www.pudn.com > mitab-1.5.1.zip > mitab_tabseamless.cpp
/********************************************************************** * $Id: mitab_tabseamless.cpp,v 1.6 2004/06/30 20:29:04 dmorissette Exp $ * * Name: mitab_tabseamless.cpp * Project: MapInfo TAB Read/Write library * Language: C++ * Purpose: Implementation of the TABSeamless class, used to handle seamless * .TAB datasets. * Author: Daniel Morissette, dmorissette@dmsolutions.ca * ********************************************************************** * Copyright (c) 1999-2004, 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_tabseamless.cpp,v $ * Revision 1.6 2004/06/30 20:29:04 dmorissette * Fixed refs to old address danmo@videotron.ca * * Revision 1.5 2004/03/12 16:29:05 dmorissette * Fixed 2 memory leaks (bug 283) * * Revision 1.4 2002/06/28 18:32:37 julien * Add SetSpatialFilter() in TABSeamless class (Bug 164, MapServer) * Use double for comparison in Coordsys2Int() in mitab_mapheaderblock.cpp * * Revision 1.3 2001/09/19 14:21:36 daniel * On Unix: replace '\\' in file path read from tab index with '/' * * Revision 1.2 2001/03/15 03:57:51 daniel * Added implementation for new OGRLayer::GetExtent(), returning data MBR. * * Revision 1.1 2001/03/09 04:38:04 danmo * Update from master - version 1.1.0 * * Revision 1.1 2001/03/09 04:16:02 daniel * Added TABSeamless for reading seamless TAB files * **********************************************************************/ #include "mitab.h" #include "mitab_utils.h" #include/* isspace() */ /*===================================================================== * class TABSeamless * * Support for seamless vector datasets. * * The current implementation has some limitations (base assumptions): * - Read-only * - Base tables can only be of type TABFile * - Feature Ids are build using the id of the base table in the main * index table and the actual feature id of each object inside the base * tables. Since we are limited to 32 bits for feature ids, this implies * a limit on the (number of base tables) * (features/table) * The current implementation can support up to 2047 (0x7ff) base tables * and a max of 1048575 (0xfffff) features per base table. * - Only relative paths are supported for base tables names. * *====================================================================*/ /********************************************************************** * TABSeamless::TABSeamless() * * Constructor. **********************************************************************/ TABSeamless::TABSeamless() { m_pszFname = NULL; m_pszPath = NULL; m_eAccessMode = TABRead; m_poFeatureDefnRef = NULL; m_poCurFeature = NULL; m_nCurFeatureId = -1; m_poIndexTable = NULL; m_nTableNameField = -1; m_nCurBaseTableId = -1; m_poCurBaseTable = NULL; m_bEOF = FALSE; } /********************************************************************** * TABSeamless::~TABSeamless() * * Destructor. **********************************************************************/ TABSeamless::~TABSeamless() { Close(); } void TABSeamless::ResetReading() { if (m_poIndexTable) OpenBaseTable(-1); // Asking for first table resets everything } /********************************************************************** * TABSeamless::Open() * * Open a seamless .TAB dataset and initialize the structures to be ready * to read features from it. * * Seamless .TAB files are composed of a main .TAB file in which each * feature is the MBR of a base table. * * Set bTestOpenNoError=TRUE to silently return -1 with no error message * if the file cannot be opened. This is intended to be used in the * context of a TestOpen() function. The default value is FALSE which * means that an error is reported if the file cannot be opened. * * Returns 0 on success, -1 on error. **********************************************************************/ int TABSeamless::Open(const char *pszFname, const char *pszAccess, GBool bTestOpenNoError /*= FALSE*/ ) { char nStatus = 0; if (m_poIndexTable) { CPLError(CE_Failure, CPLE_AssertionFailed, "Open() failed: object already contains an open file"); return -1; } /*----------------------------------------------------------------- * Validate