/**@file
  UEFI and Custom Decompress Library 
  
Copyright (c) 2006, Intel Corporation                                                         
All rights reserved. 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 "BaseUefiTianoCustomDecompressLibInternals.h"

VOID
FillBuf (
  IN  SCRATCH_DATA  *Sd,
  IN  UINT16        NumOfBits
  )
/*++

Routine Description:

  Shift mBitBuf NumOfBits left. Read in NumOfBits of bits from source.

Arguments:

  Sd        - The global scratch data
  NumOfBits  - The number of bits to shift and read.

Returns: (VOID)

--*/
{
  Sd->mBitBuf = (UINT32) (Sd->mBitBuf << NumOfBits);

  while (NumOfBits > Sd->mBitCount) {

    Sd->mBitBuf |= (UINT32) (Sd->mSubBitBuf << (NumOfBits = (UINT16) (NumOfBits - Sd->mBitCount)));

    if (Sd->mCompSize > 0) {
      //
      // Get 1 byte into SubBitBuf
      //
      Sd->mCompSize--;
      Sd->mSubBitBuf  = 0;
      Sd->mSubBitBuf  = Sd->mSrcBase[Sd->mInBuf++];
      Sd->mBitCount   = 8;

    } else {
      //
      // No more bits from the source, just pad zero bit.
      //
      Sd->mSubBitBuf  = 0;
      Sd->mBitCount   = 8;

    }
  }

  Sd->mBitCount = (UINT16) (Sd->mBitCount - NumOfBits);
  Sd->mBitBuf |= Sd->mSubBitBuf >> Sd->mBitCount;
}

UINT32
GetBits (
  IN  SCRATCH_DATA  *Sd,
  IN  UINT16        NumOfBits
  )
/*++

Routine Description:

  Get NumOfBits of bits out from mBitBuf. Fill mBitBuf with subsequent 
  NumOfBits of bits from source. Returns NumOfBits of bits that are 
  popped out.

Arguments:

  Sd            - The global scratch data.
  NumOfBits     - The number of bits to pop and read.

Returns:

  The bits that are popped out.

--*/
{
  UINT32  OutBits;

  OutBits = (UINT32) (Sd->mBitBuf >> (BITBUFSIZ - NumOfBits));

  FillBuf (Sd, NumOfBits);

  return OutBits;
}

UINT16
MakeTable (
  IN  SCRATCH_DATA  *Sd,
  IN  UINT16        NumOfChar,
  IN  UINT8         *BitLen,
  IN  UINT16        TableBits,
  OUT UINT16        *Table
  )
/*++

Routine Description:

  Creates Huffman Code mapping table according to code length array.

Arguments:

  Sd        - The global scratch data
  NumOfChar - Number of symbols in the symbol set
  BitLen    - Code length array
  TableBits - The width of the mapping table
  Table     - The table
  
Returns:
  
  0         - OK.
  BAD_TABLE - The table is corrupted.

--*/
{
  UINT16  Count[17];
  UINT16  Weight[17];
  UINT16  Start[18];
  UINT16  *Pointer;
  UINT16  Index3;
  volatile UINT16  Index;
  UINT16  Len;
  UINT16  Char;
  UINT16  JuBits;
  UINT16  Avail;
  UINT16  NextCode;
  UINT16  Mask;
  UINT16  WordOfStart;
  UINT16  WordOfCount;

  for (Index = 1; Index <= 16; Index++) {
    Count[Index] = 0;
  }

  for (Index = 0; Index < NumOfChar; Index++) {
    Count[BitLen[Index]]++;
  }

  Start[1] = 0;

  for (Index = 1; Index <= 16; Index++) {
    WordOfStart = Start[Index];
    WordOfCount = Count[Index];
    Start[Index + 1] = (UINT16) (WordOfStart + (WordOfCount << (16 - Index)));
  }

  if (Start[17] != 0) {
    /*(1U << 16)*/
    return (UINT16) BAD_TABLE;
  }

  JuBits = (UINT16) (16 - TableBits);

  for (Index = 1; Index <= TableBits; Index++) {
    Start[Index] >>= JuBits;
    Weight[Index] = (UINT16) (1U << (TableBits - Index));
  }

  while (Index <= 16) {
    Weight[Index] = (UINT16) (1U << (16 - Index));
    Index++;
  }

