Only initialize FrescoModule once

Summary:
Fresco should only be initialized once. Re-initializing causes a few problems (https://github.com/facebook/react-native/issues/8677) and we don't need to do it.
If a Fresco configuration needs to change, you can just restart the application or add delegates for parts that can change and manually update them instead.

Reviewed By: astreet

Differential Revision: D3790908

fbshipit-source-id: 9df4c3be15ca49433120abd7ba1a4f5ae2a3f1c1

ReactAndroid/src/main/java/com/facebook/react/modules/fresco/BUCK

@@ -5,6 +5,7 @@ android_library(
   srcs = glob(['**/*.java']),
   deps = [
     react_native_dep('java/com/facebook/systrace:systrace'),
+    react_native_dep('libraries/fbcore/src/main/java/com/facebook/common/logging:logging'),
     react_native_dep('libraries/fresco/fresco-react-native:fbcore'),
     react_native_dep('libraries/fresco/fresco-react-native:fresco-drawee'),
     react_native_dep('libraries/fresco/fresco-react-native:fresco-react-native'),
@@ -16,6 +17,7 @@ android_library(
     react_native_dep('third-party/java/jsr-305:jsr-305'),
     react_native_dep('third-party/java/okhttp:okhttp3'),
     react_native_target('java/com/facebook/react/bridge:bridge'),
+    react_native_target('java/com/facebook/react/common:common'),
     react_native_target('java/com/facebook/react/modules/common:common'),
     react_native_target('java/com/facebook/react/modules/network:network'),
   ],

ReactAndroid/src/main/java/com/facebook/react/modules/fresco/FrescoModule.java

@@ -14,20 +14,19 @@ import java.util.HashSet;
 import android.content.Context;
 import android.support.annotation.Nullable;
 
-import com.facebook.cache.disk.DiskCacheConfig;
 import com.facebook.common.soloader.SoLoaderShim;
+import com.facebook.common.logging.FLog;
 import com.facebook.drawee.backends.pipeline.Fresco;
 import com.facebook.imagepipeline.backends.okhttp3.OkHttpImagePipelineConfigFactory;
 import com.facebook.imagepipeline.core.ImagePipelineConfig;
 import com.facebook.imagepipeline.listener.RequestListener;
 import com.facebook.react.bridge.ReactApplicationContext;
 import com.facebook.react.bridge.ReactContextBaseJavaModule;
+import com.facebook.react.common.ReactConstants;
 import com.facebook.react.modules.common.ModuleDataCleaner;
 import com.facebook.react.modules.network.OkHttpClientProvider;
 import com.facebook.soloader.SoLoader;
 
-import okhttp3.OkHttpClient;
-
 /**
  * Module to initialize the Fresco library.
  *
@@ -38,22 +37,29 @@ public class FrescoModule extends ReactContextBaseJavaModule implements
 
   private @Nullable ImagePipelineConfig mConfig;
 
+  private static boolean sHasBeenInitialized = false;
+
+  /**
+   * Create a new Fresco module with a default configuration (or the previously given
+   * configuration via {@link #FrescoModule(ReactApplicationContext, ImagePipelineConfig)}.
+   *
+   * @param reactContext the context to use
+   */
   public FrescoModule(ReactApplicationContext reactContext) {
-    this(reactContext, getDefaultConfig(reactContext, null, null));
+    this(reactContext, null);
   }
 
-  public FrescoModule(ReactApplicationContext reactContext, RequestListener listener) {
-    this(reactContext, getDefaultConfig(reactContext, listener, null));
-  }
-
-  public FrescoModule(
-      ReactApplicationContext reactContext,
-      RequestListener listener,
-      DiskCacheConfig diskCacheConfig) {
-    this(reactContext, getDefaultConfig(reactContext, listener, diskCacheConfig));
-  }
-
-  public FrescoModule(ReactApplicationContext reactContext, ImagePipelineConfig config) {
+  /**
+   * Create a new Fresco module with a given ImagePipelineConfig.
+   * This should only be called when the module has not been initialized yet.
+   * You can use {@link #hasBeenInitialized()} to check this and call
+   * {@link #FrescoModule(ReactApplicationContext)} if it is already initialized.
+   * Otherwise, the given Fresco configuration will be ignored.
+   *
+   * @param reactContext the context to use
+   * @param config the Fresco configuration, which will only be used for the first initialization
+   */
+  public FrescoModule(ReactApplicationContext reactContext, @Nullable ImagePipelineConfig config) {
     super(reactContext);
     mConfig = config;
   }
@@ -61,12 +67,22 @@ public class FrescoModule extends ReactContextBaseJavaModule implements
   @Override
   public void initialize() {
     super.initialize();
-    // Make sure the SoLoaderShim is configured to use our loader for native libraries.
-    // This code can be removed if using Fresco from Maven rather than from source
-    SoLoaderShim.setHandler(new FrescoHandler());
-
-    Context context = getReactApplicationContext().getApplicationContext();
-    Fresco.initialize(context, mConfig);
+    if (!hasBeenInitialized()) {
+      // Make sure the SoLoaderShim is configured to use our loader for native libraries.
+      // This code can be removed if using Fresco from Maven rather than from source
+      SoLoaderShim.setHandler(new FrescoHandler());
+      if (mConfig == null) {
+        mConfig = getDefaultConfig(getReactApplicationContext());
+      }
+      Context context = getReactApplicationContext().getApplicationContext();
+      Fresco.initialize(context, mConfig);
+      sHasBeenInitialized = true;
+    } else if (mConfig != null) {
+      FLog.w(
+          ReactConstants.TAG,
+          "Fresco has already been initialized with a different config. "
+          + "The new Fresco configuration will be ignored!");
+    }
     mConfig = null;
   }
 
@@ -81,29 +97,26 @@ public class FrescoModule extends ReactContextBaseJavaModule implements
     Fresco.getImagePipeline().clearCaches();
   }
 
-  private static ImagePipelineConfig getDefaultConfig(
-      Context context,
-      @Nullable RequestListener listener,
-      @Nullable DiskCacheConfig diskCacheConfig) {
+  /**
+   * Check whether the FrescoModule has already been initialized. If this is the case,
+   * Calls to {@link #FrescoModule(ReactApplicationContext, ImagePipelineConfig)} will
+   * ignore the given configuration.
+   *
+   * @return true if this module has already been initialized
+   */
+  public static boolean hasBeenInitialized() {
+    return sHasBeenInitialized;
+  }
+
+  private static ImagePipelineConfig getDefaultConfig(Context context) {
     HashSet<RequestListener> requestListeners = new HashSet<>();
     requestListeners.add(new SystraceRequestListener());
-    if (listener != null) {
-      requestListeners.add(listener);
-    }
 
-    OkHttpClient okHttpClient = OkHttpClientProvider.getOkHttpClient();
-    ImagePipelineConfig.Builder builder =
-        OkHttpImagePipelineConfigFactory.newBuilder(context.getApplicationContext(), okHttpClient);
-
-    builder
-        .setDownsampleEnabled(false)
-        .setRequestListeners(requestListeners);
-
-    if (diskCacheConfig != null) {
-      builder.setMainDiskCacheConfig(diskCacheConfig);
-    }
-
-    return builder.build();
+    return OkHttpImagePipelineConfigFactory
+      .newBuilder(context.getApplicationContext(), OkHttpClientProvider.getOkHttpClient())
+      .setDownsampleEnabled(false)
+      .setRequestListeners(requestListeners)
+      .build();
   }
 
   private static class FrescoHandler implements SoLoaderShim.Handler {