www.pudn.com > mitab-1.5.1.zip > mitab_idfile.cpp
/**********************************************************************
* $Id: mitab_idfile.cpp,v 1.7 2004/06/30 20:29:04 dmorissette Exp $
*
* Name: mitab_idfile.cpp
* Project: MapInfo TAB Read/Write library
* Language: C++
* Purpose: Implementation of the TABIDFile class used to handle
* reading/writing of the .ID file attached to a .MAP file
* Author: Daniel Morissette, dmorissette@dmsolutions.ca
*
**********************************************************************
* Copyright (c) 1999, 2000, Daniel Morissette
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
**********************************************************************
*
* $Log: mitab_idfile.cpp,v $
* Revision 1.7 2004/06/30 20:29:04 dmorissette
* Fixed refs to old address danmo@videotron.ca
*
* Revision 1.6 2000/01/18 22:08:56 daniel
* Allow opening of 0-size .ID file (dataset with 0 features)
*
* Revision 1.5 2000/01/15 22:30:44 daniel
* Switch to MIT/X-Consortium OpenSource license
*
* Revision 1.4 1999/09/26 14:59:36 daniel
* Implemented write support
*
* Revision 1.3 1999/09/20 18:43:01 daniel
* Use binary acces to open file.
*
* Revision 1.2 1999/09/16 02:39:16 daniel
* Completed read support for most feature types
*
* Revision 1.1 1999/07/12 04:18:24 daniel
* Initial checkin
*
**********************************************************************/
#include "mitab.h"
#include "mitab_utils.h"
/*=====================================================================
* class TABIDFile
*====================================================================*/
/**********************************************************************
* TABIDFile::TABIDFile()
*
* Constructor.
**********************************************************************/
TABIDFile::TABIDFile()
{
m_fp = NULL;
m_pszFname = NULL;
m_poIDBlock = NULL;
m_nMaxId = -1;
}
/**********************************************************************
* TABIDFile::~TABIDFile()
*
* Destructor.
**********************************************************************/
TABIDFile::~TABIDFile()
{
Close();
}
/**********************************************************************
* TABIDFile::Open()
*
* Open a .ID file, and initialize the structures to be ready to read
* objects from it.
*
* If the filename that is passed in contains a .MAP extension then
* the extension will be changed to .ID before trying to open the file.
*
* Returns 0 on success, -1 on error.
**********************************************************************/
int TABIDFile::Open(const char *pszFname, const char *pszAccess)
{
int nLen;
if (m_fp)
{
CPLError(CE_Failure, CPLE_FileIO,
"Open() failed: object already contains an open file");
return -1;
}
/*-----------------------------------------------------------------
* Validate access mode and make sure we use binary access.
*----------------------------------------------------------------*/
if (EQUALN(pszAccess, "r", 1))
{
m_eAccessMode = TABRead;
pszAccess = "rb";
}
else if (EQUALN(pszAccess, "w", 1))
{
m_eAccessMode = TABWrite;
pszAccess = "wb";
}
else
{
CPLError(CE_Failure, CPLE_FileIO,
"Open() failed: access mode \"%s\" not supported", pszAccess);
return -1;
}
/*-----------------------------------------------------------------
* Change .MAP extension to .ID if necessary
*----------------------------------------------------------------*/
m_pszFname = CPLStrdup(pszFname);
nLen = strlen(m_pszFname);
if (nLen > 4 && strcmp(m_pszFname+nLen-4, ".MAP")==0)
strcpy(m_pszFname+nLen-4, ".ID");
else if (nLen > 4 && strcmp(m_pszFname+nLen-4, ".map")==0)
strcpy(m_pszFname+nLen-4, ".id");
/*-----------------------------------------------------------------
* Change .MAP extension to .ID if necessary
*----------------------------------------------------------------*/
#ifndef _WIN32
TABAdjustFilenameExtension(m_pszFname);
#endif
/*-----------------------------------------------------------------
* Open file
*----------------------------------------------------------------*/
m_fp = VSIFOpen(m_pszFname, pszAccess);
if (m_fp == NULL)
{
CPLError(CE_Failure, CPLE_FileIO,
"Open() failed for %s", m_pszFname);
CPLFree(m_pszFname);
m_pszFname = NULL;
return -1;
}
if (m_eAccessMode == TABRead)
{
/*-------------------------------------------------------------
* READ access:
* Establish the number of object IDs from the size of the file
*------------------------------------------------------------*/
VSIStatBuf sStatBuf;
if ( VSIStat(m_pszFname, &sStatBuf) == -1 )
{
CPLError(CE_Failure, CPLE_FileIO,
"stat() failed for %s\n", m_pszFname);
Close();
return -1;
}
m_nMaxId = sStatBuf.st_size/4;
m_nBlockSize = MIN(1024, m_nMaxId*4);
/*-------------------------------------------------------------
* Read the first block from the file
*------------------------------------------------------------*/
m_poIDBlock = new TABRawBinBlock(m_eAccessMode, FALSE);
if (m_nMaxId == 0)
{
// .ID file size = 0 ... just allocate a blank block but
// it won't get really used anyways.
m_nBlockSize = 512;
m_poIDBlock->InitNewBlock(m_fp, m_nBlockSize, 0);
}
else if (m_poIDBlock->ReadFromFile(m_fp, 0, m_nBlockSize) != 0)
{
// CPLError() has already been called.
