/*
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 *  SCR_Page.c
 *  Managment of pages for high level saving functions.
 *
 *  Scripts, Beaudet Christophe
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 */
 
/*
 *=================================================================================================
 *  Includes.
 *=================================================================================================
 */
 
#include <memory.h>
#include "SCR.h"
 
/*
 *=================================================================================================
 *  Functions.
 *=================================================================================================
 */
 
/*
 *-------------------------------------------------------------------------------------------------
 *  To allocate and initialize a new page.
 *  Returns allocated structure.
 *-------------------------------------------------------------------------------------------------
 */
SCR_tdst_Page_Description *fnp_st_Page_Allocate(void)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_tdst_Page_Description   *p_stPage;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
	fn_v_Mem_SetMode(0);
 
    /*
     *  Allocate the page.
     */
    SCR_M_Mem_Alloc(SCR_tdst_Page_Description, p_stPage, 1);
 
    /*
     *  Initialize the page.
     */
    SCR_M_Dbg_UpdateSizeOf_P(SCR_tdst_Page_Description, p_stPage);
    p_stPage->iNumOfChars = 0;
    p_stPage->p_stNext = p_stPage->p_stPrev = NULL;
    SCR_M_Mem_Alloc(char, p_stPage->d_cBuffer, SCR_CV_ui_Cfg_SizePageBuf);
 
    return p_stPage;
}
 
/*
 *-------------------------------------------------------------------------------------------------
 *  To delete an existing page.
 *  Returns allocated structure.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_Free(SCR_tdst_Page_Description *_p_stPage)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_AssertStruct_P(SCR_tdst_Page_Description, _p_stPage);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
	fn_v_Mem_SetMode(0);
    SCR_M_Mem_Free(_p_stPage->d_cBuffer);
    SCR_M_Mem_Free(_p_stPage);
}
 
/*
 *-------------------------------------------------------------------------------------------------
 *  To delete all pages of a file.
 *  _p_stFile   :   File concerned.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_DeleteAll(SCR_tdst_File_Description *_p_stFile)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_tdst_Page_Description   *p_stPage, *p_stNext;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    p_stPage = _p_stFile->d_stFirstPage;
    while(p_stPage)
    {
        p_stNext = p_stPage->p_stNext;
        fn_v_Page_Free(p_stPage);
        p_stPage = p_stNext;
    }
}
 
/*===============================================================================================*/
 
/*
 *-------------------------------------------------------------------------------------------------
 *  Link a page after another one.
 *  _p_stFile   :   File concerned.
 *  _p_stPage   :   Page to link.
 *  _p_stRef    :   Reference page.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_LinkAfter
(
    SCR_tdst_File_Description   *_p_stFile, 
    SCR_tdst_Page_Description   *_p_stPage, 
    SCR_tdst_Page_Description   *_p_stRef
)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
    SCR_M_Dbg_AssertStruct_P(SCR_tdst_Page_Description, _p_stPage);
    SCR_M_Dbg_AssertStruct_P(SCR_tdst_Page_Description, _p_stRef);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    _p_stPage->p_stNext = _p_stRef->p_stNext;
    _p_stPage->p_stPrev = _p_stRef;
    if(_p_stRef->p_stNext)
        _p_stRef->p_stNext->p_stPrev = _p_stPage;
    else
        _p_stFile->d_stLastPage = _p_stPage;
    _p_stRef->p_stNext = _p_stPage;
}
 
/*
 *-------------------------------------------------------------------------------------------------
 *  To unlink a page from a list of page.
 *  _p_stFile   :   File concerned.
 *  _p_stPage   :   Page to unlink.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_Unlink
(
    SCR_tdst_File_Description   *_p_stFile, 
    SCR_tdst_Page_Description   *_p_stPage
)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
    SCR_M_Dbg_AssertStruct_P(SCR_tdst_Page_Description, _p_stPage);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    if(_p_stFile->d_stFirstPage == _p_stPage)
    {
        _p_stFile->d_stFirstPage = _p_stPage->p_stNext;
        if(_p_stFile->d_stFirstPage == NULL)
            _p_stFile->d_stFirstPage = _p_stPage->p_stPrev;
    }
    if(_p_stFile->d_stLastPage == _p_stPage)
    {
        _p_stFile->d_stLastPage = _p_stPage->p_stNext;
        if(_p_stFile->d_stLastPage == NULL)
            _p_stFile->d_stLastPage = _p_stPage->p_stPrev;
    }
    if(_p_stPage->p_stNext)
        _p_stPage->p_stNext->p_stPrev = _p_stPage->p_stPrev;
    if(_p_stPage->p_stPrev)
        _p_stPage->p_stPrev->p_stNext = _p_stPage->p_stNext;
}
 
