| /* |
| * Copyright (c) 2012, 2020, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| /* |
| * halfsiphash code adapted from reference implementation |
| * (https://github.com/veorq/SipHash/blob/master/halfsiphash.c) |
| * which is distributed with the following copyright: |
| */ |
| |
| /* |
| SipHash reference C implementation |
| |
| Copyright (c) 2012-2021 Jean-Philippe Aumasson |
| <jeanphilippe.aumasson@gmail.com> |
| Copyright (c) 2012-2014 Daniel J. Bernstein <djb@cr.yp.to> |
| |
| To the extent possible under law, the author(s) have dedicated all copyright |
| and related and neighboring rights to this software to the public domain |
| worldwide. This software is distributed without any warranty. |
| |
| You should have received a copy of the CC0 Public Domain Dedication along |
| with |
| this software. If not, see |
| <http://creativecommons.org/publicdomain/zero/1.0/>. |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/altHashing.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "oops/markOop.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/os.hpp" |
| |
| // Get the hash code of the classes mirror if it exists, otherwise just |
| // return a random number, which is one of the possible hash code used for |
| // objects. We don't want to call the synchronizer hash code to install |
| // this value because it may safepoint. |
| static intptr_t object_hash(Klass* k) { |
| intptr_t hc = k->java_mirror()->mark().hash(); |
| return hc != markOop::no_hash ? hc : os::random(); |
| } |
| |
| // Seed value used for each alternative hash calculated. |
| uint64_t AltHashing::compute_seed() { |
| uint64_t nanos = os::javaTimeNanos(); |
| uint64_t now = os::javaTimeMillis(); |
| uint32_t SEED_MATERIAL[8] = { |
| (uint32_t) object_hash(SystemDictionary::String_klass()), |
| (uint32_t) object_hash(SystemDictionary::System_klass()), |
| (uint32_t) os::random(), // current thread isn't a java thread |
| (uint32_t) (((uint64_t)nanos) >> 32), |
| (uint32_t) nanos, |
| (uint32_t) (((uint64_t)now) >> 32), |
| (uint32_t) now, |
| (uint32_t) (os::javaTimeNanos() >> 2) |
| }; |
| |
| return halfsiphash_64(SEED_MATERIAL, 8); |
| } |
| |
| // utility function copied from java/lang/Integer |
| static uint32_t Integer_rotateLeft(uint32_t i, int distance) { |
| return (i << distance) | (i >> (32 - distance)); |
| } |
| |
| static void halfsiphash_rounds(uint32_t v[4], int rounds) { |
| while (rounds-- > 0) { |
| v[0] += v[1]; |
| v[1] = Integer_rotateLeft(v[1], 5); |
| v[1] ^= v[0]; |
| v[0] = Integer_rotateLeft(v[0], 16); |
| v[2] += v[3]; |
| v[3] = Integer_rotateLeft(v[3], 8); |
| v[3] ^= v[2]; |
| v[0] += v[3]; |
| v[3] = Integer_rotateLeft(v[3], 7); |
| v[3] ^= v[0]; |
| v[2] += v[1]; |
| v[1] = Integer_rotateLeft(v[1], 13); |
| v[1] ^= v[2]; |
| v[2] = Integer_rotateLeft(v[2], 16); |
| } |
| } |
| |
| static void halfsiphash_adddata(uint32_t v[4], uint32_t newdata, int rounds) { |
| v[3] ^= newdata; |
| halfsiphash_rounds(v, rounds); |
| v[0] ^= newdata; |
| } |
| |
| static void halfsiphash_init32(uint32_t v[4], uint64_t seed) { |
| v[0] = seed & 0xffffffff; |
| v[1] = seed >> 32; |
| v[2] = 0x6c796765 ^ v[0]; |
| v[3] = 0x74656462 ^ v[1]; |
