ossimDDFField Class Reference

This object represents one field in a DDFRecord. More...

#include <ossimIso8211.h>

Public Member Functions
void	Initialize (ossimDDFFieldDefn *, const char *pszData, int nSize)
void	Dump (FILE *fp)
	Write out field contents to debugging file. More...
const char *	GetSubfieldData (ossimDDFSubfieldDefn *, int *=NULL, int=0)
	Fetch raw data pointer for a particular subfield of this field. More...
const char *	GetInstanceData (int nInstance, int *pnSize)
	Get field instance data and size. More...
const char *	GetData ()
	Return the pointer to the entire data block for this record. More...
int	GetDataSize ()
	Return the number of bytes in the data block returned by GetData(). More...
int	GetRepeatCount ()
	How many times do the subfields of this record repeat? This will always be one for non-repeating fields. More...
ossimDDFFieldDefn *	GetFieldDefn ()
	Fetch the corresponding DDFFieldDefn. More...

Private Attributes
ossimDDFFieldDefn *	poDefn
int	nDataSize
const char *	pachData

Detailed Description

This object represents one field in a DDFRecord.

This models an instance of the fields data, rather than it's data definition which is handled by the DDFFieldDefn class. Note that a DDFField doesn't have DDFSubfield children as you would expect. To extract subfield values use GetSubfieldData() to find the right data pointer and then use ExtractIntData(), ExtractFloatData() or ExtractStringData().

Definition at line 492 of file ossimIso8211.h.

Member Function Documentation

Dump()

void ossimDDFField::Dump

(

FILE *

fp

)

Write out field contents to debugging file.

A variety of information about this field, and all it's subfields is written to the given debugging file handle. Note that field definition information (ala DDFFieldDefn) isn't written.

Parameters

fp	The standard io file handle to write to. ie. stderr

Definition at line 71 of file ossimDdffield.cpp.

References ossimDDFSubfieldDefn::DumpData(), ossimDDFSubfieldDefn::GetDataLength(), ossimDDFFieldDefn::GetName(), GetRepeatCount(), ossimDDFFieldDefn::GetSubfield(), ossimDDFFieldDefn::GetSubfieldCount(), min, nDataSize, pachData, and poDefn.

Referenced by ossimDDFRecord::Dump().

{
    int         nMaxRepeat = 8;

    if( getenv("DDF_MAXDUMP") != NULL )
        nMaxRepeat = atoi(getenv("DDF_MAXDUMP"));

    fprintf( fp, "  DDFField:\n" );
    fprintf( fp, "      Tag = `%s'\n", poDefn->GetName() );
    fprintf( fp, "      DataSize = %d\n", nDataSize );

    fprintf( fp, "      Data = `" );
    for( int i = 0; i < std::min(nDataSize,40); i++ )
    {
        if( pachData[i] < 32 || pachData[i] > 126 )
            fprintf( fp, "\\%02X", ((unsigned char *) pachData)[i] );
        else
            fprintf( fp, "%c", pachData[i] );
    }

    if( nDataSize > 40 )
        fprintf( fp, "..." );
    fprintf( fp, "'\n" );

/* -------------------------------------------------------------------- */
/*      dump the data of the subfields.                                 */
/* -------------------------------------------------------------------- */
    int         iOffset = 0, nLoopCount;

    for( nLoopCount = 0; nLoopCount < GetRepeatCount(); nLoopCount++ )
    {
        if( nLoopCount > nMaxRepeat )
        {
            fprintf( fp, "      ...\n" );
            break;
        }
        
        for( int i = 0; i < poDefn->GetSubfieldCount(); i++ )
        {
            int         nBytesConsumed;

            poDefn->GetSubfield(i)->DumpData( pachData + iOffset,
                                              nDataSize - iOffset, fp );
        
            poDefn->GetSubfield(i)->GetDataLength( pachData + iOffset,
                                                   nDataSize - iOffset,
                                                   &nBytesConsumed );

            iOffset += nBytesConsumed;
        }
    }
}

GetData()

const char* ossimDDFField::GetData ( )

inline

Return the pointer to the entire data block for this record.