access mode and call the right open method *----------------------------------------------------------------*/ if (EQUALN(pszAccess, "r", 1)) { m_eAccessMode = TABRead; nStatus = OpenForRead(pszFname, bTestOpenNoError); } else { CPLError(CE_Failure, CPLE_NotSupported, "Open() failed: access mode \"%s\" not supported", pszAccess); return -1; } return nStatus; } /********************************************************************** * TABSeamless::OpenForRead() * * Open for reading * * Returns 0 on success, -1 on error. **********************************************************************/ int TABSeamless::OpenForRead(const char *pszFname, GBool bTestOpenNoError /*= FALSE*/ ) { int nFnameLen = 0; m_eAccessMode = TABRead; /*----------------------------------------------------------------- * Read main .TAB (text) file *----------------------------------------------------------------*/ m_pszFname = CPLStrdup(pszFname); #ifndef _WIN32 /*----------------------------------------------------------------- * On Unix, make sure extension uses the right cases * We do it even for write access because if a file with the same * extension already exists we want to overwrite it. *----------------------------------------------------------------*/ TABAdjustFilenameExtension(m_pszFname); #endif /*----------------------------------------------------------------- * Open .TAB file... since it's a small text file, we will just load * it as a stringlist in memory. *----------------------------------------------------------------*/ char **papszTABFile = TAB_CSLLoad(m_pszFname); if (papszTABFile == NULL) { if (!bTestOpenNoError) { CPLError(CE_Failure, CPLE_FileIO, "Failed opening %s.", m_pszFname); } CPLFree(m_pszFname); CSLDestroy(papszTABFile); return -1; } /*------------------------------------------------------------- * Look for a metadata line with "\IsSeamless" = "TRUE". * If there is no such line, then we may have a valid .TAB file, * but we do not support it in this class. *------------------------------------------------------------*/ GBool bSeamlessFound = FALSE; for (int i=0; !bSeamlessFound && papszTABFile && papszTABFile[i]; i++) { const char *pszStr = papszTABFile[i]; while(*pszStr != '\0' && isspace(*pszStr)) pszStr++; if (EQUALN(pszStr, "\"\\IsSeamless\" = \"TRUE\"", 21)) bSeamlessFound = TRUE; } CSLDestroy(papszTABFile); if ( !bSeamlessFound ) { if (!bTestOpenNoError) CPLError(CE_Failure, CPLE_NotSupported, "%s does not appear to be a Seamless TAB File. " "This type of .TAB file cannot be read by this library.", m_pszFname); else CPLErrorReset(); CPLFree(m_pszFname); return -1; } /*----------------------------------------------------------------- * OK, this appears to be a valid seamless TAB dataset... * Extract the path component from the main .TAB filename * to build the filename of the base tables *----------------------------------------------------------------*/ m_pszPath = CPLStrdup(m_pszFname); nFnameLen = strlen(m_pszPath); for( ; nFnameLen > 0; nFnameLen--) { if (m_pszPath[nFnameLen-1] == '/' || m_pszPath[nFnameLen-1] == '\\' ) { break; } m_pszPath[nFnameLen-1] = '\0'; } /*----------------------------------------------------------------- * Open the main Index table and look for the "Table" field that * should contain the path to the base table for each rectangle MBR *----------------------------------------------------------------*/ m_poIndexTable = new TABFile; if (m_poIndexTable->Open(m_pszFname, "rb", bTestOpenNoError) != 0) { // Open Failed... an error has already been reported, just return. if (bTestOpenNoError) CPLErrorReset(); Close(); return -1; } OGRFeatureDefn *poDefn = m_poIndexTable->GetLayerDefn(); if (poDefn == NULL || (m_nTableNameField = poDefn->GetFieldIndex("Table")) == -1) { if (!bTestOpenNoError) CPLError(CE_Failure, CPLE_NotSupported, "Open Failed: Field 'Table' not found in Seamless " "Dataset '%s'. This is type of file not currently " "supported.", m_pszFname); Close(); return -1; } /*----------------------------------------------------------------- * Check number of features in index table to make