CHash – Hash calculator. More...
#include <util/checksum.hpp>
Inheritance diagram for CHash:
Collaboration diagram for CHash:
Public Types | |
| enum | EMethod { eCRC32 = CChecksumBase::eCRC32C , eCRC32ZIP = CChecksumBase::eCRC32ZIP , eCRC32INSD = CChecksumBase::eCRC32INSD , eCRC32CKSUM = CChecksumBase::eCRC32CKSUM , eCRC32C = CChecksumBase::eCRC32C , eAdler32 = CChecksumBase::eAdler32 , eCityHash32 = CChecksumBase::eCityHash32 , eCityHash64 = CChecksumBase::eCityHash64 , eFarmHash32 = CChecksumBase::eFarmHash32 , eFarmHash64 = CChecksumBase::eFarmHash64 , eMurmurHash2_32 = CChecksumBase::eMurmurHash2_32 , eMurmurHash2_64 = CChecksumBase::eMurmurHash2_64 , eMurmurHash3_32 = CChecksumBase::eMurmurHash3_32 , eDefault = eCityHash64 } |
| Method used to compute hash. More... | |
Public Member Functions | |
| CHash (EMethod method=eDefault) | |
| Default constructor. More... | |
| CHash (const CHash &other) | |
| Copy constructor. More... | |
| CHash & | operator= (const CHash &other) |
| Assignment operator. More... | |
| EMethod | GetMethod (void) const |
| Get current method used to compute hash. More... | |
| void | Calculate (const CTempString str) |
| Calculate hash. More... | |
| void | Calculate (const char *str, size_t len) |
| void | Reset (EMethod method) |
| Reset the object to prepare it to the next computation using another method. More... | |
| Public Member Functions inherited from CChecksumBase | |
| CChecksumBase (EMethodDef method) | |
| Default constructor. More... | |
| ~CChecksumBase () | |
| Destructor. More... | |
| CChecksumBase (const CChecksumBase &other) | |
| Copy constructor. More... | |
| CChecksumBase & | operator= (const CChecksumBase &other) |
| Assignment operator. More... | |
| size_t | GetSize (void) const |
| Return size of checksum/hash in bytes, depending on used method. More... | |
| size_t | GetBits (void) const |
| Return size of checksum/hash in bits (32, 64). More... | |
| Uint4 | GetResult32 (void) const |
| Return calculated result. More... | |
| Uint8 | GetResult64 (void) const |
| Return calculated result. More... | |
| string | GetResultHex (void) const |
| Return string with checksum/hash in hexadecimal form. More... | |
| EMethodDef | x_GetMethod (void) const |
Static Public Member Functions | |
| static void | SetSeed (Uint8 seed) |
| Unique seed used by some hash methods. More... | |
| static void | Calculate (const CTempString str, EMethod method, Uint4 &hash) |
| Static methods for simplified one line calculations. More... | |
| static void | Calculate (const CTempString str, EMethod method, Uint8 &hash) |
| static void | Calculate (const char *str, size_t len, EMethod method, Uint4 &hash) |
| static void | Calculate (const char *str, size_t len, EMethod method, Uint8 &hash) |
| Static Public Member Functions inherited from CChecksumBase | |
| static void | InitTables (void) |
| Initialize static tables used in CRC32 calculation. More... | |
| static void | PrintTables (CNcbiOstream &out) |
| Print C++ code for CRC32 tables for direct inclusion into library. More... | |
Additional Inherited Members | |
| Protected Types inherited from CChecksumBase | |
| enum | EMethodDef { eNone , eCRC32 , eCRC32ZIP , eCRC32INSD , eCRC32CKSUM , eCRC32C , eAdler32 , eMD5 , eCityHash32 , eCityHash64 , eFarmHash32 , eFarmHash64 , eMurmurHash2_32 , eMurmurHash2_64 , eMurmurHash3_32 } |
| All supported methods for CHash and CCheksum. More... | |
| Protected Member Functions inherited from CChecksumBase | |
| void | x_Update (const char *str, size_t len) |
| Update current control sum with data provided. More... | |
| void | x_Reset (EMethodDef method) |
| Reset the object to prepare it to the next computation using selected method. More... | |
| void | x_Free (void) |
| Cleanup (used in destructor and assignment operator). More... | |
| Protected Attributes inherited from CChecksumBase | |
| EMethodDef | m_Method |
| Current method. More... | |
| size_t | m_CharCount |
| Number of processed chars. More... | |
| union { | |
| Uint4 CChecksumBase::v32 | |
| Used to store 32-bit results. More... | |
| Uint8 CChecksumBase::v64 | |
| Used to store 64-bit results. More... | |
| CMD5 * CChecksumBase::md5 | |
| Used for MD5 calculation. More... | |
| } | m_Value |
| Checksum/Hash computation result. More... | |
| Static Protected Attributes inherited from CChecksumBase | |
| static Uint8 | m_Seed = 0 |
| Unique seed used by some hash methods. More... | |
Detailed Description
CHash – Hash calculator.
This class is used to compute hash.
- Note
- This class may use static tables (for CRC32 based methods only). This presents a potential race condition in MT programs. To avoid races call static InitTables() method before first concurrent use of CHash if use it with CRC32-based methods.
- Attention
- You should not use some CHash methods for persistent storage, like CityHash, FarmHash or Murmur. Many hash methods designed to be used inside current process only, here and now. Please use CChecksum class if you need to store checksums for later usage.
- Some hash methods have 32/64 bit variants. Usually 32-bit version works faster on 32-bit machines and vice versa.
Definition at line 194 of file checksum.hpp.
The documentation for this class was generated from the following files:
- include/util/checksum.hpp
- src/util/checksum.cpp
