Files
mcpe/thirdparty/raknet/BitStream.cpp
iProgramInCpp 9642818a88 * Initial commit.
:)
2023-07-30 22:22:02 +03:00

1183 lines
31 KiB
C++

/*
* Copyright (c) 2014, Oculus VR, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
*/
/// \file
///
#if defined(_MSC_VER) && _MSC_VER < 1299 // VC6 doesn't support template specialization
#include "BitStream_NoTemplate.cpp"
#else
#include "BitStream.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "SocketIncludes.h"
#include "RakNetDefines.h"
#if defined(_WIN32)
#include "WindowsIncludes.h"
#include <memory.h>
#include <cmath>
#include <float.h>
#else
#include <arpa/inet.h>
#include <memory.h>
#if defined(ANDROID)
#include <math.h>
#else
#include <cmath>
#endif
#include <float.h>
#endif
// MSWin uses _copysign, others use copysign...
#ifndef _WIN32
#define _copysign copysign
#endif
using namespace RakNet;
#ifdef _MSC_VER
#pragma warning( push )
#endif
STATIC_FACTORY_DEFINITIONS(BitStream,BitStream)
BitStream::BitStream()
{
numberOfBitsUsed = 0;
//numberOfBitsAllocated = 32 * 8;
numberOfBitsAllocated = BITSTREAM_STACK_ALLOCATION_SIZE * 8;
readOffset = 0;
//data = ( unsigned char* ) rakMalloc_Ex( 32, _FILE_AND_LINE_ );
data = ( unsigned char* ) stackData;
#ifdef _DEBUG
// RakAssert( data );
#endif
//memset(data, 0, 32);
copyData = true;
}
BitStream::BitStream( const unsigned int initialBytesToAllocate )
{
numberOfBitsUsed = 0;
readOffset = 0;
if (initialBytesToAllocate <= BITSTREAM_STACK_ALLOCATION_SIZE)
{
data = ( unsigned char* ) stackData;
numberOfBitsAllocated = BITSTREAM_STACK_ALLOCATION_SIZE * 8;
}
else
{
data = ( unsigned char* ) rakMalloc_Ex( (size_t) initialBytesToAllocate, _FILE_AND_LINE_ );
numberOfBitsAllocated = initialBytesToAllocate << 3;
}
#ifdef _DEBUG
RakAssert( data );
#endif
// memset(data, 0, initialBytesToAllocate);
copyData = true;
}
BitStream::BitStream( unsigned char* _data, const unsigned int lengthInBytes, bool _copyData )
{
numberOfBitsUsed = lengthInBytes << 3;
readOffset = 0;
copyData = _copyData;
numberOfBitsAllocated = lengthInBytes << 3;
if ( copyData )
{
if ( lengthInBytes > 0 )
{
if (lengthInBytes < BITSTREAM_STACK_ALLOCATION_SIZE)
{
data = ( unsigned char* ) stackData;
numberOfBitsAllocated = BITSTREAM_STACK_ALLOCATION_SIZE << 3;
}
else
{
data = ( unsigned char* ) rakMalloc_Ex( (size_t) lengthInBytes, _FILE_AND_LINE_ );
}
#ifdef _DEBUG
RakAssert( data );
#endif
memcpy( data, _data, (size_t) lengthInBytes );
}
else
data = 0;
}
else
data = ( unsigned char* ) _data;
}
// Use this if you pass a pointer copy to the constructor (_copyData==false) and want to overallocate to prevent reallocation
void BitStream::SetNumberOfBitsAllocated( const BitSize_t lengthInBits )
{
#ifdef _DEBUG
RakAssert( lengthInBits >= ( BitSize_t ) numberOfBitsAllocated );
#endif
numberOfBitsAllocated = lengthInBits;
}
BitStream::~BitStream()
{
if ( copyData && numberOfBitsAllocated > (BITSTREAM_STACK_ALLOCATION_SIZE << 3))
rakFree_Ex( data , _FILE_AND_LINE_ ); // Use realloc and free so we are more efficient than delete and new for resizing
}
void BitStream::Reset( void )
{
// Note: Do NOT reallocate memory because BitStream is used
// in places to serialize/deserialize a buffer. Reallocation
// is a dangerous operation (may result in leaks).
