Implement android.hardware.health@2.0.

healthd_common.cpp uses health@2.0 for health@2.0-service
and healthd.

charger and recovery will be fixed in a follow up change.
(They still use libbatterymonitor for now).

Test: adb logcat -e "health@2.0"
Test: adb shell lshal --debug

Change-Id: I9ff0691d467df37118d7f143693c1bcd17a5bcbf
diff --git a/healthd/Health.cpp b/healthd/Health.cpp
new file mode 100644
index 0000000..74f3eec
--- /dev/null
+++ b/healthd/Health.cpp
@@ -0,0 +1,163 @@
+#define LOG_TAG "Health"
+#include <android-base/logging.h>
+
+#include <health2/Health.h>
+
+#include <hidl/HidlTransportSupport.h>
+
+extern void healthd_battery_update_internal(bool);
+
+namespace android {
+namespace hardware {
+namespace health {
+namespace V2_0 {
+namespace implementation {
+
+Health::Health(struct healthd_config* c) {
+    battery_monitor_ = std::make_unique<BatteryMonitor>();
+    battery_monitor_->init(c);
+}
+
+// Methods from IHealth follow.
+Return<Result> Health::registerCallback(const sp<IHealthInfoCallback>& callback) {
+    if (callback == nullptr) {
+        return Result::SUCCESS;
+    }
+
+    {
+        std::lock_guard<std::mutex> _lock(callbacks_lock_);
+        callbacks_.push_back(callback);
+        // unlock
+    }
+
+    auto linkRet = callback->linkToDeath(this, 0u /* cookie */);
+    if (!linkRet.withDefault(false)) {
+        LOG(WARNING) << __func__ << "Cannot link to death: "
+                     << (linkRet.isOk() ? "linkToDeath returns false" : linkRet.description());
+        // ignore the error
+    }
+
+    return update();
+}
+
+bool Health::unregisterCallbackInternal(const sp<IBase>& callback) {
+    if (callback == nullptr) return false;
+
+    bool removed = false;
+    std::lock_guard<std::mutex> _lock(callbacks_lock_);
+    for (auto it = callbacks_.begin(); it != callbacks_.end();) {
+        if (interfacesEqual(*it, callback)) {
+            it = callbacks_.erase(it);
+            removed = true;
+        } else {
+            ++it;
+        }
+    }
+    (void)callback->unlinkToDeath(this).isOk();  // ignore errors
+    return removed;
+}
+
+Return<Result> Health::unregisterCallback(const sp<IHealthInfoCallback>& callback) {
+    return unregisterCallbackInternal(callback) ? Result::SUCCESS : Result::NOT_FOUND;
+}
+
+template<typename T>
+void getProperty(const std::unique_ptr<BatteryMonitor>& monitor, int id, T defaultValue,
+                 const std::function<void(Result, T)>& callback) {
+    struct BatteryProperty prop;
+    T ret = defaultValue;
+    Result result = Result::SUCCESS;
+    status_t err = monitor->getProperty(static_cast<int>(id), &prop);
+    if (err != OK) {
+        LOG(DEBUG) << "getProperty(" << id << ")" << " fails: (" << err << ") " << strerror(-err);
+    } else {
+        ret = static_cast<T>(prop.valueInt64);
+    }
+    switch (err) {
+        case OK:             result = Result::SUCCESS; break;
+        case NAME_NOT_FOUND: result = Result::NOT_SUPPORTED; break;
+        default:             result = Result::UNKNOWN; break;
+    }
+    callback(result, static_cast<T>(ret));
+}
+
+Return<void> Health::getChargeCounter(getChargeCounter_cb _hidl_cb) {
+    getProperty(battery_monitor_, BATTERY_PROP_CHARGE_COUNTER, INT32_MIN, _hidl_cb);
+    return Void();
+}
+
+Return<void> Health::getCurrentNow(getCurrentNow_cb _hidl_cb) {
+    getProperty(battery_monitor_, BATTERY_PROP_CURRENT_NOW, INT32_MIN, _hidl_cb);
+    return Void();
+}
+
+Return<void> Health::getCurrentAverage(getCurrentAverage_cb _hidl_cb) {
+    getProperty(battery_monitor_, BATTERY_PROP_CURRENT_AVG, INT32_MIN, _hidl_cb);
+    return Void();
+}
+
+Return<void> Health::getCapacity(getCapacity_cb _hidl_cb) {
+    getProperty(battery_monitor_, BATTERY_PROP_CAPACITY, INT32_MIN, _hidl_cb);
+    return Void();
+}
+
+Return<void> Health::getEnergyCounter(getEnergyCounter_cb _hidl_cb) {
+    getProperty(battery_monitor_, BATTERY_PROP_ENERGY_COUNTER, INT64_MIN, _hidl_cb);
+    return Void();
+}
+
+Return<void> Health::getChargeStatus(getChargeStatus_cb _hidl_cb) {
+    getProperty(battery_monitor_, BATTERY_PROP_BATTERY_STATUS, BatteryStatus::UNKNOWN, _hidl_cb);
+    return Void();
+}
+
+
+Return<Result> Health::update() {
+    if (!healthd_mode_ops || !healthd_mode_ops->battery_update) {
+        LOG(WARNING) << "health@2.0: update: not initialized. "
+                     << "update() should not be called in charger / recovery.";
+        return Result::UNKNOWN;
+    }
+
+    // Retrieve all information and call healthd_mode_ops->battery_update, which calls
+    // notifyListeners.
+    bool chargerOnline = battery_monitor_->update();
+
+    // adjust uevent / wakealarm periods
+    healthd_battery_update_internal(chargerOnline);
+
+    return Result::SUCCESS;
+}
+
+void Health::notifyListeners(const HealthInfo& info) {
+    std::lock_guard<std::mutex> _lock(callbacks_lock_);
+    for (auto it = callbacks_.begin(); it != callbacks_.end();) {
+        auto ret = (*it)->healthInfoChanged(info);
+        if (!ret.isOk() && ret.isDeadObject()) {
+            it = callbacks_.erase(it);
+        } else {
+            ++it;
+        }
+    }
+}
+
+Return<void> Health::debug(const hidl_handle& handle, const hidl_vec<hidl_string>&) {
+    if (handle != nullptr && handle->numFds >= 1) {
+        int fd = handle->data[0];
+        battery_monitor_->dumpState(fd);
+        fsync(fd);
+    }
+    return Void();
+}
+
+void Health::serviceDied(uint64_t /* cookie */, const wp<IBase>& who) {
+    (void)unregisterCallbackInternal(who.promote());
+}
+
+// Methods from ::android::hidl::base::V1_0::IBase follow.
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace health
+}  // namespace hardware
+}  // namespace android