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Diffstat (limited to 'indra/llcommon/bitpack.h')
| -rw-r--r-- | indra/llcommon/bitpack.h | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/indra/llcommon/bitpack.h b/indra/llcommon/bitpack.h new file mode 100644 index 0000000000..2303aad8ea --- /dev/null +++ b/indra/llcommon/bitpack.h @@ -0,0 +1,190 @@ +/** + * @file bitpack.h + * @brief Convert data to packed bit stream + * + * Copyright (c) 2000-$CurrentYear$, Linden Research, Inc. + * $License$ + */ + +#ifndef LL_BITPACK_H +#define LL_BITPACK_H + +#include "llerror.h" + +const U32 MAX_DATA_BITS = 8; + + +class LLBitPack +{ +public: + LLBitPack(U8 *buffer, U32 max_size) : mBuffer(buffer), mBufferSize(0), mLoad(0), mLoadSize(0), mTotalBits(0), mMaxSize(max_size) + { + } + + ~LLBitPack() + { + } + + void resetBitPacking() + { + mLoad = 0; + mLoadSize = 0; + mTotalBits = 0; + mBufferSize = 0; + } + + U32 bitPack(U8 *total_data, U32 total_dsize) + { + U32 dsize; + U8 data; + + while (total_dsize > 0) + { + if (total_dsize > MAX_DATA_BITS) + { + dsize = MAX_DATA_BITS; + total_dsize -= MAX_DATA_BITS; + } + else + { + dsize = total_dsize; + total_dsize = 0; + } + + data = *total_data++; + + data <<= (MAX_DATA_BITS - dsize); + while (dsize > 0) + { + if (mLoadSize == MAX_DATA_BITS) + { + *(mBuffer + mBufferSize++) = mLoad; + if (mBufferSize > mMaxSize) + { + llerror("mBufferSize exceeding mMaxSize!", 0); + } + mLoadSize = 0; + mLoad = 0x00; + } + mLoad <<= 1; + mLoad |= (data >> (MAX_DATA_BITS - 1)); + data <<= 1; + mLoadSize++; + mTotalBits++; + dsize--; + } + } + return mBufferSize; + } + + U32 bitCopy(U8 *total_data, U32 total_dsize) + { + U32 dsize; + U8 data; + + while (total_dsize > 0) + { + if (total_dsize > MAX_DATA_BITS) + { + dsize = MAX_DATA_BITS; + total_dsize -= MAX_DATA_BITS; + } + else + { + dsize = total_dsize; + total_dsize = 0; + } + + data = *total_data++; + + while (dsize > 0) + { + if (mLoadSize == MAX_DATA_BITS) + { + *(mBuffer + mBufferSize++) = mLoad; + if (mBufferSize > mMaxSize) + { + llerror("mBufferSize exceeding mMaxSize!", 0); + } + mLoadSize = 0; + mLoad = 0x00; + } + mLoad <<= 1; + mLoad |= (data >> (MAX_DATA_BITS - 1)); + data <<= 1; + mLoadSize++; + mTotalBits++; + dsize--; + } + } + return mBufferSize; + } + + U32 bitUnpack(U8 *total_retval, U32 total_dsize) + { + U32 dsize; + U8 *retval; + + while (total_dsize > 0) + { + if (total_dsize > MAX_DATA_BITS) + { + dsize = MAX_DATA_BITS; + total_dsize -= MAX_DATA_BITS; + } + else + { + dsize = total_dsize; + total_dsize = 0; + } + + retval = total_retval++; + *retval = 0x00; + while (dsize > 0) + { + if (mLoadSize == 0) + { +#ifdef _DEBUG + if (mBufferSize > mMaxSize) + { + llerrs << "mBufferSize exceeding mMaxSize" << llendl; + llerrs << mBufferSize << " > " << mMaxSize << llendl; + } +#endif + mLoad = *(mBuffer + mBufferSize++); + mLoadSize = MAX_DATA_BITS; + } + *retval <<= 1; + *retval |= (mLoad >> (MAX_DATA_BITS - 1)); + mLoadSize--; + mLoad <<= 1; + dsize--; + } + } + return mBufferSize; + } + + U32 flushBitPack() + { + if (mLoadSize) + { + mLoad <<= (MAX_DATA_BITS - mLoadSize); + *(mBuffer + mBufferSize++) = mLoad; + if (mBufferSize > mMaxSize) + { + llerror("mBufferSize exceeding mMaxSize!", 0); + } + mLoadSize = 0; + } + return mBufferSize; + } + + U8 *mBuffer; + U32 mBufferSize; + U8 mLoad; + U32 mLoadSize; + U32 mTotalBits; + U32 mMaxSize; +}; + +#endif |