libcruft-util/log/level.cpp

170 lines
4.3 KiB
C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2012-2016 Danny Robson <danny@nerdcruft.net>
*/
#include "level.hpp"
#include "../debug/assert.hpp"
#include <iostream>
#include <cstring>
///////////////////////////////////////////////////////////////////////////////
/// convert a string representation of a log-level into an enumeration value.
///
/// conversion is case insensitive
/// throws std::range_error if unable to convert
cruft::log::level_t
cruft::log::to_level (std::string_view name)
{
if (std::empty (name))
return cruft::log::EMERGENCY;
std::string upper (name.size (), char{});
std::transform (
name.cbegin (),
name.cend (),
upper.begin (),
::toupper
);
static constexpr struct {
char const *name;
cruft::log::level_t value;
} VALUES[] = {
{ "EMERGENCY", cruft::log::EMERGENCY },
{ "ALERT", cruft::log::ALERT },
{ "CRITICAL", cruft::log::CRITICAL },
{ "ERROR", cruft::log::ERROR },
{ "WARN", cruft::log::WARN },
{ "WARNING", cruft::log::WARN },
{ "NOTICE", cruft::log::NOTICE },
{ "INFO", cruft::log::INFO },
{ "INFORMATIONAL", cruft::log::INFO },
{ "DEBUG", cruft::log::DEBUG }
};
for (auto const [key, val]: VALUES)
if (!strcmp (upper.data (), key))
return val;
throw std::invalid_argument (std::string (name));
}
///////////////////////////////////////////////////////////////////////////////
const std::string&
cruft::log::to_string (level_t l)
{
switch (l) {
#define CASE(L) \
case cruft::log::L: { \
static const std::string STR = #L; \
return STR; \
}
MAP_LEVEL_T(CASE)
#undef CASE
}
unreachable ();
}
//-----------------------------------------------------------------------------
std::ostream&
cruft::log::operator<< (std::ostream& os, level_t l)
{
return os << to_string (l);
}
///////////////////////////////////////////////////////////////////////////////
// Determine what the value for LOG_LEVEL should be at the beginning of
// execution given the system environment.
//
// Note that the LOG macros _cannot_ be used from within this function as it
// will likely result in infinite recursion.
static cruft::log::level_t
initial_log_level (void)
{
const char *env = getenv ("LOG_LEVEL");
if (!env)
return cruft::log::DEFAULT_LOG_LEVEL;
try {
return cruft::log::to_level (env);
} catch (...) {
std::clog << "Invalid environment LOG_LEVEL: '" << env << "'\n";
return cruft::log::DEFAULT_LOG_LEVEL;
}
}
//-----------------------------------------------------------------------------
// We shouldn't ever actually get to use the default value, but we set it to
// the most verbose option just in case we've made a mistake elsewhere.
static bool s_log_level_done;
static cruft::log::level_t s_log_level_value;
//-----------------------------------------------------------------------------
cruft::log::level_t
cruft::log::log_level (level_t _level)
{
s_log_level_value = _level;
s_log_level_done = true;
return s_log_level_value;
}
//-----------------------------------------------------------------------------
cruft::log::level_t
cruft::log::log_level (void)
{
if (!s_log_level_done) {
s_log_level_value = initial_log_level ();
s_log_level_done = true;
}
return s_log_level_value;
}
///////////////////////////////////////////////////////////////////////////////
std::size_t
cruft::log::level_width (void)
{
static constexpr
cruft::log::level_t
ALL_LEVELS[] = {
cruft::log::EMERGENCY,
cruft::log::ALERT,
cruft::log::CRITICAL,
cruft::log::ERROR,
cruft::log::WARN,
cruft::log::NOTICE,
cruft::log::INFO,
cruft::log::DEBUG,
};
static std::size_t width = [] {
size_t hi = 0;
for (auto i: ALL_LEVELS)
hi = cruft::max (to_string (i).size (), hi);
return hi;
} ();
return width;
}