winix/confparser/confparser.cpp

/*
 * This file is a part of Winix
 * and is not publicly distributed
 * 
 * Copyright (c) 2008-2010, Tomasz Sowa
 * All rights reserved.
 * 
 */
 
#include "confparser.h"




ConfParser::ConfParser()
{
	// you can change this separators to what you want
	// you shoud not use only white characters here (as expected by IsWhite() method)
	// and new line characters ('\n')
	separator      = '=';
	commentary     = '#';
	list_start     = '(';
	list_end       = ')';
	list_delimiter = ',';
	split_single   = false;
	skip_empty     = false;
}


void ConfParser::SplitSingle(bool split)
{
	split_single = split;
}


void ConfParser::SkipEmpty(bool skip)
{
	skip_empty = skip;
}


ConfParser::Status ConfParser::Parse(const char * file_name)
{
	line = 1;
	table.clear();
	table_single.clear();

	file.clear();
	file.open( file_name );
	
	if( file )
	{
		status = ParseFile();
		file.close();
	}
	else
	{
		status = cant_open_file;
	}
	
return status;
}



ConfParser::Status ConfParser::Parse(const std::string & file_name)
{
	return Parse(file_name.c_str());
}



ConfParser::Status ConfParser::ParseFile()
{
	ReadChar();
	SkipWhiteLines();

	while( lastc != -1 )
	{
		if( !ReadVariable() )
			return syntax_error;

		if( lastc != separator )
			return syntax_error;
		
		if( !ReadValue() )
			return syntax_error;

		AddOption();
		SkipWhite();

		if( lastc != -1 && lastc != '\n' )
			return syntax_error; // some characters have left at the end of an option
		
		SkipWhiteLines();
	}
	
return ok;	
}



bool ConfParser::IsVariableChar(int c)
{
	if( (c>='a' && c<='z') ||
	    (c>='A' && c<='Z') ||
	    (c>='0' && c<='9') ||
	    c=='.' || c==',' || c=='_' )
		return true;
	
return false;
}



void ConfParser::AddOption()
{
	if( value.empty() && skip_empty )
	{
		DeleteFromTable(variable);
		DeleteFromTableSingle(variable);
		return;
	}

	if( split_single && value.size() == 1 )
	{
		table_single[variable] = value[0];
		DeleteFromTable(variable);
	}
	else
	{
		table[variable] = value;
		DeleteFromTableSingle(variable);
	}
}



void ConfParser::DeleteFromTable(const std::string & var)
{
	Table::iterator i = table.find(var);

	if( i != table.end() )
		table.erase(i);
}



void ConfParser::DeleteFromTableSingle(const std::string & var)
{
	TableSingle::iterator i = table_single.find(var);

	if( i != table_single.end() )
		table_single.erase(i);
}



bool ConfParser::ReadVariable()
{
	variable.clear();
	SkipWhite();
	
	while( IsVariableChar(lastc) )
	{
		variable += lastc;
		ReadChar();
	}

	SkipWhite();

return !variable.empty();
}



bool ConfParser::ReadValue()
{
	value.clear();
	ReadChar();     // skipping separator '='
	SkipWhite();

	if( lastc == list_start )
		return ReadValueList();
	else
		return ReadValueNoList();
}



bool ConfParser::ReadValueList()
{
	ReadChar();			// skipping first list character '('
	SkipWhiteLines();	// lists can be split into several lines

	while( lastc != -1 && lastc != list_end )
	{
		if( !ReadValueNoList(true) )
			return false;

		if( lastc == list_delimiter )
			ReadChar();

		SkipWhiteLines();
	}

	if( lastc != list_end )
		return false;

	ReadChar();		// skipping last list character ')'
	SkipWhite();

return true;
}



bool ConfParser::ReadValueNoList(bool use_list_delimiter)
{
bool res;

	value_item.clear();

	if( lastc == '"' )
	{
		res = ReadValueQuoted(); // quoted value

		if( res )
			value.push_back(value_item);
	}
	else
	{
		res = ReadValueSimple(use_list_delimiter);

		if( res && !value_item.empty() )
			value.push_back(value_item);
	}

return res;
}



bool ConfParser::ReadValueQuoted()
{
	ReadChar();		// skipping the first quote
	
	while( lastc != '"' && lastc != -1 )
	{
		if( lastc == '\\' )
			ReadChar();
		
		value_item += lastc;
		ReadChar();
	}
	
	if( lastc != '"' )
		return false;
		
	ReadChar();		// skipping the last quote
	SkipWhite();
	
return true;
}



bool ConfParser::ReadValueSimple(bool use_list_delimiter)
{
	int list_delimiter1 = -1;
	int list_delimiter2 = -1;

	if( use_list_delimiter )
	{
		list_delimiter1 = list_delimiter;
		list_delimiter2 = list_end;
	}

	while(	lastc!=-1 && lastc!='\n' && lastc!=commentary &&
			lastc!=list_delimiter1 && lastc!=list_delimiter2 )
	{
		value_item += lastc;
		ReadChar();
	}
	
	Trim(value_item);
	SkipWhite();
	
return true;	
}


int ConfParser::ReadChar()
{
	lastc = file.get();

	if( lastc == '\n' )
		++line;
	
return lastc;
}


bool ConfParser::IsWhite(int c)
{
	// dont use '\n' here
	// 13 (\r) is at the end of a line in a dos file \r\n
	// 160 is an unbreakable space
	if( c==' ' || c=='\t' || c==13 || c==160 )
		return true;
		
return false;	
}



void ConfParser::SkipWhite()
{
	while( IsWhite(lastc) || lastc == commentary )
	{
		if( lastc == commentary )
			SkipLine();
		else
			ReadChar();
	}
}


void ConfParser::SkipWhiteLines()
{
	while( IsWhite(lastc) || lastc == commentary || lastc=='\n' )
	{
		if( lastc == commentary )
			SkipLine();
		else
			ReadChar();
	}
}


void ConfParser::SkipLine()
{
	while( lastc != -1 && lastc != '\n' )
		ReadChar();	
}



void ConfParser::Trim(std::string & s)
{
std::string::size_type i;
	
	if( s.empty() )
		return;
	
	// looking for white characters at the end
	for(i=s.size()-1 ; i>0 && IsWhite(s[i]) ; --i);
	
	if( i==0 && IsWhite(s[i]) )
	{
		// the whole string has white characters
		s.clear();
		return;
	}
	
	// deleting white characters at the end
	if( i != s.size() - 1 )
		s.erase(i+1, std::string::npos);
	
	// looking for white characters at the beginning
	for(i=0 ; i<s.size() && IsWhite(s[i]) ; ++i);
	
	// deleting white characters at the beginning
	if( i != 0 )
		s.erase(0, i);
}