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construct/ircd/conf.cc

709 lines
11 KiB
C++

// Matrix Construct
//
// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice is present in all copies. The
// full license for this software is available in the LICENSE file.
namespace ircd::conf
{
static string_view make_env_name(const mutable_buffer &, const string_view &) noexcept;
static string_view make_env_name(const mutable_buffer &, const item<void> &) noexcept;
static string_view make_env_name(const mutable_buffer &, const item<void> &, const string_view &);
static void prepend_from_env(item<void> &) noexcept;
static void append_from_env(item<void> &) noexcept;
static void set_from_env(item<void> &) noexcept;
static void set_from_closure(item<void> &) noexcept;
}
decltype(ircd::conf::items)
ircd::conf::items;
decltype(ircd::conf::on_init)
ircd::conf::on_init;
decltype(ircd::defaults)
ircd::defaults
{
{ "name", "ircd.defaults" },
{ "default", false },
{ "persist", false },
};
size_t
ircd::conf::reset()
{
size_t ret{0};
for(const auto &p : items)
ret += reset(p.first);
return ret;
}
bool
ircd::conf::reset(const string_view &key)
try
{
return reset(std::nothrow, key);
}
catch(const std::exception &e)
{
return false;
}
bool
ircd::conf::reset(std::nothrow_t,
const string_view &key)
try
{
auto &item(*items.at(key));
if(!item.set_cb)
return false;
item.set_cb();
return true;
}
catch(const std::out_of_range &e)
{
throw not_found
{
"Conf item '%s' is not available", key
};
}
catch(const std::exception &e)
{
log::error
{
"conf item[%s] set callback :%s",
key,
e.what()
};
throw;
}
void
ircd::conf::fault(const string_view &key)
try
{
auto &item(*items.at(key));
item.fault();
}
catch(const std::out_of_range &e)
{
throw not_found
{
"Conf item '%s' is not available", key
};
}
bool
ircd::conf::fault(std::nothrow_t,
const string_view &key)
noexcept try
{
auto &item(*items.at(key));
item.fault();
return true;
}
catch(const std::out_of_range &e)
{
return false;
}
bool
ircd::conf::set(std::nothrow_t,
const string_view &key,
const string_view &value)
try
{
return set(key, value);
}
catch(const std::exception &e)
{
log::error
{
"%s", e.what()
};
return false;
}
bool
ircd::conf::set(const string_view &key,
const string_view &value)
try
{
auto &item(*items.at(key));
return item.set(value);
}
catch(const bad_lex_cast &e)
{
throw bad_value
{
"Conf item '%s' rejected value '%s'", key, value
};
}
catch(const std::out_of_range &e)
{
throw not_found
{
"Conf item '%s' is not available", key
};
}
template<>
bool
ircd::conf::as(const string_view &key)
{
char buf[5]; // "true" or "false"
const auto val
{
get(buf, key)
};
return lex_cast<bool>(val);
}
template<>
bool
ircd::conf::as(const string_view &key,
bool def)
{
char buf[5]; // "true" or "false"
const auto val
{
get(std::nothrow, buf, key)
};
if(val && ircd::lex_castable<bool>(val))
def = lex_cast<bool>(val);
return def;
}
std::string
ircd::conf::get(const string_view &key)
try
{
const auto &item(*items.at(key));
return item.get();
}
catch(const std::out_of_range &e)
{
throw not_found
{
"Conf item '%s' is not available", key
};
}
ircd::string_view
ircd::conf::get(const mutable_buffer &out,
const string_view &key)
try
{
const auto &item(*items.at(key));
return item.get(out);
}
catch(const std::out_of_range &e)
{
throw not_found
{
"Conf item '%s' is not available", key
};
}
std::string
ircd::conf::get(std::nothrow_t,
const string_view &key)
{
const auto it(items.find(key));
if(it == end(items))
return {};
const auto &item(*it->second);
return item.get();
}
ircd::string_view
ircd::conf::get(std::nothrow_t,
const mutable_buffer &out,
const string_view &key)
{
const auto it(items.find(key));
if(it == end(items))
return {};
const auto &item(*it->second);
return item.get(out);
}
bool
ircd::conf::persists(const string_view &key)
try
{
const auto &item(*items.at(key));
return item.feature.get("persist", true);
}
catch(const std::out_of_range &e)
{
throw not_found
{
"Conf item '%s' is not available", key
};
}
bool
ircd::conf::environ(const string_view &key)
noexcept try
{
char buf[conf::NAME_MAX_LEN];
const auto env_key
{
make_env_name(buf, key)
};
const auto val
{
util::getenv(env_key)
};
return bool(val);
}
catch(const std::exception &e)
{
log::error
{
"%s", e.what()
};
return false;
}
bool
ircd::conf::exists(const string_view &key)
noexcept
{
return items.count(key);
}
//
// item
//
/// Conf item abstract constructor.
ircd::conf::item<void>::item(const json::members &opts,
conf::set_cb set_cb)
:feature_
{
opts
}
,feature
{
feature_
}
,name
{
unquote(feature.at("name"))
}
,set_cb
{
std::move(set_cb)
}
{
if(name.size() > NAME_MAX_LEN)
throw error
{
"Conf item '%s' name length:%zu exceeds max:%zu",
name,
name.size(),
NAME_MAX_LEN
};
if(!items.emplace(name, this).second)
throw error
{
"Conf item named '%s' already exists", name
};
}
ircd::conf::item<void>::~item()
noexcept
{
if(name)
{
const auto it{items.find(name)};
assert(data(it->first) == data(name));
items.erase(it);
}
}
void
ircd::conf::item<void>::fault()
noexcept try
{
const json::string &default_
{
feature.get("default")
};
log::warning
{
"conf item[%s] defaulting with featured value :%s",
name,
string_view{default_}
};
if(on_set(default_))
if(set_cb)
set_cb();
}
catch(const std::exception &e)
{
terminate
{
panic
{
"Conf item '%s' failed to set its default value (double-fault) :%s",
name,
e.what()
}
};
}
bool
ircd::conf::item<void>::set(const string_view &val)
{
std::string existing(get()); try
{
if(on_set(val))
if(set_cb)
set_cb();
}
catch(...)
