boost/property_tree/ini_parser.hpp
// ----------------------------------------------------------------------------
// Copyright (C) 2002-2006 Marcin Kalicinski
// Copyright (C) 2009 Sebastian Redl
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// For more information, see www.boost.org
// ----------------------------------------------------------------------------
#ifndef BOOST_PROPERTY_TREE_INI_PARSER_HPP_INCLUDED
#define BOOST_PROPERTY_TREE_INI_PARSER_HPP_INCLUDED
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/detail/ptree_utils.hpp>
#include <boost/property_tree/detail/file_parser_error.hpp>
#include <fstream>
#include <string>
#include <sstream>
#include <stdexcept>
#include <locale>
namespace boost { namespace property_tree { namespace ini_parser
{
/**
* Determines whether the @c flags are valid for use with the ini_parser.
* @param flags value to check for validity as flags to ini_parser.
* @return true if the flags are valid, false otherwise.
*/
inline bool validate_flags(int flags)
{
return flags == 0;
}
/** Indicates an error parsing INI formatted data. */
class ini_parser_error: public file_parser_error
{
public:
/**
* Construct an @c ini_parser_error
* @param message Message describing the parser error.
* @param filename The name of the file being parsed containing the
* error.
* @param line The line in the given file where an error was
* encountered.
*/
ini_parser_error(const std::string &message,
const std::string &filename,
unsigned long line)
: file_parser_error(message, filename, line)
{
}
};
/**
* Read INI from a the given stream and translate it to a property tree.
* @note Clears existing contents of property tree. In case of error
* the property tree is not modified.
* @throw ini_parser_error If a format violation is found.
* @param stream Stream from which to read in the property tree.
* @param[out] pt The property tree to populate.
*/
template<class Ptree>
void read_ini(std::basic_istream<
typename Ptree::key_type::value_type> &stream,
Ptree &pt)
{
typedef typename Ptree::key_type::value_type Ch;
typedef std::basic_string<Ch> Str;
const Ch semicolon = stream.widen(';');
const Ch hash = stream.widen('#');
const Ch lbracket = stream.widen('[');
const Ch rbracket = stream.widen(']');
Ptree local;
unsigned long line_no = 0;
Ptree *section = 0;
Str line;
// For all lines
while (stream.good())
{
// Get line from stream
++line_no;
std::getline(stream, line);
if (!stream.good() && !stream.eof())
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"read error", "", line_no));
// If line is non-empty
line = property_tree::detail::trim(line, stream.getloc());
if (!line.empty())
{
// Comment, section or key?
if (line[0] == semicolon || line[0] == hash)
{
// Ignore comments
}
else if (line[0] == lbracket)
{
// If the previous section was empty, drop it again.
if (section && section->empty())
local.pop_back();
typename Str::size_type end = line.find(rbracket);
if (end == Str::npos)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"unmatched '['", "", line_no));
Str key = property_tree::detail::trim(
line.substr(1, end - 1), stream.getloc());
if (local.find(key) != local.not_found())
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"duplicate section name", "", line_no));
section = &local.push_back(
std::make_pair(key, Ptree()))->second;
}
else
{
Ptree &container = section ? *section : local;
typename Str::size_type eqpos = line.find(Ch('='));
if (eqpos == Str::npos)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"'=' character not found in line", "", line_no));
if (eqpos == 0)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"key expected", "", line_no));
Str key = property_tree::detail::trim(
line.substr(0, eqpos), stream.getloc());
Str data = property_tree::detail::trim(
line.substr(eqpos + 1, Str::npos), stream.getloc());
if (container.find(key) != container.not_found())
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"duplicate key name", "", line_no));
container.push_back(std::make_pair(key, Ptree(data)));
}
}
}
// If the last section was empty, drop it again.
if (section && section->empty())
local.pop_back();
// Swap local ptree with result ptree
pt.swap(local);
}
/**
* Read INI from a the given file and translate it to a property tree.
* @note Clears existing contents of property tree. In case of error the
* property tree unmodified.
* @throw ini_parser_error In case of error deserializing the property tree.
* @param filename Name of file from which to read in the property tree.
* @param[out] pt The property tree to populate.
* @param loc The locale to use when reading in the file contents.
