cxdatastructs.cpp

这个是基于在CCS开发环境下

/* initializes sequence writer */
CV_IMPL void
cvStartAppendToSeq( CvSeq *seq, CvSeqWriter * writer )
{
    CV_FUNCNAME( "cvStartAppendToSeq" );

    __BEGIN__;

    if( !seq || !writer )
        CV_ERROR( CV_StsNullPtr, "" );

    memset( writer, 0, sizeof( *writer ));
    writer->header_size = sizeof( CvSeqWriter );

    writer->seq = seq;
    writer->block = seq->first ? seq->first->prev : 0;
    writer->ptr = seq->ptr;
    writer->block_max = seq->block_max;

    __END__;
}


/* initializes sequence writer */
CV_IMPL void
cvStartWriteSeq( int seq_flags, int header_size,
                 int elem_size, CvMemStorage * storage, CvSeqWriter * writer )
{
    CvSeq *seq = 0;

    CV_FUNCNAME( "cvStartWriteSeq" );

    __BEGIN__;

    if( !storage || !writer )
        CV_ERROR( CV_StsNullPtr, "" );

    CV_CALL( seq = cvCreateSeq( seq_flags, header_size, elem_size, storage ));
    cvStartAppendToSeq( seq, writer );

    __END__;
}


/* updates sequence header */
CV_IMPL void
cvFlushSeqWriter( CvSeqWriter * writer )
{
    CvSeq *seq = 0;

    CV_FUNCNAME( "cvFlushSeqWriter" );

    __BEGIN__;

    if( !writer )
        CV_ERROR( CV_StsNullPtr, "" );

    seq = writer->seq;
    seq->ptr = writer->ptr;

    if( writer->block )
    {
        int total = 0;
        CvSeqBlock *first_block = writer->seq->first;
        CvSeqBlock *block = first_block;

        writer->block->count = (int)((writer->ptr - writer->block->data) / seq->elem_size);
        assert( writer->block->count > 0 );

        do
        {
            total += block->count;
            block = block->next;
        }
        while( block != first_block );

        writer->seq->total = total;
    }

    __END__;
}


/* calls icvFlushSeqWriter and finishes writing process */
CV_IMPL CvSeq *
cvEndWriteSeq( CvSeqWriter * writer )
{
    CvSeq *seq = 0;

    CV_FUNCNAME( "cvEndWriteSeq" );

    __BEGIN__;

    if( !writer )
        CV_ERROR( CV_StsNullPtr, "" );

    CV_CALL( cvFlushSeqWriter( writer ));
    seq = writer->seq;

    /* truncate the last block */
    if( writer->block && writer->seq->storage )
    {
        CvMemStorage *storage = seq->storage;
        char *storage_block_max = (char *) storage->top + storage->block_size;

        assert( writer->block->count > 0 );

        if( (unsigned)((storage_block_max - storage->free_space)
            - seq->block_max) < CV_STRUCT_ALIGN )
        {
            storage->free_space = cvAlignLeft((int)(storage_block_max - seq->ptr), CV_STRUCT_ALIGN);
            seq->block_max = seq->ptr;
        }
    }

    writer->ptr = 0;

    __END__;

    return seq;
}


/* creates new sequence block */
CV_IMPL void
cvCreateSeqBlock( CvSeqWriter * writer )
{
    CV_FUNCNAME( "cvCreateSeqBlock" );

    __BEGIN__;

    CvSeq *seq;

    if( !writer || !writer->seq )
        CV_ERROR( CV_StsNullPtr, "" );

    seq = writer->seq;

    cvFlushSeqWriter( writer );

    CV_CALL( icvGrowSeq( seq, 0 ));

    writer->block = seq->first->prev;
    writer->ptr = seq->ptr;
    writer->block_max = seq->block_max;

    __END__;
}


/****************************************************************************************\
*                               Sequence Reader implementation                           *
\****************************************************************************************/

/* initializes sequence reader */
CV_IMPL void
cvStartReadSeq( const CvSeq *seq, CvSeqReader * reader, int reverse )
{
    CvSeqBlock *first_block;
    CvSeqBlock *last_block;

    CV_FUNCNAME( "cvStartReadSeq" );

    if( reader )
    {
        reader->seq = 0;
        reader->block = 0;
        reader->ptr = reader->block_max = reader->block_min = 0;
    }

    __BEGIN__;

    if( !seq || !reader )
        CV_ERROR( CV_StsNullPtr, "" );

    reader->header_size = sizeof( CvSeqReader );
    reader->seq = (CvSeq*)seq;

    first_block = seq->first;

    if( first_block )
    {
        last_block = first_block->prev;
        reader->ptr = first_block->data;
        reader->prev_elem = CV_GET_LAST_ELEM( seq, last_block );
        reader->delta_index = seq->first->start_index;

        if( reverse )
        {
            char *temp = reader->ptr;

            reader->ptr = reader->prev_elem;
            reader->prev_elem = temp;

            reader->block = last_block;
        }
        else
        {
            reader->block = first_block;
        }

        reader->block_min = reader->block->data;
        reader->block_max = reader->block_min + reader->block->count * seq->elem_size;
    }
    else
    {
        reader->delta_index = 0;
        reader->block = 0;

        reader->ptr = reader->prev_elem = reader->block_min = reader->block_max = 0;
    }

    __END__;
}


/* changes the current reading block to the previous or to the next */
CV_IMPL void
cvChangeSeqBlock( void* _reader, int direction )
{
    CV_FUNCNAME( "cvChangeSeqBlock" );

