C++ VSIFTellL函数代码示例

bool OGRDXFWriterDS::TransferUpdateHeader( VSILFILE *fpOut )

{
    oHeaderDS.ResetReadPointer( 0 );

/* -------------------------------------------------------------------- */
/*      Copy header, inserting in new objects as needed.                */
/* -------------------------------------------------------------------- */
    char szLineBuf[257];
    int nCode = 0;
    CPLString osSection;
    CPLString osTable;
    CPLString osEntity;

    while( (nCode = oHeaderDS.ReadValue( szLineBuf, sizeof(szLineBuf) )) != -1
           && osSection != "ENTITIES" )
    {
        if( nCode == 0 && EQUAL(szLineBuf,"ENDTAB") )
        {
            // If we are at the end of the LAYER TABLE consider inserting
            // missing definitions.
            if( osTable == "LAYER" )
            {
                if( !WriteNewLayerDefinitions( fp ) )
                    return false;
            }

            // If at the end of the BLOCK_RECORD TABLE consider inserting
            // missing definitions.
            if( osTable == "BLOCK_RECORD" && poBlocksLayer )
            {
                if( !WriteNewBlockRecords( fp ) )
                    return false;
            }

            // If at the end of the LTYPE TABLE consider inserting
            // missing layer type definitions.
            if( osTable == "LTYPE" )
            {
                if( !WriteNewLineTypeRecords( fp ) )
                    return false;
            }

            osTable = "";
        }

        // If we are at the end of the BLOCKS section, consider inserting
        // supplementary blocks.
        if( nCode == 0 && osSection == "BLOCKS" && EQUAL(szLineBuf,"ENDSEC")
            && poBlocksLayer != NULL )
        {
            if( !WriteNewBlockDefinitions( fp ) )
                return false;
        }

        // We need to keep track of where $HANDSEED is so that we can
        // come back and fix it up when we have generated all entity ids.
        if( nCode == 9 && EQUAL(szLineBuf,"$HANDSEED") )
        {
            if( !WriteValue( fpOut, nCode, szLineBuf ) )
                return false;

            nCode = oHeaderDS.ReadValue( szLineBuf, sizeof(szLineBuf) );

            // ensure we have room to overwrite with a longer value.
            while( strlen(szLineBuf) < 8 )
            {
                memmove( szLineBuf+1, szLineBuf, strlen(szLineBuf)+1 );
                szLineBuf[0] = '0';
            }

            nHANDSEEDOffset = VSIFTellL( fpOut );
        }

        // Patch EXTMIN with minx and miny
        if( nCode == 9 && EQUAL(szLineBuf,"$EXTMIN") )
        {
            if( !WriteValue( fpOut, nCode, szLineBuf ) )
                return false;

            nCode = oHeaderDS.ReadValue( szLineBuf, sizeof(szLineBuf) );
            if (nCode == 10)
            {
                if( !WriteValue( fpOut, nCode, oGlobalEnvelope.MinX ) )
                    return false;

                nCode = oHeaderDS.ReadValue( szLineBuf, sizeof(szLineBuf) );
                if (nCode == 20)
                {
                    if( !WriteValue( fpOut, nCode, oGlobalEnvelope.MinY ) )
                        return false;

                    continue;
                }
            }
        }

        // Patch EXTMAX with maxx and maxy
        if( nCode == 9 && EQUAL(szLineBuf,"$EXTMAX") )
        {
//.........这里部分代码省略.........

//.........这里部分代码省略.........
        delete poDS;
        return NULL;
    }

    GDALDataType eDT = GDT_Float32;

    if (STARTS_WITH_CI(pszLine + E00_INT_SIZE + E00_INT_SIZE, " 1"))
        eDT = GDT_Int32;
    else if (STARTS_WITH_CI(pszLine + E00_INT_SIZE + E00_INT_SIZE, " 2"))
        eDT = GDT_Float32;
    else
    {
        CPLDebug("E00GRID", "Unknown data type : %s", pszLine);
    }

    const double dfNoData = CPLAtof(pszLine + E00_INT_SIZE + E00_INT_SIZE + 2);

    /* read pixel size */
    if (e00ReadPtr)
        pszLine = E00ReadNextLine(e00ReadPtr);
    else
        pszLine = CPLReadLine2L(fp, 81, NULL);
    if (pszLine == NULL || strlen(pszLine) < 2*E00_DOUBLE_SIZE)
    {
        CPLDebug("E00GRID", "Bad 4th line");
        delete poDS;
        return NULL;
    }
/*
    double dfPixelX = CPLAtof(pszLine);
    double dfPixelY = CPLAtof(pszLine + E00_DOUBLE_SIZE);
*/

    /* read xmin, ymin */
    if (e00ReadPtr)
        pszLine = E00ReadNextLine(e00ReadPtr);
    else
        pszLine = CPLReadLine2L(fp, 81, NULL);
    if (pszLine == NULL || strlen(pszLine) < 2*E00_DOUBLE_SIZE)
    {
        CPLDebug("E00GRID", "Bad 5th line");
        delete poDS;
        return NULL;
    }
    const double dfMinX = CPLAtof(pszLine);
    const double dfMinY = CPLAtof(pszLine + E00_DOUBLE_SIZE);

