The Tor Browser / file comparison
comparison: other-licenses/7zstub/src/Common/CRC.cpp
other-licenses/7zstub/src/Common/CRC.cpp
- branch
- TOR_BUG_9701
- changeset 14
- 925c144e1f1f
equal
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| -1:000000000000 | 0:faa5da3f2f0d |
|---|---|
| 1 // Common/CRC.cpp | |
| 2 | |
| 3 #include "StdAfx.h" | |
| 4 | |
| 5 #include "CRC.h" | |
| 6 | |
| 7 static const UInt32 kCRCPoly = 0xEDB88320; | |
| 8 | |
| 9 UInt32 CCRC::Table[256]; | |
| 10 | |
| 11 void CCRC::InitTable() | |
| 12 { | |
| 13 for (UInt32 i = 0; i < 256; i++) | |
| 14 { | |
| 15 UInt32 r = i; | |
| 16 for (int j = 0; j < 8; j++) | |
| 17 if (r & 1) | |
| 18 r = (r >> 1) ^ kCRCPoly; | |
| 19 else | |
| 20 r >>= 1; | |
| 21 CCRC::Table[i] = r; | |
| 22 } | |
| 23 } | |
| 24 | |
| 25 class CCRCTableInit | |
| 26 { | |
| 27 public: | |
| 28 CCRCTableInit() { CCRC::InitTable(); } | |
| 29 } g_CRCTableInit; | |
| 30 | |
| 31 void CCRC::UpdateByte(Byte b) | |
| 32 { | |
| 33 _value = Table[((Byte)(_value)) ^ b] ^ (_value >> 8); | |
| 34 } | |
| 35 | |
| 36 void CCRC::UpdateUInt16(UInt16 v) | |
| 37 { | |
| 38 UpdateByte(Byte(v)); | |
| 39 UpdateByte(Byte(v >> 8)); | |
| 40 } | |
| 41 | |
| 42 void CCRC::UpdateUInt32(UInt32 v) | |
| 43 { | |
| 44 for (int i = 0; i < 4; i++) | |
| 45 UpdateByte((Byte)(v >> (8 * i))); | |
| 46 } | |
| 47 | |
| 48 void CCRC::UpdateUInt64(UInt64 v) | |
| 49 { | |
| 50 for (int i = 0; i < 8; i++) | |
| 51 UpdateByte((Byte)(v >> (8 * i))); | |
| 52 } | |
| 53 | |
| 54 void CCRC::Update(const void *data, size_t size) | |
| 55 { | |
| 56 UInt32 v = _value; | |
| 57 const Byte *p = (const Byte *)data; | |
| 58 for (; size > 0 ; size--, p++) | |
| 59 v = Table[((Byte)(v)) ^ *p] ^ (v >> 8); | |
| 60 _value = v; | |
| 61 } |
