Implement InstanceIDAndroid using InstanceIDWithSubtype.java

components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java

Index: components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java
diff --git a/components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java b/components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java
new file mode 100644
index 0000000000000000000000000000000000000000..fabf769870b774f23030401a7629de9081d8a7e5
--- /dev/null
+++ b/components/gcm_driver/instance_id/android/java/src/org/chromium/components/gcm_driver/instance_id/InstanceIDBridge.java
@@ -0,0 +1,146 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.components.gcm_driver.instance_id;
+
+import android.content.Context;
+import android.os.AsyncTask;
+import android.os.Bundle;
+import android.text.TextUtils;
+
+import com.google.android.gms.iid.InstanceID;
+
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+
+import java.io.IOException;
+
+/**
+ * Wraps InstanceID and InstanceIDWithSubtype so they can be used over JNI.
+ * Performs disk/network operations on a background thread and replies asynchronously.
+ */
+@JNINamespace("instance_id")
+public class InstanceIDBridge {
+    /** Underlying InstanceID. May be shared by multiple InstanceIDBridges. */
+    private final InstanceID mInstanceID;
+    private final long mNativeInstanceIDAndroid;
+
+    private InstanceIDBridge(InstanceID instanceID, long nativeInstanceIDAndroid) {
+        mInstanceID = instanceID;
+        mNativeInstanceIDAndroid = nativeInstanceIDAndroid;
+    }
+
+    /**
+     * Returns a wrapped {@link InstanceIDWithSubtype} or {@link InstanceID}, depending on whether
+     * subtype is empty. Multiple InstanceIDBridge instances may share an underlying InstanceID.
+     */
+    @CalledByNative
+    public static InstanceIDBridge getInstance(
+            long nativeInstanceIDAndroid, Context context, String subtype) {
+        InstanceID instanceID = TextUtils.isEmpty(subtype)

[Peter Beverloo, 2016/04/14 14:30:47]

There's a DCHECK in the C++ code to make sure the subtype is not empty, why do
you special case for it here?

Could we simplify this class, get rid of the getInstance() method completely and
just instantiate it directly from C++? Throw an exception when |subtype| is
empty, and assign InstanceIDWithSubtype.getInstance() to mInstanceID :-).

[johnme, 2016/04/14 18:00:15]

It would be valid for Chrome components to use an empty subtype (and hence
InstanceID.getInstance) to access Chrome's default InstanceID. But since I don't
currently support that in C++, there's not much point supporting it in Java
either, so done. Our JNI generator doesn't support calling constructors from
C++, so getInstance remains (renamed to create), though simplified.

+                                ? InstanceID.getInstance(context)
+                                : InstanceIDWithSubtype.getInstance(context, subtype);
+        return new InstanceIDBridge(instanceID, nativeInstanceIDAndroid);
+    }
+
+    /**
+     * Called when our C++ counterpart is destroyed. Clears the handle to our native C++ object,
+     * ensuring it's not called by pending async tasks.
+     */
+    @CalledByNative
+    private void destroy() {
+        mNativeInstanceIDAndroid = 0;
+    }
+
+    /** Wrapper for {@link InstanceID#getId}. */
+    @CalledByNative
+    public String getId() {
+        return mInstanceID.getId();

[Peter Beverloo, 2016/04/14 14:30:47]

Any reason for not making this asynchronous immediately? If it's convenience,
I'm OK with postponing but then please add a TODO since these methods violate
the class-level documentation on line 21. 

[johnme, 2016/04/14 18:00:15]

Convenience (note that create will also need to be async, so it's not trivial).
Added TODOs.

+    }
+
+    /** Wrapper for {@link InstanceID#getCreationTime}. */
+    @CalledByNative
+    public long getCreationTime() {
+        return mInstanceID.getCreationTime();
+    }
+
+    /** Async wrapper for {@link InstanceID#getToken(String, String, Bundle)}. */
+    @CalledByNative
+    private void getToken(final int requestId, final String authorizedEntity, final String scope,
+            String[] extrasStrings) {
+        final Bundle extras = new Bundle();
+        assert extrasStrings.length % 2 == 0;
+        for (int i = 0; i < extrasStrings.length; i += 2) {
+            extras.putString(extrasStrings[i], extrasStrings[i + 1]);
+        }
+        new AsyncTask<Void, Void, String>() {
+            @Override
+            protected String doInBackground(Void... params) {
+                try {
+                    return mInstanceID.getToken(authorizedEntity, scope, extras);
+                } catch (IOException ex) {
+                    return "";
+                }
+            }
+            @Override
+            protected void onPostExecute(String token) {
+                if (mNativeInstanceIDAndroid != 0) {
+                    nativeDidGetToken(mNativeInstanceIDAndroid, requestId, token);
+                }
+            }
+        }.execute();
+    }
+
+    /** Async wrapper for {@link InstanceID#deleteToken(String, String)}. */
+    @CalledByNative
+    private void deleteToken(
+            final int requestId, final String authorizedEntity, final String scope) {
+        new AsyncTask<Void, Void, Boolean>() {
+            @Override
+            protected Boolean doInBackground(Void... params) {
+                try {
+                    mInstanceID.deleteToken(authorizedEntity, scope);
+                    return true;
+                } catch (IOException ex) {
+                    return false;
+                }
+            }
+            @Override
+            protected void onPostExecute(Boolean success) {
+                if (mNativeInstanceIDAndroid != 0) {
+                    nativeDidDeleteToken(mNativeInstanceIDAndroid, requestId, success);
+                }
+            }
+        }.execute();
+    }
+
+    /** Async wrapper for {@link InstanceID#deleteInstanceID}. */
+    @CalledByNative
+    private void deleteInstanceID(final int requestId) {
+        new AsyncTask<Void, Void, Boolean>() {
+            @Override
+            protected Boolean doInBackground(Void... params) {
+                try {
+                    mInstanceID.deleteInstanceID();
+                    return true;
+                } catch (IOException ex) {
+                    return false;
+                }
+            }
+            @Override
+            protected void onPostExecute(Boolean success) {
+                if (mNativeInstanceIDAndroid != 0) {
+                    nativeDidDeleteID(mNativeInstanceIDAndroid, requestId, success);
+                }
+            }
+        }.execute();
+    }
+
+    private native void nativeDidGetToken(
+            long nativeInstanceIDAndroid, int requestId, String token);
+    private native void nativeDidDeleteToken(
+            long nativeInstanceIDAndroid, int requestId, boolean success);
+    private native void nativeDidDeleteID(
+            long nativeInstanceIDAndroid, int requestId, boolean success);
+}