Add some counters and tracking to torrentfs events

diff --git a/fs/torrentfs.go b/fs/torrentfs.go
index dd10d413975a45b320244cd6a2c7ff6eaa23f703..41877908a7e246b00e1c4d6e35b204b1252ac2fd 100644 (file)
--- a/fs/torrentfs.go
+++ b/fs/torrentfs.go
@@ -1,10 +1,12 @@
 package torrentfs
 
 import (
+       "expvar"
        "log"
        "os"
        "strings"
        "sync"
+       "time"
 
        "bazil.org/fuse"
        fusefs "bazil.org/fuse/fs"
@@ -16,6 +18,12 @@ const (
        defaultMode = 0555
 )
 
+var (
+       torrentfsReadRequests        = expvar.NewInt("torrentfsReadRequests")
+       torrentfsDelayedReadRequests = expvar.NewInt("torrentfsDelayedReadRequests")
+       interruptedReads             = expvar.NewInt("interruptedReads")
+)
+
 type torrentFS struct {
        Client    *torrent.Client
        destroyed chan struct{}
@@ -54,10 +62,18 @@ func (n *node) fsPath() string {
 }
 
 func (fn fileNode) Read(req *fuse.ReadRequest, resp *fuse.ReadResponse, intr fusefs.Intr) fuse.Error {
+       torrentfsReadRequests.Add(1)
+       started := time.Now()
        if req.Dir {
                panic("read on directory")
        }
-       log.Printf("read request for %s: offset=%d size=%d", fn.fsPath(), req.Offset, req.Size)
+       defer func() {
+               ms := time.Now().Sub(started).Nanoseconds() / 1000000
+               if ms < 20 {
+                       return
+               }
+               log.Printf("torrentfs read took %dms", ms)
+       }()
        size := req.Size
        fileLeft := int64(fn.size) - req.Offset
        if fileLeft < int64(size) {
@@ -74,6 +90,7 @@ func (fn fileNode) Read(req *fuse.ReadRequest, resp *fuse.ReadResponse, intr fus
                        panic(err)
                }
        }()
+       delayed := false
        for {
                dataWaiter := fn.FS.Client.DataWaiter()
                n, err := fn.FS.Client.TorrentReadAt(infoHash, torrentOff, resp.Data)
@@ -82,6 +99,10 @@ func (fn fileNode) Read(req *fuse.ReadRequest, resp *fuse.ReadResponse, intr fus
                        resp.Data = resp.Data[:n]
                        return nil
                case torrent.ErrDataNotReady:
+                       if !delayed {
+                               torrentfsDelayedReadRequests.Add(1)
+                               delayed = true
+                       }
                        select {
                        case <-dataWaiter:
                        case <-fn.FS.destroyed: