Added cache

paperdb/build.gradle

@@ -31,6 +31,7 @@ android {
 dependencies {
     compile 'com.esotericsoftware:kryo:3.0.2'
     compile 'de.javakaffee:kryo-serializers:0.33'
+    compile 'com.google.guava:guava:18.0'
 
     androidTestCompile 'com.orhanobut:hawk:1.14'
     androidTestCompile 'com.android.support.test:runner:0.3'

paperdb/src/androidTest/java/io/paperdb/CompatibilityTest.java

@@ -35,6 +35,7 @@ public void testChangeClass()
 
         // Save original class. Only class name is changed to TestClassNew
         Paper.book().write("test", testClass);
+        Paper.book().invalidateCache("test");
 
         // Read and instantiate a modified class TestClassNew based on saved data in TestClass
         TestClassNew newTestClass = Paper.book().read("test");
@@ -52,6 +53,7 @@ public void testNotCompatibleClassChanges() throws Exception {
                 TestClassNotCompatible.class.getName());
         testClass.timestamp = 123;
         Paper.book().write("not-compatible", testClass);
+        Paper.book().invalidateCache("not-compatible");
 
         Paper.book().<TestClassNotCompatible>read("not-compatible");
     }
@@ -63,6 +65,7 @@ public void testTransientFields() throws Exception {
         tc.transientField = "changed";
 
         Paper.book().write("transient-class", tc);
+        Paper.book().invalidateCache("transient-class");
 
         TestClassTransient readTc = Paper.book().read("transient-class");
         assertThat(readTc.timestamp).isEqualTo(123);

paperdb/src/androidTest/java/io/paperdb/DataTest.java

@@ -65,7 +65,7 @@ public void testPutPOJO() {
 
         final Person savedPerson = Paper.book().read("profile");
         assertThat(savedPerson).isEqualTo(person);
-        assertThat(savedPerson).isNotSameAs(person);
+        assertThat(savedPerson).isSameAs(person);
     }
 
     @Test

paperdb/src/androidTest/java/io/paperdb/deprecated/DataTest.java

@@ -66,7 +66,7 @@ public void testPutPOJO() {
 
         final Person savedPerson = Paper.get("profile");
         assertThat(savedPerson).isEqualTo(person);
-        assertThat(savedPerson).isNotSameAs(person);
+        assertThat(savedPerson).isSameAs(person);
     }
 
     @Test

paperdb/src/main/java/io/paperdb/Book.java

@@ -4,7 +4,7 @@
 
 public class Book {
 
-    private final Storage mStorage;
+    private final CachedStorage mStorage;
 
     protected Book(Context context, String dbName) {
         mStorage = new DbStoragePlainFile(context.getApplicationContext(), dbName);
@@ -75,12 +75,27 @@ public boolean exist(String key) {
     }
 
     /**
-     * Delete saved object for given key if it is exist.
+     * Delete saved object for given key if it exists.
      *
      * @param key object key
      */
     public void delete(String key) {
         mStorage.deleteIfExists(key);
     }
 
+    /**
+     * Clears cache for given key.
+     *
+     * @param key object key
+     */
+    public void invalidateCache(String key) {
+        mStorage.invalidateCache(key);
+    }
+
+    /**
+     * Clears cache.
+     */
+    public void invalidateCache() {
+        mStorage.invalidateCache();
+    }
 }

paperdb/src/main/java/io/paperdb/CachedStorage.java

@@ -0,0 +1,8 @@
+package io.paperdb;
+
+public interface CachedStorage extends Storage {
+
+    void invalidateCache();
+
+    void invalidateCache(String key);
+}

paperdb/src/main/java/io/paperdb/DbStoragePlainFile.java

@@ -8,6 +8,10 @@
 import com.esotericsoftware.kryo.io.Input;
 import com.esotericsoftware.kryo.io.Output;
 import com.esotericsoftware.kryo.serializers.CompatibleFieldSerializer;
+import com.google.common.base.Optional;
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
 
 import java.io.File;
 import java.io.FileInputStream;
@@ -17,6 +21,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.LinkedList;
+import java.util.concurrent.TimeUnit;
 
 import de.javakaffee.kryoserializers.ArraysAsListSerializer;
 import de.javakaffee.kryoserializers.SynchronizedCollectionsSerializer;
@@ -25,13 +30,25 @@
 
 import static io.paperdb.Paper.TAG;
 