| } |
| |
| static void halfsiphash_init64(uint32_t v[4], uint64_t seed) { |
| halfsiphash_init32(v, seed); |
| v[1] ^= 0xee; |
| } |
| |
| uint32_t halfsiphash_finish32(uint32_t v[4], int rounds) { |
| v[2] ^= 0xff; |
| halfsiphash_rounds(v, rounds); |
| return (v[1] ^ v[3]); |
| } |
| |
| static uint64_t halfsiphash_finish64(uint32_t v[4], int rounds) { |
| uint64_t rv; |
| v[2] ^= 0xee; |
| halfsiphash_rounds(v, rounds); |
| rv = v[1] ^ v[3]; |
| v[1] ^= 0xdd; |
| halfsiphash_rounds(v, rounds); |
| rv |= (uint64_t)(v[1] ^ v[3]) << 32; |
| return rv; |
| } |
| |
| // HalfSipHash-2-4 (32-bit output) for Symbols |
| uint32_t AltHashing::halfsiphash_32(uint64_t seed, const void* in, int len) { |
| |
| const unsigned char* data = (const unsigned char*)in; |
| uint32_t v[4]; |
| uint32_t newdata; |
| int off = 0; |
| int count = len; |
| |
| halfsiphash_init32(v, seed); |
| |
| // body |
| while (count >= 4) { |
| |
| // Avoid sign extension with 0x0ff |
| newdata = (data[off] & 0x0FF) |
| | (data[off + 1] & 0x0FF) << 8 |
| | (data[off + 2] & 0x0FF) << 16 |
| | data[off + 3] << 24; |
| |
| count -= 4; |
| off += 4; |
| |
| halfsiphash_adddata(v, newdata, 2); |
| } |
| |
| // tail |
| newdata = ((uint32_t)len) << 24; // (Byte.SIZE / Byte.SIZE); |
| |
| if (count > 0) { |
| switch (count) { |
| case 3: |
| newdata |= (data[off + 2] & 0x0ff) << 16; |
| // fall through |
| case 2: |
| newdata |= (data[off + 1] & 0x0ff) << 8; |
| // fall through |
| case 1: |
| newdata |= (data[off] & 0x0ff); |
| // fall through |
| } |
| } |
| |
| halfsiphash_adddata(v, newdata, 2); |
| |
| // finalization |
| return halfsiphash_finish32(v, 4); |
| } |
| |
| // HalfSipHash-2-4 (32-bit output) for Strings |
| uint32_t AltHashing::halfsiphash_32(uint64_t seed, const uint16_t* data, int len) { |
| uint32_t v[4]; |
| uint32_t newdata; |
| int off = 0; |
| int count = len; |
| |
| halfsiphash_init32(v, seed); |
| |
| // body |
| while (count >= 2) { |
| uint16_t d1 = data[off++] & 0x0FFFF; |
| uint16_t d2 = data[off++]; |
| newdata = (d1 | d2 << 16); |
| |
| count -= 2; |
| |
| halfsiphash_adddata(v, newdata, 2); |
| } |
| |
| // tail |
| newdata = ((uint32_t)len * 2) << 24; // (Character.SIZE / Byte.SIZE); |
| if (count > 0) { |
| newdata |= (uint32_t)data[off]; |
| } |
| halfsiphash_adddata(v, newdata, 2); |
| |
| // finalization |
| return halfsiphash_finish32(v, 4); |
| } |
| |
| // HalfSipHash-2-4 (64-bit output) for integers (used to create seed) |
| uint64_t AltHashing::halfsiphash_64(uint64_t seed, const uint32_t* data, int len) { |
| uint32_t v[4]; |
| |
| int off = 0; |
| int end = len; |
| |
| halfsiphash_init64(v, seed); |
| |
| // body |
| while (off < end) { |
| halfsiphash_adddata(v, (uint32_t)data[off++], 2); |
| } |
| |
| // tail (always empty, as body is always 32-bit chunks) |
| |
| // finalization |
| halfsiphash_adddata(v, ((uint32_t)len * 4) << 24, 2); // (Integer.SIZE / Byte.SIZE); |
| return halfsiphash_finish64(v, 4); |
| } |
| |
| // HalfSipHash-2-4 (64-bit output) for integers (used to create seed) |
| uint64_t AltHashing::halfsiphash_64(const uint32_t* data, int len) { |
| return halfsiphash_64((uint64_t)0, data, len); |
| } |