  Index = (UINT16) (Start[TableBits + 1] >> JuBits);

  if (Index != 0) {
    Index3 = (UINT16) (1U << TableBits);
    while (Index != Index3) {
      Table[Index++] = 0;
    }
  }

  Avail = NumOfChar;
  Mask  = (UINT16) (1U << (15 - TableBits));

  for (Char = 0; Char < NumOfChar; Char++) {

    Len = BitLen[Char];
    if (Len == 0) {
      continue;
    }

    NextCode = (UINT16) (Start[Len] + Weight[Len]);

    if (Len <= TableBits) {

      for (Index = Start[Len]; Index < NextCode; Index++) {
        Table[Index] = Char;
      }

    } else {

      Index3  = Start[Len];
      Pointer = &Table[Index3 >> JuBits];
      Index   = (UINT16) (Len - TableBits);

      while (Index != 0) {
        if (*Pointer == 0) {
          Sd->mRight[Avail]                     = Sd->mLeft[Avail] = 0;
          *Pointer = Avail++;
        }

        if (Index3 & Mask) {
          Pointer = &Sd->mRight[*Pointer];
        } else {
          Pointer = &Sd->mLeft[*Pointer];
        }

        Index3 <<= 1;
        Index--;
      }

      *Pointer = Char;

    }

    Start[Len] = NextCode;
  }
  //
  // Succeeds
  //
  return 0;
}

UINT32
DecodeP (
  IN  SCRATCH_DATA  *Sd
  )
/*++

Routine Description:

  Decodes a position value.

Arguments:

  Sd      - the global scratch data

Returns:

  The position value decoded.

--*/
{
  UINT16  Val;
  UINT32  Mask;
  UINT32  Pos;

  Val = Sd->mPTTable[Sd->mBitBuf >> (BITBUFSIZ - 8)];

  if (Val >= MAXNP) {
    Mask = 1U << (BITBUFSIZ - 1 - 8);

    do {

      if (Sd->mBitBuf & Mask) {
        Val = Sd->mRight[Val];
      } else {
        Val = Sd->mLeft[Val];
      }

      Mask >>= 1;
    } while (Val >= MAXNP);
  }
  //
  // Advance what we have read
  //
  FillBuf (Sd, Sd->mPTLen[Val]);

  Pos = Val;
  if (Val > 1) {
    Pos = (UINT32) ((1U << (Val - 1)) + GetBits (Sd, (UINT16) (Val - 1)));
  }

  return Pos;
}

UINT16
ReadPTLen (
  IN  SCRATCH_DATA  *Sd,
  IN  UINT16        nn,
  IN  UINT16        nbit,
  IN  UINT16        Special
  )
/*++

Routine Description:

  Reads code lengths for the Extra Set or the Position Set

Arguments:

  Sd        - The global scratch data
  nn        - Number of symbols
  nbit      - Number of bits needed to represent nn
  Special   - The special symbol that needs to be taken care of 

Returns:

  0         - OK.
  BAD_TABLE - Table is corrupted.

--*/
{
  UINT16  Number;
  UINT16  CharC;
  volatile UINT16  Index;
  UINT32  Mask;

  Number = (UINT16) GetBits (Sd, nbit);

  if (Number == 0) {
    CharC = (UINT16) GetBits (Sd, nbit);

    for (Index = 0; Index < 256; Index++) {
      Sd->mPTTable[Index] = CharC;
    }

    for (Index = 0; Index < nn; Index++) {
      Sd->mPTLen[Index] = 0;
    }

    return 0;
  }

  Index = 0;

  while (Index < Number) {

    CharC = (UINT16) (Sd->mBitBuf >> (BITBUFSIZ - 3));

    if (CharC == 7) {
      Mask = 1U << (BITBUFSIZ - 1 - 3);
      while (Mask & Sd->mBitBuf) {
        Mask >>= 1;
        CharC += 1;
      }
    }

