mitab_mapfile.cpp

GIS系统支持库Geospatial Data Abstraction Library代码.GDAL is a translator library for raster geospatial dat

    /*-----------------------------------------------------------------
     * Make sure all previous calls succeded.
     *----------------------------------------------------------------*/
    if (CPLGetLastErrorNo() != 0)
    {
        // Open Failed... an error has already been reported
        Close();
        return -1;
    }

    return 0;
}

/**********************************************************************
 *                   TABMAPFile::Close()
 *
 * Close current file, and release all memory used.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABMAPFile::Close()
{
    // Check if file is opened... it is possible to have a fake header
    // without an actual file attached to it.
    if (m_fp == NULL && m_poHeader == NULL)
        return 0;

    /*----------------------------------------------------------------
     * Write access: commit latest changes to the file.
     *---------------------------------------------------------------*/
    if (m_eAccessMode == TABWrite)
    {
        // Start by committing current object and coord blocks
        // Nothing happens if none has been created yet.
        CommitObjBlock(FALSE);

        // Write the drawing tools definitions now.
        CommitDrawingTools();

        // Commit spatial index blocks
        CommitSpatialIndex();

        // __TODO__ We probably need to update some header fields first.
        if (m_poHeader)
        {
            // OK, with V450 files, objects are not limited to 32k nodes
            // any more, and this means that m_nMaxCoordBufSize can become
            // huge, and actually more huge than can be held in memory.
            // MapInfo counts m_nMaxCoordBufSize=0 for V450 objects, but 
            // until this is cleanly implented, we will just prevent 
            // m_nMaxCoordBufSizefrom going beyond 512k in V450 files.
            if (m_nMinTABVersion >= 450)
            {
                m_poHeader->m_nMaxCoordBufSize = 
                                 MIN(m_poHeader->m_nMaxCoordBufSize, 512*1024);
            }
            m_poHeader->CommitToFile();
        }
    }
    
    // Check for overflow of internal coordinates and produce a warning
    // if that happened...
    if (m_poHeader && m_poHeader->m_bIntBoundsOverflow)
    {
        double dBoundsMinX, dBoundsMinY, dBoundsMaxX, dBoundsMaxY;
        Int2Coordsys(-1000000000, -1000000000, dBoundsMinX, dBoundsMinY);
        Int2Coordsys(1000000000, 1000000000, dBoundsMaxX, dBoundsMaxY);

        CPLError(CE_Warning, TAB_WarningBoundsOverflow,
                 "Some objects were written outside of the file's "
                 "predefined bounds.\n"
                 "These objects may have invalid coordinates when the file "
                 "is reopened.\n"
                 "Predefined bounds: (%.15g,%.15g)-(%.15g,%.15g)\n",
                 dBoundsMinX, dBoundsMinY, dBoundsMaxX, dBoundsMaxY );
    }

    // Delete all structures 
    if (m_poHeader)
        delete m_poHeader;
    m_poHeader = NULL;

    if (m_poIdIndex)
    {
        m_poIdIndex->Close();
        delete m_poIdIndex;
        m_poIdIndex = NULL;
    }

    if (m_poCurObjBlock)
    {
        delete m_poCurObjBlock;
        m_poCurObjBlock = NULL;
        m_nCurObjPtr = -1;
        m_nCurObjType = -1;
        m_nCurObjId = -1;
    }

    if (m_poCurCoordBlock)
    {
        delete m_poCurCoordBlock;
        m_poCurCoordBlock = NULL;
    }

    if (m_poSpIndex)
    {
        delete m_poSpIndex;
        m_poSpIndex = NULL;
        m_poSpIndexLeaf = NULL;
    }

    if (m_poToolDefTable)
    {
        delete m_poToolDefTable;
        m_poToolDefTable = NULL;
    }

    // Close file
    if (m_fp)
        VSIFClose(m_fp);
    m_fp = NULL;