sure we won't * overflow the number of bytes used for table ids in the encoded * feature ids. We currently use 12 bits for table id + 20 bits for FID *----------------------------------------------------------------*/ if (m_poIndexTable->GetFeatureCount(FALSE) > 0x7ff) { if (!bTestOpenNoError) CPLError(CE_Failure, CPLE_NotSupported, "Open Failed: The current implementation is limited " "to 2047 base tables. The seamless file '%s' contains " "%d tables and cannot be opened.", m_pszFname, m_poIndexTable->GetFeatureCount(FALSE)); Close(); return -1; } /*----------------------------------------------------------------- * We need to open the first table to get its FeatureDefn *----------------------------------------------------------------*/ if (OpenBaseTable(-1, bTestOpenNoError) != 0 ) { // Open Failed... an error has already been reported, just return. if (bTestOpenNoError) CPLErrorReset(); Close(); return -1; } CPLAssert(m_poCurBaseTable); m_poFeatureDefnRef = m_poCurBaseTable->GetLayerDefn(); m_poFeatureDefnRef->Reference(); return 0; } /********************************************************************** * TABSeamless::Close() * * Close current file, and release all memory used. * * Returns 0 on success, -1 on error. **********************************************************************/ int TABSeamless::Close() { if (m_poIndexTable) delete m_poIndexTable; // Automatically closes. m_poIndexTable = NULL; if (m_poFeatureDefnRef && m_poFeatureDefnRef->Dereference() == 0) delete m_poFeatureDefnRef; m_poFeatureDefnRef = NULL; if (m_poCurFeature) delete m_poCurFeature; m_poCurFeature = NULL; m_nCurFeatureId = -1; CPLFree(m_pszFname); m_pszFname = NULL; CPLFree(m_pszPath); m_pszPath = NULL; m_nTableNameField = -1; m_nCurBaseTableId = -1; if (m_poCurBaseTable) delete m_poCurBaseTable; m_poCurBaseTable = NULL; return 0; } /********************************************************************** * TABSeamless::OpenBaseTable() * * Open the base table for specified IndexFeature. * * Returns 0 on success, -1 on error. **********************************************************************/ int TABSeamless::OpenBaseTable(TABFeature *poIndexFeature, GBool bTestOpenNoError /*=FALSE*/) { CPLAssert(poIndexFeature); /*----------------------------------------------------------------- * Fetch table id. We actually use the index feature's ids as the * base table ids. *----------------------------------------------------------------*/ int nTableId = poIndexFeature->GetFID(); if (m_nCurBaseTableId == nTableId && m_poCurBaseTable != NULL) { // The right table is already opened. Not much to do! m_poCurBaseTable->ResetReading(); return 0; } // Close current base table if (m_poCurBaseTable) delete m_poCurBaseTable; m_nCurBaseTableId = -1; m_bEOF = FALSE; /*----------------------------------------------------------------- * Build full path to the table and open it. * __TODO__ For now we assume that all table filename paths are relative * but we may have to deal with absolute filenames as well. *----------------------------------------------------------------*/ const char *pszName = poIndexFeature->GetFieldAsString(m_nTableNameField); char *pszFname = CPLStrdup(CPLSPrintf("%s%s", m_pszPath, pszName)); #ifndef _WIN32 // On Unix, replace any '\\' in path with '/' char *pszPtr = pszFname; while((pszPtr = strchr(pszPtr, '\\')) != NULL) { *pszPtr = '/'; pszPtr++; } #endif m_poCurBaseTable = new TABFile; if (m_poCurBaseTable->Open(pszFname, "rb", bTestOpenNoError) != 0) { // Open Failed... an error has already been reported, just return. if (bTestOpenNoError) CPLErrorReset(); delete m_poCurBaseTable; m_poCurBaseTable = NULL; CPLFree(pszFname); return -1; } // Set the spatial filter to the new table if( m_poFilterGeom != NULL && m_poCurBaseTable ) { m_poCurBaseTable->SetSpatialFilter( m_poFilterGeom ); } m_nCurBaseTableId = nTableId; CPLFree(pszFname); return 0; } /********************************************************************** * TABSeamless::OpenBaseTable() * * Open the base table for specified IndexFeature. * * Returns 0 on success, -1 on error. **********************************************************************/ int TABSeamless::OpenBaseTable(int nTableId, GBool bTestOpenNoError /*=FALSE*/) { if (nTableId == -1) { // Open first table from dataset m_poIndexTable->ResetReading(); if (OpenNextBaseTable(bTestOpenNoError) != 0) { // Open Failed... an error has already been reported. if (bTestOpenNoError) CPLErrorReset(); return -1; } } else if (nTableId == m_nCurBaseTableId && m_poCurBaseTable != NULL) { // The right table is already opened. Not much to do! m_poCurBaseTable->ResetReading(); return 0; } else { TABFeature *poIndexFeature = m_poIndexTable->GetFeatureRef(nTableId); if (poIndexFeature) { if (OpenBaseTable(poIndexFeature, bTestOpenNoError) != 0) { // Open Failed... an error has already been reported. if (bTestOpenNoError) CPLErrorReset(); return -1; } } } return 0; } /********************************************************************** * TABSeamless::OpenNextBaseTable() * * Open the next base table in the dataset, using GetNextFeature() so that * the spatial filter is respected. * * m_bEOF will be set if there are no more base tables to read. * * Returns 0 on success, -1 on error. **********************************************************************/ int TABSeamless::OpenNextBaseTable(GBool bTestOpenNoError /*=FALSE*/) { CPLAssert(m_poIndexTable); TABFeature *poIndexFeature = (TABFeature*)m_poIndexTable->GetNextFeature(); if (poIndexFeature) { if (OpenBaseTable(poIndexFeature, bTestOpenNoError) != 0) { // Open Failed... an error has already been reported. if (bTestOpenNoError) CPLErrorReset(); delete poIndexFeature; return -1; } delete poIndexFeature; m_bEOF = FALSE; } else { // Reached EOF m_bEOF = TRUE; } return 0; } /********************************************************************** * TABSeamless::EncodeFeatureId() * * Combine the table id + feature id into a single feature id that should * be unique amongst all base tables in this seamless dataset. * * We reserve some bits in the feature id for the table id based on the * number of features in the index table. This reduces the available range * of feature ids for each base table... for instance, if the index contains * 65000 entries, then each base table will be limited to 65535 features. * * If the number of features in a base table exceeds the number of bits * available (e.g. 65535 inthe above example) then the feature ids will * wrap for this table and thus it will be impossible to access some of * the features unless the caller uses only calls to GetNextFeature() and * avoids calls to GetFeatureRef(). **********************************************************************/ int TABSeamless::EncodeFeatureId(int nTableId, int nBaseFeatureId) { if (nTableId == -1 || nBaseFeatureId == -1) return -1; /*----------------------------------------------------------------- * __TODO__ For now we hardcode the bitmasks to be 12 bits for tableid * and 20 bits for base feature id, but we should really * base the numbers of bits on the number of features in * the index table. *----------------------------------------------------------------*/ return (nTableId*0x00100000 + nBaseFeatureId); } int TABSeamless::ExtractBaseTableId(int nEncodedFeatureId) { if (nEncodedFeatureId == -1) return -1; return (nEncodedFeatureId/0x00100000); } int TABSeamless::ExtractBaseFeatureId(int nEncodedFeatureId) { if (nEncodedFeatureId == -1) return -1; return (nEncodedFeatureId & 0x000fffff); } /********************************************************************** * TABSeamless::GetNextFeatureId() * * Returns feature id that follows nPrevId, or -1 if it is the * last feature id. Pass nPrevId=-1 to fetch the first valid feature id. **********************************************************************/ int TABSeamless::GetNextFeatureId(int nPrevId) { if (m_poIndexTable == NULL) return -1; // File is not opened yet if (nPrevId == -1 || m_nCurBaseTableId != ExtractBaseTableId(nPrevId)) { if (OpenBaseTable(ExtractBaseTableId(nPrevId)) != 0) return -1; } int nId = ExtractBaseFeatureId(nPrevId); do { nId = m_poCurBaseTable->GetNextFeatureId(nId); if (nId != -1) return EncodeFeatureId(m_nCurBaseTableId, nId); // Found