datafile.cpp

Convert Interface on a embedded System

//
// CDataFile Class Implementation
//
// The purpose of this class is to provide a simple, full featured means to
// store persistent data to a text file.  It uses a simple key/value paradigm
// to achieve this.  The class can read/write to standard Windows .ini files,
// and yet does not rely on any windows specific calls.  It should work as
// well in a linux environment (with some minor adjustments) as it does in
// a Windows one.
//
// Written July, 2002 by Gary McNickle <gary#sunstorm.net>
// If you use this class in your application, credit would be appreciated.
//

//
// CDataFile
// The purpose of this class is to provide the means to easily store key/value
// pairs in a config file, seperated by independant sections. Sections may not
// have duplicate keys, although two or more sections can have the same key.
// Simple support for comments is included. Each key, and each section may have
// it's own multiline comment.
//
// An example might look like this;
//
// [UserSettings]
// Name=Joe User
// Date of Birth=12/25/01
//
// ;
// ; Settings unique to this server
// ;
// [ServerSettings]
// Port=1200
// IP_Address=127.0.0.1
// MachineName=ADMIN
//

#include <vector>
#include <string>
#include <ctype.h>
#include <stdio.h>
#include <stdarg.h>
//#include <fstream.h>
#include <float.h>

#ifdef WIN32
#include <windows.h>
#endif

#include "DataFile.h"

using namespace std;
#include <iosfwd>
#include <fstream>

// Compatibility Defines ////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////
#ifdef WIN32
  #define snprintf  _snprintf
  #define vsnprintf _vsnprintf
#endif


// CDataFile
// Our default contstructor.  If it can load the file, it will do so and populate
// the section list with the values from the file.
CDataFile::CDataFile(t_Str szFileName)
{
	m_bDirty = false;
	m_szFileName = szFileName;
	m_Flags = (AUTOCREATE_SECTIONS | AUTOCREATE_KEYS);
	m_Sections.push_back( *(new t_Section) );

	Load(m_szFileName);
}

CDataFile::CDataFile()
{
	Clear();
	m_Flags = (AUTOCREATE_SECTIONS | AUTOCREATE_KEYS);
	m_Sections.push_back( *(new t_Section) );
}

// ~CDataFile
// Saves the file if any values have changed since the last save.
CDataFile::~CDataFile()
{
	if ( m_bDirty )
		Save();
}

// Clear
// Resets the member variables to their defaults
void CDataFile::Clear()
{
	m_bDirty = false;
	m_szFileName = t_Str("");
	m_Sections.clear();
}

// SetFileName
// Set's the m_szFileName member variable. For use when creating the CDataFile
// object by hand (-vs- loading it from a file
void CDataFile::SetFileName(t_Str szFileName)
{
	if (m_szFileName.size() != 0 && CompareNoCase(szFileName, m_szFileName) != 0)
	{
		m_bDirty = true;

		Report(E_WARN, "[CDataFile::SetFileName] The filename has changed from <%s> to <%s>.",
			   m_szFileName.c_str(), szFileName.c_str());
	}

	m_szFileName = szFileName;
}

// Load
// Attempts to load in the text file. If successful it will populate the 
// Section list with the key/value pairs found in the file. Note that comments
// are saved so that they can be rewritten to the file later.
bool CDataFile::Load(t_Str szFileName)
{
	// We dont want to create a new file here.  If it doesn't exist, just
	// return false and report the failure.
	fstream File(szFileName.c_str(), ios::in/*|ios::nocreate*/);

	if ( File.is_open() )
	{
		bool bDone = false;
		bool bAutoKey = (m_Flags & AUTOCREATE_KEYS) == AUTOCREATE_KEYS;
		bool bAutoSec = (m_Flags & AUTOCREATE_SECTIONS) == AUTOCREATE_SECTIONS;
		
		t_Str szLine;
		t_Str szComment;
		char buffer[MAX_BUFFER_LEN]; 
		t_Section* pSection = GetSection("");

		// These need to be set, we'll restore the original values later.
		m_Flags |= AUTOCREATE_KEYS;
		m_Flags |= AUTOCREATE_SECTIONS;

		while ( !bDone )
		{
			memset(buffer, 0, MAX_BUFFER_LEN);
			File.getline(buffer, MAX_BUFFER_LEN);

			szLine = buffer;
			Trim(szLine);

			bDone = ( File.eof() || File.bad() || File.fail() );

			if ( szLine.find_first_of(CommentIndicators) == 0 )
			{
				szComment += "\n";
				szComment += szLine;
			}
			else
			if ( szLine.find_first_of('[') == 0 ) // new section
			{
				szLine.erase( 0, 1 );
				szLine.erase( szLine.find_last_of(']'), 1 );

				CreateSection(szLine, szComment);
				pSection = GetSection(szLine);
				szComment = t_Str("");
			}
			else 
			if ( szLine.size() > 0 ) // we have a key, add this key/value pair
			{
				t_Str szKey = GetNextWord(szLine);
				t_Str szValue = szLine;

				if ( szKey.size() > 0 && szValue.size() > 0 )
				{
					SetValue(szKey, szValue, szComment, pSection->szName);
					szComment = t_Str("");
				}
			}
		}

		// Restore the original flag values.
		if ( !bAutoKey )
			m_Flags &= ~AUTOCREATE_KEYS;

		if ( !bAutoSec )
			m_Flags &= ~AUTOCREATE_SECTIONS;
	}
	else
	{
		Report(E_INFO, "[CDataFile::Load] Unable to open file. Does it exist?");
		return false;
	}

