Mercurial > vba-linux

     1 // Archive/GZipIn.cpp

     2 

     3 #include "StdAfx.h"

     4 

     5 #include "GZipIn.h"

     6 

     7 #include "Common/Defs.h"

     8 #include "Common/MyCom.h"

     9 #include "Windows/Defs.h"

    10 

    11 #include "../../Common/StreamUtils.h"

    12 

    13 extern "C"

    14 {

    15   #include "../../../../C/7zCrc.h"

    16 }

    17 

    18 namespace NArchive {

    19 namespace NGZip {

    20  

    21 HRESULT CInArchive::ReadBytes(ISequentialInStream *inStream, void *data, UInt32 size)

    22 {

    23   RINOK(ReadStream_FALSE(inStream, data, size));

    24   m_Position += size;

    25   return S_OK;

    26 }

    27 

    28 HRESULT CInArchive::ReadByte(ISequentialInStream *inStream, Byte &value, UInt32 &crc)

    29 {

    30   RINOK(ReadBytes(inStream, &value, 1));

    31   crc = CRC_UPDATE_BYTE(crc, value);

    32   return S_OK;

    33 }

    34 

    35 HRESULT CInArchive::ReadUInt16(ISequentialInStream *inStream, UInt16 &value, UInt32 &crc)

    36 {

    37   value = 0;

    38   for (int i = 0; i < 2; i++)

    39   {

    40     Byte b;

    41     RINOK(ReadByte(inStream, b, crc));

    42     value |= (UInt16(b) << (8 * i));

    43   }

    44   return S_OK;

    45 }

    46 

    47 HRESULT CInArchive::ReadUInt32(ISequentialInStream *inStream, UInt32 &value, UInt32 &crc)

    48 {

    49   value = 0;

    50   for (int i = 0; i < 4; i++)

    51   {

    52     Byte b;

    53     RINOK(ReadByte(inStream, b, crc));

    54     value |= (UInt32(b) << (8 * i));

    55   }

    56   return S_OK;

    57 }

    58 

    59 HRESULT CInArchive::ReadZeroTerminatedString(ISequentialInStream *inStream, AString &resString, UInt32 &crc)

    60 {

    61   resString.Empty();

    62   for (;;)

    63   {

    64     Byte c;

    65     RINOK(ReadByte(inStream, c, crc));

    66     if (c == 0)

    67       return S_OK;

    68     resString += char(c);

    69   }

    70 }

    71 

    72 HRESULT CInArchive::ReadHeader(ISequentialInStream *inStream, CItem &item)

    73 {

    74   item.Clear();

    75   m_Position = 0;

    76 

    77   UInt16 signature;

    78   UInt32 crc = CRC_INIT_VAL;;

    79   RINOK(ReadUInt16(inStream, signature, crc));

    80   if (signature != kSignature)

    81     return S_FALSE;

    82   

    83   RINOK(ReadByte(inStream, item.CompressionMethod, crc));

    84   RINOK(ReadByte(inStream, item.Flags, crc));

    85   RINOK(ReadUInt32(inStream, item.Time, crc));

    86   RINOK(ReadByte(inStream, item.ExtraFlags, crc));

    87   RINOK(ReadByte(inStream, item.HostOS, crc));

    88   

    89   if (item.ExtraFieldIsPresent())

    90   {

    91     UInt16 extraSize;

    92     RINOK(ReadUInt16(inStream, extraSize, crc));

    93     item.Extra.SetCapacity(extraSize);

    94     RINOK(ReadBytes(inStream, item.Extra, extraSize));

    95     crc = CrcUpdate(crc, item.Extra, extraSize);

    96   }

    97   if (item.NameIsPresent())

    98     RINOK(ReadZeroTerminatedString(inStream, item.Name, crc));

    99   if (item.CommentIsPresent())

   100     RINOK(ReadZeroTerminatedString(inStream, item.Comment, crc));

   101   if (item.HeaderCRCIsPresent())

   102   {

   103     UInt16 headerCRC;

   104     UInt32 dummy = 0;

   105     RINOK(ReadUInt16(inStream, headerCRC, dummy));

   106     if ((UInt16)CRC_GET_DIGEST(crc) != headerCRC)

   107       return S_FALSE;

   108   }

   109   return S_OK;

   110 }

   111 

   112 HRESULT CInArchive::ReadPostHeader(ISequentialInStream *inStream, CItem &item)

   113 {

   114   UInt32 dummy = 0;

   115   RINOK(ReadUInt32(inStream, item.FileCRC, dummy));

   116   return ReadUInt32(inStream, item.UnPackSize32, dummy);

   117 }

   118 

   119 }}
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 03 Mar 2012 10:31:27 -0600
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