// Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of the License "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
//
// Collection of common constants, utility functions, etc. for the file server and file systems.
// Definitions here must be filesystem-agnostic, i.e. generic enougs to be used by every file system
//
// This is the internal file and must not be exported.
/**
@file
@internalTechnology
*/
#include "bit_vector.h"
//#######################################################################################################################################
//# RBitVector class implementation
//#######################################################################################################################################
const TUint32 K_FFFF = 0xFFFFFFFF; //-- all one bits, beware rigth shifts of signed integers!
RBitVector::RBitVector()
:iNumBits(0), ipData(NULL), iNumWords(0)
{
}
RBitVector::~RBitVector()
{
Close();
}
/**
Panics.
@param aPanicCode a panic code
*/
void RBitVector::Panic(TPanicCode aPanicCode) const
{
_LIT(KPanicCat,"RBitVector");
User::Panic(KPanicCat, aPanicCode);
}
/** explicitly closes the object and deallocates memory */
void RBitVector::Close()
{
iNumBits = 0;
iNumWords =0;
User::Free(ipData);
ipData = NULL;
}
//-----------------------------------------------------------------------------
/**
Comparison perator.
@param aRhs a vector to compate with.
@panic ESizeMismatch in the case of different vector sizes
*/
TBool RBitVector::operator==(const RBitVector& aRhs) const
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
__ASSERT_ALWAYS(iNumBits == aRhs.iNumBits, Panic(ESizeMismatch));
if(!iNumBits)
return ETrue; //-- comparing 0-lenght arrays
if(this == &aRhs)
{//-- comparing with itself, potential source of errors
ASSERT(0);
return ETrue;
}
if(iNumWords >= 1)
{
const TUint32 cntBytes = (iNumBits >> 5) << 2; //-- bytes to compare
if(memcompare((const TUint8*)ipData, cntBytes, (const TUint8*)aRhs.ipData, cntBytes))
return EFalse;
}
const TUint32 bitsRest = iNumBits & 0x1F;
if(bitsRest)
{
const TUint32 mask = K_FFFF >> (32-bitsRest);
return ( (ipData[iNumWords-1] & mask) == (aRhs.ipData[iNumWords-1] & mask) );
}
return ETrue;
}
TBool RBitVector::operator!=(const RBitVector& aRhs) const
{
return ! ((*this) == aRhs);
}
//-----------------------------------------------------------------------------
/** The same as Create(), but leaves on error */
void RBitVector::CreateL(TUint32 aNumBits)
{
User::LeaveIfError(Create(aNumBits));
}
/**
Create the vector with the size of aNumBits bits.
@return system-wide error codes:
KErrNoMemory unable to allocate sufficient amount of memory for the array
KErrInUse an attempt to call Create() for non-empty vector. Close it first.
KErrArgument invalid aNumBits value == 0
*/
TInt RBitVector::Create(TUint32 aNumBits)
{
if(ipData)
return KErrInUse; //-- array is already in use. Close it first.
if(!aNumBits)
return KErrArgument;
//-- memory is allocated by word (32 bit) quiantities
const TUint32 numWords = (aNumBits >> 5) + ((aNumBits & 0x1F) > 0 ? 1:0);
ipData = (TUint32*)User::AllocZ(numWords << 2);
if(!ipData)
return KErrNoMemory;
iNumBits = aNumBits;
iNumWords = numWords;
return KErrNone;
}
/**
Fill a bit vector with a given bit value
@param aVal a bit value
*/
void RBitVector::Fill(TBool aVal)
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
memset(ipData, (aVal ? 0xFF : 0x00), iNumWords << 2);
}
/** Invert all bits in a bit vector */
void RBitVector::Invert()
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
for(TUint32 i=0; i<iNumWords; ++i)
ipData[i] ^= K_FFFF;
}
/**
Perform "And" operation between 2 vectors. They shall be the same size.
