cmd/geth, eth/downloader: rough guess at the import eta

cmd/geth/admin.go

@@ -325,8 +325,13 @@ func (js *jsre) setHead(call otto.FunctionCall) otto.Value {
 }
 
 func (js *jsre) syncProgress(call otto.FunctionCall) otto.Value {
-	pending, cached, importing := js.ethereum.Downloader().Stats()
-	v, _ := call.Otto.ToValue(map[string]interface{}{"pending": pending, "cached": cached, "importing": importing})
+	pending, cached, importing, eta := js.ethereum.Downloader().Stats()
+	v, _ := call.Otto.ToValue(map[string]interface{}{
+		"pending":   pending,
+		"cached":    cached,
+		"importing": importing,
+		"estimate":  eta.String(),
+	})
 	return v
 }
 

eth/downloader/downloader.go

@@ -79,7 +79,9 @@ type Downloader struct {
 	banned *set.Set                    // Set of hashes we've received and banned
 
 	// Statistics
+	importStart time.Time     // Instance when the last blocks were taken from the cache
 	importQueue []common.Hash // Hashes of the previously taken blocks to check import progress
+	importDone  int           // Number of taken blocks already imported from the last batch
 	importLock  sync.Mutex
 
 	// Callbacks
@@ -126,19 +128,25 @@ func New(mux *event.TypeMux, hasBlock hashCheckFn, getBlock getBlockFn) *Downloa
 }
 
 // Stats retrieves the current status of the downloader.
-func (d *Downloader) Stats() (pending int, cached int, importing int) {
+func (d *Downloader) Stats() (pending int, cached int, importing int, estimate time.Duration) {
 	// Fetch the download status
 	pending, cached = d.queue.Size()
 
-	// Generate the import status
+	// Figure out the import progress
 	d.importLock.Lock()
 	defer d.importLock.Unlock()
 
 	for len(d.importQueue) > 0 && d.hasBlock(d.importQueue[0]) {
 		d.importQueue = d.importQueue[1:]
+		d.importDone++
 	}
 	importing = len(d.importQueue)
 
+	// Make an estimate on the total sync
+	estimate = 0
+	if d.importDone > 0 {
+		estimate = time.Since(d.importStart) / time.Duration(d.importDone) * time.Duration(pending+cached+importing)
+	}
 	return
 }
 
@@ -226,7 +234,9 @@ func (d *Downloader) TakeBlocks() []*Block {
 			hashes[i] = block.RawBlock.Hash()
 		}
 		d.importLock.Lock()
+		d.importStart = time.Now()
 		d.importQueue = hashes
+		d.importDone = 0
 		d.importLock.Unlock()
 	}
 	return blocks
@@ -287,6 +297,7 @@ func (d *Downloader) Cancel() bool {
 
 	d.importLock.Lock()
 	d.importQueue = nil
+	d.importDone = 0
 	d.importLock.Unlock()
 
 	return true