/** @file Compression routine. The compression algorithm is a mixture of LZ77 and Huffman coding. LZ77 transforms the source data into a sequence of Original Characters and Pointers to repeated strings. This sequence is further divided into Blocks and Huffman codings are applied to each Block. Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR> This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at http://opensource.org/licenses/bsd-license.php THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. **/ #include "Compress.h" // // Macro Definitions // #undef UINT8_MAX typedef INT32 NODE; #define UINT8_MAX 0xff #define UINT8_BIT 8 #define THRESHOLD 3 #define INIT_CRC 0 #define WNDBIT 19 #define WNDSIZ (1U << WNDBIT) #define MAXMATCH 256 #define BLKSIZ (1U << 14) // 16 * 1024U #define PERC_FLAG 0x80000000U #define CODE_BIT 16 #define NIL 0 #define MAX_HASH_VAL (3 * WNDSIZ + (WNDSIZ / 512 + 1) * UINT8_MAX) #define HASH(p, c) ((p) + ((c) << (WNDBIT - 9)) + WNDSIZ * 2) #define CRCPOLY 0xA001 #define UPDATE_CRC(c) mCrc = mCrcTable[(mCrc ^ (c)) & 0xFF] ^ (mCrc >> UINT8_BIT) // // C: the Char&Len Set; P: the Position Set; T: the exTra Set // #define NC (UINT8_MAX + MAXMATCH + 2 - THRESHOLD) #define CBIT 9 #define NP (WNDBIT + 1) #define PBIT 5 #define NT (CODE_BIT + 3) #define TBIT 5 #if NT > NP #define NPT NT #else #define NPT NP #endif // // Function Prototypes // STATIC VOID PutDword( IN UINT32 Data ); STATIC EFI_STATUS AllocateMemory ( VOID ); STATIC VOID FreeMemory ( VOID ); STATIC VOID InitSlide ( VOID ); STATIC NODE Child ( IN NODE NodeQ, IN UINT8 CharC ); STATIC VOID MakeChild ( IN NODE NodeQ, IN UINT8 CharC, IN NODE NodeR ); STATIC VOID Split ( IN NODE Old ); STATIC VOID InsertNode ( VOID ); STATIC VOID DeleteNode ( VOID ); STATIC VOID GetNextMatch ( VOID ); STATIC EFI_STATUS Encode ( VOID ); STATIC VOID CountTFreq ( VOID ); STATIC VOID WritePTLen ( IN INT32 Number, IN INT32 nbit, IN INT32 Special ); STATIC VOID WriteCLen ( VOID ); STATIC VOID EncodeC ( IN INT32 Value ); STATIC VOID EncodeP ( IN UINT32 Value ); STATIC VOID SendBlock ( VOID ); STATIC VOID Output ( IN UINT32 c, IN UINT32 p ); STATIC VOID HufEncodeStart ( VOID ); STATIC VOID HufEncodeEnd ( VOID ); STATIC VOID MakeCrcTable ( VOID ); STATIC VOID PutBits ( IN INT32 Number, IN UINT32 Value ); STATIC INT32 FreadCrc ( OUT UINT8 *Pointer, IN INT32 Number ); STATIC VOID InitPutBits ( VOID ); STATIC VOID CountLen ( IN INT32 Index ); STATIC VOID MakeLen ( IN INT32 Root ); STATIC VOID DownHeap ( IN INT32 Index ); STATIC VOID MakeCode ( IN INT32 Number, IN UINT8 Len[ ], OUT UINT16 Code[] ); STATIC INT32 MakeTree ( IN INT32 NParm, IN UINT16 FreqParm[], OUT UINT8 LenParm[ ], OUT UINT16 CodeParm[] ); // // Global Variables // STATIC UINT8 *mSrc, *mDst, *mSrcUpperLimit, *mDstUpperLimit; STATIC UINT8 *mLevel, *mText, *mChildCount, *mBuf, mCLen[NC], mPTLen[NPT], *mLen; STATIC INT16 mHeap[NC + 1]; STATIC INT32 mRemainder, mMatchLen, mBitCount, mHeapSize, mN; STATIC UINT32 mBufSiz = 0, mOutputPos, mOutputMask, mSubBitBuf, mCrc; STATIC UINT32 mCompSize, mOrigSize; STATIC UINT16 *mFreq, *mSortPtr, mLenCnt[17], mLeft[2 * NC - 1], mRight[2 * NC - 1], mCrcTable[UINT8_MAX + 1], mCFreq[2 * NC - 1], mCCode[NC], mPFreq[2 * NP - 1], mPTCode[NPT], mTFreq[2 * NT - 1]; STATIC NODE mPos, mMatchPos, mAvail, *mPosition, *mParent, *mPrev, *mNext = NULL; // // functions // EFI_STATUS TianoCompress ( IN UINT8 *SrcBuffer, IN UINT32 SrcSize, IN UINT8 *DstBuffer, IN OUT UINT32 *DstSize ) /*++ Routine Description: The internal implementation of [Efi/Tiano]Compress(). Arguments: SrcBuffer - The buffer storing the source data SrcSize - The size of source data DstBuffer - The buffer to store the compressed data DstSize - On input, the size of DstBuffer; On output, the size of the actual compressed data. Version - The version of de/compression algorithm. Version 1 for UEFI 2.0 de/compression algorithm. Version 2 for Tiano de/compression algorithm. Returns: EFI_BUFFER_TOO_SMALL - The DstBuffer is too small. In this case, DstSize contains the size needed. EFI_SUCCESS - Compression is successful. EFI_OUT_OF_RESOURCES - No resource to complete function. EFI_INVALID_PARAMETER - Parameter supplied is wrong. --*/ { EFI_STATUS Status; // // Initializations // mBufSiz = 0; mBuf = NULL; mText = NULL; mLevel = NULL; mChildCount = NULL; mPosition = NULL; mParent = NULL; mPrev = NULL; mNext = NULL; mSrc = SrcBuffer; mSrcUpperLimit = mSrc + SrcSize; mDst = DstBuffer; mDstUpperLimit = mDst +*DstSize; PutDword (0L); PutDword (0L); MakeCrcTable (); mOrigSize = mCompSize = 0; mCrc = INIT_CRC; // // Compress it // Status = Encode (); if (EFI_ERROR (Status)) { return EFI_OUT_OF_RESOURCES; } // // Null terminate the compressed data // if (mDst < mDstUpperLimit) { *mDst++ = 0; } // // Fill in compressed size and original size // mDst = DstBuffer; PutDword (mCompSize + 1); PutDword (mOrigSize); // // Return // if (mCompSize + 1 + 8 > *DstSize) { *DstSize = mCompSize + 1 + 8; return EFI_BUFFER_TOO_SMALL; } else { *DstSize = mCompSize + 1 + 8; return EFI_SUCCESS; } } STATIC VOID PutDword ( IN UINT32 Data ) /*++ Routine Description: Put a dword to output stream Arguments: Data - the dword to put Returns: (VOID) --*/ { if (mDst < mDstUpperLimit) { *mDst++ = (UINT8) (((UINT8) (Data)) & 0xff); } if (mDst < mDstUpperLimit) { *mDst++ = (UINT8) (((UINT8) (Data >> 0x08)) & 0xff); } if (mDst < mDstUpperLimit) { *mDst++ = (UINT8) (((UINT8) (Data >> 0x10)) & 0xff); } if (mDst < mDstUpperLimit) { *mDst++ = (UINT8) (((UINT8) (Data >> 0x18)) & 0xff); } } STATIC EFI_STATUS AllocateMemory ( VOID ) /*++ Routine Description: Allocate memory spaces for data structures used in compression process Argements: VOID Returns: EFI_SUCCESS - Memory is allocated successfully EFI_OUT_OF_RESOURCES - Allocation fails --*/ { UINT32 Index; mText = malloc (WNDSIZ * 2 + MAXMATCH); if (mText == NULL) { return EFI_OUT_OF_RESOURCES; } for (Index = 0; Index < WNDSIZ * 2 + MAXMATCH; Index++) { mText[Index] = 0; } mLevel = malloc ((WNDSIZ + UINT8_MAX + 1) * sizeof (*mLevel)); mChildCount = malloc ((WNDSIZ + UINT8_MAX + 1) * sizeof (*mChildCount)); mPosition = malloc ((WNDSIZ + UINT8_MAX + 1) * sizeof (*mPosition)); mParent = malloc (WNDSIZ * 2 * sizeof (*mParent)); mPrev = malloc (WNDSIZ * 2 * sizeof (*mPrev)); mNext = malloc ((MAX_HASH_VAL + 1) * sizeof (*mNext)); if (mLevel == NULL || mChildCount == NULL || mPosition == NULL || mParent == NULL || mPrev == NULL || mNext == NULL) { return EFI_OUT_OF_RESOURCES; } mBufSiz = BLKSIZ; mBuf = malloc (mBufSiz); while (mBuf == NULL) { mBufSiz = (mBufSiz / 10U) * 9U; if (mBufSiz < 4 * 1024U) { return EFI_OUT_OF_RESOURCES; } mBuf = malloc (mBufSiz); } mBuf[0] = 0; return EFI_SUCCESS; } VOID FreeMemory ( VOID ) /*++ Routine Description: Called when compression is completed to free memory previously allocated. Arguments: (VOID) Returns: (VOID) --*/ { if (mText != NULL) { free (mText); } if (mLevel != NULL) { free (mLevel); } if (mChildCount != NULL) { free (mChildCount); } if (mPosition != NULL) { free (mPosition); } if (mParent != NULL) { free (mParent); } if (mPrev != NULL) { free (mPrev); } if (mNext != NULL) { free (mNext); } if (mBuf != NULL) { free (mBuf); } return ; } STATIC VOID InitSlide ( VOID ) /*++ Routine Description: Initialize String Info Log data structures Arguments: (VOID) Returns: (VOID) --*/ { NODE Index; for (Index = WNDSIZ; Index <= WNDSIZ + UINT8_MAX; Index++) { mLevel[Index] = 1; mPosition[Index] = NIL; /* sentinel */ } for (Index = WNDSIZ; Index < WNDSIZ * 2; Index++) { mParent[Index] = NIL; } mAvail = 1; for (Index = 1; Index < WNDSIZ - 1; Index++) { mNext[Index] = (NODE) (Index + 1); } mNext[WNDSIZ - 1] = NIL; for (Index = WNDSIZ * 2; Index <= MAX_HASH_VAL; Index++) { mNext[Index] = NIL; } } STATIC NODE Child ( IN NODE NodeQ, IN UINT8 CharC ) /*++ Routine Description: Find child node given the parent node and the edge character Arguments: NodeQ - the parent node CharC - the edge character Returns: The child node (NIL if not found) --*/ { NODE NodeR; NodeR = mNext[HASH (NodeQ, CharC)]; // // sentinel // mParent[NIL] = NodeQ; while (mParent[NodeR] != NodeQ) { NodeR = mNext[NodeR]; } return NodeR; } STATIC VOID MakeChild ( IN NODE Parent, IN UINT8 CharC, IN NODE Child ) /*++ Routine Description: Create a new child for a given parent node. Arguments: Parent - the parent node CharC - the edge character Child - the child node Returns: (VOID) --*/ { NODE Node1; NODE Node2; Node1 = (NODE) HASH (Parent, CharC); Node2 = mNext[Node1]; mNext[Node1] = Child; mNext[Child] = Node2; mPrev[Node2] = Child; mPrev[Child] = Node1; mParent[Child] = Parent; mChildCount[Parent]++; } STATIC VOID Split ( NODE Old ) /*++ Routine Description: Split a node. Arguments: Old - the node to split Returns: (VOID) --*/ { NODE New; NODE TempNode; New = mAvail; mAvail = mNext[New]; mChildCount[New] = 0; TempNode = mPrev[Old]; mPrev[New] = TempNode; mNext[TempNode] = New; TempNode = mNext[Old]; mNext[New] = TempNode; mPrev[TempNode] = New; mParent[New] = mParent[Old]; mLevel[New] = (UINT8) mMatchLen; mPosition[New] = mPos; MakeChild (New, mText[mMatchPos + mMatchLen], Old); MakeChild (New, mText[mPos + mMatchLen], mPos); } STATIC VOID InsertNode ( VOID ) /*++ Routine Description: Insert string info for current