@param aRhs a vector from the right hand side
@panic ESizeMismatch in the case of different vector sizes
*/
void RBitVector::And(const RBitVector& aRhs)
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
__ASSERT_ALWAYS(iNumBits == aRhs.iNumBits, Panic(ESizeMismatch));
for(TUint32 i=0; i<iNumWords; ++i)
{
ipData[i] &= aRhs.ipData[i];
}
}
/**
Perform "Or" operation between 2 vectors. They shall be the same size.
@param aRhs a vector from the right hand side
@panic ESizeMismatch in the case of different vector sizes
*/
void RBitVector::Or(const RBitVector& aRhs)
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
__ASSERT_ALWAYS(iNumBits == aRhs.iNumBits, Panic(ESizeMismatch));
for(TUint32 i=0; i<iNumWords; ++i)
{
ipData[i] |= aRhs.ipData[i];
}
}
/**
Perform "Xor" operation between 2 vectors. They shall be the same size.
@param aRhs a vector from the right hand side
@panic ESizeMismatch in the case of different vector sizes
*/
void RBitVector::Xor(const RBitVector& aRhs)
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
__ASSERT_ALWAYS(iNumBits == aRhs.iNumBits, Panic(ESizeMismatch));
for(TUint32 i=0; i<iNumWords; ++i)
{
ipData[i] ^= aRhs.ipData[i];
}
}
//-----------------------------------------------------------------------------
/**
Fill a range from bit number "aIndexFrom" to "aIndexTo" inclusively with the value of aVal
@param aIndexFrom start bit number (inclusive)
@param aIndexTo end bit number (inclusive)
@param aVal the value to be used to fill the range (0s or 1s)
*/
void RBitVector::Fill(TUint32 aIndexFrom, TUint32 aIndexTo, TBool aVal)
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
//-- swap indexes if they are not in order
if(aIndexFrom > aIndexTo)
{
const TUint32 tmp = aIndexFrom;
aIndexFrom = aIndexTo;
aIndexTo = tmp;
}
__ASSERT_ALWAYS((aIndexFrom < iNumBits) && (aIndexTo < iNumBits), Panic(EIndexOutOfRange));
const TUint32 wordStart = WordNum(aIndexFrom);
const TUint32 wordTo = WordNum(aIndexTo);
if(aVal)
{//-- filling a range with '1'
TUint32 shift = BitInWord(aIndexFrom);
const TUint32 mask1 = (K_FFFF >> shift) << shift;
TUint32 mask2 = K_FFFF;
shift = 1+BitInWord(aIndexTo);
if(shift < 32)
{
mask2 = ~((mask2 >> shift) << shift);
}
if(wordTo == wordStart)
{//-- a special case, filling is in the same word
ipData[wordStart] |= (mask1 & mask2);
}
else
{
ipData[wordStart] |= mask1;
ipData[wordTo] |= mask2;
const TUint32 wholeWordsBetween = wordTo - wordStart - 1; //-- whole words that can be bulk filled
if(wholeWordsBetween)
memset(ipData+wordStart+1, 0xFF, wholeWordsBetween << 2);
}
}
else
{//-- filling a range with '0'
TUint32 shift = BitInWord(aIndexFrom);
const TUint32 mask1 = ~((K_FFFF >> shift) << shift);
TUint32 mask2 = 0;
shift = 1+BitInWord(aIndexTo);
if(shift < 32)
{
mask2 = ((K_FFFF >> shift) << shift);
}
if(wordTo == wordStart)
{//-- a special case, filling is in the same word
ipData[wordStart] &= (mask1 | mask2);
}
else
{
ipData[wordStart] &= mask1;
ipData[wordTo] &= mask2;
const TUint32 wholeWordsBetween = wordTo - wordStart - 1; //-- whole words that can be bulk filled
if(wholeWordsBetween)
memset(ipData+wordStart+1, 0x00, wholeWordsBetween << 2);
}
}
}
//-----------------------------------------------------------------------------
/**
Search for a specified bit value ('0' or '1') in the vector from the given position.
@param aStartPos zero-based index; from this position the search will start. This position isn't included to the search.
On return may contain a new position if the specified bit is found in specified direction.
@param aBitVal zero or non-zero bit to search.
@param aDir Specifies the search direction
@return ETrue if the specified bit value is found; aStartPos gets updated.
