Add Ml shared preferences for custom model storage

firebase-ml-modeldownloader/firebase-ml-modeldownloader.gradle

@@ -47,6 +47,7 @@ dependencies {
     implementation project(':firebase-components')
 
     implementation 'com.google.android.gms:play-services-tasks:17.2.0'
+    implementation 'javax.inject:javax.inject:1'
 
     compileOnly "com.google.auto.value:auto-value-annotations:1.6.6"
     annotationProcessor "com.google.auto.value:auto-value:1.6.5"

firebase-ml-modeldownloader/src/main/java/com/google/firebase/ml/modeldownloader/CustomModel.java

@@ -16,6 +16,7 @@
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import com.google.android.gms.common.internal.Objects;
 import java.io.File;
 
 /**
@@ -28,7 +29,44 @@ public class CustomModel {
   private final long downloadId;
   private final long fileSize;
   private final String modelHash;
-  private final String localFilePath = "";
+  private final String localFilePath;
+
+  /**
+   * Use when creating a custom model while the initial download is still in progress.
+   *
+   * @param name - model name
+   * @param downloadId - Android Download Manger - download id
+   * @param fileSize - model file size
+   * @param modelHash - model hash size
+   * @hide
+   */
+  public CustomModel(
+      @NonNull String name, long downloadId, long fileSize, @NonNull String modelHash) {
+    this(name, downloadId, fileSize, modelHash, "");
+  }
+
+  /**
+   * Use when creating a custom model while the initial download is still in progress.
+   *
+   * @param name - model name
+   * @param downloadId - Android Download Manger - download id
+   * @param fileSize - model file size
+   * @param modelHash - model hash size
+   * @param localFilePath - location of the current file
+   * @hide
+   */
+  public CustomModel(
+      @NonNull String name,
+      long downloadId,
+      long fileSize,
+      @NonNull String modelHash,
+      @NonNull String localFilePath) {
+    this.modelHash = modelHash;
+    this.name = name;
+    this.fileSize = fileSize;
+    this.downloadId = downloadId;
+    this.localFilePath = localFilePath;
+  }
 
   @NonNull
   public String getName() {
@@ -76,18 +114,36 @@ public long getDownloadId() {
     return downloadId;
   }
 
+  @Override
+  public boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    }
+
+    if (!(o instanceof CustomModel)) {
+      return false;
+    }
+
+    CustomModel other = (CustomModel) o;
+
+    return Objects.equal(name, other.name)
+        && Objects.equal(modelHash, other.modelHash)
+        && Objects.equal(fileSize, other.fileSize)
+        && Objects.equal(localFilePath, other.localFilePath)
+        && Objects.equal(downloadId, other.downloadId);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hashCode(name, modelHash, fileSize, localFilePath, downloadId);
+  }
+
   /**
-   * Use when creating a custom model while the initial download is still in progress.
-   *
-   * @param name - model name
-   * @param downloadId - Android Download Manger - download id
-   * @param fileSize - model file size
-   * @param modelHash - model hash size
+   * @return the model file path
+   * @hide
    */
-  CustomModel(String name, long downloadId, long fileSize, String modelHash) {
-    this.modelHash = modelHash;
-    this.name = name;
-    this.fileSize = fileSize;
-    this.downloadId = downloadId;
+  @NonNull
+  public String getLocalFilePath() {
+    return localFilePath;
   }
 }

firebase-ml-modeldownloader/src/main/java/com/google/firebase/ml/modeldownloader/FirebaseModelDownloaderRegistrar.java

@@ -15,6 +15,7 @@
 package com.google.firebase.ml.modeldownloader;
 
 import androidx.annotation.NonNull;
+import com.google.firebase.FirebaseApp;
 import com.google.firebase.FirebaseOptions;
 import com.google.firebase.components.Component;
 import com.google.firebase.components.ComponentRegistrar;
@@ -36,6 +37,7 @@ public class FirebaseModelDownloaderRegistrar implements ComponentRegistrar {
   public List<Component<?>> getComponents() {
     return Arrays.asList(
         Component.builder(FirebaseModelDownloader.class)
+            .add(Dependency.required(FirebaseApp.class))
             .add(Dependency.required(FirebaseOptions.class))
             .factory(c -> new FirebaseModelDownloader(c.get(FirebaseOptions.class)))
             .build(),

firebase-ml-modeldownloader/src/main/java/com/google/firebase/ml/modeldownloader/internal/SharedPreferencesUtil.java

