ns3::Hash::Function::Fnv1a Class Reference

Fnv1a hash function implementation. More...

#include <hash-fnv.h>

Inheritance diagram for ns3::Hash::Function::Fnv1a:

Collaboration diagram for ns3::Hash::Function::Fnv1a:

Public Member Functions
	Fnv1a ()
	Constructor. More...
virtual void	clear (void)
	Restore initial state. More...
uint32_t	GetHash32 (const char *buffer, const size_t size)
	Compute 32-bit hash of a byte buffer. More...
uint64_t	GetHash64 (const char *buffer, const size_t size)
	Compute 64-bit hash of a byte buffer. More...
Public Member Functions inherited from ns3::Hash::Implementation
	Implementation ()
	Constructor. More...
virtual	~Implementation ()
	Destructor. More...
Public Member Functions inherited from ns3::SimpleRefCount< Implementation >
	SimpleRefCount ()
	Constructor. More...
	SimpleRefCount (const SimpleRefCount &o)
	Copy constructor. More...
uint32_t	GetReferenceCount (void) const
	Get the reference count of the object. More...
SimpleRefCount &	operator= (const SimpleRefCount &o)
	Assignment. More...
void	Ref (void) const
	Increment the reference count. More...
void	Unref (void) const
	Decrement the reference count. More...

Private Types
enum	seed { SEED = 0x8BADF00D }
	Seed value. More...

Private Attributes
uint32_t	m_hash32
	Cache last hash value, for incremental hashing. More...
uint64_t	m_hash64
	Cache last hash value, for incremental hashing. More...

Additional Inherited Members
Static Public Member Functions inherited from ns3::SimpleRefCount< Implementation >
static void	Cleanup (void)
	Noop. More...

Detailed Description

Fnv1a hash function implementation.

This is the venerable Fowler-Noll-Vo hash, version 1A. (See the FNV page.)

The implementation here is taken directly from the published FNV reference code, with minor modifications to wrap into this class. See the hash-fnv.cc file for details.

Definition at line 47 of file hash-fnv.h.

Member Enumeration Documentation

enum ns3::Hash::Function::Fnv1a::seed

private

Seed value.

Enumerator
SEED

Definition at line 93 of file hash-fnv.h.

Constructor & Destructor Documentation

ns3::Hash::Function::Fnv1a::Fnv1a

(

)

Constructor.

Definition at line 732 of file hash-fnv.cc.

References clear().

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Member Function Documentation

void ns3::Hash::Function::Fnv1a::clear ( void  )

virtual

Restore initial state.

Implements ns3::Hash::Implementation.

Definition at line 754 of file hash-fnv.cc.

References FNV1_32A_INIT, FNV1A_64_INIT, m_hash32, and m_hash64.

Referenced by Fnv1a().

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uint32_t ns3::Hash::Function::Fnv1a::GetHash32 ( const char *  buffer, const size_t  size  )

virtual

Compute 32-bit hash of a byte buffer.

Call clear () between calls to GetHash32() to reset the internal state and hash each buffer separately.

If you don't call clear() between calls to GetHash32, you can hash successive buffers. The final return value will be the cumulative hash across all calls.

Parameters

[in]	buffer	pointer to the beginning of the buffer
[in]	size	length of the buffer, in bytes

Returns

32-bit hash of the buffer

Implements ns3::Hash::Implementation.

Definition at line 738 of file hash-fnv.cc.

References ns3::Hash::Function::Fnv1aImplementation::fnv_32a_buf(), and m_hash32.

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uint64_t ns3::Hash::Function::Fnv1a::GetHash64 ( const char *  buffer, const size_t  size  )

virtual

Compute 64-bit hash of a byte buffer.

Call clear () between calls to GetHash64() to reset the internal state and hash each buffer separately.

If you don't call clear() between calls to GetHash64, you can hash successive buffers. The final return value will be the cumulative hash across all calls.

Parameters

[in]	buffer	pointer to the beginning of the buffer
[in]	size	length of the buffer, in bytes

Returns

64-bit hash of the buffer

Reimplemented from ns3::Hash::Implementation.

Definition at line 746 of file hash-fnv.cc.

References ns3::Hash::Function::Fnv1aImplementation::fnv_64a_buf(), and m_hash64.

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Member Data Documentation

uint32_t ns3::Hash::Function::Fnv1a::m_hash32

private

Cache last hash value, for incremental hashing.

Definition at line 101 of file hash-fnv.h.

Referenced by clear(), and GetHash32().

uint64_t ns3::Hash::Function::Fnv1a::m_hash64

private

Cache last hash value, for incremental hashing.

Definition at line 102 of file hash-fnv.h.

Referenced by clear(), and GetHash64().

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

• src/core/model/hash-fnv.h
• src/core/model/hash-fnv.cc