EFalse otherwise.
*/
TBool RBitVector::Find(TUint32& aStartPos, TBool aBitVal, TFindDirection aDir) const
{
__ASSERT_ALWAYS(aStartPos < iNumBits, Panic(EIndexOutOfRange));
ASSERT(iNumWords && ipData);
switch(aDir)
{
case ERight: //-- Search from the given position to the right
return FindToRight(aStartPos, aBitVal);
case ELeft: //-- Search from the given position to the left (towards lower index)
return FindToLeft(aStartPos, aBitVal);
case ENearestL: //-- Search for the nearest value in both directions starting from left
return FindNearest(aStartPos, aBitVal, ETrue);
case ENearestR: //-- Search for the nearest value in both directions starting from right
return FindNearest(aStartPos, aBitVal, EFalse);
default:
Panic(EWrondFindDirection);
return EFalse;
};
}
//-----------------------------------------------------------------------------
/**
Internal method to look for a given bit value in the right direction.
see TBool RBitVector::Find(...)
*/
TBool RBitVector::FindToRight(TUint32& aStartPos, TBool aBitVal) const
{
if(aStartPos >= iNumBits-1)
return EFalse; //-- no way to the right
const TUint32 startPos = aStartPos+1;
const TUint32 fInvert = aBitVal ? 0 : K_FFFF; //-- invert everything if we are looking for '0' bit
TUint32 wordNum = WordNum(startPos);
TUint32 val = ipData[wordNum] ^ fInvert;
if(wordNum == iNumWords-1)
{//-- process the last word in the array, some higher bits might not belong to the bit vector
val = MaskLastWord(val);
}
const TUint32 shift = BitInWord(startPos);
val = (val >> shift) << shift; //-- mask unused low bits
if(val)
{//-- there are '1' bits in the current word
goto found;
}
else
{//-- search in higher words
wordNum++;
while(iNumWords-wordNum > 1)
{
val = ipData[wordNum] ^ fInvert;
if(val)
goto found;
wordNum++;
}
if(wordNum == iNumWords-1)
{//-- process the last word in the array, some higher bith might not belong to the bit vector
val = ipData[wordNum] ^ fInvert;
val = MaskLastWord(val);
if(val)
goto found;
}
}
return EFalse; //-- haven't found anything
found:
val &= (~val+1); //-- select rightmost bit
aStartPos = (wordNum << 5)+Log2(val);
return ETrue;
}
//-----------------------------------------------------------------------------
/**
Internal method to look for a given bit value in the left direction.
see TBool RBitVector::Find(...)
*/
TBool RBitVector::FindToLeft(TUint32& aStartPos, TBool aBitVal) const
{
if(!aStartPos)
return EFalse; //-- no way to the left
const TUint32 startPos=aStartPos-1;
const TUint32 fInvert = aBitVal ? 0 : K_FFFF; //-- invert everything if we are looking for '0' bit
TUint32 wordNum = WordNum(startPos);
TUint32 val = ipData[wordNum] ^ fInvert;
const TUint32 shift = 31-(BitInWord(startPos));
val = (val << shift) >> shift; //-- mask unused high bits
if(val)
{//-- there are '1' bits in the current word
goto found;
}
else
{//-- search in the lower words
while(wordNum)
{
wordNum--;
val=ipData[wordNum] ^ fInvert;
if(val)
goto found;
}
}
return EFalse; //-- nothing found
found:
aStartPos = (wordNum << 5)+Log2(val);
return ETrue;
}
//-----------------------------------------------------------------------------
/**
Internal method to look for a given bit value in the both directions.
see TBool RBitVector::Find(...)
