Adds methods to list all keys and clear all items except a list of keys

benchmark/src/main/java/com/orhanobut/benchmark/MainActivity.java

@@ -7,6 +7,8 @@
 import com.orhanobut.hawk.Hawk;
 import com.orhanobut.hawk.LogInterceptor;
 
+import java.util.Arrays;
+
 public class MainActivity extends Activity {
 
   @Override
@@ -19,7 +21,9 @@ protected void onCreate(Bundle savedInstanceState) {
     timeHawkGet();
     timeHawkContains();
     timeHawkCount();
+    timeHawkGetKeys();
     timeHawkDelete();
+    timeHawkSelectiveDelete();
   }
 
   private void timeHawkInit() {
@@ -79,4 +83,22 @@ private void timeHawkDelete() {
     long endTime = System.currentTimeMillis();
     System.out.println("Hawk.count: " + (endTime - startTime) + "ms");
   }
+
+  private void timeHawkGetKeys() {
+    long startTime = System.currentTimeMillis();
+
+    Hawk.getAllKeys();
+
+    long endTime = System.currentTimeMillis();
+    System.out.println("Hawk.getAllKeys: " + (endTime - startTime) + "ms");
+  }
+
+  private void timeHawkSelectiveDelete() {
+    long startTime = System.currentTimeMillis();
+
+    Hawk.selectiveDelete(Arrays.asList("key", "key2", "key3"));
+
+    long endTime = System.currentTimeMillis();
+    System.out.println("Hawk.getAllKeys: " + (endTime - startTime) + "ms");
+  }
 }

hawk/src/main/java/com/orhanobut/hawk/DefaultHawkFacade.java

@@ -1,5 +1,7 @@
 package com.orhanobut.hawk;
 
+import java.util.List;
+
 public class DefaultHawkFacade implements HawkFacade {
 
   private final Storage storage;
@@ -145,6 +147,15 @@ public DefaultHawkFacade(HawkBuilder builder) {
   @Override public void destroy() {
   }
 
+  @Override public List<String> getAllKeys() {
+    return storage.getAllKeys();
+  }
+
+  @Override
+  public long selectiveDelete(List<String> keys) {
+    return  storage.selectiveDelete(keys);
+  }
+
   private void log(String message) {
     logInterceptor.onLog(message);
   }

hawk/src/main/java/com/orhanobut/hawk/Hawk.java

@@ -2,6 +2,7 @@
 
 import android.content.Context;
 
+import java.util.List;
 
 public final class Hawk {
 
@@ -118,4 +119,21 @@ public static void destroy() {
     hawkFacade.destroy();
   }
 
+  /**
+   * Use this method to get all the keys saved
+   *
+   * @return the list of all keys saved in the DB
+   */
+  public static List<String> getAllKeys() {
+    return hawkFacade.getAllKeys();
+  }
+
+  /**
+   * Use this method to clear all, except a list of keys
+   *
+   * @return the number of objects deleted
+   */
+  public static long selectiveDelete(List<String> keys) {
+    return hawkFacade.selectiveDelete(keys);
+  }
 }

hawk/src/main/java/com/orhanobut/hawk/HawkFacade.java

@@ -1,5 +1,7 @@
 package com.orhanobut.hawk;
 
+import java.util.List;
+
 public interface HawkFacade {
 
   <T> boolean put(String key, T value);
@@ -20,6 +22,10 @@ public interface HawkFacade {
 
   void destroy();
 
+  List<String> getAllKeys();
+
+  long selectiveDelete(List<String> keys);
+
   class EmptyHawkFacade implements HawkFacade {
 
     @Override public <T> boolean put(String key, T value) {
@@ -65,6 +71,16 @@ class EmptyHawkFacade implements HawkFacade {
       throwValidation();
     }
 
+    @Override public List<String> getAllKeys() {
+      throwValidation();
+      return null;
+    }
+
+    @Override public long selectiveDelete(List<String> keys) {
+      throwValidation();
+      return 0;
+    }
+
     private void throwValidation() {
       throw new IllegalStateException("Hawk is not built. " +
           "Please call build() and wait the initialisation finishes.");

hawk/src/main/java/com/orhanobut/hawk/SharedPreferencesStorage.java

@@ -3,6 +3,10 @@
 import android.content.Context;
 import android.content.SharedPreferences;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
 final class SharedPreferencesStorage implements Storage {
 
   private final SharedPreferences preferences;
@@ -45,4 +49,26 @@ private SharedPreferences.Editor getEditor() {
     return preferences.edit();
   }
 
+  @Override
+  public List<String> getAllKeys() {
+    List<String> result = new ArrayList<>();
+    Map<String, ?> allEntries = preferences.getAll();
+    for (Map.Entry<String, ?> entry : allEntries.entrySet()) {
+      result.add(entry.getKey());
+    }
+    return result;
+  }
+
+  @Override
+  public long selectiveDelete(List<String> keys) {
+    long result = 0;
+    Map<String, ?> allEntries = preferences.getAll();
+    for (Map.Entry<String, ?> entry : allEntries.entrySet()) {
+      if (!keys.contains(entry.getKey())) {
+        delete(entry.getKey());
+        result++;
+      }
+    }
+    return result;
+  }
 }

hawk/src/main/java/com/orhanobut/hawk/Storage.java

@@ -1,5 +1,7 @@
 package com.orhanobut.hawk;
 
+import java.util.List;
+
 @SuppressWarnings("WeakerAccess")
 public interface Storage {
 
@@ -56,4 +58,17 @@ public interface Storage {
    */
   boolean contains(String key);
 
+  /**
+   * Retrieve a list with all the keys in the storage
+   *
+   * @return list of keys
+   */
+  List<String> getAllKeys();
+
+  /**
+   * Clear all the data stored except the keys specified.
+   * @param keys to don't delete
+   * @return the number of items deleted
+   */
+  long selectiveDelete(List<String> keys);
 }

hawk/src/test/java/com/orhanobut/hawk/HawkBuilderTest.java

@@ -8,6 +8,7 @@
 import org.robolectric.annotation.Config;
 
 import java.lang.reflect.Type;
+import java.util.List;
 
 import static com.google.common.truth.Truth.assertThat;
 import static junit.framework.Assert.fail;
@@ -62,6 +63,16 @@ class MyStorage implements Storage {
       @Override public boolean contains(String key) {
         return false;
       }
+
+      @Override
+      public List<String> getAllKeys() {
+        return null;
+      }
+
+      @Override
+      public long selectiveDelete(List<String> keys) {
+        return 0;
+      }
     }
     builder.setStorage(new MyStorage()).build();
     assertThat(builder.getStorage()).isInstanceOf(MyStorage.class);