	File.close();

	return true;
}


// Save
// Attempts to save the Section list and keys to the file. Note that if Load
// was never called (the CDataFile object was created manually), then you
// must set the m_szFileName variable before calling save.
bool CDataFile::Save()
{
	if ( KeyCount() == 0 && SectionCount() == 0 )
	{
		// no point in saving
		Report(E_INFO, "[CDataFile::Save] Nothing to save.");
		return false; 
	}

	if ( m_szFileName.size() == 0 )
	{
		Report(E_ERROR, "[CDataFile::Save] No filename has been set.");
		return false;
	}

	fstream File(m_szFileName.c_str(), ios::out|ios::trunc);

	if ( File.is_open() )
	{
		SectionItor s_pos;
		KeyItor k_pos;
		t_Section Section;
		t_Key Key;

		for (s_pos = m_Sections.begin(); s_pos != m_Sections.end(); s_pos++)
		{
			Section = (*s_pos);
			bool bWroteComment = false;

			if ( Section.szComment.size() > 0 )
			{
				bWroteComment = true;
				WriteLn(File, "\n%s", CommentStr(Section.szComment).c_str());
			}

			if ( Section.szName.size() > 0 )
			{
				WriteLn(File, "%s[%s]", 
						bWroteComment ? "" : "\n", 
						Section.szName.c_str());
			}

			for (k_pos = Section.Keys.begin(); k_pos != Section.Keys.end(); k_pos++)
			{
				Key = (*k_pos);

				if ( Key.szKey.size() > 0 && Key.szValue.size() > 0 )
				{
					WriteLn(File, "%s%s%s%s%c%s", 
						Key.szComment.size() > 0 ? "\n" : "",
						CommentStr(Key.szComment).c_str(),
						Key.szComment.size() > 0 ? "\n" : "",
						Key.szKey.c_str(),
						EqualIndicators[0],
						Key.szValue.c_str());
				}
			}
		}
		
	}
	else
	{
		Report(E_ERROR, "[CDataFile::Save] Unable to save file.");
		return false;
	}

	m_bDirty = false;
	
	File.flush();
	File.close();

	return true;
}

// SetKeyComment
// Set the comment of a given key. Returns true if the key is not found.
bool CDataFile::SetKeyComment(t_Str szKey, t_Str szComment, t_Str szSection)
{
	KeyItor k_pos;
	t_Section* pSection;

	if ( (pSection = GetSection(szSection)) == NULL )
		return false;

	for (k_pos = pSection->Keys.begin(); k_pos != pSection->Keys.end(); k_pos++)
	{
		if ( CompareNoCase( (*k_pos).szKey, szKey ) == 0 )
		{
			(*k_pos).szComment = szComment;
			m_bDirty = true;
			return true;
		}
	}

	return false;

}

// SetSectionComment
// Set the comment for a given section. Returns false if the section
// was not found.
bool CDataFile::SetSectionComment(t_Str szSection, t_Str szComment)
{
	SectionItor s_pos;

	for (s_pos = m_Sections.begin(); s_pos != m_Sections.end(); s_pos++)
	{
		if ( CompareNoCase( (*s_pos).szName, szSection ) == 0 ) 
		{
		    (*s_pos).szComment = szComment;
			m_bDirty = true;
			return true;
		}
	}

	return false;
}


// SetValue
// Given a key, a value and a section, this function will attempt to locate the
// Key within the given section, and if it finds it, change the keys value to
// the new value. If it does not locate the key, it will create a new key with
// the proper value and place it in the section requested.
bool CDataFile::SetValue(t_Str szKey, t_Str szValue, t_Str szComment, t_Str szSection)
{
	t_Key* pKey = GetKey(szKey, szSection);
	t_Section* pSection = GetSection(szSection);

	if (pSection == NULL)
	{
		if ( !(m_Flags & AUTOCREATE_SECTIONS) || !CreateSection(szSection,""))
			return false;

		pSection = GetSection(szSection);
	}

	// Sanity check...
	if ( pSection == NULL )
		return false;

	// if the key does not exist in that section, and the value passed 
	// is not t_Str("") then add the new key.
	if ( pKey == NULL && szValue.size() > 0 && (m_Flags & AUTOCREATE_KEYS))
	{
		pKey = new t_Key;

		pKey->szKey = szKey;
		pKey->szValue = szValue;
		pKey->szComment = szComment;
		
		m_bDirty = true;
		
		pSection->Keys.push_back(*pKey);

		return true;
	}

	if ( pKey != NULL )
	{
		pKey->szValue = szValue;
		pKey->szComment = szComment;

		m_bDirty = true;
		
		return true;
	}

	return false;
}

// SetFloat
// Passes the given float to SetValue as a string
bool CDataFile::SetFloat(t_Str szKey, float fValue, t_Str szComment, t_Str szSection)
{
	char szStr[64];

	_snprintf(szStr, 64, "%f", fValue);

	return SetValue(szKey, szStr, szComment, szSection);
}

// SetInt
// Passes the given int to SetValue as a string
bool CDataFile::SetInt(t_Str szKey, int nValue, t_Str szComment, t_Str szSection)
{
	char szStr[64];

	_snprintf(szStr, 64, "%d", nValue);

	return SetValue(szKey, szStr, szComment, szSection);

}

// SetBool
// Passes the given bool to SetValue as a string
bool CDataFile::SetBool(t_Str szKey, bool bValue, t_Str szComment, t_Str szSection)
{
	t_Str szValue = bValue ?  "True" : "False";

	return SetValue(szKey, szValue, szComment, szSection);
}

// GetValue
// Returns the key value as a t_Str object. A return value of
// t_Str("") indicates that the key could not be found.
t_Str CDataFile::GetValue(t_Str szKey, t_Str szSection) 
{
	t_Key* pKey = GetKey(szKey, szSection);