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TNL::BitStream Class Reference

BitStream provides a bit-level stream interface to a data buffer. More...

#include <tnlBitStream.h>

Inheritance diagram for TNL::BitStream:

List of all members.

Public Methods
void	setMaxSizes (U32 maxReadSize, U32 maxWriteSize=0)
	Sets the maximum read and write sizes for the BitStream.
void	setMaxBitSizes (U32 maxReadBitSize, U32 maxWriteBitSize=0)
	Sets the maximum read and write bit sizes for the BitStream.
void	reset ()
	resets the read/write position to 0 and clears any error state.
void	clearStringBuffer ()
	clears the string compression buffer.
void	setStringTable (ConnectionStringTable *table)
	sets the ConnectionStringTable for compressing string table entries across the network
void	clearError ()
	clears the error state from an attempted read or write overrun
U8 *	getBytePtr ()
	Returns a pointer to the next byte in the BitStream from the current bit position.
U32	getBytePosition () const
	Returns the current position in the stream rounded up to the next byte.
U32	getBitPosition () const
	Returns the current bit position in the stream.
void	setBytePosition (const U32 newPosition)
	Sets the position in the stream to the first bit of byte newPosition.
void	setBitPosition (const U32 newBitPosition)
	Sets the position in the stream to newBitPosition.
void	advanceBitPosition (const S32 numBits)
	Advances the position in the stream by numBits.
U32	getMaxReadBitPosition () const
	Returns the maximum readable bit position.
U32	getBitSpaceAvailable () const
	Returns the number of bits that can be written into the BitStream without resizing.
void	zeroToByteBoundary ()
	Pads the bits up to the next byte boundary with 0's.
void	writeInt (U32 value, U8 bitCount)
	Writes an unsigned integer value between 0 and 2^(bitCount - 1) into the stream.
U32	readInt (U8 bitCount)
	Reads an unsigned integer value between 0 and 2^(bitCount - 1) from the stream.
void	writeIntAt (U32 value, U8 bitCount, U32 bitPosition)
	Writes an unsigned integer value between 0 and 2^(bitCount -1) into the stream at the specified position, without changing the current write position.
void	writeSignedInt (S32 value, U8 bitCount)
	Writes a signed integer value between -2^(bitCount-1) and 2^(bitCount-1) - 1.
S32	readSignedInt (U8 bitCount)
	Reads a signed integer value between -2^(bitCount-1) and 2^(bitCount-1) - 1.
void	writeRangedU32 (U32 value, U32 rangeStart, U32 rangeEnd)
	Writes an unsigned integer value in the range rangeStart to rangeEnd inclusive.
U32	readRangedU32 (U32 rangeStart, U32 rangeEnd)
	Reads an unsigned integer value in the range rangeStart to rangeEnd inclusive.
void	writeEnum (U32 enumValue, U32 enumRange)
	Writes an enumeration value in the range of 0 ... enumRange - 1.
U32	readEnum (U32 enumRange)
	Reads an enumeration value in the range 0 ... enumRange - 1.
void	writeFloat (F32 f, U8 bitCount)
	Writes a float from 0 to 1 inclusive, using bitCount bits of precision.
F32	readFloat (U8 bitCount)
	Reads a float from 0 to 1 inclusive, using bitCount bits of precision.
void	writeSignedFloat (F32 f, U8 bitCount)
	Writes a signed float from -1 to 1 inclusive, using bitCount bits of precision.
F32	readSignedFloat (U8 bitCount)
	Reads a signed float from -1 to 1 inclusive, using bitCount bits of precision.
void	writeClassId (U32 classId, U32 classType, U32 classGroup)
	Writes an object's class ID, given its class type and class group.
U32	readClassId (U32 classType, U32 classGroup)
	Reads a class ID for an object, given a class type and class group. Returns -1 if the class type is out of range.
void	writeNormalVector (const Point3F &vec, U8 bitCount)
	Writes a normalized vector into the stream, using bitCount bits for the precision of angles phi and theta.
void	readNormalVector (Point3F *vec, U8 bitCount)
	Reads a normalized vector from the stream, using bitCount bits for the precision of angles phi and theta.
void	writeNormalVector (const Point3F &vec, U8 angleBitCount, U8 zBitCount)
	Writes a normalized vector by writing a z value and theta angle.
void	readNormalVector (Point3F *vec, U8 angleBitCount, U8 zBitCount)
	Reads a normalized vector by reading a z value and theta angle.
void	setPointCompression (const Point3F &p)
	Sets a reference point for subsequent compressed point writing.
void	clearPointCompression ()
	Disables compression of point.
void	writePointCompressed (const Point3F &p, F32 scale)
	Writes a point into the stream, to a precision denoted by scale.
void	readPointCompressed (Point3F *p, F32 scale)
	Reads a compressed point from the stream, to a precision denoted by scale.
bool	writeBits (U32 bitCount, const void *bitPtr)
	Writes bitCount bits into the stream from bitPtr.
bool	readBits (U32 bitCount, void *bitPtr)
	Reads bitCount bits from the stream into bitPtr.
bool	write (const ByteBuffer *theBuffer)
	Writes a ByteBuffer into the stream. The ByteBuffer can be no larger than 1024 bytes in size.
bool	read (ByteBuffer *theBuffer)
	Reads a ByteBuffer in from the stream.
bool	writeFlag (bool val)
	Writes a single boolean flag (bit) into the stream, and returns the boolean that was written.
bool	readFlag ()
	Reads a single bit from the stream.
void	writeString (const char *stringBuf, U8 maxLen=255)
	Writes a huffman compressed string into the stream.
void	readString (char stringBuf[256])
	Reads a huffman compressed string from the stream.
void	writeStringTableEntry (const StringTableEntry &ste)
	Writes a string table entry into the stream.
void	readStringTableEntry (StringTableEntry *ste)
	Reads a string table entry from the stream.
bool	write (const U32 in_numBytes, const void *in_pBuffer)
	Writes byte data into the stream.
bool	read (const U32 in_numBytes, void *out_pBuffer)
	Reads byte data from the stream.
bool	setBit (U32 bitCount, bool set)
	Sets the bit at position bitCount to the value of set.
bool	testBit (U32 bitCount)
	Tests the value of the bit at position bitCount.
bool	isFull ()
	Returns whether the BitStream writing has exceeded the write target size.
bool	isValid ()
	Returns whether the stream has generated an error condition due to reading or writing past the end of the buffer.
void	hashAndEncrypt (U32 hashDigestSize, U32 encryptStartOffset, SymmetricCipher *theCipher)
	Hashes the BitStream, writing the hash digest into the end of the buffer, and then encrypts with the given cipher.
bool	decryptAndCheckHash (U32 hashDigestSize, U32 decryptStartOffset, SymmetricCipher *theCipher)
	Decrypts the BitStream, then checks the hash digest at the end of the buffer to validate the contents.
Constructors
Note that the BitStream essentially wraps an existing buffer, so to use a bitstream you must have an existing buffer for it to work with!
	BitStream (U8 *bufPtr, U32 bufSize)
	Default to maximum write size being the size of the buffer.
	BitStream (U8 *bufPtr, U32 bufSize, U32 maxWriteSize)
	Optionally, specify a maximum write size.
	BitStream ()
	Creates a resizable BitStream.
Various types that the BitStream can read and write...
Static Public Methods
Point3F	dumbDownNormal (const Point3F &vec, U8 bitCount)
	Uses the same method as in writeNormalVector to reduce the precision of a normal vector to determine what will be read from the stream.
Protected Attributes
U32	bitNum
	The current bit position for reading/writing in the bit stream.
bool	error
	Flag set if a user operation attempts to read or write past the max read/write sizes.
bool	mCompressRelative
	Flag set if the bit stream should compress points relative to a compression point.
Point3F	mCompressPoint
	Reference point for relative point compression.
U32	maxReadBitNum
	Last valid read bit position.
U32	maxWriteBitNum
	Last valid write bit position.
ConnectionStringTable *	mStringTable
	String table used to compress StringTableEntries over the network.

