Allow statsd to be given empty config.

Statsd clients may want to set an empty config temporarily, so it's
more convenient to allow them to set an empty config instead of
having to use the removeConfig and then having to remember to call
StatsManager#setDataFetchOperation.

Test: Added unit-tests and check they pass on marlin-eng.
Bug: 74997752
Change-Id: I2e762e5ec01e5a2c9a3469fb330b53fefbd734d6
diff --git a/cmds/statsd/Android.mk b/cmds/statsd/Android.mk
index 5d6a1d1a..ca0611b 100644
--- a/cmds/statsd/Android.mk
+++ b/cmds/statsd/Android.mk
@@ -177,6 +177,7 @@
     tests/LogEvent_test.cpp \
     tests/MetricsManager_test.cpp \
     tests/StatsLogProcessor_test.cpp \
+    tests/StatsService_test.cpp \
     tests/UidMap_test.cpp \
     tests/FieldValue_test.cpp \
     tests/condition/CombinationConditionTracker_test.cpp \
diff --git a/cmds/statsd/src/StatsService.cpp b/cmds/statsd/src/StatsService.cpp
index c5dfc44..b86646a 100644
--- a/cmds/statsd/src/StatsService.cpp
+++ b/cmds/statsd/src/StatsService.cpp
@@ -867,14 +867,11 @@
                                       bool* success) {
     IPCThreadState* ipc = IPCThreadState::self();
     if (checkCallingPermission(String16(kPermissionDump))) {
-        ConfigKey configKey(ipc->getCallingUid(), key);
-        StatsdConfig cfg;
-        if (config.empty() || !cfg.ParseFromArray(&config[0], config.size())) {
+        if (addConfigurationChecked(ipc->getCallingUid(), key, config)) {
+            *success = true;
+        } else {
             *success = false;
-            return Status::ok();
         }
-        mConfigManager->UpdateConfig(configKey, cfg);
-        *success = true;
         return Status::ok();
     } else {
         *success = false;
@@ -882,6 +879,18 @@
     }
 }
 
+bool StatsService::addConfigurationChecked(int uid, int64_t key, const vector<uint8_t>& config) {
+    ConfigKey configKey(uid, key);
+    StatsdConfig cfg;
+    if (config.size() > 0) {  // If the config is empty, skip parsing.
+        if (!cfg.ParseFromArray(&config[0], config.size())) {
+            return false;
+        }
+    }
+    mConfigManager->UpdateConfig(configKey, cfg);
+    return true;
+}
+
 Status StatsService::removeDataFetchOperation(int64_t key, bool* success) {
     IPCThreadState* ipc = IPCThreadState::self();
     if (checkCallingPermission(String16(kPermissionDump))) {
diff --git a/cmds/statsd/src/StatsService.h b/cmds/statsd/src/StatsService.h
index 02b6124..0ec31ef 100644
--- a/cmds/statsd/src/StatsService.h
+++ b/cmds/statsd/src/StatsService.h
@@ -17,6 +17,7 @@
 #ifndef STATS_SERVICE_H
 #define STATS_SERVICE_H
 
+#include <gtest/gtest_prod.h>
 #include "StatsLogProcessor.h"
 #include "anomaly/AlarmMonitor.h"
 #include "config/ConfigManager.h"
@@ -216,6 +217,11 @@
     status_t cmd_clear_puller_cache(FILE* out);
 
     /**
+     * Adds a configuration after checking permissions and obtaining UID from binder call.
+     */
+    bool addConfigurationChecked(int uid, int64_t key, const vector<uint8_t>& config);
+
+    /**
      * Update a configuration.
      */
     void set_config(int uid, const string& name, const StatsdConfig& config);
@@ -254,6 +260,10 @@
      * Whether this is an eng build.
      */
     bool mEngBuild;
+
+    FRIEND_TEST(StatsServiceTest, TestAddConfig_simple);
+    FRIEND_TEST(StatsServiceTest, TestAddConfig_empty);
+    FRIEND_TEST(StatsServiceTest, TestAddConfig_invalid);
 };
 
 }  // namespace statsd
diff --git a/cmds/statsd/tests/StatsService_test.cpp b/cmds/statsd/tests/StatsService_test.cpp
new file mode 100644
index 0000000..a7b4136
--- /dev/null
+++ b/cmds/statsd/tests/StatsService_test.cpp
@@ -0,0 +1,67 @@
+// 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 "StatsService.h"
+#include "config/ConfigKey.h"
+#include "frameworks/base/cmds/statsd/src/statsd_config.pb.h"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <stdio.h>
+
+using namespace android;
+using namespace testing;
+
+namespace android {
+namespace os {
+namespace statsd {
+
+using android::util::ProtoOutputStream;
+
+#ifdef __ANDROID__
+
+TEST(StatsServiceTest, TestAddConfig_simple) {
+    StatsService service(nullptr);
+    StatsdConfig config;
+    config.set_id(12345);
+    string serialized = config.SerializeAsString();
+
+    EXPECT_TRUE(
+            service.addConfigurationChecked(123, 12345, {serialized.begin(), serialized.end()}));
+}
+
+TEST(StatsServiceTest, TestAddConfig_empty) {
+    StatsService service(nullptr);
+    string serialized = "";
+
+    EXPECT_TRUE(
+            service.addConfigurationChecked(123, 12345, {serialized.begin(), serialized.end()}));
+}
+
+TEST(StatsServiceTest, TestAddConfig_invalid) {
+    StatsService service(nullptr);
+    string serialized = "Invalid config!";
+
+    EXPECT_FALSE(
+            service.addConfigurationChecked(123, 12345, {serialized.begin(), serialized.end()}));
+}
+
+#else
+GTEST_LOG_(INFO) << "This test does nothing.\n";
+#endif
+
+}  // namespace statsd
+}  // namespace os
+}  // namespace android