    /* read xmax, ymax */
    if (e00ReadPtr)
        pszLine = E00ReadNextLine(e00ReadPtr);
    else
        pszLine = CPLReadLine2L(fp, 81, NULL);
    if (pszLine == NULL || strlen(pszLine) < 2*E00_DOUBLE_SIZE)
    {
        CPLDebug("E00GRID", "Bad 6th line");
        delete poDS;
        return NULL;
    }
    const double dfMaxX = CPLAtof(pszLine);
    const double dfMaxY = CPLAtof(pszLine + E00_DOUBLE_SIZE);

    poDS->nRasterXSize = nRasterXSize;
    poDS->nRasterYSize = nRasterYSize;
    poDS->dfNoData = dfNoData;
    poDS->adfGeoTransform[0] = dfMinX;
    poDS->adfGeoTransform[1] = (dfMaxX - dfMinX) / nRasterXSize;
    poDS->adfGeoTransform[2] = 0;
    poDS->adfGeoTransform[3] = dfMaxY;
    poDS->adfGeoTransform[4] = 0;
    poDS->adfGeoTransform[5] = - (dfMaxY - dfMinY) / nRasterYSize;
    poDS->nDataStart = VSIFTellL(fp);
    if (bCompressed)
    {
        poDS->panOffsets = (vsi_l_offset*)
                        VSIMalloc2(sizeof(vsi_l_offset), nRasterYSize);
        if (poDS->panOffsets == NULL)
        {
            delete poDS;
            return NULL;
        }
    }
/* -------------------------------------------------------------------- */
/*      Create band information objects.                                */
/* -------------------------------------------------------------------- */
    poDS->nBands = 1;
    for( int i = 0; i < poDS->nBands; i++ )
        poDS->SetBand( i+1, new E00GRIDRasterBand( poDS, i+1, eDT ) );

/* -------------------------------------------------------------------- */
/*      Initialize any PAM information.                                 */
/* -------------------------------------------------------------------- */
    poDS->SetDescription( poOpenInfo->pszFilename );
    poDS->TryLoadXML();

/* -------------------------------------------------------------------- */
/*      Support overviews.                                              */
/* -------------------------------------------------------------------- */
    poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename );
    return poDS;
}

OGRErr OGRCSVLayer::CreateFeature( OGRFeature *poNewFeature )

{
    int iField;

    if( !bInWriteMode )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
            "The CreateFeature() operation is not permitted on a read-only CSV." );
        return OGRERR_FAILURE;
    }

    /* If we need rewind, it means that we have just written a feature before */
    /* so there's no point seeking to the end of the file, as we're already */
    /* at the end */
    int bNeedSeekEnd = !bNeedRewindBeforeRead;

    bNeedRewindBeforeRead = TRUE;

/* -------------------------------------------------------------------- */
/*      Write field names if we haven't written them yet.               */
/*      Write .csvt file if needed                                      */
/* -------------------------------------------------------------------- */
    if( bNew )
    {
        OGRErr eErr = WriteHeader();
        if (eErr != OGRERR_NONE)
            return eErr;
        bNeedSeekEnd = FALSE;
    }

    if (fpCSV == NULL)
        return OGRERR_FAILURE;

/* -------------------------------------------------------------------- */
/*      Make sure we are at the end of the file.                        */
/* -------------------------------------------------------------------- */
    if (bNeedSeekEnd)
    {
        if (bFirstFeatureAppendedDuringSession)
        {
            /* Add a newline character to the end of the file if necessary */
            bFirstFeatureAppendedDuringSession = FALSE;
            VSIFSeekL( fpCSV, 0, SEEK_END );
            VSIFSeekL( fpCSV, VSIFTellL(fpCSV) - 1, SEEK_SET);
            char chLast;
            VSIFReadL( &chLast, 1, 1, fpCSV );
            VSIFSeekL( fpCSV, 0, SEEK_END );
            if (chLast != '\n')
            {
                if( bUseCRLF )
                    VSIFPutcL( 13, fpCSV );
                VSIFPutcL( '\n', fpCSV );
            }
        }
        else
        {
            VSIFSeekL( fpCSV, 0, SEEK_END );
        }
    }

/* -------------------------------------------------------------------- */
/*      Write out the geometry                                          */
/* -------------------------------------------------------------------- */
    if (eGeometryFormat == OGR_CSV_GEOM_AS_WKT)
    {
        OGRGeometry     *poGeom = poNewFeature->GetGeometryRef();
        char* pszWKT = NULL;
        if (poGeom && poGeom->exportToWkt(&pszWKT) == OGRERR_NONE)
        {
            VSIFPrintfL( fpCSV, "\"%s\"", pszWKT);
        }
        else
        {
            VSIFPrintfL( fpCSV, "\"\"");
        }
        CPLFree(pszWKT);
        if (poFeatureDefn->GetFieldCount() > 0)
            VSIFPrintfL( fpCSV, "%c", chDelimiter);
    }
    else if (eGeometryFormat == OGR_CSV_GEOM_AS_XYZ ||
             eGeometryFormat == OGR_CSV_GEOM_AS_XY ||
             eGeometryFormat == OGR_CSV_GEOM_AS_YX)
    {
        OGRGeometry     *poGeom = poNewFeature->GetGeometryRef();
        if (poGeom && wkbFlatten(poGeom->getGeometryType()) == wkbPoint)
        {
            OGRPoint* poPoint = (OGRPoint*) poGeom;
            char szBuffer[75];
            if (eGeometryFormat == OGR_CSV_GEOM_AS_XYZ )
                OGRMakeWktCoordinate(szBuffer, poPoint->getX(), poPoint->getY(), poPoint->getZ(), 3);
            else if (eGeometryFormat == OGR_CSV_GEOM_AS_XY )
                OGRMakeWktCoordinate(szBuffer, poPoint->getX(), poPoint->getY(), 0, 2);
            else
                OGRMakeWktCoordinate(szBuffer, poPoint->getY(), poPoint->getX(), 0, 2);
            char* pc = szBuffer;
            while(*pc != '\0')
            {
                if (*pc == ' ')
                    *pc = chDelimiter;
//.........这里部分代码省略.........