/*
 *-------------------------------------------------------------------------------------------------
 *  Split a full page in 2 parts.
 *  _p_stFile   :   File concerned.
 *  _p_stPage   :   Page to split.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_Split
(
    SCR_tdst_File_Description   *_p_stFile, 
    SCR_tdst_Page_Description   *_p_stPage
)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_tdst_Page_Description   *p_stNewPage;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
    SCR_M_Dbg_AssertStruct_P(SCR_tdst_Page_Description, _p_stPage);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    /*
     *  Allocate new page.
     */
    p_stNewPage = fnp_st_Page_Allocate();
 
    /*
     *  Copy second part of actual page to new one.
     */
    memcpy
    (
        p_stNewPage->d_cBuffer,
        &_p_stPage->d_cBuffer[SCR_CV_ui_Cfg_SizePageBuf2],
        SCR_CV_ui_Cfg_SizePageBuf2
    );
    p_stNewPage->iNumOfChars = SCR_CV_ui_Cfg_SizePageBuf2;
    _p_stPage->iNumOfChars -= SCR_CV_ui_Cfg_SizePageBuf2;
 
    /*
     *  Update current position.
     */
    if(_p_stFile->iCurPosInPage >= SCR_CV_ui_Cfg_SizePageBuf2)
    {
        _p_stFile->d_stCurPage = p_stNewPage;
        _p_stFile->iCurPosInPage -= SCR_CV_ui_Cfg_SizePageBuf2;
    }
 
    /*
     *  Link new page after slitted one.
     */
    fn_v_Page_LinkAfter(_p_stFile, p_stNewPage, _p_stPage);
}
 
/*===============================================================================================*/
 
/*
 *-------------------------------------------------------------------------------------------------
 *  Insert a character at current position.
 *  _p_stFile   :   File concerned.
 *  _cChar      :   Character to insert.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_InsertChar(SCR_tdst_File_Description *_p_stFile, char _cChar)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_tdst_Page_Description   *p_stPage;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    p_stPage = _p_stFile->d_stCurPage;
 
    /*
     *  Current page is full.
     */
    if(p_stPage->iNumOfChars == SCR_CV_ui_Cfg_SizePageBuf)
    {
        fn_v_Page_Split(_p_stFile, p_stPage);
        p_stPage = _p_stFile->d_stCurPage;
    }
 
    /*
     *  Shift buffer of page.
     */
    memmove
    (
        &p_stPage->d_cBuffer[_p_stFile->iCurPosInPage + 1],
        &p_stPage->d_cBuffer[_p_stFile->iCurPosInPage],
        p_stPage->iNumOfChars - _p_stFile->iCurPosInPage
    );
 
    /*
     *  Set character.
     */
    p_stPage->d_cBuffer[_p_stFile->iCurPosInPage] = _cChar;
    p_stPage->iNumOfChars++;
 
    /*
     *  Increment current position.
     */
    fn_v_Page_ToNextChar(_p_stFile);
}
 
/*
 *-------------------------------------------------------------------------------------------------
 *  Delete character at current position.
 *  _p_stFile   :   File concerned.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_DeleteChar(SCR_tdst_File_Description *_p_stFile)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_tdst_Page_Description   *p_stPage;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
    SCR_M_Dbg_Assert_P(_p_stFile->d_stCurPage != NULL);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    /* EOF ? */
    p_stPage = _p_stFile->d_stCurPage;
    if(p_stPage->d_cBuffer[_p_stFile->iCurPosInPage] == 0)
        return;
 
