsefh(fh)
+	v.cacheM.Lock()
+	es, ok := v.entries[ino]
+	if ok {
+		delete(es, name)
+	}
+	v.cacheM.Unlock()
+}
+
 // lookup returns the same as above, but by fh and name
 func (v *Target) lookup(fh []byte, name string) (*Fattr, []byte, error) {
 	type Lookup3Args struct {
@@ -327,7 +405,7 @@ func (v *Target) Mkdir(path string, perm os.FileMode) ([]byte, error) {
 		util.Debugf("mkdir(%s) partial response: %+v", mkdirres)
 		return nil, err
 	}
-
+	v.invalidateEntryCache(fh, newDir)
 	util.Debugf("mkdir(%s): created successfully (0x%x)", path, fh)
 	return mkdirres.FH.FH, nil
 }
@@ -391,7 +469,7 @@ func (v *Target) Create(path string, perm os.FileMode) ([]byte, error) {
 	if err = xdr.Read(res, status); err != nil {
 		return nil, err
 	}
-
+	v.invalidateEntryCache(fh, newFile)
 	util.Debugf("create(%s): created successfully", path)
 	return status.FH.FH, nil
 }
@@ -433,7 +511,7 @@ func (v *Target) remove(fh []byte, deleteFile string) error {
 		util.Debugf("remove(%s): %s", deleteFile, err.Error())
 		return err
 	}
-
+	v.invalidateEntryCache(fh, deleteFile)
 	return nil
 }
 
@@ -474,7 +552,7 @@ func (v *Target) rmDir(fh []byte, name string) error {
 		util.Debugf("rmdir(%s): %s", name, err.Error())
 		return err
 	}
-
+	v.invalidateEntryCache(fh, name)
 	util.Debugf("rmdir(%s): deleted successfully", name)
 	return nil
 }