OGRFeature *OGRBNALayer::GetNextFeature()
{
    OGRFeature  *poFeature;
    BNARecord* record;
    int offset, line;

    if (failed || eof) return NULL;

    while(1)
    {
        int ok = FALSE;
        offset = (int) VSIFTellL(fpBNA);
        line = curLine;
        if (nNextFID < nFeatures)
        {
            VSIFSeekL( fpBNA, offsetAndLineFeaturesTable[nNextFID].offset, SEEK_SET );
            curLine = offsetAndLineFeaturesTable[nNextFID].line;
        }
        record =  BNA_GetNextRecord(fpBNA, &ok, &curLine, TRUE, bnaFeatureType);
        if (ok == FALSE)
        {
            BNA_FreeRecord(record);
            failed = TRUE;
            return NULL;
        }
        if (record == NULL)
        {
            /* end of file */
            eof = TRUE;

            /* and we have finally build the whole index table */
            partialIndexTable = FALSE;
            return NULL;
        }

        if (record->featureType == bnaFeatureType)
        {
            if (nNextFID >= nFeatures)
            {
                nFeatures++;
                offsetAndLineFeaturesTable =
                    (OffsetAndLine*)CPLRealloc(offsetAndLineFeaturesTable, nFeatures * sizeof(OffsetAndLine));
                offsetAndLineFeaturesTable[nFeatures-1].offset = offset;
                offsetAndLineFeaturesTable[nFeatures-1].line = line;
            }

            poFeature = BuildFeatureFromBNARecord(record, nNextFID++);

            BNA_FreeRecord(record);

            if(   (m_poFilterGeom == NULL
                || FilterGeometry( poFeature->GetGeometryRef() ) )
            && (m_poAttrQuery == NULL
                || m_poAttrQuery->Evaluate( poFeature )) )
            {
                 return poFeature;
            }

            delete poFeature;
        }
        else
        {
            BNA_FreeRecord(record);
        }
    }
}

static void msTransformToGeospatialPDF(imageObj *img, mapObj *map, cairo_renderer *r)
{
  /* We need a GDAL 1.10 PDF driver at runtime, but as far as the C API is concerned, GDAL 1.9 is */
  /* largely sufficient. */
#if defined(USE_GDAL) && defined(GDAL_VERSION_NUM) && GDAL_VERSION_NUM >= 1900
  GDALDatasetH hDS = NULL;
  const char* pszGEO_ENCODING = NULL;
  GDALDriverH hPDFDriver = NULL;
  const char* pszVirtualIO = NULL;
  int bVirtualIO = FALSE;
  char* pszTmpFilename = NULL;
  VSILFILE* fp = NULL;

  if (map == NULL)
    return;

  pszGEO_ENCODING = msGetOutputFormatOption(img->format, "GEO_ENCODING", NULL);
  if (pszGEO_ENCODING == NULL)
    return;

  msGDALInitialize();

  hPDFDriver = GDALGetDriverByName("PDF");
  if (hPDFDriver == NULL)
    return;

  /* When compiled against libpoppler, the PDF driver is VirtualIO capable */
  /* but not, when it is compiled against libpodofo. */
  pszVirtualIO = GDALGetMetadataItem( hPDFDriver, GDAL_DCAP_VIRTUALIO, NULL );
  if (pszVirtualIO)
    bVirtualIO = CSLTestBoolean(pszVirtualIO);

  if (bVirtualIO)
    pszTmpFilename = msTmpFile(map, NULL, "/vsimem/mscairopdf/", "pdf");
  else
    pszTmpFilename = msTmpFile(map, map->mappath, NULL, "pdf");

  /* Copy content of outputStream buffer into file */
  fp = VSIFOpenL(pszTmpFilename, "wb");
  if (fp == NULL) {
    msFree(pszTmpFilename);
    return;
  }
  VSIFWriteL(r->outputStream->data, 1, r->outputStream->size, fp);
  VSIFCloseL(fp);
  fp = NULL;

  hDS = GDALOpen(pszTmpFilename, GA_Update);
  if ( hDS != NULL ) {
    char* pszWKT = msProjectionObj2OGCWKT( &(map->projection) );
    if( pszWKT != NULL ) {
      double adfGeoTransform[6];
      int i;

      /* Add user-specified options */
      for( i = 0; i < img->format->numformatoptions; i++ ) {
        const char* pszOption = img->format->formatoptions[i];
        if( strncasecmp(pszOption,"METADATA_ITEM:",14) == 0 ) {
          char* pszKey = NULL;
          const char* pszValue = CPLParseNameValue(pszOption + 14,
                                 &pszKey);
          if( pszKey != NULL ) {
            GDALSetMetadataItem(hDS, pszKey, pszValue, NULL);
            CPLFree(pszKey);
          }
        }
      }

      /* We need to rescale the geotransform because GDAL will not necessary */
      /* open the PDF with the DPI that was used to generate it */
      memcpy(adfGeoTransform, map->gt.geotransform, 6 * sizeof(double));
      adfGeoTransform[1] = adfGeoTransform[1] * map->width / GDALGetRasterXSize(hDS);
      adfGeoTransform[5] = adfGeoTransform[5] * map->height / GDALGetRasterYSize(hDS);
      GDALSetGeoTransform(hDS, adfGeoTransform);
      GDALSetProjection(hDS, pszWKT);

      msFree( pszWKT );
      pszWKT = NULL;