    FillBuf (Sd, (UINT16) ((CharC < 7) ? 3 : CharC - 3));

    Sd->mPTLen[Index++] = (UINT8) CharC;

    if (Index == Special) {
      CharC = (UINT16) GetBits (Sd, 2);
      while ((INT16) (--CharC) >= 0) {
        Sd->mPTLen[Index++] = 0;
      }
    }
  }

  while (Index < nn) {
    Sd->mPTLen[Index++] = 0;
  }

  return MakeTable (Sd, nn, Sd->mPTLen, 8, Sd->mPTTable);
}

VOID
ReadCLen (
  SCRATCH_DATA  *Sd
  )
/*++

Routine Description:

  Reads code lengths for Char&Len Set.

Arguments:

  Sd    - the global scratch data

Returns: (VOID)

--*/
{
  UINT16  Number;
  UINT16  CharC;
  volatile UINT16  Index;
  UINT32  Mask;

  Number = (UINT16) GetBits (Sd, CBIT);

  if (Number == 0) {
    CharC = (UINT16) GetBits (Sd, CBIT);

    for (Index = 0; Index < NC; Index++) {
      Sd->mCLen[Index] = 0;
    }

    for (Index = 0; Index < 4096; Index++) {
      Sd->mCTable[Index] = CharC;
    }

    return ;
  }

  Index = 0;
  while (Index < Number) {

    CharC = Sd->mPTTable[Sd->mBitBuf >> (BITBUFSIZ - 8)];
    if (CharC >= NT) {
      Mask = 1U << (BITBUFSIZ - 1 - 8);

      do {

        if (Mask & Sd->mBitBuf) {
          CharC = Sd->mRight[CharC];
        } else {
          CharC = Sd->mLeft[CharC];
        }

        Mask >>= 1;

      } while (CharC >= NT);
    }
    //
    // Advance what we have read
    //
    FillBuf (Sd, Sd->mPTLen[CharC]);

    if (CharC <= 2) {

      if (CharC == 0) {
        CharC = 1;
      } else if (CharC == 1) {
        CharC = (UINT16) (GetBits (Sd, 4) + 3);
      } else if (CharC == 2) {
        CharC = (UINT16) (GetBits (Sd, CBIT) + 20);
      }

      while ((INT16) (--CharC) >= 0) {
        Sd->mCLen[Index++] = 0;
      }

    } else {

      Sd->mCLen[Index++] = (UINT8) (CharC - 2);

    }
  }

  while (Index < NC) {
    Sd->mCLen[Index++] = 0;
  }

  MakeTable (Sd, NC, Sd->mCLen, 12, Sd->mCTable);

  return ;
}

UINT16
DecodeC (
  SCRATCH_DATA  *Sd
  )
/*++

Routine Description:

  Decode a character/length value.

Arguments:

  Sd    - The global scratch data.

Returns:

  The value decoded.

--*/
{
  UINT16  Index2;
  UINT32  Mask;

  if (Sd->mBlockSize == 0) {
    //
    // Starting a new block
    //
    Sd->mBlockSize    = (UINT16) GetBits (Sd, 16);
    Sd->mBadTableFlag = ReadPTLen (Sd, NT, TBIT, 3);
    if (Sd->mBadTableFlag != 0) {
      return 0;
    }

    ReadCLen (Sd);

    Sd->mBadTableFlag = ReadPTLen (Sd, MAXNP, Sd->mPBit, (UINT16) (-1));
    if (Sd->mBadTableFlag != 0) {
      return 0;
    }
  }

  Sd->mBlockSize--;
  Index2 = Sd->mCTable[Sd->mBitBuf >> (BITBUFSIZ - 12)];

  if (Index2 >= NC) {
    Mask = 1U << (BITBUFSIZ - 1 - 12);

    do {
      if (Sd->mBitBuf & Mask) {
        Index2 = Sd->mRight[Index2];
      } else {
        Index2 = Sd->mLeft[Index2];
      }

      Mask >>= 1;
    } while (Index2 >= NC);
  }
  //
  // Advance what we have read
  //
  FillBuf (Sd, Sd->mCLen[Index2]);

  return Index2;
}

VOID
Decode (
  SCRATCH_DATA  *Sd
  )
/*++

Routine Description:

  Decode the source data and put the resulting data into the destination buffer.

