void BitString::setString( const BitString & i_sStr, uint32_t i_sPos,
uint32_t i_sLen, uint32_t i_dPos )
{
// Ensure the source parameters are valid.
PRDF_ASSERT( nullptr != i_sStr.getBufAddr() );
PRDF_ASSERT( 0 < i_sLen ); // at least one bit to copy
PRDF_ASSERT( i_sPos + i_sLen <= i_sStr.getBitLen() );
// Ensure the destination has at least one bit available to copy.
PRDF_ASSERT( nullptr != getBufAddr() );
PRDF_ASSERT( i_dPos < getBitLen() );
// If the source length is greater than the destination length than the
// extra source bits are ignored.
uint32_t actLen = std::min( i_sLen, getBitLen() - i_dPos );
// The bit strings may be in overlapping memory spaces. So we need to copy
// the data in the correct direction to prevent overlapping.
uint32_t sRelOffset = 0, dRelOffset = 0;
CPU_WORD * sRelAddr = i_sStr.getRelativePosition( sRelOffset, i_sPos );
CPU_WORD * dRelAddr = getRelativePosition( dRelOffset, i_dPos );
// Copy the data.
if ( (dRelAddr == sRelAddr) && (dRelOffset == sRelOffset) )
{
// Do nothing. The source and destination are the same.
}
else if ( (dRelAddr < sRelAddr) ||
((dRelAddr == sRelAddr) && (dRelOffset < sRelOffset)) )
{
// Copy the data forward.
for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
{
uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );
CPU_WORD value = i_sStr.getField( i_sPos + pos, len );
setField( i_dPos + pos, len, value );
}
}
else // Copy the data backwards.
{
// Get the first position of the last chunk (CPU_WORD aligned).
uint32_t lastPos = ((actLen-1) / CPU_WORD_BIT_LEN) * CPU_WORD_BIT_LEN;
// Start with the last chunk and work backwards.
for ( int32_t pos = lastPos; 0 <= pos; pos -= CPU_WORD_BIT_LEN )
{
uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );
CPU_WORD value = i_sStr.getField( i_sPos + pos, len );
setField( i_dPos + pos, len, value );
}
}
}
void BitString::setPattern( uint32_t i_sPos, uint32_t i_sLen,
CPU_WORD i_pattern, uint32_t i_pLen )
{
PRDF_ASSERT(nullptr != getBufAddr()); // must to have a valid address
PRDF_ASSERT(0 < i_sLen); // must have at least one bit
PRDF_ASSERT(i_sPos + i_sLen <= getBitLen()); // field must be within range
PRDF_ASSERT(0 < i_pLen); // must have at least one bit
PRDF_ASSERT(i_pLen <= CPU_WORD_BIT_LEN); // i_pLen length must be valid
// Get a bit string for the pattern subset (right justified).
BitString bso ( i_pLen, &i_pattern, CPU_WORD_BIT_LEN - i_pLen );
// Iterate the range in chunks the size of i_pLen.
uint32_t endPos = i_sPos + i_sLen;
for ( uint32_t pos = i_sPos; pos < endPos; pos += i_pLen )
{
// The true chunk size is either i_pLen or the leftovers at the end.
uint32_t len = std::min( i_pLen, endPos - pos );
// Get this chunk's pattern value, truncate (left justified) if needed.
CPU_WORD pattern = bso.getField( 0, len );
// Set the pattern in this string.
setField( pos, len, pattern );
}
}
bool BitString::isEqual( const BitString & i_str ) const
{
if ( getBitLen() != i_str.getBitLen() )
return false; // size not equal
for ( uint32_t pos = 0; pos < getBitLen(); pos += CPU_WORD_BIT_LEN )
{
uint32_t len = std::min( getBitLen() - pos, CPU_WORD_BIT_LEN );
if ( getField(pos, len) != i_str.getField(pos, len) )
return false; // bit strings do not match
}
return true; // bit strings match
}
void BitString::maskString( const BitString & i_mask )
{
// Get the length of the smallest string.
uint32_t actLen = std::min( getBitLen(), i_mask.getBitLen() );
for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
{
uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );
CPU_WORD dVal = getField( pos, len );
CPU_WORD sVal = i_mask.getField( pos, len );
setField( pos, len, dVal & ~sVal );
}
}
BitStringBuffer BitString::operator|( const BitString & i_bs ) const
{
// Get the length of the smallest string.
uint32_t actLen = std::min( getBitLen(), i_bs.getBitLen() );
BitStringBuffer bsb( actLen );
for ( uint32_t pos = 0; pos < actLen; pos += CPU_WORD_BIT_LEN )
{
uint32_t len = std::min( actLen - pos, CPU_WORD_BIT_LEN );
CPU_WORD dVal = getField( pos, len );
CPU_WORD sVal = i_bs.getField( pos, len );
bsb.setField( pos, len, dVal | sVal );
}
return bsb;
}