@@ -0,0 +1,214 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.firebase.ml.modeldownloader.internal;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.Editor;
+import android.os.SystemClock;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.VisibleForTesting;
+import com.google.firebase.FirebaseApp;
+import com.google.firebase.ml.modeldownloader.CustomModel;
+
+/** @hide */
+public class SharedPreferencesUtil {
+
+  @VisibleForTesting
+  static final String PREFERENCES_PACKAGE_NAME = "com.google.firebase.ml.modelDownloader";
+
+  // local model details
+  private static final String LOCAL_MODEL_HASH_PATTERN = "current_model_hash_%s_%s";
+  private static final String LOCAL_MODEL_FILE_PATH_PATTERN = "current_model_path_%s_%s";
+  private static final String LOCAL_MODEL_FILE_SIZE_PATTERN = "current_model_size_%s_%s";
+  // details about model during download.
+  private static final String DOWNLOADING_MODEL_HASH_PATTERN = "downloading_model_hash_%s_%s";
+  private static final String DOWNLOADING_MODEL_SIZE_PATTERN = "downloading_model_size_%s_%s";
+  private static final String DOWNLOADING_MODEL_ID_PATTERN = "downloading_model_id_%s_%s";
+  private static final String DOWNLOAD_BEGIN_TIME_MS_PATTERN = "downloading_begin_time_%s_%s";
+
+  private final String persistenceKey;
+  private final FirebaseApp firebaseApp;
+
+  public SharedPreferencesUtil(FirebaseApp firebaseApp) {
+    this.firebaseApp = firebaseApp;
+    this.persistenceKey = firebaseApp.getPersistenceKey();
+  }
+
+  /**
+   * Returns the Custom Model details currently associated with this model. If a fully downloaded
+   * model is present - this returns the details of that model, including local file path. If an
+   * update of an existing model is in progress, the local model plus the download id for the new
+   * upload is returned. To get only details related to the downloading model use {@link
+   * #getDownloadingCustomModelDetails}. If this is the initial download of a local file - the
+   * downloading model details are returned.
+   *
+   * @param modelName - name of the model
+   * @return current version of the Custom Model
+   */
+  @Nullable
+  public synchronized CustomModel getCustomModelDetails(@NonNull String modelName) {
+    String modelHash =
+        getSharedPreferences()
+            .getString(String.format(LOCAL_MODEL_HASH_PATTERN, persistenceKey, modelName), null);
+
+    if (modelHash == null || modelHash.isEmpty()) {
+      // no model downloaded - check if model is being downloaded.
+      return getDownloadingCustomModelDetails(modelName);
+    }
+
+    String filePath =
+        getSharedPreferences()
+            .getString(String.format(LOCAL_MODEL_FILE_PATH_PATTERN, persistenceKey, modelName), "");
+
+    long fileSize =
+        getSharedPreferences()
+            .getLong(String.format(LOCAL_MODEL_FILE_SIZE_PATTERN, persistenceKey, modelName), 0);
+
+    // if no-zero - local model is present and new model being downloaded
+    long id =
+        getSharedPreferences()
+            .getLong(String.format(DOWNLOADING_MODEL_ID_PATTERN, persistenceKey, modelName), 0);
+
+    return new CustomModel(modelName, id, fileSize, modelHash, filePath);
+  }
+
+  /**
+   * Returns the Custom Model details associated with this version of this model currently being
+   * downloaded. If no download is in progress return null. Contains no information about local
+   * model, only download status.
+   *
+   * @param modelName name of the model
+   * @return Download version of CustomModel
+   */
+  @Nullable
+  public synchronized CustomModel getDownloadingCustomModelDetails(@NonNull String modelName) {
+    String modelHash =
+        getSharedPreferences()
+            .getString(
+                String.format(DOWNLOADING_MODEL_HASH_PATTERN, persistenceKey, modelName), null);
+
+    if (modelHash == null || modelHash.isEmpty()) {
+      // no model hash means no download in progress
+      return null;
+    }
+
+    long fileSize =
+        getSharedPreferences()
+            .getLong(String.format(DOWNLOADING_MODEL_SIZE_PATTERN, persistenceKey, modelName), 0);
+
+    long id =
+        getSharedPreferences()
+            .getLong(String.format(DOWNLOADING_MODEL_ID_PATTERN, persistenceKey, modelName), 0);
+
+    return new CustomModel(modelName, id, fileSize, modelHash);
+  }
+
+  /**
+   * The information about the new custom model download that need to be stored.
+   *
+   * @param customModel custom model details to be stored.
+   */
+  public synchronized void setDownloadingCustomModelDetails(@NonNull CustomModel customModel) {
+    String modelName = customModel.getName();
+    String modelHash = customModel.getModelHash();
+    long downloadId = customModel.getDownloadId();
+    long modelSize = customModel.getSize();
+    getSharedPreferences()
+        .edit()
+        .putString(
+            String.format(DOWNLOADING_MODEL_HASH_PATTERN, persistenceKey, modelName), modelHash)
+        .putLong(
+            String.format(DOWNLOADING_MODEL_SIZE_PATTERN, persistenceKey, modelName), modelSize)
+        .putLong(String.format(DOWNLOADING_MODEL_ID_PATTERN, persistenceKey, modelName), downloadId)
+        // The following assumes the download will finish before the system reboots.
+        // If not, the download duration won't be correct, which isn't critical.
+        .putLong(
+            String.format(DOWNLOAD_BEGIN_TIME_MS_PATTERN, persistenceKey, modelName),
+            SystemClock.elapsedRealtime())
+        .commit();
+  }
+
+  /**
+   * The information about a completed custom model download. Updates the local model information
+   * and clears the download details associated with this model.
+   *
+   * @param customModel custom model details to be stored.
+   */
+  public synchronized void setUploadedCustomModelDetails(@NonNull CustomModel customModel)
+      throws IllegalArgumentException {
+    Long id = customModel.getDownloadId();
+    // only call when download is completed and download id is reset to 0;
+    if (!id.equals(0L)) {
+      throw new IllegalArgumentException("Only call when Custom model has completed download.");
+    }
+    Editor editor = getSharedPreferences().edit();
+    clearDownloadingModelDetails(editor, customModel.getName());
+
+    String modelName = customModel.getName();
+    String hash = customModel.getModelHash();
+    long size = customModel.getSize();
+    String filePath = customModel.getLocalFilePath();
+    editor
+        .putString(String.format(LOCAL_MODEL_HASH_PATTERN, persistenceKey, modelName), hash)
+        .putLong(String.format(LOCAL_MODEL_FILE_SIZE_PATTERN, persistenceKey, modelName), size)
+        .putString(
+            String.format(LOCAL_MODEL_FILE_PATH_PATTERN, persistenceKey, modelName), filePath)
+        .commit();
+  }
+
+  /**
+   * Clears all stored data related to a local custom model, including download details.
+   *
+   * @param modelName - name of model
+   */
+  public synchronized void clearModelDetails(@NonNull String modelName, boolean cleanUpModelFile) {
+    if (cleanUpModelFile) {
+      // TODO(annz) - add code to remove model files from device
+    }
+    Editor editor = getSharedPreferences().edit();
+
+    clearDownloadingModelDetails(editor, modelName);
+
+    editor
+        .remove(String.format(LOCAL_MODEL_FILE_PATH_PATTERN, persistenceKey, modelName))
+        .remove(String.format(LOCAL_MODEL_FILE_SIZE_PATTERN, persistenceKey, modelName))
+        .remove(String.format(LOCAL_MODEL_HASH_PATTERN, persistenceKey, modelName))
+        .commit();
+  }
+
+  /**
+   * Clears all stored data related to a custom model download.
+   *
+   * @param modelName - name of model
+   */
+  @VisibleForTesting
+  synchronized void clearDownloadingModelDetails(Editor editor, @NonNull String modelName) {
+    editor
+        .remove(String.format(DOWNLOADING_MODEL_ID_PATTERN, persistenceKey, modelName))
+        .remove(String.format(DOWNLOADING_MODEL_HASH_PATTERN, persistenceKey, modelName))
+        .remove(String.format(DOWNLOADING_MODEL_SIZE_PATTERN, persistenceKey, modelName))
+        .remove(String.format(DOWNLOAD_BEGIN_TIME_MS_PATTERN, persistenceKey, modelName))
+        .apply();
+  }
+
+  @VisibleForTesting
+  SharedPreferences getSharedPreferences() {
+    return firebaseApp
+        .getApplicationContext()
+        .getSharedPreferences(PREFERENCES_PACKAGE_NAME, Context.MODE_PRIVATE);
+  }
+}

