Merge pull request #2882 from andersfr/hash-branch

Implementation of MurmurHash and CityHash
This commit is contained in:
Andrew Kelley 2019-07-13 20:08:18 -04:00 committed by GitHub
commit 7d9ee5d6d5
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4 changed files with 745 additions and 0 deletions

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@ -523,6 +523,8 @@ set(ZIG_STD_FILES
"hash/crc.zig"
"hash/fnv.zig"
"hash/siphash.zig"
"hash/murmur.zig"
"hash/cityhash.zig"
"hash_map.zig"
"heap.zig"
"heap/logging_allocator.zig"

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@ -14,9 +14,20 @@ const siphash = @import("hash/siphash.zig");
pub const SipHash64 = siphash.SipHash64;
pub const SipHash128 = siphash.SipHash128;
pub const murmur = @import("hash/murmur.zig");
pub const Murmur2_32 = murmur.Murmur2_32;
pub const Murmur2_64 = murmur.Murmur2_64;
pub const Murmur3_32 = murmur.Murmur3_32;
pub const cityhash = @import("hash/cityhash.zig");
pub const CityHash32 = cityhash.CityHash32;
pub const CityHash64 = cityhash.CityHash64;
test "hash" {
_ = @import("hash/adler.zig");
_ = @import("hash/crc.zig");
_ = @import("hash/fnv.zig");
_ = @import("hash/siphash.zig");
_ = @import("hash/murmur.zig");
_ = @import("hash/cityhash.zig");
}

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std/hash/cityhash.zig Normal file
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@ -0,0 +1,387 @@
const std = @import("std");
const builtin = @import("builtin");
pub const CityHash32 = struct {
const Self = @This();
// Magic numbers for 32-bit hashing. Copied from Murmur3.
const c1: u32 = 0xcc9e2d51;
const c2: u32 = 0x1b873593;
fn fetch32(ptr: [*]const u8) u32 {
var v: u32 = undefined;
@memcpy(@ptrCast([*]u8, &v), ptr, 4);
if (builtin.endian == builtin.Endian.Big)
return @byteSwap(u32, v);
return v;
}
// A 32-bit to 32-bit integer hash copied from Murmur3.
fn fmix(h: u32) u32 {
var h1: u32 = h;
h1 ^= h1 >> 16;
h1 *%= 0x85ebca6b;
h1 ^= h1 >> 13;
h1 *%= 0xc2b2ae35;
h1 ^= h1 >> 16;
return h1;
}
// Rotate right helper
fn rotr32(x: u32, comptime r: u32) u32 {
return (x >> r) | (x << (32 - r));
}
// Helper from Murmur3 for combining two 32-bit values.
fn mur(a: u32, h: u32) u32 {
var a1: u32 = a;
var h1: u32 = h;
a1 *%= c1;
a1 = rotr32(a1, 17);
a1 *%= c2;
h1 ^= a1;
h1 = rotr32(h1, 19);
return h1 *% 5 +% 0xe6546b64;
}
fn hash32Len0To4(str: []const u8) u32 {
const len: u32 = @truncate(u32, str.len);
var b: u32 = 0;
var c: u32 = 9;
for (str) |v| {
b = b *% c1 +% @bitCast(u32, @intCast(i32, @bitCast(i8, v)));
c ^= b;
}
return fmix(mur(b, mur(len, c)));
}
fn hash32Len5To12(str: []const u8) u32 {