    CPLFree(m_pszFname);
    m_pszFname = NULL;

    return 0;
}

/************************************************************************/
/*                             PushBlock()                              */
/*                                                                      */
/*      Install a new block (object or spatial) as being current -      */
/*      whatever that means.  This method is only intended to ever      */
/*      be called from LoadNextMatchingObjectBlock().                   */
/************************************************************************/

TABRawBinBlock *TABMAPFile::PushBlock( int nFileOffset )

{
    TABRawBinBlock *poBlock;

    poBlock = GetIndexObjectBlock( nFileOffset );
    if( poBlock == NULL )
        return NULL;

    if( poBlock->GetBlockType() == TABMAP_INDEX_BLOCK )
    {
        TABMAPIndexBlock *poIndex = (TABMAPIndexBlock *) poBlock;

        if( m_poSpIndexLeaf == NULL )
        {
            m_poSpIndexLeaf = m_poSpIndex = poIndex;
        }
        else
        {
            CPLAssert( 
                m_poSpIndexLeaf->GetEntry(
                    m_poSpIndexLeaf->GetCurChildIndex())->nBlockPtr 
                == nFileOffset );

            m_poSpIndexLeaf->SetCurChildRef( poIndex, 
                                         m_poSpIndexLeaf->GetCurChildIndex() );
            poIndex->SetParentRef( m_poSpIndexLeaf );
            m_poSpIndexLeaf = poIndex;
        }
    }
    else
    {
        CPLAssert( poBlock->GetBlockType() == TABMAP_OBJECT_BLOCK );
        
        if( m_poCurObjBlock != NULL )
            delete m_poCurObjBlock;

        m_poCurObjBlock = (TABMAPObjectBlock *) poBlock;

        m_nCurObjPtr = nFileOffset;
        m_nCurObjType = 0;
        m_nCurObjId   = -1;
    }

    return poBlock;
}

/************************************************************************/
/*                    LoadNextMatchingObjectBlock()                     */
/*                                                                      */
/*      Advance through the spatial indices till the next object        */
/*      block is loaded that matching the spatial query extents.        */
/************************************************************************/

int TABMAPFile::LoadNextMatchingObjectBlock( int bFirstObject )

{
    // If we are just starting, verify the stack is empty.
    if( bFirstObject )
    {
        CPLAssert( m_poSpIndex == NULL && m_poSpIndexLeaf == NULL );

        if( PushBlock( m_poHeader->m_nFirstIndexBlock ) == NULL )
            return FALSE;

        if( m_poSpIndex == NULL )
        {
            CPLAssert( m_poCurObjBlock != NULL );
            return TRUE;
        }
    }

    while( m_poSpIndexLeaf != NULL )
    {
        int     iEntry = m_poSpIndexLeaf->GetCurChildIndex();

        if( iEntry >= m_poSpIndexLeaf->GetNumEntries()-1 )
        {
            TABMAPIndexBlock *poParent = m_poSpIndexLeaf->GetParentRef();
            delete m_poSpIndexLeaf;
            m_poSpIndexLeaf = poParent;
            
            if( poParent != NULL )
            {
                poParent->SetCurChildRef( NULL, poParent->GetCurChildIndex() );
            }
            else
            {
                m_poSpIndex = NULL;
            }
            continue;
        }

        m_poSpIndexLeaf->SetCurChildRef( NULL, ++iEntry );

        TABMAPIndexEntry *psEntry = m_poSpIndexLeaf->GetEntry( iEntry );
        TABRawBinBlock *poBlock;
        
        if( psEntry->XMax < m_XMinFilter
            || psEntry->YMax < m_YMinFilter
            || psEntry->XMin > m_XMaxFilter
            || psEntry->YMin > m_YMaxFilter )
            continue;

        poBlock = PushBlock( psEntry->nBlockPtr );
        if( poBlock == NULL )
            return FALSE;
        else if( poBlock->GetBlockType() == TABMAP_OBJECT_BLOCK )
            return TRUE;
        else
            /* continue processing new index block */;
    }

    return m_poSpIndexLeaf != NULL;
}

/************************************************************************/
/*                            ResetReading()                            */
/*                                                                      */
/*      Ensure that any resources related to a spatial traversal of     */
/*      the file are recovered, and the state reinitialized to the      */
/*      initial conditions.                                             */
/************************************************************************/

void TABMAPFile::ResetReading()

