142 lines
4.4 KiB
C++
142 lines
4.4 KiB
C++
/*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* Copyright 2015 Danny Robson <danny@nerdcruft.net>
|
|
*/
|
|
|
|
#include "common.hpp"
|
|
|
|
#include "../../debug.hpp"
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
namespace util::hash::murmur {
|
|
template <>
|
|
uint32_t
|
|
tail<uint32_t> (const uint8_t *restrict bytes, size_t len)
|
|
{
|
|
uint32_t h = 0;
|
|
|
|
switch (len % sizeof (uint32_t)) {
|
|
case 3: h += bytes[2] << 16;
|
|
case 2: h += bytes[1] << 8;
|
|
case 1: h += bytes[0];
|
|
break;
|
|
|
|
default:
|
|
unreachable ();
|
|
}
|
|
|
|
return h;
|
|
}
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
namespace util::hash::murmur {
|
|
template <>
|
|
uint64_t
|
|
tail<uint64_t> (const uint8_t *restrict bytes, size_t len)
|
|
{
|
|
uint64_t h = 0;
|
|
|
|
switch (len % sizeof (uint64_t)) {
|
|
case 7: h += uint64_t(bytes[6]) << 48;
|
|
case 6: h += uint64_t(bytes[5]) << 40;
|
|
case 5: h += uint64_t(bytes[4]) << 32;
|
|
case 4: h += uint64_t(bytes[3]) << 24;
|
|
case 3: h += uint64_t(bytes[2]) << 16;
|
|
case 2: h += uint64_t(bytes[1]) << 8;
|
|
case 1: h += uint64_t(bytes[0]);
|
|
break;
|
|
|
|
default:
|
|
unreachable ();
|
|
}
|
|
|
|
return h;
|
|
}
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
namespace util::hash::murmur {
|
|
template <>
|
|
std::array<uint32_t,4>
|
|
tail_array<uint32_t> (const uint8_t *restrict bytes, size_t len)
|
|
{
|
|
std::array<uint32_t,4> result {0,0,0,0};
|
|
|
|
switch (len % 16) {
|
|
case 15: result[3] |= bytes[14] << 16;
|
|
case 14: result[3] |= bytes[13] << 8;
|
|
case 13: result[3] |= bytes[12] << 0;
|
|
case 12: result[2] |= bytes[11] << 24;
|
|
case 11: result[2] |= bytes[10] << 16;
|
|
case 10: result[2] |= bytes[ 9] << 8;
|
|
case 9: result[2] |= bytes[ 8] << 0;
|
|
case 8: result[1] |= bytes[ 7] << 24;
|
|
case 7: result[1] |= bytes[ 6] << 16;
|
|
case 6: result[1] |= bytes[ 5] << 8;
|
|
case 5: result[1] |= bytes[ 4] << 0;
|
|
case 4: result[0] |= bytes[ 3] << 24;
|
|
case 3: result[0] |= bytes[ 2] << 16;
|
|
case 2: result[0] |= bytes[ 1] << 8;
|
|
case 1: result[0] |= bytes[ 0] << 0;
|
|
break;
|
|
|
|
default:
|
|
unreachable ();
|
|
}
|
|
|
|
return result;
|
|
}
|
|
}
|
|
|
|
|
|
//-----------------------------------------------------------------------------
|
|
namespace util::hash::murmur {
|
|
template <>
|
|
std::array<uint64_t,2>
|
|
tail_array<uint64_t> (const uint8_t *restrict bytes, size_t len)
|
|
{
|
|
std::array<uint64_t,2> result {0, 0};
|
|
|
|
switch(len & 15)
|
|
{
|
|
case 15: result[1] |= uint64_t{bytes[14]} << 48;
|
|
case 14: result[1] |= uint64_t{bytes[13]} << 40;
|
|
case 13: result[1] |= uint64_t{bytes[12]} << 32;
|
|
case 12: result[1] |= uint64_t{bytes[11]} << 24;
|
|
case 11: result[1] |= uint64_t{bytes[10]} << 16;
|
|
case 10: result[1] |= uint64_t{bytes[ 9]} << 8;
|
|
case 9: result[1] |= uint64_t{bytes[ 8]} << 0;
|
|
|
|
case 8: result[0] |= uint64_t{bytes[ 7]} << 56;
|
|
case 7: result[0] |= uint64_t{bytes[ 6]} << 48;
|
|
case 6: result[0] |= uint64_t{bytes[ 5]} << 40;
|
|
case 5: result[0] |= uint64_t{bytes[ 4]} << 32;
|
|
case 4: result[0] |= uint64_t{bytes[ 3]} << 24;
|
|
case 3: result[0] |= uint64_t{bytes[ 2]} << 16;
|
|
case 2: result[0] |= uint64_t{bytes[ 1]} << 8;
|
|
case 1: result[0] |= uint64_t{bytes[ 0]} << 0;
|
|
break;
|
|
|
|
default:
|
|
unreachable ();
|
|
};
|
|
|
|
return result;
|
|
}
|
|
}
|