var a: u32 = @truncate(u32, str.len);
var b: u32 = a *% 5;
var c: u32 = 9;
const d: u32 = b;
a +%= fetch32(str.ptr);
b +%= fetch32(str.ptr + str.len - 4);
c +%= fetch32(str.ptr + ((str.len >> 1) & 4));
return fmix(mur(c, mur(b, mur(a, d))));
}
fn hash32Len13To24(str: []const u8) u32 {
const len: u32 = @truncate(u32, str.len);
const a: u32 = fetch32(str.ptr + (str.len >> 1) - 4);
const b: u32 = fetch32(str.ptr + 4);
const c: u32 = fetch32(str.ptr + str.len - 8);
const d: u32 = fetch32(str.ptr + (str.len >> 1));
const e: u32 = fetch32(str.ptr);
const f: u32 = fetch32(str.ptr + str.len - 4);
return fmix(mur(f, mur(e, mur(d, mur(c, mur(b, mur(a, len)))))));
}
pub fn hash(str: []const u8) u32 {
if (str.len <= 24) {
if (str.len <= 4) {
return hash32Len0To4(str);
} else {
if (str.len <= 12)
return hash32Len5To12(str);
return hash32Len13To24(str);
}
}
const len: u32 = @truncate(u32, str.len);
var h: u32 = len;
var g: u32 = c1 *% len;
var f: u32 = g;
const a0: u32 = rotr32(fetch32(str.ptr + str.len - 4) *% c1, 17) *% c2;
const a1: u32 = rotr32(fetch32(str.ptr + str.len - 8) *% c1, 17) *% c2;
const a2: u32 = rotr32(fetch32(str.ptr + str.len - 16) *% c1, 17) *% c2;
const a3: u32 = rotr32(fetch32(str.ptr + str.len - 12) *% c1, 17) *% c2;
const a4: u32 = rotr32(fetch32(str.ptr + str.len - 20) *% c1, 17) *% c2;
h ^= a0;
h = rotr32(h, 19);
h = h *% 5 +% 0xe6546b64;
h ^= a2;
h = rotr32(h, 19);
h = h *% 5 +% 0xe6546b64;
g ^= a1;
g = rotr32(g, 19);
g = g *% 5 +% 0xe6546b64;
g ^= a3;
g = rotr32(g, 19);
g = g *% 5 +% 0xe6546b64;
f +%= a4;
f = rotr32(f, 19);
f = f *% 5 +% 0xe6546b64;
var iters = (str.len - 1) / 20;
var ptr = str.ptr;
while (iters != 0) : (iters -= 1) {
const b0: u32 = rotr32(fetch32(ptr) *% c1, 17) *% c2;
const b1: u32 = fetch32(ptr + 4);
const b2: u32 = rotr32(fetch32(ptr + 8) *% c1, 17) *% c2;
const b3: u32 = rotr32(fetch32(ptr + 12) *% c1, 17) *% c2;
const b4: u32 = fetch32(ptr + 16);
h ^= b0;
h = rotr32(h, 18);
h = h *% 5 +% 0xe6546b64;
f +%= b1;
f = rotr32(f, 19);
f = f *% c1;
g +%= b2;
g = rotr32(g, 18);
g = g *% 5 +% 0xe6546b64;
h ^= b3 +% b1;
h = rotr32(h, 19);
h = h *% 5 +% 0xe6546b64;
g ^= b4;
g = @byteSwap(u32, g) *% 5;
h +%= b4 *% 5;
h = @byteSwap(u32, h);
f +%= b0;
const t: u32 = h;
h = f;
f = g;
g = t;
ptr += 20;
}
g = rotr32(g, 11) *% c1;
g = rotr32(g, 17) *% c1;
f = rotr32(f, 11) *% c1;
f = rotr32(f, 17) *% c1;
h = rotr32(h +% g, 19);
h = h *% 5 +% 0xe6546b64;
h = rotr32(h, 17) *% c1;
h = rotr32(h +% f, 19);
h = h *% 5 +% 0xe6546b64;
h = rotr32(h, 17) *% c1;
return h;
}
};
pub const CityHash64 = struct {
const Self = @This();
// Some primes between 2^63 and 2^64 for various uses.