    __BEGIN__;

    CvSeqReader* reader = (CvSeqReader*)_reader;
    
    if( !reader )
        CV_ERROR( CV_StsNullPtr, "" );

    if( direction > 0 )
    {
        reader->block = reader->block->next;
        reader->ptr = reader->block->data;
    }
    else
    {
        reader->block = reader->block->prev;
        reader->ptr = CV_GET_LAST_ELEM( reader->seq, reader->block );
    }
    reader->block_min = reader->block->data;
    reader->block_max = reader->block_min + reader->block->count * reader->seq->elem_size;

    __END__;
}


/* returns the current reader position */
CV_IMPL int
cvGetSeqReaderPos( CvSeqReader* reader )
{
    int elem_size;
    int index = -1;

    CV_FUNCNAME( "cvGetSeqReaderPos" );

    __BEGIN__;

    if( !reader || !reader->ptr )
        CV_ERROR( CV_StsNullPtr, "" );

    elem_size = reader->seq->elem_size;
    if( elem_size <= ICV_SHIFT_TAB_MAX && (index = icvPower2ShiftTab[elem_size - 1]) >= 0 )
        index = (int)((reader->ptr - reader->block_min) >> index);
    else
        index = (int)((reader->ptr - reader->block_min) / elem_size);

    index += reader->block->start_index - reader->delta_index;

    __END__;

    return index;
}


/* sets reader position to given absolute or relative
   (relatively to the current one) position */
CV_IMPL void
cvSetSeqReaderPos( CvSeqReader* reader, int index, int is_relative )
{
    CV_FUNCNAME( "cvSetSeqReaderPos" );

    __BEGIN__;

    CvSeqBlock *block;
    int elem_size, count, total;

    if( !reader || !reader->seq )
        CV_ERROR( CV_StsNullPtr, "" );

    total = reader->seq->total;
    elem_size = reader->seq->elem_size;

    if( !is_relative )
    {
        if( index < 0 )
        {
            if( index < -total )
                CV_ERROR( CV_StsOutOfRange, "" );
            index += total;
        }
        else if( index >= total )
        {
            index -= total;
            if( index >= total )
                CV_ERROR( CV_StsOutOfRange, "" );
        }

        block = reader->seq->first;
        if( index >= (count = block->count) )
        {
            if( index + index <= total )
            {
                do
                {
                    block = block->next;
                    index -= count;
                }
                while( index >= (count = block->count) );
            }
            else
            {
                do
                {
                    block = block->prev;
                    total -= block->count;
                }
                while( index < total );
                index -= total;
            }
        }
        reader->ptr = block->data + index * elem_size;
        if( reader->block != block )
        {
            reader->block = block;
            reader->block_min = block->data;
            reader->block_max = block->data + block->count * elem_size;
        }
    }
    else
    {
        char* ptr = reader->ptr;
        index *= elem_size;
        block = reader->block;

        if( index > 0 )
        {
            while( ptr + index >= reader->block_max )
            {
                int delta = (int)(reader->block_max - ptr);
                index -= delta;
                reader->block = block = block->next;
                reader->block_min = ptr = block->data;
                reader->block_max = block->data + block->count*elem_size;
            }
            reader->ptr = ptr + index;
        }
        else
        {
            while( ptr + index < reader->block_min )
            {
                int delta = (int)(ptr - reader->block_min);
                index += delta;
                reader->block = block = block->prev;
                reader->block_min = block->data;
                reader->block_max = ptr = block->data + block->count*elem_size;
            }
            reader->ptr = ptr + index;
        }
    }

    __END__;
}


/* pushes element to the sequence */
CV_IMPL char*
cvSeqPush( CvSeq *seq, void *element )
{
    char *ptr = 0;
    size_t elem_size;

    CV_FUNCNAME( "cvSeqPush" );

    __BEGIN__;

    if( !seq )
        CV_ERROR( CV_StsNullPtr, "" );

    elem_size = seq->elem_size;
    ptr = seq->ptr;

    if( ptr >= seq->block_max )
    {
        CV_CALL( icvGrowSeq( seq, 0 ));

        ptr = seq->ptr;
        assert( ptr + elem_size <= seq->block_max /*&& ptr == seq->block_min */  );
    }

    if( element )
        CV_MEMCPY_AUTO( ptr, element, elem_size );
    seq->first->prev->count++;
    seq->total++;
    seq->ptr = ptr + elem_size;

    __END__;

    return ptr;
}


/* pops the last element out of the sequence */
CV_IMPL void
cvSeqPop( CvSeq *seq, void *element )
{
    char *ptr;
    int elem_size;

    CV_FUNCNAME( "cvSeqPop" );

    __BEGIN__;

    if( !seq )
        CV_ERROR( CV_StsNullPtr, "" );
    if( seq->total <= 0 )
        CV_ERROR( CV_StsBadSize, "" );

    elem_size = seq->elem_size;
    seq->ptr = ptr = seq->ptr - elem_size;

    if( element )
        CV_MEMCPY_AUTO( element, ptr, elem_size );
    seq->ptr = ptr;
    seq->total--;

    if( --(seq->first->prev->count) == 0 )
    {
        icvFreeSeqBlock( seq, 0 );
        assert( seq->ptr == seq->block_max );
    }

    __END__;
}


/* pushes element to the front of the sequence */
CV_IMPL char*
cvSeqPushFront( CvSeq *seq, void *element )
{
    char* ptr = 0;
    int elem_size;
    CvSeqBlock *block;

    CV_FUNCNAME( "cvSeqPushFront" );

    __BEGIN__;

    if( !seq )
        CV_ERROR( CV_StsNullPtr, "" );

    elem_size = seq->elem_size;
    block = seq->first;

    if( !block || block->start_index == 0 )
    {