1 files changed, 139 insertions, 0 deletions
diff --git a/third_party/sl4a/src/main/java/com/google/android/mobly/snippet/util/RpcUtil.java b/third_party/sl4a/src/main/java/com/google/android/mobly/snippet/util/RpcUtil.java
new file mode 100644
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--- /dev/null
+++ b/third_party/sl4a/src/main/java/com/google/android/mobly/snippet/util/RpcUtil.java
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2016 Google Inc.
+ *
+ * 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 com.google.android.mobly.snippet.util;
+
+import com.google.android.mobly.snippet.event.EventCache;
+import com.google.android.mobly.snippet.event.SnippetEvent;
+import com.google.android.mobly.snippet.manager.SnippetManager;
+import com.google.android.mobly.snippet.rpc.JsonRpcResult;
+import com.google.android.mobly.snippet.rpc.MethodDescriptor;
+import com.google.android.mobly.snippet.rpc.RpcError;
+import java.util.Locale;
+import java.util.Timer;
+import java.util.TimerTask;
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+/**
+ * Class that implements APIs to schedule other RPCs.
+ *
+ * <p>If a device is required to be disconnected (e.g., USB power off), no RPCs can be made while
+ * device is offline.
+ *
+ * <p>However, We still need snippet continue to run and execute previously scheduled RPCs
+ *
+ * <p>The return value of the scheduled RPC is cached in {@link EventCache} and can be retrieved
+ * later after device is back online.
+ */
+public class RpcUtil {
+    // RPC ID is used for reporting responses back to the client. However, the results of
+    // scheduled RPCs are reported back to the client via events instead of through synchronous
+    // responses, so the RPC ID is unused. We pass an arbitrary value of 0.
+    private static final int DEFAULT_ID = 0;
+    private final SnippetManager mReceiverManager;
+    private final EventCache mEventCache = EventCache.getInstance();
+
+    public RpcUtil() {
+        mReceiverManager = SnippetManager.getInstance();
+    }
+
+    /**
+     * Schedule given RPC with some delay.
+     *
+     * @param callbackId The callback ID used to cache RPC results.
+     * @param methodName The RPC name to be scheduled.
+     * @param delayMs The delay in ms
+     * @param params Array of the parameters to the RPC
+     */
+    public void scheduleRpc(
+            final String callbackId,
+            final String methodName,
+            final long delayMs,
+            final JSONArray params)
+            throws Throwable {
+        Timer timer = new Timer();
+        TimerTask task =
+                new TimerTask() {
+                    @Override
+                    public void run() {
+                        SnippetEvent event = new SnippetEvent(callbackId, methodName);
+                        try {
+                            JSONObject obj = invokeRpc(methodName, params, DEFAULT_ID, callbackId);
+                            // Cache RPC method return value.
+                            for (int i = 0; i < obj.names().length(); i++) {
+                                String key = obj.names().getString(i);
+                                event.getData().putString(key, obj.get(key).toString());
+                            }
+                        } catch (JSONException e) {
+                            String stackTrace = JsonRpcResult.getStackTrace(e);
+                            event.getData().putString("error", stackTrace);
+                        } finally {
+                            mEventCache.postEvent(event);
+                        }
+                    }
+                };
+        timer.schedule(task, delayMs);
+    }
+
+    /**
+     * Invoke the RPC.
+     *
+     * @param methodName The RPC name to be invoked.
+     * @param params Array of the parameters to the RPC
+     * @param id The ID that identifies an RPC
+     * @param UID Globally unique session ID.
+     */
+    public JSONObject invokeRpc(String methodName, JSONArray params, int id, Integer UID)
+            throws JSONException {
+        return invokeRpc(methodName, params, id, String.format(Locale.US, "%d-%d", UID, id));
+    }
+
+    /**
+     * Invoke the RPC.
+     *
+     * @param methodName The RPC name to be invoked.
+     * @param params Array of the parameters to the RPC
+     * @param id The ID that identifies an RPC
+     * @param callbackId The callback ID used to cache RPC results.
+     */
+    public JSONObject invokeRpc(String methodName, JSONArray params, int id, String callbackId)
+            throws JSONException {
+        MethodDescriptor rpc = mReceiverManager.getMethodDescriptor(methodName);
+        if (rpc == null) {
+            return JsonRpcResult.error(id, new RpcError("Unknown RPC: " + methodName));
+        }
+        try {
+            JSONArray newParams = new JSONArray();
+            /** If calling an {@link AsyncRpc}, put the message ID as the first param. */
+            if (rpc.isAsync()) {
+                newParams.put(callbackId);
+                for (int i = 0; i < params.length(); i++) {
+                    newParams.put(params.get(i));
+                }
+                Object returnValue = rpc.invoke(mReceiverManager, newParams);
+                return JsonRpcResult.callback(id, returnValue, callbackId);
+            } else {
+                Object returnValue = rpc.invoke(mReceiverManager, params);
+                return JsonRpcResult.result(id, returnValue);
+            }
+        } catch (Throwable t) {
+            Log.e("Invocation error.", t);
+            return JsonRpcResult.error(id, t);
+        }
+    }
+}