Close();
return -1;
}
}
else
{
/*-------------------------------------------------------------
* WRITE access:
* Get ready to write to the file
*------------------------------------------------------------*/
m_poIDBlock = new TABRawBinBlock(m_eAccessMode, FALSE);
m_nMaxId = 0;
m_nBlockSize = 1024;
m_poIDBlock->InitNewBlock(m_fp, m_nBlockSize, 0);
}
return 0;
}
/**********************************************************************
* TABIDFile::Close()
*
* Close current file, and release all memory used.
*
* Returns 0 on success, -1 on error.
**********************************************************************/
int TABIDFile::Close()
{
if (m_fp == NULL)
return 0;
/*----------------------------------------------------------------
* Write access: commit latest changes to the file.
*---------------------------------------------------------------*/
if (m_eAccessMode == TABWrite && m_poIDBlock)
{
m_poIDBlock->CommitToFile();
}
// Delete all structures
delete m_poIDBlock;
m_poIDBlock = NULL;
// Close file
VSIFClose(m_fp);
m_fp = NULL;
CPLFree(m_pszFname);
m_pszFname = NULL;
return 0;
}
/**********************************************************************
* TABIDFile::GetObjPtr()
*
* Return the offset in the .MAP file where the map object with the
* specified id is located.
*
* Note that object ids are positive and start at 1.
*
* An object Id of '0' means that object has no geometry.
*
* Returns a value >= 0 on success, -1 on error.
**********************************************************************/
GInt32 TABIDFile::GetObjPtr(GInt32 nObjId)
{
if (m_poIDBlock == NULL)
return -1;
if (nObjId < 1 || nObjId > m_nMaxId)
{
CPLError(CE_Failure, CPLE_IllegalArg,
"GetObjPtr(): Invalid object ID %d (valid range is [1..%d])",
nObjId, m_nMaxId);
return -1;
}
if (m_poIDBlock->GotoByteInFile( (nObjId-1)*4 ) != 0)
return -1;
return m_poIDBlock->ReadInt32();
}
/**********************************************************************
* TABIDFile::SetObjPtr()
*
* Set the offset in the .MAP file where the map object with the
* specified id is located.
*
* Note that object ids are positive and start at 1.
*
* An object Id of '0' means that object has no geometry.
*
* Returns a value of 0 on success, -1 on error.
**********************************************************************/
int TABIDFile::SetObjPtr(GInt32 nObjId, GInt32 nObjPtr)
{
if (m_poIDBlock == NULL)
return -1;
if (m_eAccessMode != TABWrite)
{
CPLError(CE_Failure, CPLE_NotSupported,
"SetObjPtr() can be used only with Write access.");
return -1;
}
if (nObjId < 1)
{
CPLError(CE_Failure, CPLE_IllegalArg,
"GetObjPtr(): Invalid object ID %d (must be greater than zero)",
nObjId);
return -1;
}
/*-----------------------------------------------------------------
* GotoByteInFile() will automagically commit current block and init
* a new one if necessary.
*----------------------------------------------------------------*/
if (m_poIDBlock->GotoByteInFile( (nObjId-1)*4 ) != 0)
return -1;
m_nMaxId = MAX(m_nMaxId, nObjId);
return m_poIDBlock->WriteInt32(nObjPtr);
}
/**********************************************************************
* TABIDFile::GetMaxObjId()
*
* Return the value of the biggest valid object id.
*
* Note that object ids are positive and start at 1.
*
* Returns a value >= 0 on success, -1 on error.
**********************************************************************/
GInt32 TABIDFile::GetMaxObjId()
{
return m_nMaxId;
}
/**********************************************************************
* TABIDFile::Dump()
*
* Dump block contents... available only in DEBUG mode.
**********************************************************************/
#ifdef DEBUG
void TABIDFile::Dump(FILE *fpOut /*=NULL*/)
{
if (fpOut == NULL)
fpOut = stdout;
fprintf(fpOut, "----- TABIDFile::Dump() -----\n");
if (m_fp == NULL)
{
fprintf(fpOut, "File is not opened.\n");
}
else
{
fprintf(fpOut, "File is opened: %s\n", m_pszFname);
fprintf(fpOut, "Current index block follows ...\n\n");
m_poIDBlock->Dump(fpOut);
fprintf(fpOut, "... end of index block.\n\n");
}
fflush(fpOut);
}
#endif // DEBUG