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Detailed Description

BitStream provides a bit-level stream interface to a data buffer.

Definition at line 63 of file tnlBitStream.h.

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Member Function Documentation

bool TNL::BitStream::readFlag (    )  [inline]

Reads a single bit from the stream. This is set up so you can do... if(stream->readFlag()) { ... read other stuff ... } Definition at line 335 of file tnlBitStream.h. References bitNum, error, and maxReadBitNum. Referenced by TNL::NetInterface::handleArrangedConnectRequest(), TNL::NetInterface::handleConnectChallengeRequest(), TNL::NetInterface::handleConnectChallengeResponse(), TNL::NetInterface::handleConnectRequest(), TNL::NetInterface::handlePunch(), TNL::HuffmanStringProcessor::readHuffBuffer(), readNormalVector(), TNL::GhostConnection::readPacket(), TNL::EventConnection::readPacket(), TNL::NetConnection::readPacketHeader(), TNL::NetConnection::readPacketRateInfo(), readSignedInt(), readString(), and TNL::NetObjectRPCEvent::unpack().

bool TNL::BitStream::writeFlag (  bool    val )

Writes a single boolean flag (bit) into the stream, and returns the boolean that was written. This is set up so you can do... if(stream->writeFlag(foo == bar)) { ... write other stuff ... } Definition at line 227 of file bitStream.cpp. References bitNum, and maxWriteBitNum. Referenced by TNL::NetObjectRPCEvent::pack(), TNL::NetInterface::sendArrangedConnectRequest(), TNL::NetInterface::sendConnectChallengeRequest(), TNL::NetInterface::sendConnectChallengeResponse(), TNL::NetInterface::sendConnectRequest(), TNL::NetInterface::sendPunchPackets(), TNL::HuffmanStringProcessor::writeHuffBuffer(), writeNormalVector(), TNL::GhostConnection::writePacket(), TNL::EventConnection::writePacket(), TNL::NetConnection::writePacketHeader(), TNL::NetConnection::writePacketRateInfo(), writeSignedInt(), and writeString().

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Member Data Documentation

ConnectionStringTable* TNL::BitStream::mStringTable [protected]

String table used to compress StringTableEntries over the network. String buffer holds the last string written into the stream for substring compression. Definition at line 75 of file tnlBitStream.h. Referenced by readStringTableEntry(), reset(), and writeStringTableEntry().

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

• /home/rdbrown/doxygen/cse125g1/src/modules/tnl/tnlBitStream.h
• /home/rdbrown/doxygen/cse125g1/src/modules/tnl/bitStream.cpp

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