This is an internal copy, and shouldn't be freed by the application.

Definition at line 509 of file ossimIso8211.h.

References pachData.

Referenced by ossimDDFRecord::Clone(), ossimDDFRecord::CloneOn(), GetInstanceData(), ossimAdrgHeader::parse(), ossimDDFRecord::ResetDirectory(), ossimDDFRecord::ResizeField(), ossimDDFRecord::SetFieldRaw(), and ossimDDFRecord::UpdateFieldRaw().

{ return pachData; }

GetDataSize()

int ossimDDFField::GetDataSize ( )

inline

Return the number of bytes in the data block returned by GetData().

Definition at line 512 of file ossimIso8211.h.

References nDataSize.

Referenced by ossimDDFRecord::Clone(), ossimDDFRecord::CloneOn(), GetInstanceData(), ossimAdrgHeader::parse(), ossimDDFRecord::ResetDirectory(), ossimDDFRecord::ResizeField(), ossimDDFRecord::SetFieldRaw(), and ossimDDFRecord::UpdateFieldRaw().

{ return nDataSize; }

GetFieldDefn()

ossimDDFFieldDefn* ossimDDFField::GetFieldDefn ( )

inline

Fetch the corresponding DDFFieldDefn.

Definition at line 517 of file ossimIso8211.h.

References poDefn.

Referenced by ossimDDFRecord::CloneOn(), ossimDDFRecord::CreateDefaultFieldInstance(), ossimDDFRecord::FindField(), ossimDDFRecord::GetFloatSubfield(), ossimDDFRecord::GetIntSubfield(), ossimDDFRecord::GetStringSubfield(), ossimAdrgHeader::parse(), ossimDDFRecord::ResetDirectory(), ossimDDFRecord::ResizeField(), ossimDDFRecord::SetFieldRaw(), ossimDDFRecord::SetFloatSubfield(), ossimDDFRecord::SetIntSubfield(), and ossimDDFRecord::SetStringSubfield().

{ return poDefn; }

GetInstanceData()

const char * ossimDDFField::GetInstanceData	(	int	nInstance,
		int *	pnInstanceSize
	)

Get field instance data and size.

The returned data pointer and size values are suitable for use with DDFRecord::SetFieldRaw().

Parameters

nInstance	a value from 0 to GetRepeatCount()-1.
pnInstanceSize	a location to put the size (in bytes) of the field instance data returned. This size will include the unit terminator (if any), but not the field terminator. This size pointer may be NULL if not needed.

Returns

the data pointer, or NULL on error.

Definition at line 280 of file ossimDdffield.cpp.

References GetData(), ossimDDFSubfieldDefn::GetDataLength(), GetDataSize(), GetRepeatCount(), ossimDDFFieldDefn::GetSubfield(), ossimDDFFieldDefn::GetSubfieldCount(), GetSubfieldData(), and poDefn.

Referenced by ossimDDFRecord::SetFieldRaw(), ossimDDFRecord::SetFloatSubfield(), ossimDDFRecord::SetIntSubfield(), ossimDDFRecord::SetStringSubfield(), and ossimDDFRecord::UpdateFieldRaw().

{
    int nRepeatCount = GetRepeatCount();
    const char *pachWrkData;

    if( nInstance < 0 || nInstance >= nRepeatCount )
        return NULL;

/* -------------------------------------------------------------------- */
/*      Special case for fields without subfields (like "0001").  We    */
/*      don't currently handle repeating simple fields.                 */
/* -------------------------------------------------------------------- */
    if( poDefn->GetSubfieldCount() == 0 )
    {
        pachWrkData = GetData();
        if( pnInstanceSize != 0 )
            *pnInstanceSize = GetDataSize();
        return pachWrkData;
    }

/* -------------------------------------------------------------------- */
/*      Get a pointer to the start of the existing data for this        */
/*      iteration of the field.                                         */
/* -------------------------------------------------------------------- */
    int         nBytesRemaining1=0, nBytesRemaining2=0;
    ossimDDFSubfieldDefn *poFirstSubfield;

    poFirstSubfield = poDefn->GetSubfield(0);

    pachWrkData = GetSubfieldData(poFirstSubfield, &nBytesRemaining1,
                               nInstance);