if ( numberOfBitsUsed > 0 )
{
// memset(data, 0, BITS_TO_BYTES(numberOfBitsUsed));
}
// Don't free memory here for speed efficiency
//free(data); // Use realloc and free so we are more efficient than delete and new for resizing
numberOfBitsUsed = 0;
//numberOfBitsAllocated=8;
readOffset = 0;
//data=(unsigned char*)rakMalloc_Ex(1, _FILE_AND_LINE_);
// if (numberOfBitsAllocated>0)
// memset(data, 0, BITS_TO_BYTES(numberOfBitsAllocated));
}
// Write an array or casted stream
void BitStream::Write( const char* inputByteArray, const unsigned int numberOfBytes )
{
if (numberOfBytes==0)
return;
// Optimization:
if ((numberOfBitsUsed & 7) == 0)
{
AddBitsAndReallocate( BYTES_TO_BITS(numberOfBytes) );
memcpy(data+BITS_TO_BYTES(numberOfBitsUsed), inputByteArray, (size_t) numberOfBytes);
numberOfBitsUsed+=BYTES_TO_BITS(numberOfBytes);
}
else
{
WriteBits( ( unsigned char* ) inputByteArray, numberOfBytes * 8, true );
}
}
void BitStream::Write( BitStream *bitStream)
{
Write(bitStream, bitStream->GetNumberOfBitsUsed()-bitStream->GetReadOffset());
}
void BitStream::Write( BitStream *bitStream, BitSize_t numberOfBits )
{
AddBitsAndReallocate( numberOfBits );
BitSize_t numberOfBitsMod8;
if ((bitStream->GetReadOffset()&7)==0 && (numberOfBitsUsed&7)==0)
{
int readOffsetBytes=bitStream->GetReadOffset()/8;
int numBytes=numberOfBits/8;
memcpy(data + (numberOfBitsUsed >> 3), bitStream->GetData()+readOffsetBytes, numBytes);
numberOfBits-=BYTES_TO_BITS(numBytes);
bitStream->SetReadOffset(BYTES_TO_BITS(numBytes+readOffsetBytes));
numberOfBitsUsed+=BYTES_TO_BITS(numBytes);
}
while (numberOfBits-->0 && bitStream->readOffset + 1 <= bitStream->numberOfBitsUsed)
{
numberOfBitsMod8 = numberOfBitsUsed & 7;
if ( numberOfBitsMod8 == 0 )
{
// New byte
if (bitStream->data[ bitStream->readOffset >> 3 ] & ( 0x80 >> ( bitStream->readOffset & 7 ) ) )
{
// Write 1
data[ numberOfBitsUsed >> 3 ] = 0x80;
}
else
{
// Write 0
data[ numberOfBitsUsed >> 3 ] = 0;
}
}
else
{
// Existing byte
if (bitStream->data[ bitStream->readOffset >> 3 ] & ( 0x80 >> ( bitStream->readOffset & 7 ) ) )
data[ numberOfBitsUsed >> 3 ] |= 0x80 >> ( numberOfBitsMod8 ); // Set the bit to 1
// else 0, do nothing
}
bitStream->readOffset++;
numberOfBitsUsed++;
}
}
void BitStream::Write( BitStream &bitStream, BitSize_t numberOfBits )
{
Write(&bitStream, numberOfBits);
}
void BitStream::Write( BitStream &bitStream )
{
Write(&bitStream);
}
bool BitStream::Read( BitStream *bitStream, BitSize_t numberOfBits )
{
if (GetNumberOfUnreadBits() < numberOfBits)
return false;
bitStream->Write(this, numberOfBits);
return true;
}
bool BitStream::Read( BitStream *bitStream )
{
bitStream->Write(this);
return true;
}
bool BitStream::Read( BitStream &bitStream, BitSize_t numberOfBits )
{
if (GetNumberOfUnreadBits() < numberOfBits)
return false;
bitStream.Write(this, numberOfBits);
return true;
}
bool BitStream::Read( BitStream &bitStream )
{
bitStream.Write(this);
return true;
}
// Read an array or casted stream
bool BitStream::Read( char* outByteArray, const unsigned int numberOfBytes )
{
// Optimization:
if ((readOffset & 7) == 0)
{
if ( readOffset + ( numberOfBytes << 3 ) > numberOfBitsUsed )
return false;
// Write the data
memcpy( outByteArray, data + ( readOffset >> 3 ), (size_t) numberOfBytes );
readOffset += numberOfBytes << 3;
return true;
}
else
{
return ReadBits( ( unsigned char* ) outByteArray, numberOfBytes * 8 );
}
}
// Sets the read pointer back to the beginning of your data.
void BitStream::ResetReadPointer( void )
{
readOffset = 0;
}
// Sets the write pointer back to the beginning of your data.
void BitStream::ResetWritePointer( void )
{
numberOfBitsUsed = 0;
}
// Write a 0
void BitStream::Write0( void )
{
AddBitsAndReallocate( 1 );
// New bytes need to be zeroed
if ( ( numberOfBitsUsed & 7 ) == 0 )
data[ numberOfBitsUsed >> 3 ] = 0;
numberOfBitsUsed++;
}
// Write a 1
void BitStream::Write1( void )
{
AddBitsAndReallocate( 1 );
BitSize_t numberOfBitsMod8 = numberOfBitsUsed & 7;
if ( numberOfBitsMod8 == 0 )
data[ numberOfBitsUsed >> 3 ] = 0x80;
else
data[ numberOfBitsUsed >> 3 ] |= 0x80 >> ( numberOfBitsMod8 ); // Set the bit to 1
numberOfBitsUsed++;
}
// Returns true if the next data read is a 1, false if it is a 0
bool BitStream::ReadBit( void )
{
bool result = ( data[ readOffset >> 3 ] & ( 0x80 >> ( readOffset & 7 ) ) ) !=0;
readOffset++;
return result;
}
// Align the bitstream to the byte boundary and then write the specified number of bits.
