more accurate speed measurement. Makes a difference if MW is minimized for a long time

core/src/main/groovy/com/muwire/core/download/DownloadSession.groovy

@@ -21,6 +21,7 @@ import java.nio.file.Files
 import java.nio.file.StandardOpenOption
 import java.security.MessageDigest
 import java.security.NoSuchAlgorithmException
+import java.util.concurrent.atomic.AtomicLong
 import java.util.logging.Level
 
 @Log
@@ -37,13 +38,12 @@ class DownloadSession {
     private final Set<Integer> available
     private final MessageDigest digest
 
-    private long lastSpeedRead = System.currentTimeMillis()
-    private long dataSinceLastRead
+    private final AtomicLong dataSinceLastRead
 
     private MappedByteBuffer mapped
 
     DownloadSession(EventBus eventBus, String meB64, Pieces pieces, InfoHash infoHash, Endpoint endpoint, File file,
-        int pieceSize, long fileLength, Set<Integer> available) {
+        int pieceSize, long fileLength, Set<Integer> available, AtomicLong dataSinceLastRead) {
         this.eventBus = eventBus
         this.meB64 = meB64
         this.pieces = pieces
@@ -53,6 +53,7 @@ class DownloadSession {
         this.pieceSize = pieceSize
         this.fileLength = fileLength
         this.available = available
+        this.dataSinceLastRead = dataSinceLastRead
         try {
             digest = MessageDigest.getInstance("SHA-256")
         } catch (NoSuchAlgorithmException impossible) {
@@ -190,7 +191,7 @@ class DownloadSession {
                         throw new IOException()
                     synchronized(this) {
                         mapped.put(tmp, 0, read)
-                        dataSinceLastRead += read
+                        dataSinceLastRead.addAndGet(read)
                         pieces.markPartial(piece, mapped.position())
                     }
                 }
@@ -222,13 +223,4 @@ class DownloadSession {
             return 0
         mapped.position()
     }
-
-    synchronized int speed() {
-        final long now = System.currentTimeMillis()
-        long interval = Math.max(1000, now - lastSpeedRead)
-        lastSpeedRead = now;
-        int rv = (int) (dataSinceLastRead * 1000.0 / interval)
-        dataSinceLastRead = 0
-        rv
-    }
 }

core/src/main/groovy/com/muwire/core/download/Downloader.groovy

@@ -12,6 +12,7 @@ import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.ExecutorService
 import java.util.concurrent.Executors
 import java.util.concurrent.atomic.AtomicBoolean
+import java.util.concurrent.atomic.AtomicLong
 import java.util.logging.Level
 
 import com.muwire.core.Constants
@@ -61,10 +62,11 @@ public class Downloader {
     private final AtomicBoolean eventFired = new AtomicBoolean()
     private boolean piecesFileClosed
 
+    private final AtomicLong dataSinceLastRead = new AtomicLong(0)
+    private volatile long lastSpeedRead = System.currentTimeMillis()
     private ArrayList speedArr = new ArrayList<Integer>()
     private int speedPos = 0
     private int speedAvg = 0
-    private long timestamp = Instant.now().toEpochMilli()
 
     public Downloader(EventBus eventBus, DownloadManager downloadManager,
         Persona me, File file, long length, InfoHash infoHash,
@@ -139,10 +141,11 @@ public class Downloader {
     public int speed() {
         int currSpeed = 0
         if (getCurrentState() == DownloadState.DOWNLOADING) {
-            activeWorkers.values().each {
-                if (it.currentState == WorkerState.DOWNLOADING)
-                    currSpeed += it.speed()
-            }
+            long dataRead = dataSinceLastRead.getAndSet(0)
+            long now = System.currentTimeMillis()
+            if (now > lastSpeedRead)
+                currSpeed = (int) (dataRead * 1000.0 / (now - lastSpeedRead))
+            lastSpeedRead = now
         }
         
         if (speedArr.size() != downloadManager.muSettings.speedSmoothSeconds) {
@@ -302,7 +305,7 @@ public class Downloader {
                 boolean requestPerformed
                 while(!pieces.isComplete()) {
                     currentSession = new DownloadSession(eventBus, me.toBase64(), pieces, getInfoHash(),
-                        endpoint, incompleteFile, pieceSize, length, available)
+                        endpoint, incompleteFile, pieceSize, length, available, dataSinceLastRead)
                     requestPerformed = currentSession.request()
                     if (!requestPerformed)
                         break
@@ -339,12 +342,6 @@ public class Downloader {
             }
         }
 
-        int speed() {
-            if (currentSession == null)
-                return 0
-            currentSession.speed()
-        }
-
         void cancel() {
             downloadThread?.interrupt()
         }

core/src/test/groovy/com/muwire/core/download/DownloadSessionTest.groovy

@@ -2,6 +2,8 @@ package com.muwire.core.download
 
 import static org.junit.Assert.fail
 
+import java.util.concurrent.atomic.AtomicLong
+
 import org.junit.After
 import org.junit.Before
 import org.junit.Ignore
@@ -76,7 +78,7 @@ class DownloadSessionTest {
         toUploader = new PipedOutputStream(fromDownloader)
         endpoint = new Endpoint(null, fromUploader, toUploader, null)
 
-        session = new DownloadSession(eventBus, "",pieces, infoHash, endpoint, target, pieceSize, size, available)
+        session = new DownloadSession(eventBus, "",pieces, infoHash, endpoint, target, pieceSize, size, available, new AtomicLong())
         downloadThread = new Thread( { perform() } as Runnable)
         downloadThread.setDaemon(true)
         downloadThread.start()