const k0: u64 = 0xc3a5c85c97cb3127;
const k1: u64 = 0xb492b66fbe98f273;
const k2: u64 = 0x9ae16a3b2f90404f;
fn fetch32(ptr: [*]const u8) u32 {
var v: u32 = undefined;
@memcpy(@ptrCast([*]u8, &v), ptr, 4);
if (builtin.endian == builtin.Endian.Big)
return @byteSwap(u32, v);
return v;
}
fn fetch64(ptr: [*]const u8) u64 {
var v: u64 = undefined;
@memcpy(@ptrCast([*]u8, &v), ptr, 8);
if (builtin.endian == builtin.Endian.Big)
return @byteSwap(u64, v);
return v;
}
// Rotate right helper
fn rotr64(x: u64, comptime r: u64) u64 {
return (x >> r) | (x << (64 - r));
}
fn shiftmix(v: u64) u64 {
return v ^ (v >> 47);
}
fn hashLen16(u: u64, v: u64) u64 {
return @inlineCall(hash128To64, u, v);
}
fn hashLen16Mul(low: u64, high: u64, mul: u64) u64 {
var a: u64 = (low ^ high) *% mul;
a ^= (a >> 47);
var b: u64 = (high ^ a) *% mul;
b ^= (b >> 47);
b *%= mul;
return b;
}
fn hash128To64(low: u64, high: u64) u64 {
return @inlineCall(hashLen16Mul, low, high, 0x9ddfea08eb382d69);
}
fn hashLen0To16(str: []const u8) u64 {
const len: u64 = @truncate(u64, str.len);
if (len >= 8) {
const mul: u64 = k2 +% len *% 2;
const a: u64 = fetch64(str.ptr) +% k2;
const b: u64 = fetch64(str.ptr + str.len - 8);
const c: u64 = rotr64(b, 37) *% mul +% a;
const d: u64 = (rotr64(a, 25) +% b) *% mul;
return hashLen16Mul(c, d, mul);
}
if (len >= 4) {
const mul: u64 = k2 +% len *% 2;
const a: u64 = fetch32(str.ptr);
return hashLen16Mul(len +% (a << 3), fetch32(str.ptr + str.len - 4), mul);
}
if (len > 0) {
const a: u8 = str[0];
const b: u8 = str[str.len >> 1];
const c: u8 = str[str.len - 1];
const y: u32 = @intCast(u32, a) +% (@intCast(u32, b) << 8);
const z: u32 = @truncate(u32, str.len) +% (@intCast(u32, c) << 2);
return shiftmix(@intCast(u64, y) *% k2 ^ @intCast(u64, z) *% k0) *% k2;
}
return k2;
}
fn hashLen17To32(str: []const u8) u64 {
const len: u64 = @truncate(u64, str.len);
const mul: u64 = k2 +% len *% 2;
const a: u64 = fetch64(str.ptr) *% k1;
const b: u64 = fetch64(str.ptr + 8);
const c: u64 = fetch64(str.ptr + str.len - 8) *% mul;
const d: u64 = fetch64(str.ptr + str.len - 16) *% k2;
return hashLen16Mul(rotr64(a +% b, 43) +% rotr64(c, 30) +% d, a +% rotr64(b +% k2, 18) +% c, mul);
}
fn hashLen33To64(str: []const u8) u64 {
const len: u64 = @truncate(u64, str.len);
const mul: u64 = k2 +% len *% 2;
const a: u64 = fetch64(str.ptr) *% k2;
const b: u64 = fetch64(str.ptr + 8);
const c: u64 = fetch64(str.ptr + str.len - 24);
const d: u64 = fetch64(str.ptr + str.len - 32);
const e: u64 = fetch64(str.ptr + 16) *% k2;
const f: u64 = fetch64(str.ptr + 24) *% 9;
const g: u64 = fetch64(str.ptr + str.len - 8);
const h: u64 = fetch64(str.ptr + str.len - 16) *% mul;
const u: u64 = rotr64(a +% g, 43) +% (rotr64(b, 30) +% c) *% 9;
const v: u64 = ((a +% g) ^ d) +% f +% 1;
const w: u64 = @byteSwap(u64, (u +% v) *% mul) +% h;
const x: u64 = rotr64(e +% f, 42) +% c;
const y: u64 = (@byteSwap(u64, (v +% w) *% mul) +% g) *% mul;
const z: u64 = e +% f +% c;
const a1: u64 = @byteSwap(u64, (x +% z) *% mul +% y) +% b;
const b1: u64 = shiftmix((z +% a1) *% mul +% d +% h) *% mul;
return b1 +% x;
}
const WeakPair = struct {
first: u64,
second: u64,