Arguments:

  Sd            - The global scratch data

Returns: (VOID)

 --*/
{
  UINT16  BytesRemain;
  UINT32  DataIdx;
  UINT16  CharC;

  BytesRemain = (UINT16) (-1);

  DataIdx     = 0;

  for (;;) {
    CharC = DecodeC (Sd);
    if (Sd->mBadTableFlag != 0) {
      goto Done ;
    }

    if (CharC < 256) {
      //
      // Process an Original character
      //
      if (Sd->mOutBuf >= Sd->mOrigSize) {
        goto Done ;
      } else {
        Sd->mDstBase[Sd->mOutBuf++] = (UINT8) CharC;
      }

    } else {
      //
      // Process a Pointer
      //
      CharC       = (UINT16) (CharC - (UINT8_MAX + 1 - THRESHOLD));

      BytesRemain = CharC;

      DataIdx     = Sd->mOutBuf - DecodeP (Sd) - 1;

      BytesRemain--;
      while ((INT16) (BytesRemain) >= 0) {
        Sd->mDstBase[Sd->mOutBuf++] = Sd->mDstBase[DataIdx++];
        if (Sd->mOutBuf >= Sd->mOrigSize) {
          goto Done ;
        }

        BytesRemain--;
      }
    }
  }

Done:
  return ;
}

RETURN_STATUS
EFIAPI
UefiDecompressGetInfo (
  IN  CONST VOID  *Source,
  IN  UINT32      SourceSize,
  OUT UINT32      *DestinationSize,
  OUT UINT32      *ScratchSize
  )
/*++

Routine Description:

  The internal implementation of *_DECOMPRESS_PROTOCOL.GetInfo().

Arguments:

  Source          - The source buffer containing the compressed data.
  SourceSize      - The size of source buffer
  DestinationSize - The size of destination buffer.
  ScratchSize     - The size of scratch buffer.

Returns:

  RETURN_SUCCESS           - The size of destination buffer and the size of scratch buffer are successull retrieved.
  RETURN_INVALID_PARAMETER - The source data is corrupted

--*/
{
  UINT32  CompressedSize;

  ASSERT (Source != NULL);
  ASSERT (DestinationSize != NULL);
  ASSERT (ScratchSize != NULL);

  *ScratchSize  = sizeof (SCRATCH_DATA);

  if (SourceSize < 8) {
    return RETURN_INVALID_PARAMETER;
  }

  CopyMem (&CompressedSize, Source, sizeof (UINT32));
  CopyMem (DestinationSize, (VOID *)((UINT8 *)Source + 4), sizeof (UINT32));

  if (SourceSize < (CompressedSize + 8)) {
    return RETURN_INVALID_PARAMETER;
  }

  return RETURN_SUCCESS;
}

RETURN_STATUS
EFIAPI
UefiTianoDecompress (
  IN CONST VOID  *Source,
  IN OUT VOID    *Destination,
  IN OUT VOID    *Scratch,
  IN UINT32      Version
  )
/*++

Routine Description:

  The internal implementation of *_DECOMPRESS_PROTOCOL.Decompress().

Arguments:

  Source          - The source buffer containing the compressed data.
  Destination     - The destination buffer to store the decompressed data
  Scratch         - The buffer used internally by the decompress routine. This  buffer is needed to store intermediate data.
  Version         - 1 for UEFI Decompress algoruthm, 2 for Tiano Decompess algorithm

Returns:

  RETURN_SUCCESS           - Decompression is successfull
  RETURN_INVALID_PARAMETER - The source data is corrupted

--*/
{
  volatile UINT32  Index;
  UINT32           CompSize;
  UINT32           OrigSize;
  SCRATCH_DATA     *Sd;
  CONST UINT8      *Src;
  UINT8            *Dst;

  ASSERT (Source != NULL);
  ASSERT (Destination != NULL);
  ASSERT (Scratch != NULL);

