From 408164c8dc2153b60df92b6c0e66471026b4648d Mon Sep 17 00:00:00 2001
From: pilgr <aleksey.masny@gmail.com>
Date: Thu, 21 Sep 2017 11:52:46 +0300
Subject: [PATCH] Fix crash and data corruption during 1.5 => 2.0 transition

---
 .../java/io/paperdb/VersionUpgradeTest.java   |  6 +-
 .../java/io/paperdb/DbStoragePlainFile.java   | 55 ++++++++++---------
 2 files changed, 33 insertions(+), 28 deletions(-)

diff --git a/paperdb/src/androidTest/java/io/paperdb/VersionUpgradeTest.java b/paperdb/src/androidTest/java/io/paperdb/VersionUpgradeTest.java
index 241fb4d..5d59338 100644
--- a/paperdb/src/androidTest/java/io/paperdb/VersionUpgradeTest.java
+++ b/paperdb/src/androidTest/java/io/paperdb/VersionUpgradeTest.java
@@ -28,7 +28,7 @@ public void setUp() throws Exception {
     public void testWrite() {
         Recipe recipe = new Recipe();
         recipe.name = "chocolate cake";
-        recipe.ingredients = new HashMap<String, Integer>();
+        recipe.ingredients = new HashMap<>();
         recipe.ingredients.put("flour", 300);
         recipe.ingredients.put("eggs", 4);
         recipe.ingredients.put("chocolate", 200);
@@ -41,6 +41,7 @@ public void testWrite() {
     public void testRead() throws IOException {
         File filesDir = new File(getTargetContext().getFilesDir(), "io.paperdb");
         if (!filesDir.exists()) {
+            //noinspection ResultOfMethodCallIgnored
             filesDir.mkdirs();
         }
 
@@ -51,13 +52,12 @@ public void testRead() throws IOException {
 
         Recipe recipe = Paper.book().read("recipe");
         assertThat(recipe.name).isEqualTo("chocolate cake");
-
     }
 
     private void copyFile(InputStream inputStream, OutputStream outputStream) throws IOException {
         byte buffer[] = new byte[2048];
 
-        while(true) {
+        while (true) {
             int r = inputStream.read(buffer);
             if (r < 0) {
                 break;
diff --git a/paperdb/src/main/java/io/paperdb/DbStoragePlainFile.java b/paperdb/src/main/java/io/paperdb/DbStoragePlainFile.java
index e77f619..0167e54 100644
--- a/paperdb/src/main/java/io/paperdb/DbStoragePlainFile.java
+++ b/paperdb/src/main/java/io/paperdb/DbStoragePlainFile.java
@@ -47,13 +47,17 @@ private Kryo getKryo() {
     private final ThreadLocal<Kryo> mKryo = new ThreadLocal<Kryo>() {
         @Override
         protected Kryo initialValue() {
-            return createKryoInstance();
+            return createKryoInstance(false);
         }
     };
 
-    private Kryo createKryoInstance() {
+    private Kryo createKryoInstance(boolean compatibilityMode) {
         Kryo kryo = new Kryo();
 
+        if (compatibilityMode) {
+            kryo.getFieldSerializerConfig().setOptimizedGenerics(true);
+        }
+
         kryo.register(PaperTable.class);
         kryo.setDefaultSerializer(CompatibleFieldSerializer.class);
         kryo.setReferences(false);
@@ -245,40 +249,41 @@ private <E> void writeTableFile(String key, PaperTable<E> paperTable,
     }
 
     private <E> E readTableFile(String key, File originalFile) {
-        return readTableFile(key, originalFile, false);
-    }
-
-    private <E> E readTableFile(String key, File originalFile,
-                                boolean v1CompatibilityMode) {
         try {
-            final Input i = new Input(new FileInputStream(originalFile));
-            final Kryo kryo = getKryo();
-            if (v1CompatibilityMode) {
-                // Set temporary generic optimization to support Kryo 3.x format
-                kryo.getFieldSerializerConfig().setOptimizedGenerics(true);
-            }
-            //noinspection unchecked
-            final PaperTable<E> paperTable = kryo.readObject(i, PaperTable.class);
-            i.close();
-            if (v1CompatibilityMode) {
-                kryo.getFieldSerializerConfig().setOptimizedGenerics(false);
-            }
-            return paperTable.mContent;
+            return readContent(originalFile, getKryo());
         } catch (FileNotFoundException | KryoException | ClassCastException e) {
-            // Give one more chance, reread data in compatibility mode
-            if (!v1CompatibilityMode) {
-                return readTableFile(key, originalFile, true);
+            Throwable exception = e;
+            // Give one more chance, read data in paper 1.x compatibility mode
+            if (e instanceof KryoException) {
+                try {
+                    return readContent(originalFile, createKryoInstance(true));
+                } catch (FileNotFoundException | KryoException | ClassCastException compatibleReadException) {
+                    exception = compatibleReadException;
+                }
             }
+            // TODO Delete this
             // Clean up an unsuccessfully written file
             if (originalFile.exists()) {
                 if (!originalFile.delete()) {
                     throw new PaperDbException("Couldn't clean up broken/unserializable file "
-                            + originalFile, e);
+                            + originalFile, exception);
                 }
             }
             String errorMessage = "Couldn't read/deserialize file "
                     + originalFile + " for table " + key;
-            throw new PaperDbException(errorMessage, e);
+            throw new PaperDbException(errorMessage, exception);
+        }
+    }
+
+    private <E> E readContent(File originalFile, Kryo kryo) throws FileNotFoundException, KryoException {
+        final Input i = new Input(new FileInputStream(originalFile));
+        //noinspection TryFinallyCanBeTryWithResources
+        try {
+            //noinspection unchecked
+            final PaperTable<E> paperTable = kryo.readObject(i, PaperTable.class);
+            return paperTable.mContent;
+        } finally {
+            i.close();
         }
     }