};
fn weakHashLen32WithSeedsHelper(w: u64, x: u64, y: u64, z: u64, a: u64, b: u64) WeakPair {
var a1: u64 = a;
var b1: u64 = b;
a1 +%= w;
b1 = rotr64(b1 +% a1 +% z, 21);
var c: u64 = a1;
a1 +%= x;
a1 +%= y;
b1 +%= rotr64(a1, 44);
return WeakPair{ .first = a1 +% z, .second = b1 +% c };
}
fn weakHashLen32WithSeeds(ptr: [*]const u8, a: u64, b: u64) WeakPair {
return @inlineCall(weakHashLen32WithSeedsHelper, fetch64(ptr), fetch64(ptr + 8), fetch64(ptr + 16), fetch64(ptr + 24), a, b);
}
pub fn hash(str: []const u8) u64 {
if (str.len <= 32) {
if (str.len <= 16) {
return hashLen0To16(str);
} else {
return hashLen17To32(str);
}
} else if (str.len <= 64) {
return hashLen33To64(str);
}
var len: u64 = @truncate(u64, str.len);
var x: u64 = fetch64(str.ptr + str.len - 40);
var y: u64 = fetch64(str.ptr + str.len - 16) +% fetch64(str.ptr + str.len - 56);
var z: u64 = hashLen16(fetch64(str.ptr + str.len - 48) +% len, fetch64(str.ptr + str.len - 24));
var v: WeakPair = weakHashLen32WithSeeds(str.ptr + str.len - 64, len, z);
var w: WeakPair = weakHashLen32WithSeeds(str.ptr + str.len - 32, y +% k1, x);
x = x *% k1 +% fetch64(str.ptr);
len = (len - 1) & ~@intCast(u64, 63);
var ptr: [*]const u8 = str.ptr;
while (true) {
x = rotr64(x +% y +% v.first +% fetch64(ptr + 8), 37) *% k1;
y = rotr64(y +% v.second +% fetch64(ptr + 48), 42) *% k1;
x ^= w.second;
y +%= v.first +% fetch64(ptr + 40);
z = rotr64(z +% w.first, 33) *% k1;
v = weakHashLen32WithSeeds(ptr, v.second *% k1, x +% w.first);
w = weakHashLen32WithSeeds(ptr + 32, z +% w.second, y +% fetch64(ptr + 16));
const t: u64 = z;
z = x;
x = t;
ptr += 64;
len -= 64;
if (len == 0)
break;
}
return hashLen16(hashLen16(v.first, w.first) +% shiftmix(y) *% k1 +% z, hashLen16(v.second, w.second) +% x);
}
pub fn hashWithSeed(str: []const u8, seed: u64) u64 {
return @inlineCall(Self.hashWithSeeds, str, k2, seed);
}
pub fn hashWithSeeds(str: []const u8, seed0: u64, seed1: u64) u64 {
return hashLen16(hash(str) -% seed0, seed1);
}
};
fn SMHasherTest(comptime hash_fn: var, comptime hashbits: u32) u32 {
const hashbytes = hashbits / 8;
var key: [256]u8 = undefined;
var hashes: [hashbytes * 256]u8 = undefined;
var final: [hashbytes]u8 = undefined;
@memset(@ptrCast([*]u8, &key[0]), 0, @sizeOf(@typeOf(key)));
@memset(@ptrCast([*]u8, &hashes[0]), 0, @sizeOf(@typeOf(hashes)));
@memset(@ptrCast([*]u8, &final[0]), 0, @sizeOf(@typeOf(final)));
var i: u32 = 0;
while (i < 256) : (i += 1) {
key[i] = @intCast(u8, i);
var h = hash_fn(key[0..i], 256 - i);
if (builtin.endian == builtin.Endian.Big)
h = @byteSwap(@typeOf(h), h);
@memcpy(@ptrCast([*]u8, &hashes[i * hashbytes]), @ptrCast([*]u8, &h), hashbytes);
}
return @truncate(u32, hash_fn(hashes, 0));
}
fn CityHash32hashIgnoreSeed(str: []const u8, seed: u32) u32 {
return CityHash32.hash(str);
}
test "cityhash32" {
// Note: SMHasher doesn't provide a 32bit version of the algorithm.
// Note: The implementation was verified against the Google Abseil version.
std.testing.expectEqual(SMHasherTest(CityHash32hashIgnoreSeed, 32), 0x68254F81);
}
test "cityhash64" {
// Note: This is not compliant with the SMHasher implementation of CityHash64!
