From d1eb5b5fb33b29d22ed7d8fc0ba96e1c1762ba4f Mon Sep 17 00:00:00 2001
From: Hans-Christoph Steiner <hans@eds.org>
Date: Mon, 15 Aug 2016 23:47:19 +0200
Subject: [PATCH] avoid deleting cached files while they are being used

If CleanCacheService runs while an APK is being installed, it should not
delete the APK that is in the process of being installed.  This does that
by only deleting those files if they are older than an hour. Same goes for
the index files.

#738
---
 .../org/fdroid/fdroid/CleanCacheService.java  | 51 +++++++++----------
 1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/app/src/main/java/org/fdroid/fdroid/CleanCacheService.java b/app/src/main/java/org/fdroid/fdroid/CleanCacheService.java
index b5731304c..bb1267cf7 100644
--- a/app/src/main/java/org/fdroid/fdroid/CleanCacheService.java
+++ b/app/src/main/java/org/fdroid/fdroid/CleanCacheService.java
@@ -80,7 +80,7 @@ public class CleanCacheService extends IntentService {
 
         for (File f : files) {
             if (f.getName().startsWith("install-")) {
-                FileUtils.deleteQuietly(f);
+                clearOldFiles(f, TimeUnit.HOURS.toMillis(1));
             }
         }
     }
@@ -110,52 +110,51 @@ public class CleanCacheService extends IntentService {
 
         for (File f : files) {
             if (f.getName().startsWith("index-")) {
-                FileUtils.deleteQuietly(f);
+                clearOldFiles(f, TimeUnit.HOURS.toMillis(1));
             }
             if (f.getName().startsWith("dl-")) {
-                FileUtils.deleteQuietly(f);
+                clearOldFiles(f, TimeUnit.HOURS.toMillis(1));
             }
         }
     }
 
     /**
-     * Recursively delete files in {@code dir} that were last used
+     * Recursively delete files in {@code f} that were last used
      * {@code millisAgo} milliseconds ago.  On {@code android-21} and newer, this
      * is based on the last access of the file, on older Android versions, it is
      * based on the last time the file was modified, e.g. downloaded.
      *
-     * @param dir        The directory to recurse in
+     * @param f         The file or directory to clean
      * @param millisAgo The number of milliseconds old that marks a file for deletion.
      */
     @TargetApi(21)
-    public static void clearOldFiles(File dir, long millisAgo) {
-        if (dir == null) {
-            return;
-        }
-        File[] files = dir.listFiles();
-        if (files == null) {
+    public static void clearOldFiles(File f, long millisAgo) {
+        if (f == null) {
             return;
         }
         long olderThan = System.currentTimeMillis() - millisAgo;
-        for (File f : files) {
-            if (f.isDirectory()) {
-                clearOldFiles(f, millisAgo);
+        if (f.isDirectory()) {
+            File[] files = f.listFiles();
+            if (files == null) {
+                return;
+            }
+            for (File file : files) {
+                clearOldFiles(file, millisAgo);
+            }
+            f.delete();
+        } else if (Build.VERSION.SDK_INT < 21) {
+            if (FileUtils.isFileOlder(f, olderThan)) {
                 f.delete();
             }
-            if (Build.VERSION.SDK_INT < 21) {
-                if (FileUtils.isFileOlder(f, olderThan)) {
+        } else {
+            try {
+                StructStat stat = Os.lstat(f.getAbsolutePath());
+                if ((stat.st_atime * 1000L) < olderThan) {
                     f.delete();
                 }
-            } else {
-                try {
-                    StructStat stat = Os.lstat(f.getAbsolutePath());
-                    if ((stat.st_atime * 1000L) < olderThan) {
-                        f.delete();
-                    }
-                } catch (ErrnoException e) {
-                    e.printStackTrace();
-                }
+            } catch (ErrnoException e) {
+                e.printStackTrace();
             }
         }
     }
-}
+}
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