      CPLSetThreadLocalConfigOption("GDAL_PDF_GEO_ENCODING", pszGEO_ENCODING);

      GDALClose(hDS);
      hDS = NULL;

      CPLSetThreadLocalConfigOption("GDAL_PDF_GEO_ENCODING", NULL);

      /* We need to replace the buffer with the content of the GDAL file */
      fp = VSIFOpenL(pszTmpFilename, "rb");
      if( fp != NULL ) {
        int nFileSize;

        VSIFSeekL(fp, 0, SEEK_END);
        nFileSize = (int)VSIFTellL(fp);

        msBufferResize(r->outputStream, nFileSize);

        VSIFSeekL(fp, 0, SEEK_SET);
        VSIFReadL(r->outputStream->data, 1, nFileSize, fp);

        r->outputStream->size = nFileSize;
//.........这里部分代码省略.........

//.........这里部分代码省略.........
/* -------------------------------------------------------------------- */
/*      If the header is invalid, then clean up, report the error       */
/*      and return.                                                     */
/* -------------------------------------------------------------------- */
    if( !bValid )
    {
        CPL_IGNORE_RET_VAL(VSIFCloseL( fpDDF ));
        fpDDF = NULL;

        if( !bFailQuietly )
            CPLError( CE_Failure, CPLE_AppDefined,
                      "File `%s' does not appear to have\n"
                      "a valid ISO 8211 header.\n",
                      pszFilename );
        return FALSE;
    }

/* -------------------------------------------------------------------- */
/*      Read the whole record info memory.                              */
/* -------------------------------------------------------------------- */
    char        *pachRecord;

    pachRecord = (char *) CPLMalloc(_recLength);
    memcpy( pachRecord, achLeader, nLeaderSize );

    if( (int)VSIFReadL( pachRecord+nLeaderSize, 1, _recLength-nLeaderSize, fpDDF )
        != _recLength - nLeaderSize )
    {
        if( !bFailQuietly )
            CPLError( CE_Failure, CPLE_FileIO,
                      "Header record is short on DDF file `%s'.",
                      pszFilename );

        return FALSE;
    }

/* -------------------------------------------------------------------- */
/*      First make a pass counting the directory entries.               */
/* -------------------------------------------------------------------- */
    int         nFieldEntryWidth, nFDCount = 0;

    nFieldEntryWidth = _sizeFieldLength + _sizeFieldPos + _sizeFieldTag;

    for( i = nLeaderSize; i < _recLength; i += nFieldEntryWidth )
    {
        if( pachRecord[i] == DDF_FIELD_TERMINATOR )
            break;

        nFDCount++;
    }

/* -------------------------------------------------------------------- */
/*      Allocate, and read field definitions.                           */
/* -------------------------------------------------------------------- */
    for( i = 0; i < nFDCount; i++ )
    {
        char    szTag[128];
        int     nEntryOffset = nLeaderSize + i*nFieldEntryWidth;
        int     nFieldLength, nFieldPos;
        DDFFieldDefn *poFDefn;

        strncpy( szTag, pachRecord+nEntryOffset, _sizeFieldTag );
        szTag[_sizeFieldTag] = '\0';

        nEntryOffset += _sizeFieldTag;
        nFieldLength = DDFScanInt( pachRecord+nEntryOffset, _sizeFieldLength );

        nEntryOffset += _sizeFieldLength;
        nFieldPos = DDFScanInt( pachRecord+nEntryOffset, _sizeFieldPos );

        if (_fieldAreaStart+nFieldPos < 0 ||
            _recLength - (_fieldAreaStart+nFieldPos) < nFieldLength)
        {
            if( !bFailQuietly )
                CPLError( CE_Failure, CPLE_FileIO,
                        "Header record invalid on DDF file `%s'.",
                        pszFilename );

            CPLFree( pachRecord );
            return FALSE;
        }

        poFDefn = new DDFFieldDefn();
        if( poFDefn->Initialize( this, szTag, nFieldLength,
                                 pachRecord+_fieldAreaStart+nFieldPos ) )
            AddField( poFDefn );
        else
            delete poFDefn;
    }

    CPLFree( pachRecord );

/* -------------------------------------------------------------------- */
/*      Record the current file offset, the beginning of the first      */
/*      data record.                                                    */
/* -------------------------------------------------------------------- */
    nFirstRecordOffset = (long)VSIFTellL( fpDDF );

    return TRUE;
}

void GDALPamProxyDB::LoadDB()

{
/* -------------------------------------------------------------------- */
/*      Open the database relating original names to proxy .aux.xml     */
/*      file names.                                                     */
/* -------------------------------------------------------------------- */
    CPLString osDBName = 
        CPLFormFilename( osProxyDBDir, "gdal_pam_proxy", "dat" );
    FILE *fpDB = VSIFOpenL( osDBName, "r" );

    nUpdateCounter = 0;
    if( fpDB == NULL )
        return;

/* -------------------------------------------------------------------- */
/*      Read header, verify and extract update counter.                 */
/* -------------------------------------------------------------------- */
    GByte  abyHeader[100];

    if( VSIFReadL( abyHeader, 1, 100, fpDB ) != 100 
        || strncmp( (const char *) abyHeader, "GDAL_PROXY", 10 ) != 0 )
    {
        CPLError( CE_Failure, CPLE_AppDefined, 
                  "Problem reading %s header - short or corrupt?", 
                  osDBName.c_str() );
        return;
    }

    nUpdateCounter = atoi((const char *) abyHeader + 10);

