uhd: work on the backend for a logging facility

host/include/uhd/CMakeLists.txt

@@ -26,6 +26,7 @@ INSTALL(FILES
     convert.hpp
     device.hpp
     exception.hpp
+    log.hpp
     version.hpp
     wax.hpp
     DESTINATION ${INCLUDE_DIR}/uhd

host/include/uhd/log.hpp

@@ -0,0 +1,64 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// 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/>.
+//
+
+#ifndef INCLUDED_UHD_LOG_HPP
+#define INCLUDED_UHD_LOG_HPP
+
+#include <uhd/config.hpp>
+#include <boost/current_function.hpp>
+#include <ostream>
+#include <string>
+
+//! uhd logger macro with default verbosity
+#define UHD_LOG \
+    uhd::_log::log(uhd::_log::regularly, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION)
+
+//! uhd logger macro with configurable verbosity
+#define UHD_LOGV(verbosity) \
+    uhd::_log::log(uhd::_log::verbosity, __FILE__, __LINE__, BOOST_CURRENT_FUNCTION)
+
+namespace uhd{ namespace _log{
+
+    //! Verbosity levels for the logger
+    enum verbosity_t{
+        always      = 1,
+        often       = 2,
+        regularly   = 3,
+        rarely      = 4,
+        very_rarely = 5,
+    };
+
+    //! Internal logging object (called by UHD_LOG macros)
+    struct UHD_API log{
+        log(
+            const verbosity_t verbosity,
+            const std::string &file,
+            const unsigned int line,
+            const std::string &function
+        );
+        ~log(void);
+
+        std::ostream &get(void);
+
+        template <typename T> std::ostream &operator<<(const T &x){
+            return get() << x;
+        }
+    };
+
+}} //namespace uhd::_log
+
+#endif /* INCLUDED_UHD_LOG_HPP */

host/lib/CMakeLists.txt

@@ -93,6 +93,7 @@ SET_SOURCE_FILES_PROPERTIES(
 LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/device.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/exception.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/log.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/version.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/wax.cpp
 )

host/lib/log.cpp

@@ -0,0 +1,133 @@
+//
+// Copyright 2011 Ettus Research LLC
+//
+// 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/>.
+//
+
+#include <uhd/log.hpp>
+#include <uhd/utils/static.hpp>
+#include <boost/filesystem.hpp>
+#include <boost/format.hpp>
+#include <boost/thread/mutex.hpp>
+#include <boost/date_time/posix_time/posix_time.hpp>
+#ifdef BOOST_MSVC
+#define USE_GET_TEMP_PATH
+#include <Windows.h> //GetTempPath
+#endif
+#include <stdio.h> //P_tmpdir
+#include <cstdlib> //getenv
+#include <fstream>
+
+namespace fs = boost::filesystem;
+namespace pt = boost::posix_time;
+
+/***********************************************************************
+ * Helper function to get the system's temporary path
+ **********************************************************************/
+static fs::path get_temp_path(void){
+    const char *tmp_path = NULL;
+
+    //try the official uhd temp path environment variable
+    tmp_path = std::getenv("UHD_TEMP_PATH");
+    if (tmp_path != NULL) return tmp_path;
+
+    //try the windows function if available
+    #ifdef USE_GET_TEMP_PATH
+    LPTSTR lpBuffer[2048];
+    if (GetTempPath(sizeof(lpBuffer)/sizeof(*lpBuffer), lpBuffer)) return lpBuffer;
+    #endif
+
+    //try windows environment variables
+    tmp_path = std::getenv("TMP");
+    if (tmp_path != NULL) return tmp_path;
+
+    tmp_path = std::getenv("TEMP");
+    if (tmp_path != NULL) return tmp_path;
+
+    //try the stdio define if available
+    #ifdef P_tmpdir
+        return P_tmpdir;
+    #endif
+
+    //try unix environment variables
+    tmp_path = std::getenv("TMPDIR");
+    if (tmp_path != NULL) return tmp_path;
+
+    //give up and use the unix default
+    return "/tmp";
+}
+
+/***********************************************************************
+ * The library's streamer resource (static initialization)
+ **********************************************************************/
+class uhd_logger_stream_resource_class{
+public:
+    uhd_logger_stream_resource_class(void){
+        const std::string log_path = (get_temp_path() / "uhd.log").string();
+        _streamer.open(log_path.c_str(), std::fstream::out | std::fstream::app);
+    }
+
+    ~uhd_logger_stream_resource_class(void){
+        _streamer.close();
+    }
+
+    std::ostream &get(void){
+        return _streamer;
+    }
+
+    void aquire(bool lock){
+        if (lock) _mutex.lock();
+        else _mutex.unlock();
+    }
+
+private:
+    std::ofstream _streamer;
+    boost::mutex _mutex;
+};
+
+UHD_SINGLETON_FCN(uhd_logger_stream_resource_class, uhd_logger_stream_resource);
+
+/***********************************************************************
+ * The logger function implementation
+ **********************************************************************/
+uhd::_log::log::log(
+    const verbosity_t verbosity,
+    const std::string &file,
+    const unsigned int line,
+    const std::string &function
+){
+    uhd_logger_stream_resource().aquire(true);
+    const std::string time = pt::to_simple_string(pt::microsec_clock::local_time());
+    const std::string header = str(boost::format(
+        "-- %s - lvl %d - %s @ %s:%u"
+    ) % time % int(verbosity) % function % fs::path(file).leaf() % line);
+    uhd_logger_stream_resource().get()
+        << std::endl
+        << std::string(header.size(), '-') << std::endl
+        << header << std::endl
+        << std::string(header.size(), '-') << std::endl
+    ;
+}
+
+uhd::_log::log::~log(void){
+    uhd_logger_stream_resource().aquire(false);
+}
+
+std::ostream & uhd::_log::log::get(void){
+    return uhd_logger_stream_resource().get();
+}
+
+UHD_STATIC_BLOCK(logger_begin){
+    UHD_LOG << "Logger has started" << std::endl;
+}