// Note: The implementation was verified against the Google Abseil version.
std.testing.expectEqual(SMHasherTest(CityHash64.hashWithSeed, 64), 0x5FABC5C5);
}

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std/hash/murmur.zig Normal file
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@ -0,0 +1,345 @@
const std = @import("std");
const builtin = @import("builtin");
const testing = std.testing;
const default_seed: u32 = 0xc70f6907;
pub const Murmur2_32 = struct {
const Self = @This();
pub fn hash(str: []const u8) u32 {
return @inlineCall(Self.hashWithSeed, str, default_seed);
}
pub fn hashWithSeed(str: []const u8, seed: u32) u32 {
const m: u32 = 0x5bd1e995;
const len = @truncate(u32, str.len);
var h1: u32 = seed ^ len;
for (@ptrCast([*]allowzero align(1) const u32, str.ptr)[0..(len >> 2)]) |v| {
var k1: u32 = v;
if (builtin.endian == builtin.Endian.Big)
k1 = @byteSwap(u32, k1);
k1 *%= m;
k1 ^= k1 >> 24;
k1 *%= m;
h1 *%= m;
h1 ^= k1;
}
const offset = len & 0xfffffffc;
const rest = len & 3;
if (rest >= 3) {
h1 ^= @intCast(u32, str[offset + 2]) << 16;
}
if (rest >= 2) {
h1 ^= @intCast(u32, str[offset + 1]) << 8;
}
if (rest >= 1) {
h1 ^= @intCast(u32, str[offset + 0]);
h1 *%= m;
}
h1 ^= h1 >> 13;
h1 *%= m;
h1 ^= h1 >> 15;
return h1;
}
pub fn hashUint32(v: u32) u32 {
return @inlineCall(Self.hashUint32WithSeed, v, default_seed);
}
pub fn hashUint32WithSeed(v: u32, seed: u32) u32 {
const m: u32 = 0x5bd1e995;
const len: u32 = 4;
var h1: u32 = seed ^ len;
var k1: u32 = undefined;
k1 = v *% m;
k1 ^= k1 >> 24;
k1 *%= m;
h1 *%= m;
h1 ^= k1;
h1 ^= h1 >> 13;
h1 *%= m;
h1 ^= h1 >> 15;
return h1;
}
pub fn hashUint64(v: u64) u32 {
return @inlineCall(Self.hashUint64WithSeed, v, default_seed);
}
pub fn hashUint64WithSeed(v: u64, seed: u32) u32 {
const m: u32 = 0x5bd1e995;
const len: u32 = 8;
var h1: u32 = seed ^ len;
var k1: u32 = undefined;
k1 = @truncate(u32, v) *% m;
k1 ^= k1 >> 24;
k1 *%= m;
h1 *%= m;
h1 ^= k1;
k1 = @truncate(u32, v >> 32) *% m;
k1 ^= k1 >> 24;
k1 *%= m;
h1 *%= m;
h1 ^= k1;
h1 ^= h1 >> 13;
h1 *%= m;
h1 ^= h1 >> 15;
return h1;
}
};
pub const Murmur2_64 = struct {
const Self = @This();
pub fn hash(str: []const u8) u64 {
return @inlineCall(Self.hashWithSeed, str, default_seed);
}
pub fn hashWithSeed(str: []const u8, seed: u64) u64 {
const m: u64 = 0xc6a4a7935bd1e995;
const len = @truncate(u64, str.len);
var h1: u64 = seed ^ (len *% m);
for (@ptrCast([*]allowzero align(1) const u64, str.ptr)[0..(len >> 3)]) |v| {
var k1: u64 = v;
if (builtin.endian == builtin.Endian.Big)
k1 = @byteSwap(u64, k1);
k1 *%= m;
k1 ^= k1 >> 47;
k1 *%= m;
h1 ^= k1;
h1 *%= m;
}
const rest = len & 7;
const offset = len - rest;
if (rest > 0) {
