Volume annotation download: zip with BEST_SPEED

CHANGELOG.unreleased.md

@@ -16,6 +16,7 @@ For upgrade instructions, please check the [migration guide](MIGRATIONS.released
 - Added a button next to the histogram which adapts the contrast and brightness to the currently visible data. [#5961](https://github.com/scalableminds/webknossos/pull/5961)
 - Running uploads can now be cancelled. [#5958](https://github.com/scalableminds/webknossos/pull/5958)
 - Annotations with multiple volume layers can now be uploaded. (Note that merging multiple annotations with multiple volume layers each is not supported.) [#6028](https://github.com/scalableminds/webknossos/pull/6028)
+- Decrease volume annotation download latency by using a different compression level. [#6036](https://github.com/scalableminds/webknossos/pull/6036)
 
 ### Changed
 - Upgraded webpack build tool to v5 and all other webpack related dependencies to their latest version. Enabled persistent caching which speeds up server restarts during development as well as production builds. [#5969](https://github.com/scalableminds/webknossos/pull/5969)

app/controllers/AnnotationIOController.scala

@@ -1,6 +1,7 @@
 package controllers
 
 import java.io.{BufferedOutputStream, File, FileOutputStream}
+import java.util.zip.Deflater
 
 import akka.actor.ActorSystem
 import akka.stream.Materializer
@@ -377,6 +378,7 @@ Expects:
           case (volumeLayer, index) =>
             volumeLayer.volumeDataOpt.foreach { volumeData =>
               val dataZipName = volumeLayer.volumeDataZipName(index, fetchedVolumeLayers.length == 1)
+              zipper.stream.setLevel(Deflater.BEST_SPEED)
               zipper.addFileFromBytes(dataZipName, volumeData)
             }
         }

util/src/main/scala/com/scalableminds/util/io/ZipIO.scala

@@ -93,8 +93,12 @@ object ZipIO extends LazyLogging {
   def zip(sources: List[NamedStream], out: OutputStream)(implicit ec: ExecutionContext): Future[Unit] =
     zip(sources.toIterator, out)
 
-  def zip(sources: Iterator[NamedStream], out: OutputStream)(implicit ec: ExecutionContext): Future[Unit] = {
+  def zip(sources: Iterator[NamedStream], out: OutputStream, level: Int = -1)(
+      implicit ec: ExecutionContext): Future[Unit] = {
     val zip = startZip(out)
+    if (level != -1) {
+      zip.stream.setLevel(level)
+    }
     if (sources.nonEmpty) {
       for {
         _ <- zipIterator(sources, zip)

webknossos-tracingstore/app/com/scalableminds/webknossos/tracingstore/tracings/volume/VolumeTracingService.scala

@@ -23,9 +23,10 @@ import play.api.libs.Files
 import play.api.libs.Files.TemporaryFileCreator
 import play.api.libs.iteratee.Enumerator
 import play.api.libs.json.{JsObject, JsValue, Json}
-
 import java.io._
 import java.nio.file.Paths
+import java.util.zip.Deflater
+
 import scala.collection.mutable
 import scala.concurrent.ExecutionContext.Implicits.global
 import scala.concurrent.Future
@@ -220,13 +221,16 @@ class VolumeTracingService @Inject()(
     val buckets: Iterator[NamedStream] =
       new WKWBucketStreamSink(dataLayer)(dataLayer.bucketProvider.bucketStream(Some(tracing.version)))
 
-    val zipResult = ZipIO.zip(buckets, os)
+    val before = System.currentTimeMillis()
+    val zipResult = ZipIO.zip(buckets, os, level = Deflater.BEST_SPEED)
 
     zipResult.onComplete {
       case failure: scala.util.Failure[Unit] =>
         logger.debug(
           s"Failed to send zipped volume data for $tracingId: ${TextUtils.stackTraceAsString(failure.exception)}")
-      case _: scala.util.Success[Unit] => logger.debug(s"Successfully sent zipped volume data for $tracingId")
+      case _: scala.util.Success[Unit] =>
+        val after = System.currentTimeMillis()
+        logger.info(s"Zipping volume data for $tracingId took ${after - before} ms")
     }
     zipResult
   }