{
    if (m_poSpIndex && m_eAccessMode == TABRead )
    {
        delete m_poSpIndex;
        m_poSpIndex = NULL;
        m_poSpIndexLeaf = NULL;
    }
}

/************************************************************************/
/*                          GetNextFeatureId()                          */
/*                                                                      */
/*      Fetch the next feature id based on a traversal of the           */
/*      spatial index.                                                  */
/************************************************************************/

int TABMAPFile::GetNextFeatureId( int nPrevId )

{
/* -------------------------------------------------------------------- */
/*      m_fp is NULL when all geometry are NONE and/or there's          */
/*          no .map file and/or there's no spatial indexes              */
/* -------------------------------------------------------------------- */
    if( m_fp == NULL )
        return -1;

    if( nPrevId == 0 )
        nPrevId = -1;

/* -------------------------------------------------------------------- */
/*      This should always be true if we are being called properly.     */
/* -------------------------------------------------------------------- */
    if( nPrevId != -1 && m_nCurObjId != nPrevId )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "TABMAPFile::GetNextFeatureId(%d) called out of sequence.", 
                  nPrevId );
        return -1;
    }

    CPLAssert( nPrevId == -1 || m_poCurObjBlock != NULL );

/* -------------------------------------------------------------------- */
/*      Ensure things are initialized properly if this is a request     */
/*      for the first feature.                                          */
/* -------------------------------------------------------------------- */
    if( nPrevId == -1 )
    {
        m_nCurObjId = -1;
    }

/* -------------------------------------------------------------------- */
/*      Try to advance to the next object in the current object         */
/*      block.                                                          */
/* -------------------------------------------------------------------- */
    if( nPrevId == -1 
        || m_poCurObjBlock->AdvanceToNextObject(m_poHeader) == -1 )
    {
        // If not, try to advance to the next object block, and get
        // first object from it.  Note that some object blocks actually
        // have no objects, so we may have to advance to additional 
        // object blocks till we find a non-empty one.
        GBool bFirstCall = (nPrevId == -1);
        do 
        {
            if( !LoadNextMatchingObjectBlock( bFirstCall ) )
                return -1;

            bFirstCall = FALSE;
        } while( m_poCurObjBlock->AdvanceToNextObject(m_poHeader) == -1 );
    }

    m_nCurObjType = m_poCurObjBlock->GetCurObjectType();
    m_nCurObjId = m_poCurObjBlock->GetCurObjectId();
    m_nCurObjPtr = m_poCurObjBlock->GetStartAddress() 
        + m_poCurObjBlock->GetCurObjectOffset();

    CPLAssert( m_nCurObjId != -1 );

    return m_nCurObjId;
}

/**********************************************************************
 *                   TABMAPFile::Int2Coordsys()
 *
 * Convert from long integer (internal) to coordinates system units
 * as defined in the file's coordsys clause.
 *
 * Note that the false easting/northing and the conversion factor from
 * datum to coordsys units are not included in the calculation.
 *
 * Returns 0 on success, -1 on error.
 **********************************************************************/
int TABMAPFile::Int2Coordsys(GInt32 nX, GInt32 nY, double &dX, double &dY)
{
    if (m_poHeader == NULL)
        return -1;

    return m_poHeader->Int2Coordsys(nX, nY, dX, dY);
}

/**********************************************************************
 *                   TABMAPFile::Coordsys2Int()
 *