*/
TBool RBitVector::FindNearest(TUint32& aStartPos, TBool aBitVal, TBool aToLeft) const
{
if(iNumBits < 2)
return EFalse;
if(aStartPos == 0)
return FindToRight(aStartPos, aBitVal);
if(aStartPos == iNumBits-1)
return FindToLeft(aStartPos, aBitVal);
const TUint32 fInvert = aBitVal ? 0 : K_FFFF; //-- invert everything if we are looking for '0' bit
TUint32 wordNum = WordNum(aStartPos);
TUint32 l_Idx; //-- index of the word to the left
TUint32 r_Idx; //-- index of the word to the right
l_Idx = r_Idx = wordNum;
TBool noWayLeft = (wordNum == 0); //-- if we are in the first word
TBool noWayRight = (wordNum == iNumWords-1); //-- if we are in the last word
//-- look in the current word first
TUint32 val = ipData[wordNum] ^ fInvert;
if(noWayRight)
{ //-- this is the last word in the array, mask unused high bits in the last word
val = MaskLastWord(val);
}
const TUint32 bitPos = aStartPos & 0x1F;
val &= ~(1<<bitPos); //-- mask the bit at current position
if(val == 0)
{//-- no '1' bits in the current word
noWayLeft = ItrLeft(l_Idx);
noWayRight = ItrRight(r_Idx);
}
else if(bitPos == 0)
{
noWayLeft = ItrLeft(l_Idx); //-- move to the previous word
}
else if(bitPos == 31)
{
noWayRight = ItrRight(r_Idx); //-- move to the next word
}
else
{//-- look in the current word, in both halves to the left and right from the start position
const TUint32 shift1 = 32-bitPos;
const TUint32 partLo = (val << shift1) >> shift1; //-- towards lower bits
const TUint32 shift2 = bitPos+1;
const TUint32 partHi = (val >> shift2) << shift2; //-- towards higher bits
if(partLo && !partHi) //-- only lower part has '1' bits
{
aStartPos = (wordNum << 5)+Log2(partLo);
return ETrue;
}
else if(!partLo && partHi) //-- only higher part has '1' bits
{
aStartPos = (wordNum << 5)+Log2( (partHi & (~partHi+1)) );
return ETrue;
}
else if(partLo && partHi) //-- both parts contain '1' bits, select the nearest one
{
const TUint32 posL = (wordNum << 5)+Log2(partLo);
const TUint32 posR = (wordNum << 5)+Log2( (partHi & (~partHi+1)) );
ASSERT(aStartPos > posL);
ASSERT(posR > aStartPos);
const TUint32 distL = aStartPos-posL;
const TUint32 distR = posR-aStartPos;
if(distL < distR)
{
aStartPos = posL;
return ETrue;
}
else if(distL > distR)
{
aStartPos = posR;
return ETrue;
}
else
{//-- distL == distR, take into account search priority
aStartPos = aToLeft ? posL : posR;
return ETrue;
}
}
else //-- (!partLo && !partHi), nothing in the current word
{
ASSERT(0);
}
}// if(bitPos > 0 && bitPos < 31)
//-- now we are processing separate words from both sides of the search position
for(;;)
{
TUint32 wL = ipData[l_Idx] ^ fInvert;
TUint32 wR = ipData[r_Idx] ^ fInvert;
if(r_Idx == iNumWords-1)
{ //-- this is the last word in the array, mask unused high bits in the last word
wR = MaskLastWord(wR);
}
if(wL && !wR)
{
aStartPos = (l_Idx << 5)+Log2(wL);
return ETrue;
}
else if(!wL && wR)
{
aStartPos = (r_Idx << 5)+Log2( (wR & (~wR+1)) );
return ETrue;
}
else if(wL && wR)
{
const TUint32 posL = (l_Idx << 5)+Log2(wL);
const TUint32 posR = (r_Idx << 5)+Log2( (wR & (~wR+1)) );
ASSERT(aStartPos > posL);
ASSERT(posR > aStartPos);
const TUint32 distL = aStartPos-posL;
const TUint32 distR = posR-aStartPos;
if(distL < distR)
{
aStartPos = posL;
return ETrue;
}
else if(distL > distR)
{
aStartPos = posR;
return ETrue;
}
else
{//-- distL == distR, take into account search priority
aStartPos = aToLeft ? posL : posR;
return ETrue;
}
}//else if(wL && wR)
if(noWayLeft)
{
aStartPos = r_Idx << 5;
return FindToRight(aStartPos, aBitVal);
}
else
{
noWayLeft = ItrLeft(l_Idx);
}
if(noWayRight)
{
aStartPos = l_Idx << 5;
return FindToLeft(aStartPos, aBitVal);
}
else
{
noWayRight = ItrRight(r_Idx);
}
}//for(;;)
//return EFalse;
}
//-----------------------------------------------------------------------------
/**
Find out if two vectors are different.