/* -------------------------------------------------------------------- */
/*      Figure out the size of the entire field instance, including     */
/*      unit terminators, but not any trailing field terminator.        */
/* -------------------------------------------------------------------- */
    if( pnInstanceSize != NULL )
    {
        ossimDDFSubfieldDefn *poLastSubfield;
        int              nLastSubfieldWidth;
        const char          *pachLastData;
        
        poLastSubfield = poDefn->GetSubfield(poDefn->GetSubfieldCount()-1);
        
        pachLastData = GetSubfieldData( poLastSubfield, &nBytesRemaining2, 
                                        nInstance );
        poLastSubfield->GetDataLength( pachLastData, nBytesRemaining2, 
                                       &nLastSubfieldWidth );
        
        *pnInstanceSize = 
            nBytesRemaining1 - (nBytesRemaining2 - nLastSubfieldWidth);
    }

    return pachWrkData;
}

GetRepeatCount()

int ossimDDFField::GetRepeatCount

(

)

How many times do the subfields of this record repeat? This
will always be one for non-repeating fields.

Returns

The number of times that the subfields of this record occur in this record. This will be one for non-repeating fields.

See also

8211view example program for demonstation of handling repeated fields properly.

Definition at line 209 of file ossimDdffield.cpp.

References ossimDDFSubfieldDefn::GetDataLength(), ossimDDFFieldDefn::GetFixedWidth(), ossimDDFFieldDefn::GetSubfield(), ossimDDFFieldDefn::GetSubfieldCount(), ossimDDFSubfieldDefn::GetWidth(), ossimDDFFieldDefn::IsRepeating(), nDataSize, pachData, and poDefn.

Referenced by Dump(), GetInstanceData(), ossimDDFRecord::SetFieldRaw(), and ossimDDFRecord::UpdateFieldRaw().

{
    if( !poDefn->IsRepeating() )
        return 1;

/* -------------------------------------------------------------------- */
/*      The occurance count depends on how many copies of this          */
/*      field's list of subfields can fit into the data space.          */
/* -------------------------------------------------------------------- */
    if( poDefn->GetFixedWidth() )
    {
        return nDataSize / poDefn->GetFixedWidth();
    }

/* -------------------------------------------------------------------- */
/*      Note that it may be legal to have repeating variable width      */
/*      subfields, but I don't have any samples, so I ignore it for     */
/*      now.                                                            */
/*                                                                      */
/*      The file data/cape_royal_AZ_DEM/1183XREF.DDF has a repeating    */
/*      variable length field, but the count is one, so it isn't        */
/*      much value for testing.                                         */
/* -------------------------------------------------------------------- */
    int         iOffset = 0, iRepeatCount = 1;
    
    while( true )
    {
        for( int iSF = 0; iSF < poDefn->GetSubfieldCount(); iSF++ )
        {
            int nBytesConsumed;
            ossimDDFSubfieldDefn * poThisSFDefn = poDefn->GetSubfield( iSF );

            if( poThisSFDefn->GetWidth() > nDataSize - iOffset )
                nBytesConsumed = poThisSFDefn->GetWidth();
            else
                poThisSFDefn->GetDataLength( pachData+iOffset, 
                                             nDataSize - iOffset,
                                             &nBytesConsumed);

            iOffset += nBytesConsumed;
            if( iOffset > nDataSize )
                return iRepeatCount - 1;
        }

        if( iOffset > nDataSize - 2 )
            return iRepeatCount;

        iRepeatCount++;
    }
}

GetSubfieldData()

const char * ossimDDFField::GetSubfieldData	(	ossimDDFSubfieldDefn *	poSFDefn,
		int *	pnMaxBytes = NULL,
		int	iSubfieldIndex = 0
	)

Fetch raw data pointer for a particular subfield of this field.