// This is faster than WriteBits but wastes the bits to do the alignment and requires you to call
// SetReadToByteAlignment at the corresponding read position
void BitStream::WriteAlignedBytes( const unsigned char* inByteArray, const unsigned int numberOfBytesToWrite )
{
AlignWriteToByteBoundary();
Write((const char*) inByteArray, numberOfBytesToWrite);
}
void BitStream::EndianSwapBytes( int byteOffset, int length )
{
if (DoEndianSwap())
{
ReverseBytesInPlace(data+byteOffset, length);
}
}
/// Aligns the bitstream, writes inputLength, and writes input. Won't write beyond maxBytesToWrite
void BitStream::WriteAlignedBytesSafe( const char *inByteArray, const unsigned int inputLength, const unsigned int maxBytesToWrite )
{
if (inByteArray==0 || inputLength==0)
{
WriteCompressed((unsigned int)0);
return;
}
WriteCompressed(inputLength);
WriteAlignedBytes((const unsigned char*) inByteArray, inputLength < maxBytesToWrite ? inputLength : maxBytesToWrite);
}
// Read bits, starting at the next aligned bits. Note that the modulus 8 starting offset of the
// sequence must be the same as was used with WriteBits. This will be a problem with packet coalescence
// unless you byte align the coalesced packets.
bool BitStream::ReadAlignedBytes( unsigned char* inOutByteArray, const unsigned int numberOfBytesToRead )
{
#ifdef _DEBUG
RakAssert( numberOfBytesToRead > 0 );
#endif
if ( numberOfBytesToRead <= 0 )
return false;
// Byte align
AlignReadToByteBoundary();
if ( readOffset + ( numberOfBytesToRead << 3 ) > numberOfBitsUsed )
return false;
// Write the data
memcpy( inOutByteArray, data + ( readOffset >> 3 ), (size_t) numberOfBytesToRead );
readOffset += numberOfBytesToRead << 3;
return true;
}
bool BitStream::ReadAlignedBytesSafe( char *inOutByteArray, int &inputLength, const int maxBytesToRead )
{
return ReadAlignedBytesSafe(inOutByteArray,(unsigned int&) inputLength,(unsigned int)maxBytesToRead);
}
bool BitStream::ReadAlignedBytesSafe( char *inOutByteArray, unsigned int &inputLength, const unsigned int maxBytesToRead )
{
if (ReadCompressed(inputLength)==false)
return false;
if (inputLength > maxBytesToRead)
inputLength=maxBytesToRead;
if (inputLength==0)
return true;
return ReadAlignedBytes((unsigned char*) inOutByteArray, inputLength);
}
bool BitStream::ReadAlignedBytesSafeAlloc( char **outByteArray, int &inputLength, const unsigned int maxBytesToRead )
{
return ReadAlignedBytesSafeAlloc(outByteArray,(unsigned int&) inputLength, maxBytesToRead);
}
bool BitStream::ReadAlignedBytesSafeAlloc( char ** outByteArray, unsigned int &inputLength, const unsigned int maxBytesToRead )
{
rakFree_Ex(*outByteArray, _FILE_AND_LINE_ );
*outByteArray=0;
if (ReadCompressed(inputLength)==false)
return false;
if (inputLength > maxBytesToRead)
inputLength=maxBytesToRead;
if (inputLength==0)
return true;
*outByteArray = (char*) rakMalloc_Ex( (size_t) inputLength, _FILE_AND_LINE_ );
return ReadAlignedBytes((unsigned char*) *outByteArray, inputLength);
}
// Write numberToWrite bits from the input source
void BitStream::WriteBits( const unsigned char* inByteArray, BitSize_t numberOfBitsToWrite, const bool rightAlignedBits )
{
// if (numberOfBitsToWrite<=0)
// return;
AddBitsAndReallocate( numberOfBitsToWrite );
const BitSize_t numberOfBitsUsedMod8 = numberOfBitsUsed & 7;
// If currently aligned and numberOfBits is a multiple of 8, just memcpy for speed
if (numberOfBitsUsedMod8==0 && (numberOfBitsToWrite&7)==0)
{
memcpy( data + ( numberOfBitsUsed >> 3 ), inByteArray, numberOfBitsToWrite>>3);
numberOfBitsUsed+=numberOfBitsToWrite;
return;
}
unsigned char dataByte;
const unsigned char* inputPtr=inByteArray;
// Faster to put the while at the top surprisingly enough
while ( numberOfBitsToWrite > 0 )
//do
{
dataByte = *( inputPtr++ );
if ( numberOfBitsToWrite < 8 && rightAlignedBits ) // rightAlignedBits means in the case of a partial byte, the bits are aligned from the right (bit 0) rather than the left (as in the normal internal representation)
dataByte <<= 8 - numberOfBitsToWrite; // shift left to get the bits on the left, as in our internal representation
// Writing to a new byte each time
if ( numberOfBitsUsedMod8 == 0 )
* ( data + ( numberOfBitsUsed >> 3 ) ) = dataByte;
else
{
// Copy over the new data.