position into the String Info Log Arguments: (VOID) Returns: (VOID) --*/ { NODE NodeQ; NODE NodeR; NODE Index2; NODE NodeT; UINT8 CharC; UINT8 *t1; UINT8 *t2; if (mMatchLen >= 4) { // // We have just got a long match, the target tree // can be located by MatchPos + 1. Travese the tree // from bottom up to get to a proper starting point. // The usage of PERC_FLAG ensures proper node deletion // in DeleteNode() later. // mMatchLen--; NodeR = (NODE) ((mMatchPos + 1) | WNDSIZ); NodeQ = mParent[NodeR]; while (NodeQ == NIL) { NodeR = mNext[NodeR]; NodeQ = mParent[NodeR]; } while (mLevel[NodeQ] >= mMatchLen) { NodeR = NodeQ; NodeQ = mParent[NodeQ]; } NodeT = NodeQ; while (mPosition[NodeT] < 0) { mPosition[NodeT] = mPos; NodeT = mParent[NodeT]; } if (NodeT < WNDSIZ) { mPosition[NodeT] = (NODE) (mPos | (UINT32) PERC_FLAG); } } else { // // Locate the target tree // NodeQ = (NODE) (mText[mPos] + WNDSIZ); CharC = mText[mPos + 1]; NodeR = Child (NodeQ, CharC); if (NodeR == NIL) { MakeChild (NodeQ, CharC, mPos); mMatchLen = 1; return ; } mMatchLen = 2; } // // Traverse down the tree to find a match. // Update Position value along the route. // Node split or creation is involved. // for (;;) { if (NodeR >= WNDSIZ) { Index2 = MAXMATCH; mMatchPos = NodeR; } else { Index2 = mLevel[NodeR]; mMatchPos = (NODE) (mPosition[NodeR] & (UINT32)~PERC_FLAG); } if (mMatchPos >= mPos) { mMatchPos -= WNDSIZ; } t1 = &mText[mPos + mMatchLen]; t2 = &mText[mMatchPos + mMatchLen]; while (mMatchLen < Index2) { if (*t1 != *t2) { Split (NodeR); return ; } mMatchLen++; t1++; t2++; } if (mMatchLen >= MAXMATCH) { break; } mPosition[NodeR] = mPos; NodeQ = NodeR; NodeR = Child (NodeQ, *t1); if (NodeR == NIL) { MakeChild (NodeQ, *t1, mPos); return ; } mMatchLen++; } NodeT = mPrev[NodeR]; mPrev[mPos] = NodeT; mNext[NodeT] = mPos; NodeT = mNext[NodeR]; mNext[mPos] = NodeT; mPrev[NodeT] = mPos; mParent[mPos] = NodeQ; mParent[NodeR] = NIL; // // Special usage of 'next' // mNext[NodeR] = mPos; } STATIC VOID DeleteNode ( VOID ) /*++ Routine Description: Delete outdated string info. (The Usage of PERC_FLAG ensures a clean deletion) Arguments: (VOID) Returns: (VOID) --*/ { NODE NodeQ; NODE NodeR; NODE NodeS; NODE NodeT; NODE NodeU; if (mParent[mPos] == NIL) { return ; } NodeR = mPrev[mPos]; NodeS = mNext[mPos]; mNext[NodeR] = NodeS; mPrev[NodeS] = NodeR; NodeR = mParent[mPos]; mParent[mPos] = NIL; if (NodeR >= WNDSIZ) { return ; } mChildCount[NodeR]--; if (mChildCount[NodeR] > 1) { return ; } NodeT = (NODE) (mPosition[NodeR] & (UINT32)~PERC_FLAG); if (NodeT >= mPos) { NodeT -= WNDSIZ; } NodeS = NodeT; NodeQ = mParent[NodeR]; NodeU = mPosition[NodeQ]; while (NodeU & (UINT32) PERC_FLAG) { NodeU &= (UINT32)~PERC_FLAG; if (NodeU >= mPos) { NodeU -= WNDSIZ; } if (NodeU > NodeS) { NodeS = NodeU; } mPosition[NodeQ] = (NODE) (NodeS | WNDSIZ); NodeQ = mParent[NodeQ]; NodeU = mPosition[NodeQ]; } if (NodeQ < WNDSIZ) { if (NodeU >= mPos) { NodeU -= WNDSIZ; } if (NodeU > NodeS) { NodeS = NodeU; } mPosition[NodeQ] = (NODE) (NodeS | WNDSIZ | (UINT32) PERC_FLAG); } NodeS = Child (NodeR, mText[NodeT + mLevel[NodeR]]); NodeT = mPrev[NodeS]; NodeU = mNext[NodeS]; mNext[NodeT] = NodeU; mPrev[NodeU] = NodeT; NodeT = mPrev[NodeR]; mNext[NodeT] = NodeS; mPrev[NodeS] = NodeT; NodeT = mNext[NodeR]; mPrev[NodeT] = NodeS; mNext[NodeS] = NodeT; mParent[NodeS] = mParent[NodeR]; mParent[NodeR] = NIL; mNext[NodeR] = mAvail; mAvail = NodeR; } STATIC VOID GetNextMatch ( VOID ) /*++ Routine Description: Advance the current position (read in new data if needed). Delete outdated string info. Find a match string for current position. Arguments: (VOID) Returns: (VOID) --*/ { INT32 Number; mRemainder--; mPos++; if (mPos == WNDSIZ * 2) { memmove (&mText[0], &mText[WNDSIZ], WNDSIZ + MAXMATCH); Number = FreadCrc (&mText[WNDSIZ + MAXMATCH], WNDSIZ); mRemainder += Number; mPos = WNDSIZ; } DeleteNode (); InsertNode (); } STATIC EFI_STATUS Encode ( VOID ) /*++ Routine Description: The main controlling routine for compression process. Arguments: (VOID) Returns: EFI_SUCCESS - The compression is successful EFI_OUT_0F_RESOURCES - Not enough memory for compression process --*/ { EFI_STATUS Status; INT32 LastMatchLen; NODE LastMatchPos; Status = AllocateMemory (); if (EFI_ERROR (Status)) { FreeMemory (); return Status; } InitSlide (); HufEncodeStart (); mRemainder = FreadCrc (&mText[WNDSIZ], WNDSIZ + MAXMATCH); mMatchLen = 0; mPos = WNDSIZ; InsertNode (); if (mMatchLen > mRemainder) { mMatchLen = mRemainder; } while (mRemainder > 0) { LastMatchLen = mMatchLen; LastMatchPos = mMatchPos; GetNextMatch (); if (mMatchLen > mRemainder) { mMatchLen = mRemainder; } if (mMatchLen > LastMatchLen || LastMatchLen < THRESHOLD) { // // Not enough benefits are gained by outputting a pointer, // so just output the original character // Output (mText[mPos - 1], 0); } else { if (LastMatchLen == THRESHOLD) { if (((mPos - LastMatchPos - 2) & (WNDSIZ - 1)) > (1U << 11)) { Output (mText[mPos - 1], 0); continue; } } // // Outputting a pointer is beneficial enough, do it. // Output ( LastMatchLen + (UINT8_MAX + 1 - THRESHOLD), (mPos - LastMatchPos - 2) & (WNDSIZ - 1) ); LastMatchLen--; while (LastMatchLen > 0) { GetNextMatch (); LastMatchLen--; } if (mMatchLen > mRemainder) { mMatchLen = mRemainder; } } } HufEncodeEnd (); FreeMemory (); return EFI_SUCCESS; } STATIC VOID CountTFreq ( VOID ) /*++ Routine Description: Count the frequencies for the Extra Set Arguments: (VOID) Returns: (VOID) --*/ { INT32 Index; INT32 Index3; INT32 Number; INT32 Count; for (Index = 0; Index < NT; Index++) { mTFreq[Index] = 0; } Number = NC; while (Number > 0 && mCLen[Number - 1] == 0) { Number--; } Index = 0; while (Index < Number) { Index3 = mCLen[Index++]; if (Index3 == 0) { Count = 1; while (Index < Number && mCLen[Index] == 0) { Index++; Count++; } if (Count <= 2) { mTFreq[0] = (UINT16) (mTFreq[0] + Count); } else if (Count <= 18) { mTFreq[1]++; } else if (Count == 19) { mTFreq[0]++; mTFreq[1]++; } else { mTFreq[2]++; } } else { mTFreq[Index3 + 2]++; } } } STATIC VOID WritePTLen ( IN INT32 Number, IN INT32 nbit, IN INT32 Special ) /*++ Routine Description: Outputs the code length array for the Extra Set or