firebase-ml-modeldownloader/src/test/java/com/google/firebase/ml/modeldownloader/CustomModelTest.java

@@ -15,7 +15,10 @@
 package com.google.firebase.ml.modeldownloader;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -52,4 +55,21 @@ public void customModel_getDownloadId() {
   public void customModel_getFile_downloadIncomplete() {
     assertNull(CUSTOM_MODEL.getFile());
   }
+
+  @Test
+  public void customModel_equals() {
+    assertTrue(CUSTOM_MODEL.equals(new CustomModel(MODEL_NAME, 0, 100, MODEL_HASH)));
+    assertFalse(CUSTOM_MODEL.equals(new CustomModel(MODEL_NAME, 0, 101, MODEL_HASH)));
+    assertFalse(CUSTOM_MODEL.equals(new CustomModel(MODEL_NAME, 101, 100, MODEL_HASH)));
+  }
+
+  @Test
+  public void customModel_hashCode() {
+    assertEquals(
+        CUSTOM_MODEL.hashCode(), new CustomModel(MODEL_NAME, 0, 100, MODEL_HASH).hashCode());
+    assertNotEquals(
+        CUSTOM_MODEL.hashCode(), new CustomModel(MODEL_NAME, 0, 101, MODEL_HASH).hashCode());
+    assertNotEquals(
+        CUSTOM_MODEL.hashCode(), new CustomModel(MODEL_NAME, 101, 100, MODEL_HASH).hashCode());
+  }
 }