libandroid_net_lowpan: Reintroduce new unit tests for data classesoreo-mr1-dev

This change introduces new unit tests which confirm that various data
classes are being property marshalled between their Java and C++
implementations.

This was originally added to platform/frameworks/base via change id
I41d590b1e77dc41873c4b9e9bf1b7f1bf859f74e, but that change was
reverted (via ag/2553741) due the failure of build 4190632 on the
branch `git_wear-master`. Moving these specific tests into this
repository avoids this failure case.

This change is dependent on the following change id:

    I70fe6be8d71424e11a537daaa69c3f6cfae8e49d

Bug: b/63707448 b/63708348
Change-Id: I41d590b1e77dc41873c4b9e9bf1b7f1bf859f74e
Test: These tests both compile and pass

1 files changed, 66 insertions, 0 deletions

diff --git a/libandroid_net_lowpan/tests/jni/LowpanCredentialTest.cpp b/libandroid_net_lowpan/tests/jni/LowpanCredentialTest.cpp
new file mode 100644
index 0000000..fc860b2
--- /dev/null
+++ b/libandroid_net_lowpan/tests/jni/LowpanCredentialTest.cpp
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include <memory>
+
+#include <binder/Parcel.h>
+
+#include "LowpanCredentialTest.h"
+
+using android::net::lowpan::LowpanCredential;
+
+/**
+ * Reads exactly one LowpanCredential from 'parcelData' assuming that it is a Parcel. Any bytes afterward
+ * are ignored.
+ */
+static LowpanCredential unmarshall(JNIEnv* env, jbyteArray parcelData) {
+    const int length = env->GetArrayLength(parcelData);
+
+    std::unique_ptr<uint8_t> bytes(new uint8_t[length]);
+    env->GetByteArrayRegion(parcelData, 0, length, reinterpret_cast<jbyte*>(bytes.get()));
+
+    android::Parcel p;
+    p.setData(bytes.get(), length);
+
+    LowpanCredential value;
+    value.readFromParcel(&p);
+    return value;
+}
+
+/**
+ * Creates a Java byte[] array and writes the contents of 'addr' to it as a Parcel containing
+ * exactly one object.
+ *
+ * Every LowpanCredential maps to a unique parcel object, so both 'marshall(e, unmarshall(e, x))' and
+ * 'unmarshall(e, marshall(e, x))' should be fixed points.
+ */
+static jbyteArray marshall(JNIEnv* env, const LowpanCredential& addr) {
+    android::Parcel p;
+    addr.writeToParcel(&p);
+    const int length = p.dataSize();
+
+    jbyteArray parcelData = env->NewByteArray(length);
+    env->SetByteArrayRegion(parcelData, 0, length, reinterpret_cast<const jbyte*>(p.data()));
+
+    return parcelData;
+}
+
+extern "C"
+JNIEXPORT jbyteArray Java_android_net_lowpan_LowpanCredentialTest_readAndWriteNative(JNIEnv* env, jclass,
+        jbyteArray inParcel) {
+    const LowpanCredential value = unmarshall(env, inParcel);
+    return marshall(env, value);
+}