CHash Class Reference

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Detailed Description

Collection of Hashing Functions.

This class implements a number of hashing functions like crc32, md5 and murmur.

Definition at line 55 of file Hash.h.

Inheritance diagram for CHash:

List of all members.

Public Member Functions
	CHash ()
virtual	~CHash ()
virtual const char *	get_name () const
Static Public Member Functions
static uint32_t	crc32 (uint8_t *data, int32_t len)
static void	MD5 (unsigned char *x, unsigned l, unsigned char *buf)
static uint32_t	MurmurHash2 (uint8_t *data, int32_t len, uint32_t seed)
static uint32_t	IncrementalMurmurHash2 (uint8_t data, uint32_t h)
static uint32_t	MurmurHashString (substring s, uint32_t h)
Static Protected Member Functions
static void	MD5Init (struct MD5Context *context)
static void	MD5Update (struct MD5Context *context, unsigned char const *buf, unsigned len)
static void	MD5Final (unsigned char digest[16], struct MD5Context *context)
static void	MD5Transform (uint32_t buf[4], uint32_t const in[16])

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Constructor & Destructor Documentation

CHash

(

)

default constructor

Definition at line 59 of file Hash.h.

virtual ~CHash

(

)

[virtual]

default destructor

Definition at line 61 of file Hash.h.

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Member Function Documentation

uint32_t crc32	(	uint8_t *	data,
		int32_t	len
	)		[static]

crc32 checksumming

Parameters:

data	data to checksum
len	length in number of bytes

Definition at line 47 of file Hash.cpp.

virtual const char* get_name

(

)

const [virtual]

Returns:

object name

Implements CSGObject.

Definition at line 111 of file Hash.h.

uint32_t IncrementalMurmurHash2	(	uint8_t	data,
		uint32_t	h
	)		[static]

Incremental Murmur like Hash

Parameters:

data	byte to hash
h	initial seed / hash on subsequent calls

Returns:

hash

Definition at line 424 of file Hash.cpp.

void MD5	(	unsigned char *	x,
		unsigned	l,
		unsigned char *	buf
	)		[static]

Wrapper for MD5 function compatible to OpenSSL interface.

Parameters:

x	data
l	length
buf	buf needs to provide an allocated array of 16 bytes for the digest.

Definition at line 74 of file Hash.cpp.

void MD5Final	(	unsigned char	digest[16],
		struct MD5Context *	context
	)		[static, protected]

Final wrapup - pad to 64-byte boundary with the bit pattern 1 0* (64-bit count of bits processed, MSB-first)

Parameters:

digest	the 64 byte hash
context	initialized MD5Context

Definition at line 161 of file Hash.cpp.

void MD5Init

(

struct MD5Context *

context

)

[static, protected]

Start MD5 accumulation. Set bit count to 0 and buffer to mysterious initialization constants.

Parameters:

context

MD5Context

Definition at line 105 of file Hash.cpp.

void MD5Transform	(	uint32_t	buf[4],
		uint32_t const	in[16]
	)		[static, protected]

The core of the MD5 algorithm, this alters an existing MD5 hash to reflect the addition of 16 longwords of new data. MD5Update blocks the data and converts bytes into longwords for this routine.

Parameters:

buf	16 byte
in	64 bytes

Definition at line 221 of file Hash.cpp.

void MD5Update	(	struct MD5Context *	context,
		unsigned char const *	buf,
		unsigned	len
	)		[static, protected]

Update context to reflect the concatenation of another buffer full of bytes.

Parameters:

context	initialized MD5Context
buf	buffer to hash
len	length of buffer

Definition at line 116 of file Hash.cpp.

uint32_t MurmurHash2	(	uint8_t *	data,
		int32_t	len,
		uint32_t	seed
	)		[static]

Murmur Hash2

Parameters:

data	data to checksum (needs to be 32bit aligned on some archs)
len	length in number of bytes
seed	initial seed

Returns:

hash

Definition at line 375 of file Hash.cpp.

uint32_t MurmurHashString	(	substring	s,
		uint32_t	h
	)		[static]

Apply Murmur Hash on the non-numeric part of a substring.

The integral part is returned as-is.

Parameters:

s	substring
h	initial seed

Returns:

hash

Definition at line 444 of file Hash.cpp.

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The documentation for this class was generated from the following files:

• Hash.h
• Hash.cpp