ThumbCache.cpp

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//
// ThumbCache.cpp
//
// Copyright (c) Shareaza Development Team, 2002-2005.
// This file is part of SHAREAZA (www.shareaza.com)
//
// Shareaza is free software; you can redistribute it
// and/or modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2 of
// the License, or (at your option) any later version.
//
// Shareaza is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Shareaza; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//

#include "StdAfx.h"
#include "Shareaza.h"
#include "Settings.h"
#include "ThumbCache.h"
#include "ImageFile.h"
#include "Library.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

#define THUMB_SIGNATURE "RAZATDB1"


// CThumbCache construction

CThumbCache::CThumbCache()
{
        m_bOpen         = FALSE;
        m_nOffset       = 0;
        m_pIndex        = NULL;
        m_nIndex        = 0;
        m_nBuffer       = 0;
}

CThumbCache::~CThumbCache()
{
        Close();
}

// CThumbCache prepare

BOOL CThumbCache::Prepare(LPCTSTR pszPath, CSize* pszThumb, BOOL bCreate)
{
        CString strPath( pszPath );

        int nSlash = strPath.ReverseFind( '\\' );
        if ( nSlash >= 0 ) strPath = strPath.Left( nSlash );
        strPath += _T("\\SThumbs.dat");

        if ( m_bOpen && strPath.CompareNoCase( m_sPath ) == 0 )
        {
                if ( m_szThumb != *pszThumb )
                {
                        Close();
                        DeleteFile( strPath );
                }

                return TRUE;
        }
        else if ( m_bOpen )
        {
                Close();
        }

        if ( m_pFile.Open( strPath, CFile::modeReadWrite ) )
        {
                CHAR szID[8];
                m_pFile.Read( szID, 8 );

                if ( memcmp( szID, THUMB_SIGNATURE, 8 ) != 0 )
                {
                        m_pFile.Close();
                        return DeleteFile( strPath ) && Prepare( pszPath, pszThumb, bCreate );
                }

                m_pFile.Read( &m_szThumb.cx, 4 );
                m_pFile.Read( &m_szThumb.cy, 4 );

                if ( pszThumb->cx == 0 && pszThumb->cy == 0 ) *pszThumb = m_szThumb;

                if ( m_szThumb == *pszThumb )
                {
                        m_pFile.Read( &m_nOffset, 4 );
                        m_pFile.Read( &m_nIndex, 4 );

                        for ( m_nBuffer = m_nIndex ; m_nBuffer & 63 ; m_nBuffer++ );
                        m_pIndex = new THUMB_INDEX[ m_nBuffer ];

                        m_pFile.Seek( m_nOffset, 0 );
                        m_pFile.Read( m_pIndex, sizeof(THUMB_INDEX) * m_nIndex );

                        m_sPath = strPath;
                        m_bOpen = TRUE;
                }
                else
                {
                        m_pFile.Close();
                        DeleteFile( strPath );
                }
        }

        if ( ! m_bOpen )
        {
                if ( ! bCreate ) return FALSE;

                if ( ! m_pFile.Open( strPath, CFile::modeReadWrite|CFile::modeCreate ) ) return FALSE;

                SetFileAttributes( strPath, FILE_ATTRIBUTE_HIDDEN|FILE_ATTRIBUTE_SYSTEM );

                if ( pszThumb->cx == 0 && pszThumb->cy == 0 ) *pszThumb = CSize( Settings.Library.ThumbSize, Settings.Library.ThumbSize );

                m_szThumb = *pszThumb;

                m_pFile.Write( THUMB_SIGNATURE, 8 );
                m_pFile.Write( &m_szThumb.cx, 4 );
                m_pFile.Write( &m_szThumb.cy, 4 );
                m_pFile.Write( &m_nOffset, 4 );
                m_pFile.Write( &m_nIndex, 4 );
                m_nOffset = 24;

                m_sPath = strPath;
                m_bOpen = TRUE;
        }

        return TRUE;
}

// CThumbCache close

void CThumbCache::Close()
{
        CSingleLock pLock( &m_pSection, TRUE );

        if ( m_bOpen == FALSE ) return;

        m_sPath.Empty();
        m_pFile.Close();
        m_bOpen = FALSE;

        if ( m_pIndex != NULL ) delete [] m_pIndex;

        m_pIndex        = NULL;
        m_nIndex        = 0;
        m_nBuffer       = 0;
}

// CThumbCache load

BOOL CThumbCache::Load(LPCTSTR pszPath, CSize* pszThumb, DWORD nIndex, CImageFile* pImage)
{
        CSingleLock pLock( &m_pSection, TRUE );

        if ( ! Prepare( pszPath, pszThumb, FALSE ) ) return FALSE;

        THUMB_INDEX* pIndex = m_pIndex;

    DWORD nCount = m_nIndex;
        for ( ; nCount ; nCount--, pIndex++ )
        {
                if ( pIndex->nIndex == nIndex ) break;
        }

        if ( nCount == 0 ) return FALSE;

