Move new bridge java stuff to OSS

Reviewed By: mhorowitz

Differential Revision: D3300152

fbshipit-source-id: 9a76b10579bbfc5bde3a5094b99b64c38f4c1da9

ReactAndroid/src/main/java/com/facebook/react/cxxbridge/JSBundleLoader.java

@@ -0,0 +1,90 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.cxxbridge;
+
+import android.content.Context;
+
+/**
+ * A class that stores JS bundle information and allows {@link CatalystInstance} to load a correct
+ * bundle through {@link ReactBridge}.
+ */
+public abstract class JSBundleLoader {
+
+  /**
+   * This loader is recommended one for release version of your app. In that case local JS executor
+   * should be used. JS bundle will be read from assets directory in native code to save on passing
+   * large strings from java to native memory.
+   */
+  public static JSBundleLoader createFileLoader(
+      final Context context,
+      final String fileName) {
+    return new JSBundleLoader() {
+      @Override
+      public void loadScript(CatalystInstanceImpl instance) {
+        if (fileName.startsWith("assets://")) {
+          instance.loadScriptFromAssets(context.getAssets(), fileName);
+        } else {
+          instance.loadScriptFromFile(fileName, fileName);
+        }
+      }
+
+      @Override
+      public String getSourceUrl() {
+        return fileName;
+      }
+    };
+  }
+
+  /**
+   * This loader is used when bundle gets reloaded from dev server. In that case loader expect JS
+   * bundle to be prefetched and stored in local file. We do that to avoid passing large strings
+   * between java and native code and avoid allocating memory in java to fit whole JS bundle in it.
+   * Providing correct {@param sourceURL} of downloaded bundle is required for JS stacktraces to
+   * work correctly and allows for source maps to correctly symbolize those.
+   */
+  public static JSBundleLoader createCachedBundleFromNetworkLoader(
+      final String sourceURL,
+      final String cachedFileLocation) {
+    return new JSBundleLoader() {
+      @Override
+      public void loadScript(CatalystInstanceImpl instance) {
+        instance.loadScriptFromFile(cachedFileLocation, sourceURL);
+      }
+
+      @Override
+      public String getSourceUrl() {
+        return sourceURL;
+      }
+    };
+  }
+
+  /**
+   * This loader is used when proxy debugging is enabled. In that case there is no point in fetching
+   * the bundle from device as remote executor will have to do it anyway.
+   */
+  public static JSBundleLoader createRemoteDebuggerBundleLoader(
+      final String proxySourceURL,
+      final String realSourceURL) {
+    return new JSBundleLoader() {
+      @Override
+      public void loadScript(CatalystInstanceImpl instance) {
+        instance.loadScriptFromFile(null, proxySourceURL);
+      }
+
+      @Override
+      public String getSourceUrl() {
+        return realSourceURL;
+      }
+    };
+  }
+
+  public abstract void loadScript(CatalystInstanceImpl instance);
+  public abstract String getSourceUrl();
+}