    /* 
     *  We vill delete page ?.
     */
    if(p_stPage->iNumOfChars == 1)
    {
        SCR_M_Dbg_Assert_P(p_stPage->p_stNext);
        _p_stFile->d_stCurPage = p_stPage->p_stNext;
        _p_stFile->iCurPosInPage = 0;
 
        fn_v_Page_Unlink(_p_stFile, p_stPage);
        fn_v_Page_Free(p_stPage);
    }
    else
    {
        /*
         *  We delete the last character of page.
         *  We compute the next current position.
         */
        if(_p_stFile->iCurPosInPage == (p_stPage->iNumOfChars - 1))
        {
            SCR_M_Dbg_Assert_P(p_stPage->p_stNext != NULL);
            _p_stFile->d_stCurPage = p_stPage->p_stNext;
            _p_stFile->iCurPosInPage = 0;
            p_stPage->iNumOfChars--;
        }
        /*
         *  Else we shift the buffer normally.
         */
        else
        {
            memmove
            (
                &p_stPage->d_cBuffer[_p_stFile->iCurPosInPage],
                &p_stPage->d_cBuffer[_p_stFile->iCurPosInPage + 1],
                p_stPage->iNumOfChars - _p_stFile->iCurPosInPage - 1
            );
            p_stPage->iNumOfChars--;
        }
    }
}
 
/*===============================================================================================*/
 
/*
 *-------------------------------------------------------------------------------------------------
 *  Go to next position.
 *  _p_stFile   :   File concerned.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_ToNextChar(SCR_tdst_File_Description *_p_stFile)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
    SCR_M_Dbg_Assert_P(_p_stFile->d_stFirstPage != NULL);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    if(_p_stFile->iCurPosInPage + 1 == _p_stFile->d_stCurPage->iNumOfChars)
    {
        if(_p_stFile->d_stCurPage->p_stNext)
        {
            _p_stFile->iCurPosInPage = 0;
            _p_stFile->d_stCurPage = _p_stFile->d_stCurPage->p_stNext;
        }
    }
    else
        _p_stFile->iCurPosInPage++;
}
 
/*
 *-------------------------------------------------------------------------------------------------
 *  Go to previous position.
 *  _p_stFile   :   File concerned.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_ToPrevChar(SCR_tdst_File_Description *_p_stFile)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
    SCR_M_Dbg_Assert_P(_p_stFile->d_stFirstPage != NULL);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    if(_p_stFile->iCurPosInPage == 0)
    {
        if(_p_stFile->d_stCurPage->p_stPrev)
        {
            _p_stFile->d_stCurPage = _p_stFile->d_stCurPage->p_stPrev;
            _p_stFile->iCurPosInPage = _p_stFile->d_stCurPage->iNumOfChars - 1;
        }
    }
    else
        _p_stFile->iCurPosInPage--;
 }
 
/*===============================================================================================*/
 
/*
 *-------------------------------------------------------------------------------------------------
 *  Load a complete file in memory.
 *  _p_stFile   :   File concerned.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_LoadFile(SCR_tdst_File_Description *_p_stFile)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    size_t                      xRead;
    SCR_tdst_Page_Description   *p_stPage;
	int							iRes;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    /*
     *  Create first page.
     */
    _p_stFile->d_stFirstPage = fnp_st_Page_Allocate();
    _p_stFile->d_stLastPage = _p_stFile->d_stCurPage = _p_stFile->d_stFirstPage;
    _p_stFile->iCurPosInPage = 0;
    SCR_M_fseek(_p_stFile, 0, SEEK_SET, iRes);
	if(iRes)
	{
		SCR_M_Err_UpdateSyntaxError();
		sprintf
		(
			g_st_Err_GlobalError.a_szBufferTmp2,
			"File is \"%s\".",
			_p_stFile->a_szFileName
		);
		SCR_M_Err_RaiseError(SCR_EI_Err_ReadFile);
	}
 
