From b9795a480214232b99ec2b4ac81bb3129a5b2042 Mon Sep 17 00:00:00 2001
From: Stanislaw Adaszewski <s.adaszewski@gmail.com>
Date: Fri, 7 Feb 2020 18:18:06 +0100
Subject: [PATCH] Downloading all blocks in parallel for better performance.

---
 .../src/js/component/wb-collection-content.js |  2 +-
 frontend/src/js/misc/wb-download-file.js      | 41 +++++++++++--------
 2 files changed, 25 insertions(+), 18 deletions(-)

diff --git a/frontend/src/js/component/wb-collection-content.js b/frontend/src/js/component/wb-collection-content.js
index cc14d5c..b71cbb1 100644
--- a/frontend/src/js/component/wb-collection-content.js
+++ b/frontend/src/js/component/wb-collection-content.js
@@ -67,7 +67,7 @@ class WBCollectionContent extends Component {
           null,
           (<div></div>)
         ] : [
-          (<a href={ this.getUrl({ 'collectionPath': collectionPath + '/' + item[1], 'page': 0 }) }>{ item[1] }</a>),
+          item[1],
           'File',
           filesize(item[2]),
           (<div>
diff --git a/frontend/src/js/misc/wb-download-file.js b/frontend/src/js/misc/wb-download-file.js
index d479f81..6010736 100644
--- a/frontend/src/js/misc/wb-download-file.js
+++ b/frontend/src/js/misc/wb-download-file.js
@@ -6,7 +6,6 @@ function wbDownloadFile(arvHost, arvToken,
   const file = manifestReader.getFile(path);
   const name = path.split('/').reverse()[0];
   const blockRefs = file[0];
-  let proxy;
 
   let prom = makeArvadosRequest(arvHost, arvToken,
     '/arvados/v1/keep_services');
@@ -14,26 +13,34 @@ function wbDownloadFile(arvHost, arvToken,
     const services = xhr.response['items'];
     const proxies = services.filter(svc => (svc.service_type === 'proxy'));
     const n = Math.floor(Math.random() * proxies.length);
-    proxy = proxies[n];
-  });
+    const proxy = proxies[n];
+    const blocks = [];
+
+    let prom_2 = new Promise(accept => accept());
+
+    for (let i = 0; i < blockRefs.length; i++) {
+      const [ locator, position, size ] = blockRefs[i];
+
+      const prom_1 = makeArvadosRequest(
+        proxy.service_host + ':' + proxy.service_port,
+        arvToken,
+        '/' + locator,
+        { 'useSsl': proxy.service_ssl_flag,
+          'responseType': 'arraybuffer' }
+      );
 
-  const blocks = [];
-  for (let i = 0; i < blockRefs.length; i++) {
-    const [ locator, position, size ] = blockRefs[i];
+      prom_2 = prom_2.then(() => prom_1);
 
-    prom = prom.then(() => makeArvadosRequest(
-      proxy.service_host + ':' + proxy.service_port,
-      arvToken,
-      '/' + locator,
-      { 'useSsl': proxy.service_ssl_flag,
-        'responseType': 'arraybuffer' }
-    ));
+      prom_2 = prom_2.then(xhr => (blocks.push(xhr.response.slice(position,
+        position + size))));
+    }
+
+    prom_2 = prom_2.then(() => blocks);
+
+    return prom_2;
+  });
 
-    prom = prom.then(xhr => (blocks.push(xhr.response.slice(position,
-      position + size))));
-  }
 
-  prom = prom.then(() => blocks);
 
   /* prom = prom.then(() => {
     const blob = new Blob(blocks);