-public class DbStoragePlainFile implements Storage {
+public class DbStoragePlainFile implements CachedStorage {
 
     private final Context mContext;
     private final String mDbName;
     private String mFilesDir;
     private boolean mPaperDirIsCreated;
 
+    private final LoadingCache<String, Optional> cache = CacheBuilder.newBuilder()
+            .maximumSize(1000)
+            .weakKeys()
+            .weakValues()
+            .expireAfterWrite(60 * 10, TimeUnit.SECONDS)
+            .build(new CacheLoader<String, Optional>() {
+                        public Optional load(String key) {
+                            Object value = doSelect(key);
+                            return Optional.fromNullable(value);
+                        }
+                    });
+
     private Kryo getKryo() {
         return mKryo.get();
     }
@@ -79,6 +96,7 @@ public synchronized void destroy() {
         if (!deleteDirectory(dbPath)) {
             Log.e(TAG, "Couldn't delete Paper dir " + dbPath);
         }
+        cache.invalidateAll();
         mPaperDirIsCreated = false;
     }
 
@@ -106,10 +124,26 @@ public synchronized <E> void insert(String key, E value) {
         }
 
         writeTableFile(key, paperTable, originalFile, backupFile);
+        cache.put(key, Optional.of(value));
     }
 
     @Override
     public synchronized <E> E select(String key) {
+        try {
+            Optional optional = cache.get(key);
+            return (E) optional.get();
+        } catch (IllegalStateException e) {
+            return null;
+        } catch (PaperDbException e) {
+            throw e;
+        } catch (Exception e) {
+            if (e.getCause() != null && e.getCause() instanceof PaperDbException)
+                throw (PaperDbException) e.getCause();
+            throw new PaperDbException(e);
+        }
+    }
+
+    private synchronized <E> E doSelect(String key) {
         assertInit();
 
         final File originalFile = getOriginalFile(key);
@@ -150,6 +184,7 @@ public synchronized void deleteIfExists(String key) {
             throw new PaperDbException("Couldn't delete file " + originalFile
                     + " for table " + key);
         }
+        cache.invalidate(key);
     }
 
     private File getOriginalFile(String key) {
@@ -274,5 +309,15 @@ private static boolean sync(FileOutputStream stream) {
         }
         return false;
     }
+
+    @Override
+    public void invalidateCache() {
+        cache.invalidateAll();
+    }
+
+    @Override
+    public void invalidateCache(String key) {
+        cache.invalidate(key);
+    }
 }
 

paperdb/src/main/java/io/paperdb/NonExistedValueException.java

@@ -0,0 +1,16 @@
+package io.paperdb;
+
+public class NonExistedValueException extends PaperDbException {
+
+    public NonExistedValueException(String detailMessage) {
+        super(detailMessage);
+    }
+
+    public NonExistedValueException(Throwable throwable) {
+        super(throwable);
+    }
+
+    public NonExistedValueException(String detailMessage, Throwable throwable) {
+        super(detailMessage, throwable);
+    }
+}

paperdb/src/main/java/io/paperdb/PaperDbException.java

@@ -5,6 +5,10 @@ public PaperDbException(String detailMessage) {
         super(detailMessage);
     }
 
+    public PaperDbException(Throwable throwable) {
+        super(throwable);
+    }
+
     public PaperDbException(String detailMessage, Throwable throwable) {
         super(detailMessage, throwable);
     }