        FILETIME pTime;
        GetFileTime( pszPath, &pTime );
        if ( CompareFileTime( &pIndex->pTime, &pTime ) != 0 ) return FALSE;

        m_pFile.Seek( pIndex->nOffset, 0 );

        try
        {
                CArchive ar( &m_pFile, CArchive::load );
                pImage->Serialize( ar );
        }
        catch ( CException* pException )
        {
                pException->Delete();
                return FALSE;
        }

        return TRUE;
}

// CThumbCache save

BOOL CThumbCache::Store(LPCTSTR pszPath, CSize* pszThumb, DWORD nIndex, CImageFile* pImage)
{
        CSingleLock pLock( &m_pSection, TRUE );

        if ( ! Prepare( pszPath, pszThumb, TRUE ) ) return FALSE;

        DWORD nBlock = pImage->GetSerialSize();

        THUMB_INDEX* pIndex = m_pIndex;

    DWORD nCount = m_nIndex;
        for ( ; nCount ; nCount--, pIndex++ )
        {
                if ( pIndex->nIndex == nIndex ) break;
        }

        if ( nCount != 0 && pIndex->nLength != nBlock )
        {
                pIndex->nIndex = 0;
                nCount = 0;
        }

        if ( nCount == 0 )
        {
                THUMB_INDEX* pBestIndex         = NULL;
                DWORD nBestOverhead                     = 0xFFFFFFFF;

                for ( pIndex = m_pIndex, nCount = m_nIndex ; nCount ; nCount--, pIndex++ )
                {
                        if ( pIndex->nLength >= nBlock &&
                                ( pIndex->nIndex == 0 || Library.LookupFile( pIndex->nIndex ) == NULL ) )
                        {
                                DWORD nOverhead = pIndex->nLength - nBlock;

                                if ( nOverhead < nBestOverhead )
                                {
                                        pBestIndex = pIndex;
                                        nBestOverhead = nOverhead;
                                        if ( nOverhead == 0 ) break;
                                }
                        }
                }

                if ( pBestIndex != NULL )
                {
                        pIndex = pBestIndex;
                }
                else
                {
                        if ( m_nIndex >= m_nBuffer )
                        {
                                m_nBuffer += 64;
                                THUMB_INDEX* pNew = new THUMB_INDEX[ m_nBuffer ];
                                if ( m_nIndex ) CopyMemory( pNew, m_pIndex, sizeof(THUMB_INDEX) * m_nIndex );
                                if ( m_pIndex ) delete [] m_pIndex;
                                m_pIndex = pNew;
                        }

                        pIndex = m_pIndex + m_nIndex++;
                        pIndex->nOffset = m_nOffset;
                        pIndex->nLength = nBlock;

                        m_nOffset += nBlock;
                }

                pIndex->nIndex = nIndex;
        }

        GetFileTime( pszPath, &pIndex->pTime );

        m_pFile.Seek( pIndex->nOffset, 0 );

        try
        {
                CArchive ar( &m_pFile, CArchive::store );
                pImage->Serialize( ar );
                ar.Flush();
        }
        catch ( CException* pException )
        {
                pException->Delete();
        }

        m_pFile.SetLength( m_nOffset + sizeof(THUMB_INDEX) * m_nIndex );
        m_pFile.Seek( 16, 0 );
        m_pFile.Write( &m_nOffset, 4 );
        m_pFile.Write( &m_nIndex, 4 );
        m_pFile.Seek( m_nOffset, 0 );
        m_pFile.Write( m_pIndex, sizeof(THUMB_INDEX) * m_nIndex );

        m_pFile.Flush();

        return TRUE;
}

// CThumbCache purge

BOOL CThumbCache::Purge(LPCTSTR pszPath)
{
        CString strPath( pszPath );

        int nSlash = strPath.ReverseFind( '\\' );
        if ( nSlash >= 0 ) strPath = strPath.Left( nSlash );
        strPath += _T("\\SThumbs.dat");

        if ( GetFileAttributes( strPath ) == 0xFFFFFFFF ) return FALSE;

        DeleteFile( strPath );

        return TRUE;
}

// CThumbCache file time lookup

BOOL CThumbCache::GetFileTime(LPCTSTR pszPath, FILETIME* pTime)
{
        BOOL bSuccess = FALSE;

        if ( Library.m_pfnGFAEW != NULL )
        {
                USES_CONVERSION;
                WIN32_FILE_ATTRIBUTE_DATA pInfo;
                bSuccess = (*Library.m_pfnGFAEW)( T2CW(pszPath), GetFileExInfoStandard, &pInfo );
                *pTime = pInfo.ftLastWriteTime;
        }
        else if ( Library.m_pfnGFAEA != NULL )
        {
                USES_CONVERSION;
                WIN32_FILE_ATTRIBUTE_DATA pInfo;
                bSuccess = (*Library.m_pfnGFAEA)( T2CA(pszPath), GetFileExInfoStandard, &pInfo );
                *pTime = pInfo.ftLastWriteTime;
        }
        else
        {
                HANDLE hFile = CreateFile( pszPath, 0, FILE_SHARE_READ|FILE_SHARE_WRITE,
                        NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL );

                if ( hFile != INVALID_HANDLE_VALUE )
                {
			::GetFileTime( hFile, NULL, NULL, pTime );
                        CloseHandle( hFile );
                }
        }

        return bSuccess;
}

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