Mercurial > vba-linux
annotate src/win32/7zip/7z/CPP/7zip/Archive/Lzh/LzhCRC.cpp @ 1:f9f4f1b99eed
importing src directory
| author | Robert McIntyre <rlm@mit.edu> |
|---|---|
| date | Sat, 03 Mar 2012 10:31:27 -0600 |
| parents | |
| children |
| rev | line source |
|---|---|
| rlm@1 | 1 // LzhCRC.cpp |
| rlm@1 | 2 |
| rlm@1 | 3 #include "StdAfx.h" |
| rlm@1 | 4 |
| rlm@1 | 5 #include "LzhCRC.h" |
| rlm@1 | 6 |
| rlm@1 | 7 namespace NArchive { |
| rlm@1 | 8 namespace NLzh { |
| rlm@1 | 9 |
| rlm@1 | 10 static const UInt16 kCRCPoly = 0xA001; |
| rlm@1 | 11 |
| rlm@1 | 12 UInt16 CCRC::Table[256]; |
| rlm@1 | 13 |
| rlm@1 | 14 void CCRC::InitTable() |
| rlm@1 | 15 { |
| rlm@1 | 16 for (UInt32 i = 0; i < 256; i++) |
| rlm@1 | 17 { |
| rlm@1 | 18 UInt32 r = i; |
| rlm@1 | 19 for (int j = 0; j < 8; j++) |
| rlm@1 | 20 if (r & 1) |
| rlm@1 | 21 r = (r >> 1) ^ kCRCPoly; |
| rlm@1 | 22 else |
| rlm@1 | 23 r >>= 1; |
| rlm@1 | 24 CCRC::Table[i] = (UInt16)r; |
| rlm@1 | 25 } |
| rlm@1 | 26 } |
| rlm@1 | 27 |
| rlm@1 | 28 class CCRCTableInit |
| rlm@1 | 29 { |
| rlm@1 | 30 public: |
| rlm@1 | 31 CCRCTableInit() { CCRC::InitTable(); } |
| rlm@1 | 32 } g_CRCTableInit; |
| rlm@1 | 33 |
| rlm@1 | 34 void CCRC::Update(const void *data, size_t size) |
| rlm@1 | 35 { |
| rlm@1 | 36 UInt16 v = _value; |
| rlm@1 | 37 const Byte *p = (const Byte *)data; |
| rlm@1 | 38 for (; size > 0; size--, p++) |
| rlm@1 | 39 v = (UInt16)(Table[((Byte)(v)) ^ *p] ^ (v >> 8)); |
| rlm@1 | 40 _value = v; |
| rlm@1 | 41 } |
| rlm@1 | 42 |
| rlm@1 | 43 }} |