the Position Set. Arguments: Number - the number of symbols nbit - the number of bits needed to represent 'n' Special - the special symbol that needs to be take care of Returns: (VOID) --*/ { INT32 Index; INT32 Index3; while (Number > 0 && mPTLen[Number - 1] == 0) { Number--; } PutBits (nbit, Number); Index = 0; while (Index < Number) { Index3 = mPTLen[Index++]; if (Index3 <= 6) { PutBits (3, Index3); } else { PutBits (Index3 - 3, (1U << (Index3 - 3)) - 2); } if (Index == Special) { while (Index < 6 && mPTLen[Index] == 0) { Index++; } PutBits (2, (Index - 3) & 3); } } } STATIC VOID WriteCLen ( VOID ) /*++ Routine Description: Outputs the code length array for Char&Length Set Arguments: (VOID) Returns: (VOID) --*/ { INT32 Index; INT32 Index3; INT32 Number; INT32 Count; Number = NC; while (Number > 0 && mCLen[Number - 1] == 0) { Number--; } PutBits (CBIT, Number); Index = 0; while (Index < Number) { Index3 = mCLen[Index++]; if (Index3 == 0) { Count = 1; while (Index < Number && mCLen[Index] == 0) { Index++; Count++; } if (Count <= 2) { for (Index3 = 0; Index3 < Count; Index3++) { PutBits (mPTLen[0], mPTCode[0]); } } else if (Count <= 18) { PutBits (mPTLen[1], mPTCode[1]); PutBits (4, Count - 3); } else if (Count == 19) { PutBits (mPTLen[0], mPTCode[0]); PutBits (mPTLen[1], mPTCode[1]); PutBits (4, 15); } else { PutBits (mPTLen[2], mPTCode[2]); PutBits (CBIT, Count - 20); } } else { PutBits (mPTLen[Index3 + 2], mPTCode[Index3 + 2]); } } } STATIC VOID EncodeC ( IN INT32 Value ) { PutBits (mCLen[Value], mCCode[Value]); } STATIC VOID EncodeP ( IN UINT32 Value ) { UINT32 Index; UINT32 NodeQ; Index = 0; NodeQ = Value; while (NodeQ) { NodeQ >>= 1; Index++; } PutBits (mPTLen[Index], mPTCode[Index]); if (Index > 1) { PutBits (Index - 1, Value & (0xFFFFFFFFU >> (32 - Index + 1))); } } STATIC VOID SendBlock ( VOID ) /*++ Routine Description: Huffman code the block and output it. Arguments: (VOID) Returns: (VOID) --*/ { UINT32 Index; UINT32 Index2; UINT32 Index3; UINT32 Flags; UINT32 Root; UINT32 Pos; UINT32 Size; Flags = 0; Root = MakeTree (NC, mCFreq, mCLen, mCCode); Size = mCFreq[Root]; PutBits (16, Size); if (Root >= NC) { CountTFreq (); Root = MakeTree (NT, mTFreq, mPTLen, mPTCode); if (Root >= NT) { WritePTLen (NT, TBIT, 3); } else { PutBits (TBIT, 0); PutBits (TBIT, Root); } WriteCLen (); } else { PutBits (TBIT, 0); PutBits (TBIT, 0); PutBits (CBIT, 0); PutBits (CBIT, Root); } Root = MakeTree (NP, mPFreq, mPTLen, mPTCode); if (Root >= NP) { WritePTLen (NP, PBIT, -1); } else { PutBits (PBIT, 0); PutBits (PBIT, Root); } Pos = 0; for (Index = 0; Index < Size; Index++) { if (Index % UINT8_BIT == 0) { Flags = mBuf[Pos++]; } else { Flags <<= 1; } if (Flags & (1U << (UINT8_BIT - 1))) { EncodeC (mBuf[Pos++] + (1U << UINT8_BIT)); Index3 = mBuf[Pos++]; for (Index2 = 0; Index2 < 3; Index2++) { Index3 <<= UINT8_BIT; Index3 += mBuf[Pos++]; } EncodeP (Index3); } else { EncodeC (mBuf[Pos++]); } } for (Index = 0; Index < NC; Index++) { mCFreq[Index] = 0; } for (Index = 0; Index < NP; Index++) { mPFreq[Index] = 0; } } STATIC VOID Output ( IN UINT32 CharC, IN