var k1: u64 = 0;
@memcpy(@ptrCast([*]u8, &k1), @ptrCast([*]const u8, &str[offset]), rest);
if (builtin.endian == builtin.Endian.Big)
k1 = @byteSwap(u64, k1);
h1 ^= k1;
h1 *%= m;
}
h1 ^= h1 >> 47;
h1 *%= m;
h1 ^= h1 >> 47;
return h1;
}
pub fn hashUint32(v: u32) u64 {
return @inlineCall(Self.hashUint32WithSeed, v, default_seed);
}
pub fn hashUint32WithSeed(v: u32, seed: u32) u64 {
const m: u64 = 0xc6a4a7935bd1e995;
const len: u64 = 4;
var h1: u64 = seed ^ (len *% m);
var k1: u64 = v;
h1 ^= k1;
h1 *%= m;
h1 ^= h1 >> 47;
h1 *%= m;
h1 ^= h1 >> 47;
return h1;
}
pub fn hashUint64(v: u64) u64 {
return @inlineCall(Self.hashUint64WithSeed, v, default_seed);
}
pub fn hashUint64WithSeed(v: u64, seed: u32) u64 {
const m: u64 = 0xc6a4a7935bd1e995;
const len: u64 = 8;
var h1: u64 = seed ^ (len *% m);
var k1: u64 = undefined;
k1 = v *% m;
k1 ^= k1 >> 47;
k1 *%= m;
h1 ^= k1;
h1 *%= m;
h1 ^= h1 >> 47;
h1 *%= m;
h1 ^= h1 >> 47;
return h1;
}
};
pub const Murmur3_32 = struct {
const Self = @This();
fn rotl32(x: u32, comptime r: u32) u32 {
return (x << r) | (x >> (32 - r));
}
pub fn hash(str: []const u8) u32 {
return @inlineCall(Self.hashWithSeed, str, default_seed);
}
pub fn hashWithSeed(str: []const u8, seed: u32) u32 {
const c1: u32 = 0xcc9e2d51;
const c2: u32 = 0x1b873593;
const len = @truncate(u32, str.len);
var h1: u32 = seed;
for (@ptrCast([*]allowzero align(1) const u32, str.ptr)[0..(len >> 2)]) |v| {
var k1: u32 = v;
if (builtin.endian == builtin.Endian.Big)
k1 = @byteSwap(u32, k1);
k1 *%= c1;
k1 = rotl32(k1, 15);
k1 *%= c2;
h1 ^= k1;
h1 = rotl32(h1, 13);
h1 *%= 5;
h1 +%= 0xe6546b64;
}
{
var k1: u32 = 0;
const offset = len & 0xfffffffc;
const rest = len & 3;
if (rest == 3) {
k1 ^= @intCast(u32, str[offset + 2]) << 16;
}
if (rest >= 2) {
k1 ^= @intCast(u32, str[offset + 1]) << 8;
}
if (rest >= 1) {
k1 ^= @intCast(u32, str[offset + 0]);
k1 *%= c1;
k1 = rotl32(k1, 15);
k1 *%= c2;
h1 ^= k1;
}
}
h1 ^= len;
h1 ^= h1 >> 16;
h1 *%= 0x85ebca6b;
h1 ^= h1 >> 13;
h1 *%= 0xc2b2ae35;
h1 ^= h1 >> 16;
return h1;
}
pub fn hashUint32(v: u32) u32 {
return @inlineCall(Self.hashUint32WithSeed, v, default_seed);
}
pub fn hashUint32WithSeed(v: u32, seed: u32) u32 {
const c1: u32 = 0xcc9e2d51;
const c2: u32 = 0x1b873593;
const len: u32 = 4;
var h1: u32 = seed;
var k1: u32 = undefined;
k1 = v *% c1;
k1 = rotl32(k1, 15);
k1 *%= c2;
h1 ^= k1;
h1 = rotl32(h1, 13);
h1 *%= 5;
h1 +%= 0xe6546b64;
h1 ^= len;
h1 ^= h1 >> 16;
h1 *%= 0x85ebca6b;
h1 ^= h1 >> 13;
h1 *%= 0xc2b2ae35;
h1 ^= h1 >> 16;
return h1;
}
pub fn hashUint64(v: u64) u32 {
return @inlineCall(Self.hashUint64WithSeed, v, default_seed);
}
pub fn hashUint64WithSeed(v: u64, seed: u32) u32 {
const c1: u32 = 0xcc9e2d51;