{
try
{
if(on_set(existing))
if(set_cb)
set_cb();
}
catch(...)
{
fault();
}
throw;
}
return true;
}
std::string
ircd::conf::item<void>::get()
const
{
return ircd::string(size(), [this]
(const mutable_buffer &buf)
{
return get(buf);
});
}
ircd::string_view
ircd::conf::item<void>::get(const mutable_buffer &buf)
const
{
return on_get(buf);
}
bool
ircd::conf::item<void>::on_set(const string_view &)
{
return true;
}
ircd::string_view
ircd::conf::item<void>::on_get(const mutable_buffer &)
const
{
return {};
}
void
ircd::conf::item<void>::call_init()
{
// The conf item's default value specified by the constructor is its
// current value at this point; now we make callbacks to allow that value
// to be replaced with a better one (i.e reading a saved value from DB).
conf::set_from_closure(*this);
// Environment variables now get the final say; this allows any
// misconfiguration to be overridden by env vars. The variable name is
// the conf item name with any '.' replaced to '_', case is preserved.
// Prepend to item's current value from env.
conf::prepend_from_env(*this);
// Append to item's current value from env.
conf::append_from_env(*this);
// Overwrite item's value if env is set.
conf::set_from_env(*this);
}
void
ircd::conf::set_from_closure(item<void> &item)
noexcept try
{
on_init(item);
}
catch(const std::exception &e)
{
log::error
{
"conf item[%s] on_init callback :%s",
item.name,
e.what()
};
}
void
ircd::conf::prepend_from_env(item<void> &item)
noexcept try
{
thread_local char buf[conf::NAME_MAX_LEN];
const auto key
{
make_env_name(buf, item, "PREPEND")
};
const auto env
{
util::getenv(key)
};
if(empty(env))
return;
auto val
{
item.get()
};
val = std::string{env} + val;
item.set(val);
}
catch(const std::exception &e)
{
log::error
{
"conf item[%s] prepending from environment variable :%s",
item.name,
e.what()
};
}
void
ircd::conf::append_from_env(item<void> &item)
noexcept try
{
thread_local char buf[conf::NAME_MAX_LEN];
const auto key
{
make_env_name(buf, item, "APPEND")
};
const auto env
{
util::getenv(key)
};
if(empty(env))
return;
auto val
{
item.get()
};
val += env;
item.set(val);
}
catch(const std::exception &e)
{
log::error
{
"conf item[%s] appending from environment variable :%s",
item.name,
e.what()
};
}
void
ircd::conf::set_from_env(item<void> &item)
noexcept try
{
thread_local char buf[conf::NAME_MAX_LEN];
const auto key
{
make_env_name(buf, item)
};
const auto val
{
util::getenv(key)
};
if(empty(val) && !null(val))
return;
item.set(val);
}
catch(const std::exception &e)
{
log::error
{
"conf item[%s] setting from environment variable :%s",
item.name,
e.what()
};
}
ircd::string_view
ircd::conf::make_env_name(const mutable_buffer &buf,
const item<void> &item,
const string_view &feature)
{
char tmp[conf::NAME_MAX_LEN] {0};
const auto name
{
make_env_name(tmp, item)
};
return string_view
{
data(buf), unsigned(::snprintf
(
data(buf), size(buf), "%s__%s",
name.c_str(),
feature.c_str()
))
};
}
ircd::string_view
ircd::conf::make_env_name(const mutable_buffer &buf,
const item<void> &item)
noexcept
{
return make_env_name(buf, item.name);
}
ircd::string_view
ircd::conf::make_env_name(const mutable_buffer &buf,
const string_view &name)
noexcept
{
assert(size(name) <= conf::NAME_MAX_LEN);
return replace(buf, name, '.', '_');
}
//
// Non-inline template specialization definitions
//
//
// std::string
//
ircd::conf::item<std::string>::item(const json::members &members,
conf::set_cb set_cb)
:conf::item<>
{
members, std::move(set_cb)
}
,value
{
unquote(feature.get("default"))
}
{
call_init();
}
size_t
ircd::conf::item<std::string>::size()
const
{
return _value.size();
}
bool
ircd::conf::item<std::string>::on_set(const string_view &s)
{
_value = std::string{s};
return true;
}
ircd::string_view
ircd::conf::item<std::string>::on_get(const mutable_buffer &out)
const
{
return { data(out), _value.copy(data(out), buffer::size(out)) };
}
//
// bool
//
ircd::conf::item<bool>::item(const json::members &members,
conf::set_cb set_cb)
:conf::item<>
{
members, std::move(set_cb)
}
,value
{
feature.get<bool>("default", false)
}
{
call_init();
}
size_t
ircd::conf::item<bool>::size()
const
{
return _value?
ircd::size("true"_sv):
ircd::size("false"_sv);
}
bool
ircd::conf::item<bool>::on_set(const string_view &s)
try
{
_value = lex_cast<bool>(s);
return true;
}
catch(const bad_lex_cast &e)
{
throw bad_value
{
"Conf item '%s' not assigned a bool literal :%s",
name,
e.what()
};
}
ircd::string_view
ircd::conf::item<bool>::on_get(const mutable_buffer &out)
const
{
return _value?
string_view { data(out), copy(out, "true"_sv) }:
string_view { data(out), copy(out, "false"_sv) };
}