*( data + ( numberOfBitsUsed >> 3 ) ) |= dataByte >> ( numberOfBitsUsedMod8 ); // First half
if ( 8 - ( numberOfBitsUsedMod8 ) < 8 && 8 - ( numberOfBitsUsedMod8 ) < numberOfBitsToWrite ) // If we didn't write it all out in the first half (8 - (numberOfBitsUsed%8) is the number we wrote in the first half)
{
*( data + ( numberOfBitsUsed >> 3 ) + 1 ) = (unsigned char) ( dataByte << ( 8 - ( numberOfBitsUsedMod8 ) ) ); // Second half (overlaps byte boundary)
}
}
if ( numberOfBitsToWrite >= 8 )
{
numberOfBitsUsed += 8;
numberOfBitsToWrite -= 8;
}
else
{
numberOfBitsUsed += numberOfBitsToWrite;
numberOfBitsToWrite=0;
}
}
// } while(numberOfBitsToWrite>0);
}
// Set the stream to some initial data. For internal use
void BitStream::SetData( unsigned char *inByteArray )
{
data=inByteArray;
copyData=false;
}
// Assume the input source points to a native type, compress and write it
void BitStream::WriteCompressed( const unsigned char* inByteArray,
const unsigned int size, const bool unsignedData )
{
BitSize_t currentByte = ( size >> 3 ) - 1; // PCs
unsigned char byteMatch;
if ( unsignedData )
{
byteMatch = 0;
}
else
{
byteMatch = 0xFF;
}
// Write upper bytes with a single 1
// From high byte to low byte, if high byte is a byteMatch then write a 1 bit. Otherwise write a 0 bit and then write the remaining bytes
while ( currentByte > 0 )
{
if ( inByteArray[ currentByte ] == byteMatch ) // If high byte is byteMatch (0 of 0xff) then it would have the same value shifted
{
bool b = true;
Write( b );
}
else
{
// Write the remainder of the data after writing 0
bool b = false;
Write( b );
WriteBits( inByteArray, ( currentByte + 1 ) << 3, true );
// currentByte--;
return ;
}
currentByte--;
}
// If the upper half of the last byte is a 0 (positive) or 16 (negative) then write a 1 and the remaining 4 bits. Otherwise write a 0 and the 8 bites.
if ( ( unsignedData && ( ( *( inByteArray + currentByte ) ) & 0xF0 ) == 0x00 ) ||
( unsignedData == false && ( ( *( inByteArray + currentByte ) ) & 0xF0 ) == 0xF0 ) )
{
bool b = true;
Write( b );
WriteBits( inByteArray + currentByte, 4, true );
}
else
{
bool b = false;
Write( b );
WriteBits( inByteArray + currentByte, 8, true );
}
}
// Read numberOfBitsToRead bits to the output source
// alignBitsToRight should be set to true to convert internal bitstream data to userdata
// It should be false if you used WriteBits with rightAlignedBits false
bool BitStream::ReadBits( unsigned char *inOutByteArray, BitSize_t numberOfBitsToRead, const bool alignBitsToRight )
{
#ifdef _DEBUG
// RakAssert( numberOfBitsToRead > 0 );
#endif
if (numberOfBitsToRead<=0)
return false;
if ( readOffset + numberOfBitsToRead > numberOfBitsUsed )
return false;
const BitSize_t readOffsetMod8 = readOffset & 7;
// If currently aligned and numberOfBits is a multiple of 8, just memcpy for speed
if (readOffsetMod8==0 && (numberOfBitsToRead&7)==0)
{
memcpy( inOutByteArray, data + ( readOffset >> 3 ), numberOfBitsToRead>>3);
readOffset+=numberOfBitsToRead;
return true;
}
BitSize_t offset = 0;
memset( inOutByteArray, 0, (size_t) BITS_TO_BYTES( numberOfBitsToRead ) );
while ( numberOfBitsToRead > 0 )
{
*( inOutByteArray + offset ) |= *( data + ( readOffset >> 3 ) ) << ( readOffsetMod8 ); // First half
if ( readOffsetMod8 > 0 && numberOfBitsToRead > 8 - ( readOffsetMod8 ) ) // If we have a second half, we didn't read enough bytes in the first half
*( inOutByteArray + offset ) |= *( data + ( readOffset >> 3 ) + 1 ) >> ( 8 - ( readOffsetMod8 ) ); // Second half (overlaps byte boundary)
if (numberOfBitsToRead>=8)
{
numberOfBitsToRead -= 8;
readOffset += 8;
offset++;
}
else
{
int neg = (int) numberOfBitsToRead - 8;
if ( neg < 0 ) // Reading a partial byte for the last byte, shift right so the data is aligned on the right
{
if ( alignBitsToRight )
* ( inOutByteArray + offset ) >>= -neg;
readOffset += 8 + neg;
}
else
readOffset += 8;
offset++;
numberOfBitsToRead=0;
}
}
return true;
}
// Assume the input source points to a compressed native type. Decompress and read it
bool BitStream::ReadCompressed( unsigned char* inOutByteArray,
const unsigned int size, const bool unsignedData )
{
unsigned int currentByte = ( size >> 3 ) - 1;
unsigned char byteMatch, halfByteMatch;
if ( unsignedData )
{
byteMatch = 0;
halfByteMatch = 0;
}
else
{
byteMatch = 0xFF;
halfByteMatch = 0xF0;
}
// Upper bytes are specified with a single 1 if they match byteMatch
// From high byte to low byte, if high byte is a byteMatch then write a 1 bit. Otherwise write a 0 bit and then write the remaining bytes
while ( currentByte > 0 )
{
// If we read a 1 then the data is byteMatch.