  Src     = Source;
  Dst     = Destination;

  Sd = (SCRATCH_DATA *) Scratch;

  CompSize  = Src[0] + (Src[1] << 8) + (Src[2] << 16) + (Src[3] << 24);
  OrigSize  = Src[4] + (Src[5] << 8) + (Src[6] << 16) + (Src[7] << 24);

  //
  // If compressed file size is 0, return
  //
  if (OrigSize == 0) {
    return RETURN_SUCCESS;
  }

  Src = Src + 8;

  for (Index = 0; Index < sizeof (SCRATCH_DATA); Index++) {
    ((UINT8 *) Sd)[Index] = 0;
  }
  //
  // The length of the field 'Position Set Code Length Array Size' in Block Header.
  // For EFI 1.1 de/compression algorithm(Version 1), mPBit = 4
  // For Tiano de/compression algorithm(Version 2), mPBit = 5
  //
  switch (Version) {
    case 1 :
      Sd->mPBit = 4;
      break;
    case 2 :
      Sd->mPBit = 5;
      break;
    default:
      ASSERT (FALSE);
  }
  Sd->mSrcBase  = (UINT8 *)Src;
  Sd->mDstBase  = Dst;
  Sd->mCompSize = CompSize;
  Sd->mOrigSize = OrigSize;

  //
  // Fill the first BITBUFSIZ bits
  //
  FillBuf (Sd, BITBUFSIZ);

  //
  // Decompress it
  //
  Decode (Sd);

  if (Sd->mBadTableFlag != 0) {
    //
    // Something wrong with the source
    //
    return RETURN_INVALID_PARAMETER;
  }

  return RETURN_SUCCESS;
}

RETURN_STATUS
EFIAPI
UefiDecompress (
  IN CONST VOID  *Source,
  IN OUT VOID    *Destination,
  IN OUT VOID    *Scratch
  )
/*++

Routine Description:

  The internal implementation of *_DECOMPRESS_PROTOCOL.Decompress().

Arguments:

  Source          - The source buffer containing the compressed data.
  Destination     - The destination buffer to store the decompressed data
  Scratch         - The buffer used internally by the decompress routine. This  buffer is needed to store intermediate data.

Returns:

  RETURN_SUCCESS           - Decompression is successfull
  RETURN_INVALID_PARAMETER - The source data is corrupted

--*/
{
  return UefiTianoDecompress (Source, Destination, Scratch, 1);
}

RETURN_STATUS
EFIAPI
CustomDecompressGetInfo (
  IN  CONST VOID  *Source,
  IN  UINT32      SourceSize,
  OUT UINT32      *DestinationSize,
  OUT UINT32      *ScratchSize
  )
/*++

Routine Description:

  The internal implementation of *_DECOMPRESS_PROTOCOL.GetInfo().

Arguments:

  Source          - The source buffer containing the compressed data.
  SourceSize      - The size of source buffer
  DestinationSize - The size of destination buffer.
  ScratchSize     - The size of scratch buffer.

Returns:

  RETURN_SUCCESS           - The size of destination buffer and the size of scratch buffer are successull retrieved.
  RETURN_INVALID_PARAMETER - The source data is corrupted

--*/
{
  return UefiDecompressGetInfo (Source, SourceSize, DestinationSize, ScratchSize);
}

RETURN_STATUS
EFIAPI
CustomDecompress (
  IN CONST VOID  *Source,
  IN OUT VOID    *Destination,
  IN OUT VOID    *Scratch
  )
/*++

Routine Description:

  The internal implementation of *_DECOMPRESS_PROTOCOL.Decompress().

Arguments:

  Source          - The source buffer containing the compressed data.
  Destination     - The destination buffer to store the decompressed data
  Scratch         - The buffer used internally by the decompress routine. This  buffer is needed to store intermediate data.

Returns:

  RETURN_SUCCESS           - Decompression is successfull
  RETURN_INVALID_PARAMETER - The source data is corrupted

--*/
{
  return UefiTianoDecompress (Source, Destination, Scratch, 2);
}