/* -------------------------------------------------------------------- */
/*      Read the file in one gulp.                                      */
/* -------------------------------------------------------------------- */
    int nBufLength;
    char *pszDBData;

    VSIFSeekL( fpDB, 0, SEEK_END );
    nBufLength = (int) (VSIFTellL(fpDB) - 100);

    pszDBData = (char *) CPLCalloc(1,nBufLength+1);
    VSIFSeekL( fpDB, 100, SEEK_SET );
    VSIFReadL( pszDBData, 1, nBufLength, fpDB );

    VSIFCloseL( fpDB );

/* -------------------------------------------------------------------- */
/*      Parse the list of in/out names.                                 */
/* -------------------------------------------------------------------- */
    int iNext = 0;

    while( iNext < nBufLength )
    {
        CPLString osOriginal, osProxy;

        osOriginal.assign( pszDBData + iNext );

        for( ; iNext < nBufLength && pszDBData[iNext] != '\0'; iNext++ ) {}
        
        if( iNext == nBufLength )
            break;
        
        iNext++;

        osProxy = osProxyDBDir;
        osProxy += "/";
        osProxy += pszDBData + iNext;

        for( ; iNext < nBufLength && pszDBData[iNext] != '\0'; iNext++ ) {}
        iNext++;

        aosOriginalFiles.push_back( osOriginal );
        aosProxyFiles.push_back( osProxy );
    }        

    CPLFree( pszDBData );
}

//.........这里部分代码省略.........
/*      Read the palette.                                               */
/* -------------------------------------------------------------------- */

    GByte palette[768];

    GUInt16 i;
    for( i = 0; i < 256; i++ )
    {
        VSIFReadL( &palette[i * 3 + 2], 1, 1, poOpenInfo->fpL );
        VSIFReadL( &palette[i * 3 + 1], 1, 1, poOpenInfo->fpL );
        VSIFReadL( &palette[i * 3 + 0], 1, 1, poOpenInfo->fpL );
    }

/* -------------------------------------------------------------------- */
/*      Find block offsets.                                             */
/* -------------------------------------------------------------------- */

    GUInt32 blocks;
    GUInt32 *offsets;

    blocks = header.iHorBlocks * header.iVertBlocks;
    offsets = (GUInt32 *)CPLMalloc( blocks * sizeof(GUInt32) );

    if( !offsets )
    {
        CPLError( CE_Failure, CPLE_OpenFailed,
                  "File %s. Unable to allocate offset table.\n",
                  poOpenInfo->pszFilename );
        return NULL;
    }

    if( header.iOptions == 0x00 )
    {
        offsets[0] = VSIFTellL( poOpenInfo->fpL );

        for( GUInt32 i = 1; i < blocks; i++ )
        {
            offsets[i] = offsets[i - 1] +
                header.iBlockWidth * header.iBlockHeight;
        }
    }
    else
    {
        for( GUInt32 i = 0; i < blocks; i++ )
        {
            VSIFReadL( &offsets[i], 1, sizeof(offsets[i]), poOpenInfo->fpL );
#ifdef CPL_MSB
            CPL_SWAP32PTR( &offsets[i] );
#endif
            if( rik3header )
            {
                GUInt32 blockSize;
                VSIFReadL( &blockSize, 1, sizeof(blockSize), poOpenInfo->fpL );
#ifdef CPL_MSB
                CPL_SWAP32PTR( &blockSize );
#endif
            }
        }
    }

/* -------------------------------------------------------------------- */
/*      Final checks.                                                   */
/* -------------------------------------------------------------------- */

    // File size

//.........这里部分代码省略.........
                {
                    if (!bLastWasSep)
                        nCol ++;
                    bLastWasSep = TRUE;
                }
                else if ((ch == ',' && poGDS->chDecimalSep != ',') || ch == '\t' || ch == ';')
                {
                    nCol ++;
                    bLastWasSep = TRUE;
                }
                else
                {
                    bLastWasSep = FALSE;
                }
                pszPtr ++;
            }

            /* Skip empty line */
            if (nCol == 0 && bLastWasSep)
                continue;

            poGDS->nDataLineNum ++;
        }
    }

    double dfExpectedY = poGDS->adfGeoTransform[3] + (0.5 + nBlockYOff) * poGDS->adfGeoTransform[5];
    int idx = -1;
    while(TRUE)
    {
        int nCol;
        int bLastWasSep;
        do
        {
            vsi_l_offset nOffsetBefore = VSIFTellL(poGDS->fp);
            const char* pszLine = CPLReadLine2L(poGDS->fp, 100, 0);
            if (pszLine == NULL)
            {
                if( poGDS->bSameNumberOfValuesPerLine )
                {
                    CPLError(CE_Failure, CPLE_AppDefined, "Cannot read line %d", poGDS->nLineNum + 1);
                    return CE_Failure;
                }
                else
                {
                    nLastYOff = nBlockYOff;
                    return CE_None;
                }
            }
            poGDS->nLineNum ++;

            const char* pszPtr = pszLine;
            char ch;
            nCol = 0;
            bLastWasSep = TRUE;
            double dfX = 0.0, dfY = 0.0, dfZ = 0.0;
            int bUsefulColsFound = 0;
            while((ch = *pszPtr) != '\0')
            {
                if (ch == ' ')
                {
                    if (!bLastWasSep)
                        nCol ++;
                    bLastWasSep = TRUE;
                }
                else if ((ch == ',' && poGDS->chDecimalSep != ',') || ch == '\t' || ch == ';')
                {