bool b;
if ( Read( b ) == false )
return false;
if ( b ) // Check that bit
{
inOutByteArray[ currentByte ] = byteMatch;
currentByte--;
}
else
{
// Read the rest of the bytes
if ( ReadBits( inOutByteArray, ( currentByte + 1 ) << 3 ) == false )
return false;
return true;
}
}
// All but the first bytes are byteMatch. If the upper half of the last byte is a 0 (positive) or 16 (negative) then what we read will be a 1 and the remaining 4 bits.
// Otherwise we read a 0 and the 8 bytes
//RakAssert(readOffset+1 <=numberOfBitsUsed); // If this assert is hit the stream wasn't long enough to read from
if ( readOffset + 1 > numberOfBitsUsed )
return false;
bool b=false;
if ( Read( b ) == false )
return false;
if ( b ) // Check that bit
{
if ( ReadBits( inOutByteArray + currentByte, 4 ) == false )
return false;
inOutByteArray[ currentByte ] |= halfByteMatch; // We have to set the high 4 bits since these are set to 0 by ReadBits
}
else
{
if ( ReadBits( inOutByteArray + currentByte, 8 ) == false )
return false;
}
return true;
}
// Reallocates (if necessary) in preparation of writing numberOfBitsToWrite
void BitStream::AddBitsAndReallocate( const BitSize_t numberOfBitsToWrite )
{
BitSize_t newNumberOfBitsAllocated = numberOfBitsToWrite + numberOfBitsUsed;
if ( numberOfBitsToWrite + numberOfBitsUsed > 0 && ( ( numberOfBitsAllocated - 1 ) >> 3 ) < ( ( newNumberOfBitsAllocated - 1 ) >> 3 ) ) // If we need to allocate 1 or more new bytes
{
#ifdef _DEBUG
// If this assert hits then we need to specify true for the third parameter in the constructor
// It needs to reallocate to hold all the data and can't do it unless we allocated to begin with
// Often hits if you call Write or Serialize on a read-only bitstream
RakAssert( copyData == true );
#endif
// Less memory efficient but saves on news and deletes
/// Cap to 1 meg buffer to save on huge allocations
newNumberOfBitsAllocated = ( numberOfBitsToWrite + numberOfBitsUsed ) * 2;
if (newNumberOfBitsAllocated - ( numberOfBitsToWrite + numberOfBitsUsed ) > 1048576 )
newNumberOfBitsAllocated = numberOfBitsToWrite + numberOfBitsUsed + 1048576;
// BitSize_t newByteOffset = BITS_TO_BYTES( numberOfBitsAllocated );
// Use realloc and free so we are more efficient than delete and new for resizing
BitSize_t amountToAllocate = BITS_TO_BYTES( newNumberOfBitsAllocated );
if (data==(unsigned char*)stackData)
{
if (amountToAllocate > BITSTREAM_STACK_ALLOCATION_SIZE)
{
data = ( unsigned char* ) rakMalloc_Ex( (size_t) amountToAllocate, _FILE_AND_LINE_ );
RakAssert(data);
// need to copy the stack data over to our new memory area too
memcpy ((void *)data, (void *)stackData, (size_t) BITS_TO_BYTES( numberOfBitsAllocated ));
}
}
else
{
data = ( unsigned char* ) rakRealloc_Ex( data, (size_t) amountToAllocate, _FILE_AND_LINE_ );
}
#ifdef _DEBUG
RakAssert( data ); // Make sure realloc succeeded
#endif
// memset(data+newByteOffset, 0, ((newNumberOfBitsAllocated-1)>>3) - ((numberOfBitsAllocated-1)>>3)); // Set the new data block to 0
}
if ( newNumberOfBitsAllocated > numberOfBitsAllocated )
numberOfBitsAllocated = newNumberOfBitsAllocated;
}
BitSize_t BitStream::GetNumberOfBitsAllocated(void) const
{
return numberOfBitsAllocated;
}
void BitStream::PadWithZeroToByteLength( unsigned int bytes )
{
if (GetNumberOfBytesUsed() < bytes)
{
AlignWriteToByteBoundary();
unsigned int numToWrite = bytes - GetNumberOfBytesUsed();
AddBitsAndReallocate( BYTES_TO_BITS(numToWrite) );
memset(data+BITS_TO_BYTES(numberOfBitsUsed), 0, (size_t) numToWrite);
numberOfBitsUsed+=BYTES_TO_BITS(numToWrite);
}
}
/*
// Julius Goryavsky's version of Harley's algorithm.
