1 files changed, 102 insertions, 0 deletions
diff --git a/lib/ClockTAI.h b/lib/ClockTAI.h
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+++ b/lib/ClockTAI.h
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+/*
+   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
+   2011, 2012 Her Majesty the Queen in Right of Canada (Communications
+   Research Center Canada)
+
+   Copyright (C) 2019
+   Matthias P. Braendli, matthias.braendli@mpb.li
+
+    http://www.opendigitalradio.org
+   */
+/*
+   This file is part of the ODR-mmbTools.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as
+   published by the Free Software Foundation, either version 3 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* The EDI output needs TAI clock, according to ETSI TS 102 693 Annex F
+ * "EDI Timestamps". This module can set the local CLOCK_TAI clock by
+ * setting the TAI-UTC offset using adjtimex.
+ *
+ * This functionality requires Linux 3.10 (30 Jun 2013) or newer.
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <cstdlib>
+#include <sstream>
+#include <chrono>
+#include <future>
+#include <mutex>
+#include <string>
+#include <vector>
+#include "RemoteControl.h"
+
+// EDI needs to know UTC-TAI, but doesn't need the CLOCK_TAI to be set.
+// We can keep this code, maybe for future use
+#define SUPPORT_SETTING_CLOCK_TAI 0
+
+/* Loads, parses and represents TAI-UTC offset information from the IETF bulletin */
+class ClockTAI : public RemoteControllable {
+    public:
+        ClockTAI(const std::vector<std::string>& bulletin_urls);
+
+        // Fetch the bulletin from the IETF website and return the current
+        // TAI-UTC offset.
+        // Throws runtime_error on failure.
+        int get_offset(void);
+
+#if SUPPORT_SETTING_CLOCK_TAI
+        // Update the local TAI clock according to the TAI-UTC offset
+        // return 0 on success
+        int update_local_tai_clock(int offset);
+#endif
+
+    private:
+        class download_failed {};
+
+        // Either retrieve the bulletin from the cache or if necessarly
+        // download it, and calculate the TAI-UTC offset.
+        // Returns the offset or throws download_failed or a range_error
+        // if the offset is out of bounds.
+        int get_valid_offset(void);
+
+        // Download of new bulletin is done asynchronously
+        std::future<int> m_offset_future;
+
+        // Protect all data members, as RC functions are in another thread
+        mutable std::mutex m_data_mutex;
+
+        // The currently used TAI-UTC offset
+        int m_offset = 0;
+        int m_offset_valid = false;
+
+        std::vector<std::string> m_bulletin_urls;
+
+        std::string m_bulletin;
+        std::chrono::system_clock::time_point m_bulletin_download_time;
+
+        // Update the cache file with the current m_bulletin
+        void update_cache(const char* cache_filename);
+
+
+        /* Remote control */
+        virtual void set_parameter(const std::string& parameter,
+               const std::string& value);
+
+        /* Getting a parameter always returns a string. */
+        virtual const std::string get_parameter(const std::string& parameter) const;
+};
+