The passed DDFSubfieldDefn (poSFDefn) should be acquired from the DDFFieldDefn corresponding with this field. This is normally done once before reading any records. This method involves a series of calls to DDFSubfield::GetDataLength() in order to track through the DDFField data to that belonging to the requested subfield. This can be relatively expensive.

Parameters

poSFDefn	The definition of the subfield for which the raw data pointer is desired.
pnMaxBytes	The maximum number of bytes that can be accessed from the returned data pointer is placed in this int, unless it is NULL.
iSubfieldIndex	The instance of this subfield to fetch. Use zero (the default) for the first instance.

Returns

A pointer into the DDFField's data that belongs to the subfield. This returned pointer is invalidated by the next record read (DDFRecord::ReadRecord()) and the returned pointer should not be freed by the application.

Definition at line 152 of file ossimDdffield.cpp.

References ossimDDFSubfieldDefn::GetDataLength(), ossimDDFFieldDefn::GetFixedWidth(), ossimDDFFieldDefn::GetSubfield(), ossimDDFFieldDefn::GetSubfieldCount(), nDataSize, pachData, and poDefn.

Referenced by ossimDDFRecord::GetFloatSubfield(), GetInstanceData(), ossimDDFRecord::GetIntSubfield(), ossimDDFRecord::GetStringSubfield(), ossimAdrgHeader::parse(), ossimDDFRecord::SetFloatSubfield(), ossimDDFRecord::SetIntSubfield(), and ossimDDFRecord::SetStringSubfield().

{
    int         iOffset = 0;
    
    if( poSFDefn == NULL )
        return NULL;

    if( iSubfieldIndex > 0 && poDefn->GetFixedWidth() > 0 )
    {
        iOffset = poDefn->GetFixedWidth() * iSubfieldIndex;
        iSubfieldIndex = 0;
    }

    while( iSubfieldIndex >= 0 )
    {
        for( int iSF = 0; iSF < poDefn->GetSubfieldCount(); iSF++ )
        {
            int nBytesConsumed;
            ossimDDFSubfieldDefn * poThisSFDefn = poDefn->GetSubfield( iSF );
            
            if( poThisSFDefn == poSFDefn && iSubfieldIndex == 0 )
            {
                if( pnMaxBytes != NULL )
                    *pnMaxBytes = nDataSize - iOffset;
                
                return pachData + iOffset;
            }
            
            poThisSFDefn->GetDataLength( pachData+iOffset, nDataSize - iOffset,
                                         &nBytesConsumed);
            iOffset += nBytesConsumed;
        }

        iSubfieldIndex--;
    }

    // We didn't find our target subfield or instance!
    return NULL;
}

Initialize()

void ossimDDFField::Initialize	(	ossimDDFFieldDefn *	poDefnIn,
		const char *	pszData,
		int	nSize
	)

Definition at line 48 of file ossimDdffield.cpp.

References nDataSize, pachData, and poDefn.

Referenced by ossimDDFRecord::AddField(), ossimDDFRecord::Clone(), ossimDDFRecord::CloneOn(), ossimDDFRecord::ResetDirectory(), and ossimDDFRecord::ResizeField().

{
    pachData = pachDataIn;
    nDataSize = nDataSizeIn;
    poDefn = poDefnIn;
}

Member Data Documentation

nDataSize

int ossimDDFField::nDataSize

private

Definition at line 522 of file ossimIso8211.h.

Referenced by Dump(), GetDataSize(), GetRepeatCount(), GetSubfieldData(), and Initialize().

pachData

const char* ossimDDFField::pachData

private

Definition at line 524 of file ossimIso8211.h.

Referenced by Dump(), GetData(), GetRepeatCount(), GetSubfieldData(), and Initialize().

poDefn

ossimDDFFieldDefn* ossimDDFField::poDefn

private

Definition at line 520 of file ossimIso8211.h.

Referenced by Dump(), GetFieldDefn(), GetInstanceData(), GetRepeatCount(), GetSubfieldData(), and Initialize().

---

The documentation for this class was generated from the following files:

• ossimIso8211.h
• ossimDdffield.cpp