// 17 elementary ops plus an indexed load, if the machine
// has "and not."
int nlz10b(unsigned x) {
static char table[64] =
{32,20,19, u, u,18, u, 7, 10,17, u, u,14, u, 6, u,
u, 9, u,16, u, u, 1,26, u,13, u, u,24, 5, u, u,
u,21, u, 8,11, u,15, u, u, u, u, 2,27, 0,25, u,
22, u,12, u, u, 3,28, u, 23, u, 4,29, u, u,30,31};
x = x | (x >> 1); // Propagate leftmost
x = x | (x >> 2); // 1-bit to the right.
x = x | (x >> 4);
x = x | (x >> 8);
x = x & ~(x >> 16);
x = x*0xFD7049FF; // Activate this line or the following 3.
// x = (x << 9) - x; // Multiply by 511.
// x = (x << 11) - x; // Multiply by 2047.
// x = (x << 14) - x; // Multiply by 16383.
return table[x >> 26];
}
*/
int BitStream::NumberOfLeadingZeroes( int8_t x ) {return NumberOfLeadingZeroes((uint8_t)x);}
int BitStream::NumberOfLeadingZeroes( uint8_t x )
{
uint8_t y;
int n;
n = 8;
y = x >> 4; if (y != 0) {n = n - 4; x = y;}
y = x >> 2; if (y != 0) {n = n - 2; x = y;}
y = x >> 1; if (y != 0) return n - 2;
return (int)(n - x);
}
int BitStream::NumberOfLeadingZeroes( int16_t x ) {return NumberOfLeadingZeroes((uint16_t)x);}
int BitStream::NumberOfLeadingZeroes( uint16_t x )
{
uint16_t y;
int n;
n = 16;
y = x >> 8; if (y != 0) {n = n - 8; x = y;}
y = x >> 4; if (y != 0) {n = n - 4; x = y;}
y = x >> 2; if (y != 0) {n = n - 2; x = y;}
y = x >> 1; if (y != 0) return n - 2;
return (int)(n - x);
}
int BitStream::NumberOfLeadingZeroes( int32_t x ) {return NumberOfLeadingZeroes((uint32_t)x);}
int BitStream::NumberOfLeadingZeroes( uint32_t x )
{
uint32_t y;
int n;
n = 32;
y = x >>16; if (y != 0) {n = n -16; x = y;}
y = x >> 8; if (y != 0) {n = n - 8; x = y;}
y = x >> 4; if (y != 0) {n = n - 4; x = y;}
y = x >> 2; if (y != 0) {n = n - 2; x = y;}
y = x >> 1; if (y != 0) return n - 2;
return (int)(n - x);
}
int BitStream::NumberOfLeadingZeroes( int64_t x ) {return NumberOfLeadingZeroes((uint64_t)x);}
int BitStream::NumberOfLeadingZeroes( uint64_t x )
{
uint64_t y;
int n;
n = 64;
y = x >>32; if (y != 0) {n = n -32; x = y;}
y = x >>16; if (y != 0) {n = n -16; x = y;}
y = x >> 8; if (y != 0) {n = n - 8; x = y;}
y = x >> 4; if (y != 0) {n = n - 4; x = y;}
y = x >> 2; if (y != 0) {n = n - 2; x = y;}
y = x >> 1; if (y != 0) return n - 2;
return (int)(n - x);
}
// Should hit if reads didn't match writes
void BitStream::AssertStreamEmpty( void )
{
RakAssert( readOffset == numberOfBitsUsed );
}
void BitStream::PrintBits( char *out ) const
{
if ( numberOfBitsUsed <= 0 )
{
strcpy(out, "No bits\n" );
return;
}
unsigned int strIndex=0;
for ( BitSize_t counter = 0; counter < BITS_TO_BYTES( numberOfBitsUsed ) && strIndex < 2000 ; counter++ )
{
BitSize_t stop;
if ( counter == ( numberOfBitsUsed - 1 ) >> 3 )
stop = 8 - ( ( ( numberOfBitsUsed - 1 ) & 7 ) + 1 );
else
stop = 0;
for ( BitSize_t counter2 = 7; counter2 >= stop; counter2-- )
{
if ( ( data[ counter ] >> counter2 ) & 1 )
out[strIndex++]='1';
else
out[strIndex++]='0';
if (counter2==0)
break;
}
out[strIndex++]=' ';
}
out[strIndex++]='\n';
out[strIndex++]=0;
}
void BitStream::PrintBits( void ) const
{
char out[2048];
PrintBits(out);
RAKNET_DEBUG_PRINTF("%s", out);
}
void BitStream::PrintHex( char *out ) const
{
BitSize_t i;
for ( i=0; i < GetNumberOfBytesUsed(); i++)
{
sprintf(out+i*3, "%02x ", data[i]);
}
}
void BitStream::PrintHex( void ) const
{
char out[2048];
PrintHex(out);
RAKNET_DEBUG_PRINTF("%s", out);
}
// Exposes the data for you to look at, like PrintBits does.