Track* GTM::fetchNextTrack()
{
    /* Point to the actual track offset */
    if ( VSIFSeekL(pGTMFile, actualTrackOffset, SEEK_SET) != 0)
        return nullptr;

    /* Read string length */
    const unsigned short stringSize = readUShort(pGTMFile);
    /* Read name string */
    char* pszName = (char*) VSI_MALLOC2_VERBOSE(sizeof(char), stringSize+1);
    if( pszName == nullptr )
        return nullptr;
    if ( stringSize != 0 && !readFile( pszName, 1, sizeof(char) * stringSize ) )
    {
        CPLFree(pszName);
        return nullptr;
    }
    pszName[stringSize] = '\0';

    /* Read type */
    const unsigned char type = readUChar(pGTMFile);

    /* Read color */
    const int color = readInt(pGTMFile);

    Track* poTrack = new Track(pszName, type, color);

    CPLFree(pszName);
    /* Adjust actual Track offset */
    actualTrackOffset = VSIFTellL(pGTMFile) + 7;
    ++trackFetched;

    /* Now, We read all trackpoints for this track */
    double latitude = 0.0;
    double longitude = 0.0;
    GIntBig datetime = 0;
    unsigned char start = 0;
    float altitude = 0.0f;
    /* NOTE: Parameters are passed by reference */
    if ( !readTrackPoints(latitude, longitude, datetime, start, altitude) )
    {
        delete poTrack;
        return nullptr;
    }

    /* Check if it is the start, if not we have done something wrong */
    if (start != 1)
    {
        delete poTrack;
        return nullptr;
    }
    poTrack->addPoint(longitude, latitude, datetime, altitude);

    do
    {
        /* NOTE: Parameters are passed by reference */
        if ( !readTrackPoints(latitude, longitude, datetime, start, altitude) )
        {
            delete poTrack;
            return nullptr;
        }
        if (start == 0)
            poTrack->addPoint(longitude, latitude, datetime, altitude);
    } while(start == 0 && trackpointFetched < ntcks);

    /* We have read one more than necessary, so we adjust the offset */
    if (trackpointFetched < ntcks)
    {
        actualTrackpointOffset -= 25;
        --trackpointFetched;
    }

    return poTrack;
}

/**********************************************************************
 *                   TABRawBinBlock::CommitToFile()
 *
 * Commit the current state of the binary block to the file to which
 * it has been previously attached.
 *
 * Derived classes may want to (optionally) reimplement this method if
 * they need to do special processing before committing the block to disk.
 *
 * For files created with bHardBlockSize=TRUE, a complete block of
 * the specified size is always written, otherwise only the number of
 * used bytes in the block will be written to disk.
 *
 * Returns 0 if successful or -1 if an error happened, in which case
 * CPLError() will have been called.
 **********************************************************************/
int     TABRawBinBlock::CommitToFile()
{
    int nStatus = 0;

    if (m_fp == NULL || m_nBlockSize <= 0 || m_pabyBuf == NULL ||
        m_nFileOffset < 0)
    {
        CPLError(CE_Failure, CPLE_AssertionFailed,
        "TABRawBinBlock::CommitToFile(): Block has not been initialized yet!");
        return -1;
    }

    /*----------------------------------------------------------------
     * If block has not been modified, then just return... nothing to do.
     *---------------------------------------------------------------*/
    if (!m_bModified)
        return 0;

    /*----------------------------------------------------------------
     * Move the output file pointer to the right position...
     *---------------------------------------------------------------*/
    if (VSIFSeekL(m_fp, m_nFileOffset, SEEK_SET) != 0)
    {
        /*------------------------------------------------------------
         * Moving pointer failed... we may need to pad with zeros if
         * block destination is beyond current end of file.
         *-----------------------------------------------------------*/
        int nCurPos = (int)VSIFTellL(m_fp);

        if (nCurPos < m_nFileOffset &&
            VSIFSeekL(m_fp, 0L, SEEK_END) == 0 &&
            (nCurPos = (int)VSIFTellL(m_fp)) < m_nFileOffset)
        {
            const GByte cZero = 0;

            while(nCurPos < m_nFileOffset && nStatus == 0)
            {
                if (VSIFWriteL(&cZero, 1, 1, m_fp) != 1)
                {
                    CPLError(CE_Failure, CPLE_FileIO,
                             "Failed writing 1 byte at offset %d.", nCurPos);
                    nStatus = -1;
                    break;
                }
                nCurPos++;
            }
        }

        if (nCurPos != m_nFileOffset)
            nStatus = -1; // Error message will follow below

    }

    /*----------------------------------------------------------------
     * At this point we are ready to write to the file.
     *
     * If m_bHardBlockSize==FALSE, then we do not write a complete block;
     * we write only the part of the block that was used.
     *---------------------------------------------------------------*/
    int numBytesToWrite = m_bHardBlockSize?m_nBlockSize:m_nSizeUsed;

    /*CPLDebug("MITAB", "Committing to offset %d", m_nFileOffset);*/

    if (nStatus != 0 ||
        VSIFWriteL(m_pabyBuf,sizeof(GByte),
                    numBytesToWrite, m_fp) != (size_t)numBytesToWrite )
    {
        CPLError(CE_Failure, CPLE_FileIO,
                 "Failed writing %d bytes at offset %d.",
                 numBytesToWrite, m_nFileOffset);
        return -1;
    }
    if( m_nFileOffset + numBytesToWrite > m_nFileSize )
    {
        m_nFileSize = m_nFileOffset + numBytesToWrite;
    }