UINT32 Pos ) /*++ Routine Description: Outputs an Original Character or a Pointer Arguments: CharC - The original character or the 'String Length' element of a Pointer Pos - The 'Position' field of a Pointer Returns: (VOID) --*/ { STATIC UINT32 CPos; if ((mOutputMask >>= 1) == 0) { mOutputMask = 1U << (UINT8_BIT - 1); // // Check the buffer overflow per outputing UINT8_BIT symbols // which is an Original Character or a Pointer. The biggest // symbol is a Pointer which occupies 5 bytes. // if (mOutputPos >= mBufSiz - 5 * UINT8_BIT) { SendBlock (); mOutputPos = 0; } CPos = mOutputPos++; mBuf[CPos] = 0; } mBuf[mOutputPos++] = (UINT8) CharC; mCFreq[CharC]++; if (CharC >= (1U << UINT8_BIT)) { mBuf[CPos] |= mOutputMask; mBuf[mOutputPos++] = (UINT8) (Pos >> 24); mBuf[mOutputPos++] = (UINT8) (Pos >> 16); mBuf[mOutputPos++] = (UINT8) (Pos >> (UINT8_BIT)); mBuf[mOutputPos++] = (UINT8) Pos; CharC = 0; while (Pos) { Pos >>= 1; CharC++; } mPFreq[CharC]++; } } STATIC VOID HufEncodeStart ( VOID ) { INT32 Index; for (Index = 0; Index < NC; Index++) { mCFreq[Index] = 0; } for (Index = 0; Index < NP; Index++) { mPFreq[Index] = 0; } mOutputPos = mOutputMask = 0; InitPutBits (); return ; } STATIC VOID HufEncodeEnd ( VOID ) { SendBlock (); // // Flush remaining bits // PutBits (UINT8_BIT - 1, 0); return ; } STATIC VOID MakeCrcTable ( VOID ) { UINT32 Index; UINT32 Index2; UINT32 Temp; for (Index = 0; Index <= UINT8_MAX; Index++) { Temp = Index; for (Index2 = 0; Index2 < UINT8_BIT; Index2++) { if (Temp & 1) { Temp = (Temp >> 1) ^ CRCPOLY; } else { Temp >>= 1; } } mCrcTable[Index] = (UINT16) Temp; } } STATIC VOID PutBits ( IN INT32 Number, IN UINT32 Value ) /*++ Routine Description: Outputs rightmost n bits of x Arguments: Number - the rightmost n bits of the data is used x - the data Returns: (VOID) --*/ { UINT8 Temp; while (Number >= mBitCount) { // // Number -= mBitCount should never equal to 32 // Temp = (UINT8) (mSubBitBuf | (Value >> (Number -= mBitCount))); if (mDst < mDstUpperLimit) { *mDst++ = Temp; } mCompSize++; mSubBitBuf = 0; mBitCount = UINT8_BIT; } mSubBitBuf |= Value << (mBitCount -= Number); } STATIC INT32 FreadCrc ( OUT UINT8 *Pointer, IN INT32 Number ) /*++ Routine Description: Read in source data Arguments: Pointer - the buffer to hold the data Number - number of bytes to read Returns: number of bytes actually read --*/ { INT32 Index; for (Index = 0; mSrc < mSrcUpperLimit && Index < Number; Index++) { *Pointer++ = *mSrc++; } Number = Index; Pointer -= Number; mOrigSize += Number; Index--; while (Index >= 0) { UPDATE_CRC (*Pointer++); Index--; } return Number; } STATIC VOID InitPutBits ( VOID ) { mBitCount = UINT8_BIT; mSubBitBuf = 0; } STATIC VOID CountLen ( IN INT32 Index ) /*++ Routine Description: Count the number of each code length for a Huffman tree. Arguments: Index - the top node Returns: (VOID) --*/ { STATIC INT32 Depth = 0; if (Index < mN) { mLenCnt[(Depth < 16) ? Depth : 16]++; } else { Depth++; CountLen (mLeft[Index]); CountLen (mRight[Index]); Depth--; } } STATIC VOID MakeLen ( IN INT32 Root ) /*++ Routine Description: Create