one! else OpenNextBaseTable(); // Skip to next tile and loop again } while (nId == -1 && !m_bEOF && m_poCurBaseTable); return -1; } /********************************************************************** * TABSeamless::GetFeatureRef() * * Fill and return a TABFeature object for the specified feature id. * * The returned pointer is a reference to an object owned and maintained * by this TABSeamless object. It should not be altered or freed by the * caller and its contents is guaranteed to be valid only until the next * call to GetFeatureRef() or Close(). * * Returns NULL if the specified feature id does not exist of if an * error happened. In any case, CPLError() will have been called to * report the reason of the failure. **********************************************************************/ TABFeature *TABSeamless::GetFeatureRef(int nFeatureId) { if (m_poIndexTable == NULL) return NULL; // File is not opened yet if (nFeatureId == m_nCurFeatureId && m_poCurFeature) return m_poCurFeature; if (m_nCurBaseTableId != ExtractBaseTableId(nFeatureId)) { if (OpenBaseTable(ExtractBaseTableId(nFeatureId)) != 0) return NULL; } if (m_poCurBaseTable) { if (m_poCurFeature) delete m_poCurFeature; m_poCurFeature = (TABFeature*)m_poCurBaseTable->GetFeature(ExtractBaseFeatureId(nFeatureId)); m_nCurFeatureId = nFeatureId; m_poCurFeature->SetFID(nFeatureId); return m_poCurFeature; } return NULL; } /********************************************************************** * TABSeamless::GetLayerDefn() * * Returns a reference to the OGRFeatureDefn that will be used to create * features in this dataset. * * Returns a reference to an object that is maintained by this TABSeamless * object (and thus should not be modified or freed by the caller) or * NULL if the OGRFeatureDefn has not been initialized yet (i.e. no file * opened yet) **********************************************************************/ OGRFeatureDefn *TABSeamless::GetLayerDefn() { return m_poFeatureDefnRef; } /********************************************************************** * TABSeamless::GetNativeFieldType() * * Returns the native MapInfo field type for the specified field. * * Returns TABFUnknown if file is not opened, or if specified field index is * invalid. * * Note that field ids are positive and start at 0. **********************************************************************/ TABFieldType TABSeamless::GetNativeFieldType(int nFieldId) { if (m_poCurBaseTable) return m_poCurBaseTable->GetNativeFieldType(nFieldId); return TABFUnknown; } /********************************************************************** * TABSeamless::IsFieldIndexed() * * Returns TRUE if field is indexed, or FALSE otherwise. **********************************************************************/ GBool TABSeamless::IsFieldIndexed(int nFieldId) { if (m_poCurBaseTable) return m_poCurBaseTable->IsFieldIndexed(nFieldId); return FALSE; } /********************************************************************** * TABSeamless::IsFieldUnique() * * Returns TRUE if field is in the Unique table, or FALSE otherwise. **********************************************************************/ GBool TABSeamless::IsFieldUnique(int nFieldId) { if (m_poCurBaseTable) return m_poCurBaseTable->IsFieldUnique(nFieldId); return FALSE; } /********************************************************************** * TABSeamless::GetBounds() * * Fetch projection coordinates bounds of a dataset. * * The bForce flag has no effect on TAB files since the bounds are * always in the header. * * Returns 0 on success, -1 on error. **********************************************************************/ int TABSeamless::GetBounds(double &dXMin, double &dYMin, double &dXMax, double &dYMax, GBool bForce /*= TRUE*/) { if (m_poIndexTable == NULL) { CPLError(CE_Failure, CPLE_AppDefined, "GetBounds() can be called only after dataset has been opened."); return -1; } return m_poIndexTable->GetBounds(dXMin, dYMin, dXMax, dYMax, bForce); } /********************************************************************** * TABSeamless::GetExtent() * * Fetch extent of the data currently