From 6c9afd823e8da9393a167a89345301782ef3483b Mon Sep 17 00:00:00 2001
From: Hans-Christoph Steiner <hans@eds.org>
Date: Tue, 18 Jun 2019 15:51:10 +0200
Subject: [PATCH] speed up repo searchs by using "depth last"

Recursively search for index-v1.jar starting from the given directory,
looking at files first before recursing into directories.  This is
"depth last" since the index file is much more likely to be shallow
than deep, and there can be a lot of files to search through starting
at 4 or more levels deep, like the fdroid icons dirs and the per-app
"external storage" dirs.
---
 .../nearby/TreeUriScannerIntentService.java   | 22 ++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/app/src/full/java/org/fdroid/fdroid/nearby/TreeUriScannerIntentService.java b/app/src/full/java/org/fdroid/fdroid/nearby/TreeUriScannerIntentService.java
index e3f8679ad..11b18a468 100644
--- a/app/src/full/java/org/fdroid/fdroid/nearby/TreeUriScannerIntentService.java
+++ b/app/src/full/java/org/fdroid/fdroid/nearby/TreeUriScannerIntentService.java
@@ -46,6 +46,7 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.security.cert.Certificate;
+import java.util.ArrayList;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.jar.JarInputStream;
@@ -122,20 +123,34 @@ public class TreeUriScannerIntentService extends IntentService {
         searchDirectory(treeFile);
     }
 
+    /**
+     * Recursively search for {@link IndexV1Updater#SIGNED_FILE_NAME} starting
+     * from the given directory, looking at files first before recursing into
+     * directories.  This is "depth last" since the index file is much more
+     * likely to be shallow than deep, and there can be a lot of files to
+     * search through starting at 4 or more levels deep, like the fdroid
+     * icons dirs and the per-app "external storage" dirs.
+     */
     private void searchDirectory(DocumentFile documentFileDir) {
         DocumentFile[] documentFiles = documentFileDir.listFiles();
         if (documentFiles == null) {
             return;
         }
+        boolean foundIndex = false;
+        ArrayList<DocumentFile> dirs = new ArrayList<>();
         for (DocumentFile documentFile : documentFiles) {
             if (documentFile.isDirectory()) {
-                searchDirectory(documentFile);
-            } else {
+                dirs.add(documentFile);
+            } else if (!foundIndex) {
                 if (IndexV1Updater.SIGNED_FILE_NAME.equals(documentFile.getName())) {
                     registerRepo(documentFile);
+                    foundIndex = true;
                 }
             }
         }
+        for (DocumentFile dir : dirs) {
+            searchDirectory(dir);
+        }
     }
 
     /**
@@ -150,9 +165,7 @@ public class TreeUriScannerIntentService extends IntentService {
     private void registerRepo(DocumentFile index) {
         InputStream inputStream = null;
         try {
-            Log.i(TAG, "FOUND: " + index.getUri());
             inputStream = getContentResolver().openInputStream(index.getUri());
-            Log.i(TAG, "repo URL: " + index.getParentFile().getUri());
             registerRepo(this, inputStream, index.getParentFile().getUri());
         } catch (IOException | IndexUpdater.SigningException e) {
             e.printStackTrace();
@@ -172,7 +185,6 @@ public class TreeUriScannerIntentService extends IntentService {
         JarEntry indexEntry = (JarEntry) jarFile.getEntry(IndexV1Updater.DATA_FILE_NAME);
         IOUtils.readLines(jarFile.getInputStream(indexEntry));
         Certificate certificate = IndexUpdater.getSigningCertFromJar(indexEntry);
-        Log.i(TAG, "Got certificate: " + certificate);
         String fingerprint = Utils.calcFingerprint(certificate);
         Log.i(TAG, "Got fingerprint: " + fingerprint);
         destFile.delete();