Context hub API for applications

Adding a System API for applications to access a context hub.

The API is not expected to be exposed to third party Android
applications in the medium term.

Change-Id: Ia2222317c913de6901f3912e4c89b5cfa398be85
diff --git a/core/java/android/hardware/location/ContextHubService.java b/core/java/android/hardware/location/ContextHubService.java
new file mode 100644
index 0000000..a2a13c6
--- /dev/null
+++ b/core/java/android/hardware/location/ContextHubService.java
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+package android.hardware.location;
+
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.util.Log;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+
+/**
+ * @hide
+ */
+public class ContextHubService extends Service {
+
+    private static final String TAG = "ContextHubService";
+    private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);
+
+    private static ContextHubService sSingletonInstance;
+    private static final Object sSingletonInstanceLock = new Object();
+
+    private HashMap<Integer, ContextHubInfo> mHubHash;
+    private HashMap<Integer, NanoAppInstanceInfo> mNanoAppHash;
+    private ContextHubInfo[] mContexthubInfo;
+
+
+    private native int nativeSendMessage(int[] header, byte[] data);
+    private native ContextHubInfo[] nativeInitialize();
+
+    private int onMessageReceipt(int[] header, byte[] data) {
+        return 0;
+    }
+    private void initialize() {
+        mContexthubInfo = nativeInitialize();
+
+        mHubHash = new HashMap<Integer, ContextHubInfo>();
+
+        for (int i = 0; i < mContexthubInfo.length; i++) {
+            mHubHash.put(i + 1, mContexthubInfo[i]); // Avoiding zero
+        }
+    }
+
+    private ContextHubService(Context context) {
+        initialize();
+        Log.d(TAG, "Created from " + context.toString());
+    }
+
+    public static ContextHubService getInstance(Context context) {
+        synchronized (sSingletonInstanceLock) {
+            if (sSingletonInstance == null) {
+                sSingletonInstance = new ContextHubService(context);
+            }
+            return sSingletonInstance;
+        }
+    }
+
+    @Override
+    public void onCreate() {
+        super.onCreate();
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    private final IContextHubService.Stub mBinder = new IContextHubService.Stub() {
+
+        private  IContextHubCallback callback;
+
+        @Override
+        public int registerCallBack(IContextHubCallback callback) throws RemoteException{
+            this.callback = callback;
+            return 0;
+        }
+
+        @Override
+        public int[] getContextHubHandles() throws RemoteException {
+            int [] returnArray = new int[mHubHash.size()];
+            int i = 0;
+            for (int key : mHubHash.keySet()) {
+                // Add any filtering here
+                returnArray[i] = key;
+                i++;
+            }
+            return returnArray;
+        }
+
+        @Override
+        public ContextHubInfo getContextHubInfo(int contexthubHandle) throws RemoteException {
+            return mHubHash.get(contexthubHandle);
+        }
+
+        @Override
+        public int loadNanoApp(int hubHandle, NanoApp app) throws RemoteException {
+            if (!mHubHash.containsKey(hubHandle)) {
+                return -1;
+            } else {
+                // Call Native interface here
+                int[] msgHeader = new int[8];
+                msgHeader[0] = ContextHubManager.MSG_LOAD_NANO_APP;
+                msgHeader[1] = app.getAppId();
+                msgHeader[2] = app.getAppVersion();
+                msgHeader[3] = 0; // LOADING_HINTS
+                msgHeader[4] = hubHandle;
+
+                int handle = nativeSendMessage(msgHeader, app.getAppBinary());
+
+                // if successful, add an entry to mNanoAppHash
+
+                if(handle > 0) {
+                    return 0;
+                } else {
+
+                    return -1;
+                }
+            }
+        }
+
+        @Override
+        public int unloadNanoApp(int nanoAppInstanceHandle) throws RemoteException {
+            if(!mNanoAppHash.containsKey(nanoAppInstanceHandle)) {
+                return -1;
+            } else {
+                NanoAppInstanceInfo info = mNanoAppHash.get(nanoAppInstanceHandle);
+                // Call Native interface here
+                int[] msgHeader = new int[8];
+                msgHeader[0] = ContextHubManager.MSG_UNLOAD_NANO_APP;
+                msgHeader[1] = info.getContexthubId();
+                msgHeader[2] = info.getHandle();
+
+                int result = nativeSendMessage(msgHeader, null);
+                // if successful, remove the entry in mNanoAppHash
+                if(result == 0) {
+                    mNanoAppHash.remove(nanoAppInstanceHandle);
+                }
+                return(result);
+            }
+        }
+
+        @Override
+        public NanoAppInstanceInfo getNanoAppInstanceInfo(int nanoAppInstanceHandle) throws RemoteException {
+            // This assumes that all the nanoAppInfo is current. This is reasonable
+            // for the use cases for tightly controlled nanoApps.
+            //
+            if(!mNanoAppHash.containsKey(nanoAppInstanceHandle)) {
+                return(mNanoAppHash.get(nanoAppInstanceHandle));
+            } else {
+                return null;
+            }
+        }
+
+        @Override
+        public int[] findNanoAppOnHub(int hubHandle, NanoAppFilter filter) throws RemoteException {
+            ArrayList<Integer> foundInstances = new ArrayList<Integer>();
+
+            for(Integer nanoAppInstance : mNanoAppHash.keySet()) {
+                NanoAppInstanceInfo info = mNanoAppHash.get(nanoAppInstance);
+
+                if(filter.testMatch(info)){
+                    foundInstances.add(nanoAppInstance);
+                }
+            }
+
+            int[] retArray = new int[foundInstances.size()];
+            for (int i = 0; i < foundInstances.size(); i++) {
+                retArray[i] = foundInstances.get(i).intValue();
+            }
+
+            return retArray;
+        }
+
+        @Override
+        public int sendMessage(int hubHandle, int nanoAppHandle, ContextHubMessage msg) throws RemoteException {
+            int[] msgHeader = new int[8];
+            msgHeader[0] = ContextHubManager.MSG_DATA_SEND;
+            msgHeader[1] = hubHandle;
+            msgHeader[2] = nanoAppHandle;
+            msgHeader[3] = msg.getMsgType();
+            msgHeader[4] = msg.getVersion();
+
+            return (nativeSendMessage(msgHeader, msg.getData()));
+        }
+    };
+}