code length array for a Huffman tree Arguments: Root - the root of the tree Returns: VOID --*/ { INT32 Index; INT32 Index3; UINT32 Cum; for (Index = 0; Index <= 16; Index++) { mLenCnt[Index] = 0; } CountLen (Root); // // Adjust the length count array so that // no code will be generated longer than its designated length // Cum = 0; for (Index = 16; Index > 0; Index--) { Cum += mLenCnt[Index] << (16 - Index); } while (Cum != (1U << 16)) { mLenCnt[16]--; for (Index = 15; Index > 0; Index--) { if (mLenCnt[Index] != 0) { mLenCnt[Index]--; mLenCnt[Index + 1] += 2; break; } } Cum--; } for (Index = 16; Index > 0; Index--) { Index3 = mLenCnt[Index]; Index3--; while (Index3 >= 0) { mLen[*mSortPtr++] = (UINT8) Index; Index3--; } } } STATIC VOID DownHeap ( IN INT32 Index ) { INT32 Index2; INT32 Index3; // // priority queue: send Index-th entry down heap // Index3 = mHeap[Index]; Index2 = 2 * Index; while (Index2 <= mHeapSize) { if (Index2 < mHeapSize && mFreq[mHeap[Index2]] > mFreq[mHeap[Index2 + 1]]) { Index2++; } if (mFreq[Index3] <= mFreq[mHeap[Index2]]) { break; } mHeap[Index] = mHeap[Index2]; Index = Index2; Index2 = 2 * Index; } mHeap[Index] = (INT16) Index3; } STATIC VOID MakeCode ( IN INT32 Number, IN UINT8 Len[ ], OUT UINT16 Code[] ) /*++ Routine Description: Assign code to each symbol based on the code length array Arguments: Number - number of symbols Len - the code length array Code - stores codes for each symbol Returns: (VOID) --*/ { INT32 Index; UINT16 Start[18]; Start[1] = 0; for (Index = 1; Index <= 16; Index++) { Start[Index + 1] = (UINT16) ((Start[Index] + mLenCnt[Index]) << 1); } for (Index = 0; Index < Number; Index++) { Code[Index] = Start[Len[Index]]++; } } STATIC INT32 MakeTree ( IN INT32 NParm, IN UINT16 FreqParm[], OUT UINT8 LenParm[ ], OUT UINT16 CodeParm[] ) /*++ Routine Description: Generates Huffman codes given a frequency distribution of symbols Arguments: NParm - number of symbols FreqParm - frequency of each symbol LenParm - code length for each symbol CodeParm - code for each symbol Returns: Root of the Huffman tree. --*/ { INT32 Index; INT32 Index2; INT32 Index3; INT32 Avail; // // make tree, calculate len[], return root // mN = NParm; mFreq = FreqParm; mLen = LenParm; Avail = mN; mHeapSize = 0; mHeap[1] = 0; for (Index = 0; Index < mN; Index++) { mLen[Index] = 0; if (mFreq[Index]) { mHeapSize++; mHeap[mHeapSize] = (INT16) Index; } } if (mHeapSize < 2) { CodeParm[mHeap[1]] = 0; return mHeap[1]; } for (Index = mHeapSize / 2; Index >= 1; Index--) { // // make priority queue // DownHeap (Index); } mSortPtr = CodeParm; do { Index = mHeap[1]; if (Index < mN) { *mSortPtr++ = (UINT16) Index; } mHeap[1] = mHeap[mHeapSize--]; DownHeap (1); Index2 = mHeap[1]; if (Index2 < mN) { *mSortPtr++ = (UINT16) Index2; } Index3 = Avail++; mFreq[Index3] = (UINT16) (mFreq[Index] + mFreq[Index2]); mHeap[1] = (INT16) Index3; DownHeap (1); mLeft[Index3] = (UINT16) Index; mRight[Index3] = (UINT16) Index2; } while (mHeapSize > 1); mSortPtr = CodeParm; MakeLen (Index3); MakeCode (NParm, LenParm, CodeParm); // // return root // return Index3; }