    VSIFFlushL(m_fp);

    m_bModified = FALSE;

    return 0;
}

//.........这里部分代码省略.........
        memcpy( achHeader +  5*16+8, pszValue, MIN(16,strlen(pszValue)) );

        memcpy( achHeader +  6*16, "SYSTEM_T        ", 16 );
        pszValue = CSLFetchNameValueDef( papszOptions, "SYSTEM_T", "" );
        memcpy( achHeader +  6*16+8, pszValue, MIN(16,strlen(pszValue)) );

        memcpy( achHeader +  7*16, "MAJOR_F ", 8);
        memcpy( achHeader +  8*16, "MINOR_F ", 8 );
        memcpy( achHeader +  9*16, "MAJOR_T ", 8 );
        memcpy( achHeader + 10*16, "MINOR_T ", 8 );

        VSIFWriteL( achHeader, 1, sizeof(achHeader), fp );
    }

/* -------------------------------------------------------------------- */
/*      Otherwise update the header with an increased subfile count,    */
/*      and advanced to the last record of the file.                    */
/* -------------------------------------------------------------------- */
    else
    {
        VSIFSeekL( fp, 2*16 + 8, SEEK_SET );
        VSIFReadL( &nNumFile, 1, 4, fp );
        CPL_LSBPTR32( &nNumFile );

        nNumFile++;
        
        CPL_LSBPTR32( &nNumFile );
        VSIFSeekL( fp, 2*16 + 8, SEEK_SET );
        VSIFWriteL( &nNumFile, 1, 4, fp );

        vsi_l_offset nEnd;

        VSIFSeekL( fp, 0, SEEK_END );
        nEnd = VSIFTellL( fp );
        VSIFSeekL( fp, nEnd-16, SEEK_SET );
    }

/* -------------------------------------------------------------------- */
/*      Write the grid header.                                          */
/* -------------------------------------------------------------------- */
    memset( achHeader, 0, sizeof(achHeader) );

    memcpy( achHeader +  0*16, "SUB_NAME        ", 16 );
    pszValue = CSLFetchNameValueDef( papszOptions, "SUB_NAME", "" );
    memcpy( achHeader +  0*16+8, pszValue, MIN(16,strlen(pszValue)) );
    
    memcpy( achHeader +  1*16, "PARENT          ", 16 );
    pszValue = CSLFetchNameValueDef( papszOptions, "PARENT", "NONE" );
    memcpy( achHeader +  1*16+8, pszValue, MIN(16,strlen(pszValue)) );
    
    memcpy( achHeader +  2*16, "CREATED         ", 16 );
    pszValue = CSLFetchNameValueDef( papszOptions, "CREATED", "" );
    memcpy( achHeader +  2*16+8, pszValue, MIN(16,strlen(pszValue)) );
    
    memcpy( achHeader +  3*16, "UPDATED         ", 16 );
    pszValue = CSLFetchNameValueDef( papszOptions, "UPDATED", "" );
    memcpy( achHeader +  3*16+8, pszValue, MIN(16,strlen(pszValue)) );

    double dfValue;

    memcpy( achHeader +  4*16, "S_LAT   ", 8 );
    dfValue = 0;
    CPL_LSBPTR64( &dfValue );
    memcpy( achHeader +  4*16 + 8, &dfValue, 8 );

    memcpy( achHeader +  5*16, "N_LAT   ", 8 );

int OGRBNADataSource::Open( const char * pszFilename, int bUpdateIn)

{
    int ok = FALSE;

    pszName = CPLStrdup( pszFilename );
    bUpdate = bUpdateIn;

/* -------------------------------------------------------------------- */
/*      Determine what sort of object this is.                          */
/* -------------------------------------------------------------------- */
    VSIStatBufL sStatBuf;

    if( VSIStatL( pszFilename, &sStatBuf ) != 0 )
        return FALSE;
    
// -------------------------------------------------------------------- 
//      Does this appear to be a .bna file?
// --------------------------------------------------------------------
    if( !(EQUAL( CPLGetExtension(pszFilename), "bna" )
           || ((EQUALN( pszFilename, "/vsigzip/", 9) || EQUALN( pszFilename, "/vsizip/", 8)) &&
               (strstr( pszFilename, ".bna") || strstr( pszFilename, ".BNA")))) )
        return FALSE;
    
    VSILFILE* fp = VSIFOpenL(pszFilename, "rb");
    if (fp)
    {
        BNARecord* record;
        int curLine = 0;
        const char* layerRadixName[] = { "points", "polygons", "lines", "ellipses"};
        OGRwkbGeometryType wkbGeomTypes[] = { wkbPoint, wkbMultiPolygon, wkbLineString, wkbPolygon };
        int i;
#if defined(BNA_FAST_DS_OPEN)
        record = BNA_GetNextRecord(fp, &ok, &curLine, FALSE, BNA_READ_NONE);
        BNA_FreeRecord(record);

        if (ok)
        {
            nLayers = 4;

            papoLayers = (OGRBNALayer **) CPLMalloc(nLayers * sizeof(OGRBNALayer*));
            for(i=0;i<4;i++)
                papoLayers[i] = new OGRBNALayer( pszFilename,
                                                 layerRadixName[i],
                                                 (BNAFeatureType)i, wkbGeomTypes[i], FALSE, this );
        }
#else
        int nFeatures[4] = { 0, 0, 0, 0 };
        OffsetAndLine* offsetAndLineFeaturesTable[4] = { NULL, NULL, NULL, NULL };
        int nIDs[4] = {0, 0, 0, 0};
        int partialIndexTable = TRUE;

        while(1)
        {
            int offset = VSIFTellL(fp);
            int line = curLine;
            record =  BNA_GetNextRecord(fp, &ok, &curLine, FALSE, BNA_READ_NONE);
            if (ok == FALSE)
            {
                BNA_FreeRecord(record);
                if (line != 0)
                    ok = TRUE;
                break;
            }
            if (record == NULL)
            {
                /* end of file */
                ok = TRUE;

