Add GnssBatching AIDL HAL (hardware/interfaces)

Bug: 201253590
Test: atest VtsHalGnssTargetTest
Change-Id: Ied71c609dff714de06e2792f51d54a2dbddbb9d8
diff --git a/gnss/aidl/default/GnssBatching.cpp b/gnss/aidl/default/GnssBatching.cpp
new file mode 100644
index 0000000..2444edc
--- /dev/null
+++ b/gnss/aidl/default/GnssBatching.cpp
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+#define LOG_TAG "GnssBatchingAidl"
+
+#include "GnssBatching.h"
+#include <aidl/android/hardware/gnss/BnGnss.h>
+#include <inttypes.h>
+#include <log/log.h>
+#include <utils/SystemClock.h>
+#include "Utils.h"
+
+namespace aidl::android::hardware::gnss {
+
+using namespace ::android::hardware::gnss;
+
+constexpr int BATCH_SIZE = 10;
+
+std::shared_ptr<IGnssBatchingCallback> GnssBatching::sCallback = nullptr;
+
+GnssBatching::GnssBatching()
+    : mMinIntervalMs(1000),
+      mWakeUpOnFifoFull(false),
+      mBatchedLocations(std::vector<GnssLocation>()) {}
+GnssBatching::~GnssBatching() {
+    cleanup();
+}
+
+ndk::ScopedAStatus GnssBatching::init(const std::shared_ptr<IGnssBatchingCallback>& callback) {
+    ALOGD("init");
+    std::unique_lock<std::mutex> lock(mMutex);
+    sCallback = callback;
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus GnssBatching::getBatchSize(int* size) {
+    ALOGD("getBatchingSize");
+    *size = BATCH_SIZE;
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus GnssBatching::start(int64_t periodNanos, int flags) {
+    ALOGD("start: periodNanos=%" PRId64 ", flags=%d", periodNanos, flags);
+    if (mIsActive) {
+        ALOGW("Gnss has started. Restarting...");
+        stop();
+    }
+
+    mWakeUpOnFifoFull = (flags & IGnssBatching::WAKEUP_ON_FIFO_FULL) ? true : false;
+    // mMinIntervalMs is not smaller than 1 sec
+    periodNanos = (periodNanos < 1e9) ? 1e9 : periodNanos;
+    mMinIntervalMs = periodNanos / 1e6;
+
+    mIsActive = true;
+    mThread = std::thread([this]() {
+        while (mIsActive == true) {
+            const auto location = common::Utils::getMockLocation();
+            this->batchLocation(location);
+            std::this_thread::sleep_for(std::chrono::milliseconds(mMinIntervalMs));
+        }
+    });
+
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus GnssBatching::flush() {
+    ALOGD("flush");
+    if (mBatchedLocations.empty()) {
+        return ndk::ScopedAStatus::ok();
+    }
+    std::vector<GnssLocation> copy = std::vector<GnssLocation>(mBatchedLocations);
+    ndk::ScopedAStatus status;
+    if (sCallback != nullptr) {
+        sCallback->gnssLocationBatchCb(copy);
+        status = ndk::ScopedAStatus::ok();
+    } else {
+        ALOGE("GnssBatchingCallback is null. flush() failed.");
+        status = ndk::ScopedAStatus::fromServiceSpecificError(IGnss::ERROR_GENERIC);
+    }
+    mBatchedLocations.clear();
+    return status;
+}
+
+ndk::ScopedAStatus GnssBatching::stop() {
+    ALOGD("stop");
+    // Do not call flush() at stop()
+    mIsActive = false;
+    if (mThread.joinable()) {
+        mThread.join();
+    }
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus GnssBatching::cleanup() {
+    ALOGD("cleanup");
+    std::unique_lock<std::mutex> lock(mMutex);
+    if (mIsActive) {
+        stop();
+    }
+    flush();
+
+    sCallback = nullptr;
+    return ndk::ScopedAStatus::ok();
+}
+
+void GnssBatching::batchLocation(const GnssLocation& location) {
+    if (mBatchedLocations.size() > BATCH_SIZE) {
+        mBatchedLocations.erase(mBatchedLocations.begin());
+    }
+    mBatchedLocations.push_back(location);
+    if (mWakeUpOnFifoFull && mBatchedLocations.size() == BATCH_SIZE) {
+        flush();
+    }
+}
+
+}  // namespace aidl::android::hardware::gnss