MurmurHash3

Implements the MurmurHash3 functions. You can specify the size of the hash in bit. For 128 bit hashes you can specify whether to optimize for 32 or 64 bit architectures. If you don't specify the opt value it will select the fastest version of the host platform.

This hasher is compatible with the Digest API:

void start()
void put(scope const(ubyte)[] data...)
ubyte[Element.sizeof] finish()

It also provides a faster, low level API working with data of size Element.sizeof:

void putElements(scope const(Element[]) elements...)
void putRemainder(scope const(ubyte[]) data...)
void finalize()
Element get()
ubyte[Element.sizeof] getBytes()

@safe

struct MurmurHash3 (

uint size

uint opt = size_t.sizeof == 8 ? 64 : 32

) {

enum blockSize;

size_t element_count;

static if(size == 32)

void putElement(uint block);

static if(size == 32)

void putRemainder(const(ubyte[]) data);

static if(size == 32)

void finalize();

static if(size == 32)

Element get();

static if(size == 32)

ubyte[4] getBytes();

static if(!(size == 32))
static if(size == 128 && opt == 32)

void putElement(Element block);

static if(!(size == 32))
static if(size == 128 && opt == 32)

void putRemainder(const(ubyte[]) data);

static if(!(size == 32))
static if(size == 128 && opt == 32)

void finalize();

static if(!(size == 32))
static if(size == 128 && opt == 32)

Element get();

static if(!(size == 32))
static if(size == 128 && opt == 32)

ubyte[16] getBytes();

static if(!(size == 32))
static if(!(size == 128 && opt == 32))
static if(size == 128 && opt == 64)

void putElement(Element block);

static if(!(size == 32))
static if(!(size == 128 && opt == 32))
static if(size == 128 && opt == 64)

void putRemainder(const(ubyte[]) data);

static if(!(size == 32))
static if(!(size == 128 && opt == 32))
static if(size == 128 && opt == 64)

void finalize();

static if(!(size == 32))
static if(!(size == 128 && opt == 32))
static if(size == 128 && opt == 64)

Element get();

static if(!(size == 32))
static if(!(size == 128 && opt == 32))
static if(size == 128 && opt == 64)

ubyte[16] getBytes();

void putElements(const(Element[]) elements);

void put(const(ubyte)[] data);

ubyte[Element.sizeof] finish();

}

Postblit

A postblit is present on this object, but not explicitly documented in the source.

Members

Functions

finalize void finalize(): Incorporate element_count and finalizes the hash.
finalize void finalize(): Incorporate element_count and finalizes the hash.
finalize void finalize(): Incorporate element_count and finalizes the hash.
finish ubyte[Element.sizeof] finish(): Finalizes the computation of the hash and returns the computed value. Note that finish can be called only once and that no subsequent calls to put is allowed.
get Element get(): Returns the hash as an uint value.
get Element get(): Returns the hash as an uint[4] value.
get Element get(): Returns the hash as an ulong[2] value.
getBytes ubyte[4] getBytes(): Returns the current hashed value as an ubyte array.
getBytes ubyte[16] getBytes(): Returns the current hashed value as an ubyte array.
getBytes ubyte[16] getBytes(): Returns the current hashed value as an ubyte array.
put void put(const(ubyte)[] data): Adds data to the digester. This function can be called many times in a row after start but before finish.
putElement void putElement(uint block): Adds a single Element of data without increasing element_count. Make sure to increase element_count by Element.sizeof for each call to putElement.
putElement void putElement(Element block): Adds a single Element of data without increasing element_count. Make sure to increase element_count by Element.sizeof for each call to putElement.
putElement void putElement(Element block): Adds a single Element of data without increasing element_count. Make sure to increase element_count by Element.sizeof for each call to putElement.
putElements void putElements(const(Element[]) elements): Pushes an array of elements at once. It is more efficient to push as much data as possible in a single call. On platforms that do not support unaligned reads (MIPS or old ARM chips), the compiler may produce slower code to ensure correctness.
putRemainder void putRemainder(const(ubyte[]) data): Put remainder bytes. This must be called only once after putElement and before finalize.
putRemainder void putRemainder(const(ubyte[]) data): Put remainder bytes. This must be called only once after putElement and before finalize.
putRemainder void putRemainder(const(ubyte[]) data): Put remainder bytes. This must be called only once after putElement and before finalize.

Examples

The convenient digest template allows for quick hashing of any data.

ubyte[4] hashed = digest!(MurmurHash3!32)([1, 2, 3, 4]);
assert(hashed == [0, 173, 69, 68]);

One can also hash ubyte data piecewise by instanciating a hasher and call the 'put' method.

const(ubyte)[] data1 = [1, 2, 3];
const(ubyte)[] data2 = [4, 5, 6, 7];
// The incoming data will be buffered and hashed element by element.
MurmurHash3!32 hasher;
hasher.put(data1);
hasher.put(data2);
// The call to 'finish' ensures:
// - the remaining bits are processed
// - the hash gets finalized
auto hashed = hasher.finish();
assert(hashed == [181, 151, 88, 252]);

The OpenD Programming Language

MurmurHash3

Postblit

Members

Functions

Examples

Meta

Source