stored in the dataset. * * The bForce flag has no effect on TAB files since that value is * always in the header. * * Returns OGRERR_NONE/OGRRERR_FAILURE. **********************************************************************/ OGRErr TABSeamless::GetExtent (OGREnvelope *psExtent, int bForce) { if (m_poIndexTable == NULL) { CPLError(CE_Failure, CPLE_AppDefined, "GetExtent() can be called only after dataset has been opened."); return OGRERR_FAILURE; } return m_poIndexTable->GetExtent(psExtent, bForce); } /********************************************************************** * TABSeamless::GetFeatureCountByType() * * Return number of features of each type. * * Note that the sum of the 4 returned values may be different from * the total number of features since features with NONE geometry * are not taken into account here. * * Returns 0 on success, or silently returns -1 (with no error) if this * information is not available. **********************************************************************/ int TABSeamless::GetFeatureCountByType(int &numPoints, int &numLines, int &numRegions, int &numTexts, GBool bForce /*= TRUE*/) { /*----------------------------------------------------------------- * __TODO__ This should be implemented to return -1 if force=false, * or scan all the base tables if force=true *----------------------------------------------------------------*/ return -1; } int TABSeamless::GetFeatureCount(int bForce) { /*----------------------------------------------------------------- * __TODO__ This should be implemented to return -1 if force=false, * or scan all the base tables if force=true *----------------------------------------------------------------*/ return OGRLayer::GetFeatureCount(bForce); } /********************************************************************** * TABSeamless::GetSpatialRef() * * Returns a reference to an OGRSpatialReference for this dataset. * If the projection parameters have not been parsed yet, then we will * parse them before returning. * * The returned object is owned and maintained by this TABFile and * should not be modified or freed by the caller. * * Returns NULL if the SpatialRef cannot be accessed. **********************************************************************/ OGRSpatialReference *TABSeamless::GetSpatialRef() { if (m_poIndexTable == NULL) { CPLError(CE_Failure, CPLE_AssertionFailed, "GetSpatialRef() failed: file has not been opened yet."); return NULL; } return m_poIndexTable->GetSpatialRef(); } /********************************************************************** * IMapInfoFile::SetSpatialFilter() * * Standard OGR SetSpatialFiltere implementation. This methode is used * to set a SpatialFilter for this OGRLayer **********************************************************************/ void TABSeamless::SetSpatialFilter (OGRGeometry * poGeomIn ) { IMapInfoFile::SetSpatialFilter( poGeomIn ); if( m_poIndexTable ) m_poIndexTable->SetSpatialFilter( poGeomIn ); if( m_poCurBaseTable ) m_poCurBaseTable->SetSpatialFilter( poGeomIn ); } /************************************************************************/ /* TestCapability() */ /************************************************************************/ int TABSeamless::TestCapability( const char * pszCap ) { if( EQUAL(pszCap,OLCRandomRead) ) return TRUE; else if( EQUAL(pszCap,OLCSequentialWrite) || EQUAL(pszCap,OLCRandomWrite) ) return FALSE; else if( EQUAL(pszCap,OLCFastFeatureCount) ) return FALSE; else if( EQUAL(pszCap,OLCFastSpatialFilter) ) return FALSE; else if( EQUAL(pszCap,OLCFastGetExtent) ) return TRUE; else return FALSE; } /********************************************************************** * TABSeamless::Dump() * * Dump block contents... available only in DEBUG mode. **********************************************************************/ #ifdef DEBUG void TABSeamless::Dump(FILE *fpOut /*=NULL*/) { if (fpOut == NULL) fpOut = stdout; fprintf(fpOut, "----- TABSeamless::Dump() -----\n"); if (m_poIndexTable == NULL) { fprintf(fpOut, "File is not opened.\n"); } else { fprintf(fpOut, "File is opened: %s\n", m_pszFname); } fflush(fpOut); } #endif // DEBUG