// Data will point to the stream. Returns the length in bits of the stream.
BitSize_t BitStream::CopyData( unsigned char** _data ) const
{
#ifdef _DEBUG
RakAssert( numberOfBitsUsed > 0 );
#endif
*_data = (unsigned char*) rakMalloc_Ex( (size_t) BITS_TO_BYTES( numberOfBitsUsed ), _FILE_AND_LINE_ );
memcpy( *_data, data, sizeof(unsigned char) * (size_t) ( BITS_TO_BYTES( numberOfBitsUsed ) ) );
return numberOfBitsUsed;
}
// Ignore data we don't intend to read
void BitStream::IgnoreBits( const BitSize_t numberOfBits )
{
readOffset += numberOfBits;
}
void BitStream::IgnoreBytes( const unsigned int numberOfBytes )
{
IgnoreBits(BYTES_TO_BITS(numberOfBytes));
}
// Move the write pointer to a position on the array. Dangerous if you don't know what you are doing!
// Doesn't work with non-aligned data!
void BitStream::SetWriteOffset( const BitSize_t offset )
{
numberOfBitsUsed = offset;
}
/*
BitSize_t BitStream::GetWriteOffset( void ) const
{
return numberOfBitsUsed;
}
// Returns the length in bits of the stream
BitSize_t BitStream::GetNumberOfBitsUsed( void ) const
{
return GetWriteOffset();
}
// Returns the length in bytes of the stream
BitSize_t BitStream::GetNumberOfBytesUsed( void ) const
{
return BITS_TO_BYTES( numberOfBitsUsed );
}
// Returns the number of bits into the stream that we have read
BitSize_t BitStream::GetReadOffset( void ) const
{
return readOffset;
}
// Sets the read bit index
void BitStream::SetReadOffset( const BitSize_t newReadOffset )
{
readOffset=newReadOffset;
}
// Returns the number of bits left in the stream that haven't been read
BitSize_t BitStream::GetNumberOfUnreadBits( void ) const
{
return numberOfBitsUsed - readOffset;
}
// Exposes the internal data
unsigned char* BitStream::GetData( void ) const
{
return data;
}
*/
// If we used the constructor version with copy data off, this makes sure it is set to on and the data pointed to is copied.
void BitStream::AssertCopyData( void )
{
if ( copyData == false )
{
copyData = true;
if ( numberOfBitsAllocated > 0 )
{
unsigned char * newdata = ( unsigned char* ) rakMalloc_Ex( (size_t) BITS_TO_BYTES( numberOfBitsAllocated ), _FILE_AND_LINE_ );
#ifdef _DEBUG
RakAssert( data );
#endif
memcpy( newdata, data, (size_t) BITS_TO_BYTES( numberOfBitsAllocated ) );
data = newdata;
}
else
data = 0;
}
}
bool BitStream::IsNetworkOrderInternal(void)
{
static unsigned long htonlValue = htonl(12345);
return htonlValue == 12345;
}
void BitStream::ReverseBytes(unsigned char *inByteArray, unsigned char *inOutByteArray, const unsigned int length)
{
for (BitSize_t i=0; i < length; i++)
inOutByteArray[i]=inByteArray[length-i-1];
}
void BitStream::ReverseBytesInPlace(unsigned char *inOutData,const unsigned int length)
{
unsigned char temp;
BitSize_t i;
for (i=0; i < (length>>1); i++)
{
temp = inOutData[i];
inOutData[i]=inOutData[length-i-1];
inOutData[length-i-1]=temp;
}
}
bool BitStream::Read(char *varString)
{
return RakString::Deserialize(varString,this);
}
bool BitStream::Read(unsigned char *varString)
{
return RakString::Deserialize((char*) varString,this);
}
void BitStream::WriteAlignedVar8(const char *inByteArray)
{
RakAssert((numberOfBitsUsed&7)==0);
AddBitsAndReallocate(1*8);
data[( numberOfBitsUsed >> 3 ) + 0] = inByteArray[0];
numberOfBitsUsed+=1*8;
}
bool BitStream::ReadAlignedVar8(char *inOutByteArray)
{
RakAssert((readOffset&7)==0);
if ( readOffset + 1*8 > numberOfBitsUsed )
return false;
