func (this *DataMgr) downloadLoop() {
this.Log.Printf("Entering download loop")
this.lock.Lock() // Lock is held *except* when doing remote calls & sleeping
// While I'm not closing
for !this.isClosing {
this.SyncMgr.Log.Printf("Looking things to download\n")
// Get a object to download
var key string
row := this.Db.SingleQuery("SELECT key FROM Blob WHERE needs_download = 1")
if !this.Db.MaybeScan(row, &key) {
this.Log.Printf("Nothing to download, sleeping\n")
this.download.Wait()
continue
}
friends := this.allAdverts(key)
if len(friends) == 0 {
this.Log.Printf("Strangely got a download where len(friends) = 0")
this.Db.Exec("UPDATE Blob SET needs_download = 0 WHERE key = ?", key)
continue
}
friend := friends[rand.Intn(len(friends))]
obj := this.getObj(key)
obj.startDownload()
this.writeObj(obj)
this.lock.Unlock()
this.Log.Printf("Doing a download of %s from %d!\n", key, friend)
var send_buf bytes.Buffer
transfer.Encode(&send_buf, key)
tmppath := path.Join(this.incoming, crypto.RandomString())
file, _ := os.Create(tmppath)
hasher := crypto.NewHasher()
both := io.MultiWriter(file, hasher)
tryTime := time.Now()
err := this.Send(link.ServiceData, friend, &send_buf, both)
if err != nil && time.Now().Sub(tryTime) < 5*time.Second {
// TODO: Make this not suck
time.Sleep(5 * time.Second)
}
if err != nil {
this.Log.Printf("Download failed: %s", err)
} else {
this.Log.Printf("Download worked!")
}
this.lock.Lock()
obj = this.getObj(key)
obj.finishDownload(tmppath, err == nil)
this.writeObj(obj)
}
this.lock.Unlock()
this.goRoutines.Done()
}
// Reads from io.Reader and generates a new object, put it to the meta-data layer
func (this *DataMgr) PutData(topic string, key string, writer *crypto.SecretIdentity, stream io.Reader) error {
this.Log.Printf("Putting data: %s, %s", topic, key)
// Write the object to disk
tmppath := path.Join(this.incoming, crypto.RandomString())
file, err := os.Create(tmppath)
if err != nil {
return err
}
hasher := crypto.NewHasher()
both := io.MultiWriter(file, hasher)
_, err = io.Copy(both, stream)
if err != nil {
_ = os.Remove(tmppath) // Ignore errors
return err
}
digest := hasher.Finalize()
okey := digest.String()
// Add info to DB
this.lock.Lock()
obj := this.getObj(okey)
obj.newFile(tmppath)
obj.Holds++
this.writeObj(obj)
this.lock.Unlock()
// Put to meta-data layer
data, _ := transfer.EncodeBytes(digest)
err = this.MetaMgr.Put(topic, writer, key, data)
// Remove hold
this.lock.Lock()
obj = this.getObj(okey)
obj.Holds--
this.writeObj(obj)
this.lock.Unlock()
return err
}