const c2: u32 = 0x1b873593;
const len: u32 = 8;
var h1: u32 = seed;
var k1: u32 = undefined;
k1 = @truncate(u32, v) *% c1;
k1 = rotl32(k1, 15);
k1 *%= c2;
h1 ^= k1;
h1 = rotl32(h1, 13);
h1 *%= 5;
h1 +%= 0xe6546b64;
k1 = @truncate(u32, v >> 32) *% c1;
k1 = rotl32(k1, 15);
k1 *%= c2;
h1 ^= k1;
h1 = rotl32(h1, 13);
h1 *%= 5;
h1 +%= 0xe6546b64;
h1 ^= len;
h1 ^= h1 >> 16;
h1 *%= 0x85ebca6b;
h1 ^= h1 >> 13;
h1 *%= 0xc2b2ae35;
h1 ^= h1 >> 16;
return h1;
}
};
fn SMHasherTest(comptime hash_fn: var, comptime hashbits: u32) u32 {
const hashbytes = hashbits / 8;
var key: [256]u8 = undefined;
var hashes: [hashbytes * 256]u8 = undefined;
var final: [hashbytes]u8 = undefined;
@memset(@ptrCast([*]u8, &key[0]), 0, @sizeOf(@typeOf(key)));
@memset(@ptrCast([*]u8, &hashes[0]), 0, @sizeOf(@typeOf(hashes)));
@memset(@ptrCast([*]u8, &final[0]), 0, @sizeOf(@typeOf(final)));
var i: u32 = 0;
while (i < 256) : (i += 1) {
key[i] = @truncate(u8, i);
var h = hash_fn(key[0..i], 256 - i);
if (builtin.endian == builtin.Endian.Big)
h = @byteSwap(@typeOf(h), h);
@memcpy(@ptrCast([*]u8, &hashes[i * hashbytes]), @ptrCast([*]u8, &h), hashbytes);
}
return @truncate(u32, hash_fn(hashes, 0));
}
test "murmur2_32" {
testing.expectEqual(SMHasherTest(Murmur2_32.hashWithSeed, 32), 0x27864C1E);
var v0: u32 = 0x12345678;
var v1: u64 = 0x1234567812345678;
var v0le: u32 = v0;
var v1le: u64 = v1;
if (builtin.endian == builtin.Endian.Big) {
v0le = @byteSwap(u32, v0le);
v1le = @byteSwap(u64, v1le);
}
testing.expectEqual(Murmur2_32.hash(@ptrCast([*]u8, &v0le)[0..4]), Murmur2_32.hashUint32(v0));
testing.expectEqual(Murmur2_32.hash(@ptrCast([*]u8, &v1le)[0..8]), Murmur2_32.hashUint64(v1));
}
test "murmur2_64" {
std.testing.expectEqual(SMHasherTest(Murmur2_64.hashWithSeed, 64), 0x1F0D3804);
var v0: u32 = 0x12345678;
var v1: u64 = 0x1234567812345678;
var v0le: u32 = v0;
var v1le: u64 = v1;
if (builtin.endian == builtin.Endian.Big) {
v0le = @byteSwap(u32, v0le);
v1le = @byteSwap(u64, v1le);
}
testing.expectEqual(Murmur2_64.hash(@ptrCast([*]u8, &v0le)[0..4]), Murmur2_64.hashUint32(v0));
testing.expectEqual(Murmur2_64.hash(@ptrCast([*]u8, &v1le)[0..8]), Murmur2_64.hashUint64(v1));
}
test "murmur3_32" {
std.testing.expectEqual(SMHasherTest(Murmur3_32.hashWithSeed, 32), 0xB0F57EE3);
var v0: u32 = 0x12345678;
var v1: u64 = 0x1234567812345678;
var v0le: u32 = v0;
var v1le: u64 = v1;
if (builtin.endian == builtin.Endian.Big) {
v0le = @byteSwap(u32, v0le);
v1le = @byteSwap(u64, v1le);
}
testing.expectEqual(Murmur3_32.hash(@ptrCast([*]u8, &v0le)[0..4]), Murmur3_32.hashUint32(v0));
testing.expectEqual(Murmur3_32.hash(@ptrCast([*]u8, &v1le)[0..8]), Murmur3_32.hashUint64(v1));
}