inOutByteArray[0] = data[( readOffset >> 3 ) + 0];
readOffset+=1*8;
return true;
}
void BitStream::WriteAlignedVar16(const char *inByteArray)
{
RakAssert((numberOfBitsUsed&7)==0);
AddBitsAndReallocate(2*8);
#ifndef __BITSTREAM_NATIVE_END
if (DoEndianSwap())
{
data[( numberOfBitsUsed >> 3 ) + 0] = inByteArray[1];
data[( numberOfBitsUsed >> 3 ) + 1] = inByteArray[0];
}
else
#endif
{
data[( numberOfBitsUsed >> 3 ) + 0] = inByteArray[0];
data[( numberOfBitsUsed >> 3 ) + 1] = inByteArray[1];
}
numberOfBitsUsed+=2*8;
}
bool BitStream::ReadAlignedVar16(char *inOutByteArray)
{
RakAssert((readOffset&7)==0);
if ( readOffset + 2*8 > numberOfBitsUsed )
return false;
#ifndef __BITSTREAM_NATIVE_END
if (DoEndianSwap())
{
inOutByteArray[0] = data[( readOffset >> 3 ) + 1];
inOutByteArray[1] = data[( readOffset >> 3 ) + 0];
}
else
#endif
{
inOutByteArray[0] = data[( readOffset >> 3 ) + 0];
inOutByteArray[1] = data[( readOffset >> 3 ) + 1];
}
readOffset+=2*8;
return true;
}
void BitStream::WriteAlignedVar32(const char *inByteArray)
{
RakAssert((numberOfBitsUsed&7)==0);
AddBitsAndReallocate(4*8);
#ifndef __BITSTREAM_NATIVE_END
if (DoEndianSwap())
{
data[( numberOfBitsUsed >> 3 ) + 0] = inByteArray[3];
data[( numberOfBitsUsed >> 3 ) + 1] = inByteArray[2];
data[( numberOfBitsUsed >> 3 ) + 2] = inByteArray[1];
data[( numberOfBitsUsed >> 3 ) + 3] = inByteArray[0];
}
else
#endif
{
data[( numberOfBitsUsed >> 3 ) + 0] = inByteArray[0];
data[( numberOfBitsUsed >> 3 ) + 1] = inByteArray[1];
data[( numberOfBitsUsed >> 3 ) + 2] = inByteArray[2];
data[( numberOfBitsUsed >> 3 ) + 3] = inByteArray[3];
}
numberOfBitsUsed+=4*8;
}
bool BitStream::ReadAlignedVar32(char *inOutByteArray)
{
RakAssert((readOffset&7)==0);
if ( readOffset + 4*8 > numberOfBitsUsed )
return false;
#ifndef __BITSTREAM_NATIVE_END
if (DoEndianSwap())
{
inOutByteArray[0] = data[( readOffset >> 3 ) + 3];
inOutByteArray[1] = data[( readOffset >> 3 ) + 2];
inOutByteArray[2] = data[( readOffset >> 3 ) + 1];
inOutByteArray[3] = data[( readOffset >> 3 ) + 0];
}
else
#endif
{
inOutByteArray[0] = data[( readOffset >> 3 ) + 0];
inOutByteArray[1] = data[( readOffset >> 3 ) + 1];
inOutByteArray[2] = data[( readOffset >> 3 ) + 2];
inOutByteArray[3] = data[( readOffset >> 3 ) + 3];
}
readOffset+=4*8;
return true;
}
bool BitStream::ReadFloat16( float &outFloat, float floatMin, float floatMax )
{
unsigned short percentile;
if (Read(percentile))
{
RakAssert(floatMax>floatMin);
outFloat = floatMin + ((float) percentile / 65535.0f) * (floatMax-floatMin);
if (outFloat<floatMin)
outFloat=floatMin;
else if (outFloat>floatMax)
outFloat=floatMax;
return true;
}
return false;
}
bool BitStream::SerializeFloat16(bool writeToBitstream, float &inOutFloat, float floatMin, float floatMax)
{
if (writeToBitstream)
WriteFloat16(inOutFloat, floatMin, floatMax);
else
return ReadFloat16(inOutFloat, floatMin, floatMax);
return true;
}
void BitStream::WriteFloat16( float inOutFloat, float floatMin, float floatMax )
{
RakAssert(floatMax>floatMin);
if (inOutFloat>floatMax+.001)
{
RakAssert(inOutFloat<=floatMax+.001);
}
if (inOutFloat<floatMin-.001)
{
RakAssert(inOutFloat>=floatMin-.001);
}
float percentile=65535.0f * (inOutFloat-floatMin)/(floatMax-floatMin);
if (percentile<0.0)
percentile=0.0;
if (percentile>65535.0f)
percentile=65535.0f;
Write((unsigned short)percentile);
}
#ifdef _MSC_VER
#pragma warning( pop )
#endif
#endif // #if _MSC_VER < 1299