*/
template<class Ptree>
void read_ini(const std::string &filename,
Ptree &pt,
const std::locale &loc = std::locale())
{
std::basic_ifstream<typename Ptree::key_type::value_type>
stream(filename.c_str());
if (!stream)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"cannot open file", filename, 0));
stream.imbue(loc);
try {
read_ini(stream, pt);
}
catch (ini_parser_error &e) {
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
e.message(), filename, e.line()));
}
}
namespace detail
{
template<class Ptree>
void check_dupes(const Ptree &pt)
{
if(pt.size() <= 1)
return;
const typename Ptree::key_type *lastkey = 0;
typename Ptree::const_assoc_iterator it = pt.ordered_begin(),
end = pt.not_found();
lastkey = &it->first;
for(++it; it != end; ++it) {
if(*lastkey == it->first)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"duplicate key", "", 0));
lastkey = &it->first;
}
}
template <typename Ptree>
void write_keys(std::basic_ostream<
typename Ptree::key_type::value_type
> &stream,
const Ptree& pt,
bool throw_on_children)
{
typedef typename Ptree::key_type::value_type Ch;
for (typename Ptree::const_iterator it = pt.begin(), end = pt.end();
it != end; ++it)
{
if (!it->second.empty()) {
if (throw_on_children) {
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"ptree is too deep", "", 0));
}
continue;
}
stream << it->first << Ch('=')
<< it->second.template get_value<
std::basic_string<Ch> >()
<< Ch('\n');
}
}
template <typename Ptree>
void write_top_level_keys(std::basic_ostream<
typename Ptree::key_type::value_type
> &stream,
const Ptree& pt)
{
write_keys(stream, pt, false);
}
template <typename Ptree>
void write_sections(std::basic_ostream<
typename Ptree::key_type::value_type
> &stream,
const Ptree& pt)
{
typedef typename Ptree::key_type::value_type Ch;
for (typename Ptree::const_iterator it = pt.begin(), end = pt.end();
it != end; ++it)
{
if (!it->second.empty()) {
check_dupes(it->second);
if (!it->second.data().empty())
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"mixed data and children", "", 0));
stream << Ch('[') << it->first << Ch(']') << Ch('\n');
write_keys(stream, it->second, true);
}
}
}
}
/**
* Translates the property tree to INI and writes it the given output
* stream.
* @pre @e pt cannot have data in its root.
* @pre @e pt cannot have keys both data and children.
* @pre @e pt cannot be deeper than two levels.
* @pre There cannot be duplicate keys on any given level of @e pt.
* @throw ini_parser_error In case of error translating the property tree to
* INI or writing to the output stream.
* @param stream The stream to which to write the INI representation of the
* property tree.
* @param pt The property tree to tranlsate to INI and output.
* @param flags The flags to use when writing the INI file.
* No flags are currently supported.
*/
template<class Ptree>
void write_ini(std::basic_ostream<
typename Ptree::key_type::value_type
> &stream,
const Ptree &pt,
int flags = 0)
{
BOOST_ASSERT(validate_flags(flags));
(void)flags;
if (!pt.data().empty())
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"ptree has data on root", "", 0));
detail::check_dupes(pt);
detail::write_top_level_keys(stream, pt);
detail::write_sections(stream, pt);
}
/**
* Translates the property tree to INI and writes it the given file.
* @pre @e pt cannot have data in its root.
* @pre @e pt cannot have keys both data and children.
* @pre @e pt cannot be deeper than two levels.
* @pre There cannot be duplicate keys on any given level of @e pt.
* @throw info_parser_error In case of error translating the property tree
* to INI or writing to the file.
* @param filename The name of the file to which to write the INI
* representation of the property tree.
* @param pt The property tree to tranlsate to INI and output.
* @param flags The flags to use when writing the INI file.
* The following flags are supported:
* @li @c skip_ini_validity_check -- Skip check if ptree is a valid ini. The
* validity check covers the preconditions but takes <tt>O(n log n)</tt>
* time.
* @param loc The locale to use when writing the file.
*/
template<class Ptree>
void write_ini(const std::string &filename,
const Ptree &pt,
int flags = 0,
const std::locale &loc = std::locale())
{
std::basic_ofstream<typename Ptree::key_type::value_type>
stream(filename.c_str());
if (!stream)
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
"cannot open file", filename, 0));
stream.imbue(loc);
try {
write_ini(stream, pt, flags);
}
catch (ini_parser_error &e) {
BOOST_PROPERTY_TREE_THROW(ini_parser_error(
e.message(), filename, e.line()));
}
}
} } }
namespace boost { namespace property_tree
{
using ini_parser::ini_parser_error;
using ini_parser::read_ini;
using ini_parser::write_ini;
} }
#endif