@param aRhs vector to compare with
@param aDiffIndex if there is a differene, here will be the number of the first different bit
@return ETrue if vectors differ, EFalse, if they are identical.
*/
TBool RBitVector::Diff(const RBitVector& aRhs, TUint32& aDiffIndex) const
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
__ASSERT_ALWAYS(iNumBits == aRhs.iNumBits, Panic(ESizeMismatch));
ASSERT(iNumWords > 0);
TUint32 diffWord=0;
TUint32 wordNum=0;
//-- compare all but the last word in the array
for(wordNum=0; wordNum < iNumWords-1; ++wordNum)
{
diffWord = ipData[wordNum] ^ aRhs.ipData[wordNum];
if(diffWord)
break; //-- found difference
}
//-- process the last word in the array
if(!diffWord)
{
diffWord = MaskLastWord(ipData[wordNum]) ^ MaskLastWord(aRhs.ipData[wordNum]);
}
if(!diffWord)
return EFalse; //-- vectors are the same
//-- calculate the position of the bit that different.
diffWord &= (~diffWord+1); //-- select rightmost bit
aDiffIndex = (wordNum << 5)+Log2(diffWord);
return ETrue;
}
//-----------------------------------------------------------------------------
/**
Iterate to the left (towards lower index) in the array of words ipData
@param aIdx index within ipData array to be decremented; if it's possible to move left, it will be decreased
@return ETrue if there is no way left i.e. aIdx is 0. EFalse otherwise and aIdx decreased.
*/
TBool RBitVector::ItrLeft(TUint32& aIdx) const
{
if(aIdx == 0)
return ETrue;
else
{
aIdx--;
return EFalse;
}
}
//-----------------------------------------------------------------------------
/**
Iterate to the right (towards higher index) in the array of words ipData
@param aIdx index within ipData array to be incremented; if it's possible to move right, it will be increased
@return ETrue if there is no way right i.e. aIdx corresponds to the last word. EFalse otherwise and aIdx increased.
*/
TBool RBitVector::ItrRight(TUint32& aIdx) const
{
if(aIdx < iNumWords-1)
{
aIdx++;
return EFalse;
}
else
return ETrue;
}
//-----------------------------------------------------------------------------
/**
Import data to the internal bit vector representation.
Just replaces number of bytes from apData to the ipData.
@param aStartBit starting bit number. Must have 8-bit alignment.
@param aNumBits number of bits to import; granularity: 1 bit, i.e. it can be 177, for example.
@param apData pointer to the data (bitstream) to import.
*/
void RBitVector::DoImportData(TUint32 aStartBit, TUint32 aNumBits, const TAny* apData)
{
ASSERT(aNumBits);
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
//-- check parameters granularity. aStartBit must have 8-bit alignment
__ASSERT_ALWAYS(!(aStartBit & 0x07), Panic(EDataAlignment));
__ASSERT_ALWAYS(iNumWords && (aStartBit+aNumBits <= iNumBits), Panic(EIndexOutOfRange));
const TUint bitsTail = aNumBits & 0x07;
const TUint32 nBytes = aNumBits >> 3;
if(nBytes)
{//-- copy full array of bytes
const TUint32 startByte = aStartBit >> 3;
Mem::Copy(((TUint8*)ipData) + startByte, apData, nBytes);
}
if(bitsTail)
{//-- we need to copy trailing bits from the input data to the corresponding byte of the internal array
const TUint8 mask = (TUint8)(0xFF >> (8-bitsTail));
const TUint8 orMask = (TUint8)( *((const TUint8*)apData + nBytes) & mask);
const TUint8 andMask= (TUint8)~mask;
TUint8* pbData = (TUint8*)ipData + nBytes;
*pbData &= andMask;
*pbData |= orMask;
}
}
//-----------------------------------------------------------------------------
/**
Export data from the internal bit vector buffer to the external one.