    /*
     *  Read file.
     */
    while(!SCR_M_feof(_p_stFile))
    {
        /* Read one page from file */
        xRead = SCR_M_fread
        (
            _p_stFile->d_stLastPage->d_cBuffer, 
            sizeof(char), 
            SCR_CV_ui_Cfg_SizePageBuf2, 
            _p_stFile
        ); 
        _p_stFile->d_stLastPage->iNumOfChars = xRead;
 
        /* Allocate a new page if this one is full */
        if((xRead == SCR_CV_ui_Cfg_SizePageBuf2) && (!SCR_M_feof(_p_stFile)))
        {
            p_stPage = fnp_st_Page_Allocate();
            fn_v_Page_LinkAfter(_p_stFile, p_stPage, _p_stFile->d_stLastPage);
        }
    }
 
    /*
     *  Add an '\n' and an EOF character at the end of the file.
     */
	if(_p_stFile->d_stLastPage->d_cBuffer[_p_stFile->d_stLastPage->iNumOfChars - 1] != '\n')
	{
		_p_stFile->d_stLastPage->d_cBuffer[_p_stFile->d_stLastPage->iNumOfChars ] = '\n';
		_p_stFile->d_stLastPage->iNumOfChars++;
	}
    _p_stFile->d_stLastPage->d_cBuffer[_p_stFile->d_stLastPage->iNumOfChars] = '\0';
    _p_stFile->d_stLastPage->iNumOfChars++;
}
 
/*
 *-------------------------------------------------------------------------------------------------
 *  Save a complete memory file.
 *  _p_stFile   :   File concerned.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_SaveFile(SCR_tdst_File_Description *_p_stFile)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_tdst_Page_Description   *p_stPage;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
    SCR_M_Dbg_Assert_P(_p_stFile->d_stFirstPage != NULL);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    p_stPage = _p_stFile->d_stFirstPage;
    while(p_stPage)
    {
        if(p_stPage == _p_stFile->d_stLastPage) /* Cause of EOF */
            p_stPage->iNumOfChars--;
        SCR_M_fwrite(p_stPage->d_cBuffer, sizeof(char), p_stPage->iNumOfChars, _p_stFile);
        p_stPage = p_stPage->p_stNext;
    }
}
 
/*===============================================================================================*/
 
/*
 *-------------------------------------------------------------------------------------------------
 *  To seek to a specific position.
 *  _p_stFile   :   File concerned.
 *  lOffset     :   Offset to seek.
 *  iOrigin     :   Origin to seek from.
 *-------------------------------------------------------------------------------------------------
 */
void fn_v_Page_Seek(SCR_tdst_File_Description *_p_stFile, long lOffset, int iOrigin)
{
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    long                        lCount;
    SCR_tdst_Page_Description   *p_stPage;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
    SCR_M_Dbg_Assert_P(_p_stFile != NULL);
    SCR_M_Dbg_Assert_P(_p_stFile->d_stFirstPage != NULL);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
 
    /*
     *  Place current position from the end of file.
     */
    if(iOrigin == SEEK_END)
    {
        p_stPage = _p_stFile->d_stLastPage;
        lCount = p_stPage->iNumOfChars;
        while(lCount <= lOffset)
        {
            p_stPage = p_stPage->p_stPrev;
            lCount += p_stPage->iNumOfChars;
        }
        _p_stFile->d_stCurPage = p_stPage;
        _p_stFile->iCurPosInPage = lCount - lOffset - 1;
    }
    /*
     *  Place current position from the beginning of file.
     */
    else
    {
        SCR_M_Dbg_Assert_P(iOrigin == SEEK_SET);
        p_stPage = _p_stFile->d_stFirstPage;
        lCount = p_stPage->iNumOfChars;
        while((lCount <= lOffset) && (p_stPage->p_stNext))
        {
            p_stPage = p_stPage->p_stNext;
			lCount += p_stPage->iNumOfChars;
        }
        _p_stFile->d_stCurPage = p_stPage;
        _p_stFile->iCurPosInPage = p_stPage->iNumOfChars - (lCount - lOffset);
		if((p_stPage->p_stNext == NULL) && (lCount <= lOffset))
			_p_stFile->iCurPosInPage = p_stPage->iNumOfChars - 1;
    }
}