                /* and we have finally build the whole index table */
                partialIndexTable = FALSE;
                break;
            }

            if (record->nIDs > nIDs[record->featureType])
                nIDs[record->featureType] = record->nIDs;

            nFeatures[record->featureType]++;
            offsetAndLineFeaturesTable[record->featureType] =
                (OffsetAndLine*)CPLRealloc(offsetAndLineFeaturesTable[record->featureType],
                                           nFeatures[record->featureType] * sizeof(OffsetAndLine));
            offsetAndLineFeaturesTable[record->featureType][nFeatures[record->featureType]-1].offset = offset;
            offsetAndLineFeaturesTable[record->featureType][nFeatures[record->featureType]-1].line = line;

            BNA_FreeRecord(record);
        }

        nLayers = (nFeatures[0] != 0) + (nFeatures[1] != 0) + (nFeatures[2] != 0) + (nFeatures[3] != 0);
        papoLayers = (OGRBNALayer **) CPLMalloc(nLayers * sizeof(OGRBNALayer*));
        int iLayer = 0;
        for(i=0;i<4;i++)
        {
            if (nFeatures[i])
            {
                papoLayers[iLayer] = new OGRBNALayer( pszFilename,
                                                      layerRadixName[i],
                                                      (BNAFeatureType)i,
                                                      wkbGeomTypes[i],
                                                      FALSE,
                                                      this,
//.........这里部分代码省略.........

int VSIIngestFile( VSILFILE* fp,
                   const char* pszFilename,
                   GByte** ppabyRet,
                   vsi_l_offset* pnSize,
                   GIntBig nMaxSize)
{
    vsi_l_offset nDataLen = 0;
    int bFreeFP = FALSE;

    if( fp == NULL && pszFilename == NULL )
        return FALSE;
    if( ppabyRet == NULL )
        return FALSE;

    *ppabyRet = NULL;
    if( pnSize != NULL )
        *pnSize = 0;

    if( NULL == fp )
    {
        fp = VSIFOpenL( pszFilename, "rb" );
        if( NULL == fp )
        {
            CPLError( CE_Failure, CPLE_FileIO,
                      "Cannot open file '%s'", pszFilename );
            return FALSE;
        }
        bFreeFP = TRUE;
    }
    else
        VSIFSeekL(fp, 0, SEEK_SET);

    if( pszFilename == NULL ||
        strcmp(pszFilename, "/vsistdin/") == 0 )
    {
        vsi_l_offset nDataAlloc = 0;
        VSIFSeekL( fp, 0, SEEK_SET );
        while(TRUE)
        {
            if( nDataLen + 8192 + 1 > nDataAlloc )
            {
                nDataAlloc = (nDataAlloc * 4) / 3 + 8192 + 1;
                if( nDataAlloc > (vsi_l_offset)(size_t)nDataAlloc )
                {
                    CPLError( CE_Failure, CPLE_AppDefined,
                              "Input file too large to be opened" );
                    VSIFree( *ppabyRet );
                    *ppabyRet = NULL;
                    if( bFreeFP )
                        VSIFCloseL( fp );
                    return FALSE;
                }
                GByte* pabyNew = (GByte*)VSIRealloc(*ppabyRet, (size_t)nDataAlloc);
                if( pabyNew == NULL )
                {
                    CPLError( CE_Failure, CPLE_OutOfMemory,
                              "Cannot allocated " CPL_FRMT_GIB " bytes",
                              nDataAlloc );
                    VSIFree( *ppabyRet );
                    *ppabyRet = NULL;
                    if( bFreeFP )
                        VSIFCloseL( fp );
                    return FALSE;
                }
                *ppabyRet = pabyNew;
            }
            int nRead = (int)VSIFReadL( *ppabyRet + nDataLen, 1, 8192, fp );
            nDataLen += nRead;

            if ( nMaxSize >= 0 && nDataLen > (vsi_l_offset)nMaxSize )
            {
                CPLError( CE_Failure, CPLE_AppDefined,
                              "Input file too large to be opened" );
                VSIFree( *ppabyRet );
                *ppabyRet = NULL;
                if( pnSize != NULL )
                    *pnSize = 0;
                if( bFreeFP )
                    VSIFCloseL( fp );
                return FALSE;
            }

            if( pnSize != NULL )
                *pnSize += nRead;
            (*ppabyRet)[nDataLen] = '\0';
            if( nRead == 0 )
                break;
        }
    }
    else
    {
        VSIFSeekL( fp, 0, SEEK_END );
        nDataLen = VSIFTellL( fp );

        // With "large" VSI I/O API we can read data chunks larger than VSIMalloc
        // could allocate. Catch it here.
        if ( nDataLen > (vsi_l_offset)(size_t)nDataLen ||
             (nMaxSize >= 0 && nDataLen > (vsi_l_offset)nMaxSize) )
        {
            CPLError( CE_Failure, CPLE_AppDefined,
//.........这里部分代码省略.........

static vsi_l_offset USGSDEMGetCurrentFilePos( const Buffer* psBuffer )
{
    return VSIFTellL(psBuffer->fp) - psBuffer->buffer_size + psBuffer->cur_index;
}