@param aStartBit starting bit number. Must have 8-bit alignment.
@param aNumBits number of bits to export, must comprise the whole byte, i.e. be multiple of 8.
The client is responsible for masking extra bits it doesn't need.
Another implication: e.g. if the bitvector consists of 3 bits, this value must be 8.
The value of bits 3-7 in the aData[0] will be undefined.
@param aData destination data descriptor
*/
void RBitVector::DoExportData(TUint32 aStartBit, TUint32 aNumBits, TDes8& aData) const
{
ASSERT(aNumBits);
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
//-- check parameters granularity.
__ASSERT_ALWAYS(!(aStartBit & 0x07), Panic(EDataAlignment)); //-- aStartBit must have 8-bit alignment
__ASSERT_ALWAYS(!(aNumBits & 0x07), Panic(EDataAlignment)); //-- number of bits shall comprise a byte
__ASSERT_ALWAYS(iNumWords && (aStartBit+aNumBits <= (iNumWords << (KBitsInByteLog2+sizeof(TUint32))) ), Panic(EIndexOutOfRange));
const TUint32 nBytes = aNumBits >> 3;
const TUint32 startByte = aStartBit >> 3;
aData.SetLength(nBytes);
aData.Copy(((const TUint8*)ipData) + startByte, nBytes);
}
//-----------------------------------------------------------------------------
/**
@return number of bits set to '1' in the vector
*/
TUint32 RBitVector::Num1Bits() const
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
if(!iNumBits)
return 0;
TUint32 cntBits = 0;
TUint32 wordNum;
for(wordNum=0; wordNum < iNumWords-1; ++wordNum)
{
cntBits += Count1Bits(ipData[wordNum]);
}
//-- process the last word, it shall be masked
cntBits += Count1Bits(MaskLastWord(ipData[wordNum]));
return cntBits;
}
//-----------------------------------------------------------------------------
/**
@return number of bits set to '0' in the vector
*/
TUint32 RBitVector::Num0Bits() const
{
return iNumBits - Num1Bits();
}
//-----------------------------------------------------------------------------
/**
Calculate number of '1' bits in the range from aIndexFrom to aIndexTo inclusively
@param aIndexFrom starting index; bit[aIndexFrom] is included to the search
@param aIndexTo ending index; bit[aIndexTo] is included to the search
@return number of bits set to '1' in the slice
*/
TUint32 RBitVector::Num1Bits(TUint32 aIndexFrom, TUint32 aIndexTo) const
{
__ASSERT_ALWAYS(ipData, Panic(ENotInitialised));
__ASSERT_ALWAYS(aIndexTo < iNumBits && aIndexFrom <= aIndexTo, Panic(EIndexOutOfRange));
const TUint32 wordFrom = WordNum(aIndexFrom); //?const
const TUint32 wordTo = WordNum(aIndexTo);
if(wordFrom == wordTo)
{//-- the same word
TUint32 word = ipData[wordFrom];
const TUint32 shMaskR = BitInWord(aIndexFrom);
word >>= shMaskR; word <<= shMaskR; //-- zero low bits
const TUint32 shMaskL = 31-BitInWord(aIndexTo);
word <<= shMaskL; //-- zero high bits
return Count1Bits(word);
}
TUint32 bitsCnt = 0;
TUint32 wordsBetween = wordTo - wordFrom - 1;
//-- count '1' bits in the termial words
TUint32 word = ipData[wordFrom];
const TUint32 shMaskR = BitInWord(aIndexFrom);
word >>= shMaskR; //-- zero low bits
bitsCnt += Count1Bits(word);
word = ipData[wordTo];
const TUint32 shMaskL = 31-BitInWord(aIndexTo);
word <<= shMaskL; //-- zero high bits
bitsCnt += Count1Bits(word);
//-- count '1' bits in the words between terminal ones
TUint32 wordIdx = wordFrom+1;
while(wordsBetween--)
{
bitsCnt += Count1Bits(ipData[wordIdx]);
}
return bitsCnt;
}