| /* |
| * 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. |
| */ |
| |
| package org.apache.bookkeeper.common.hash; |
| |
| import io.netty.buffer.ByteBuf; |
| |
| /** |
| * Murmur3 is successor to Murmur2 fast non-crytographic hash algorithms. |
| * |
| * Murmur3 32 and 128 bit variants. |
| * 32-bit Java port of https://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp#94 |
| * 128-bit Java port of https://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp#255 |
| * |
| * This is a public domain code with no copyrights. |
| * From homepage of MurmurHash (https://code.google.com/p/smhasher/), |
| * "All MurmurHash versions are public domain software, and the author disclaims all copyright |
| * to their code." |
| */ |
| public class Murmur3 { |
| // Constants for 32 bit variant |
| private static final int C1_32 = 0xcc9e2d51; |
| private static final int C2_32 = 0x1b873593; |
| private static final int R1_32 = 15; |
| private static final int R2_32 = 13; |
| private static final int M_32 = 5; |
| private static final int N_32 = 0xe6546b64; |
| |
| // Constants for 128 bit variant |
| private static final long C1 = 0x87c37b91114253d5L; |
| private static final long C2 = 0x4cf5ad432745937fL; |
| private static final int R1 = 31; |
| private static final int R2 = 27; |
| private static final int R3 = 33; |
| private static final int M = 5; |
| private static final int N1 = 0x52dce729; |
| private static final int N2 = 0x38495ab5; |
| |
| public static final int DEFAULT_SEED = 104729; |
| |
| /** |
| * Murmur3 32-bit variant. |
| * |
| * @param data - input byte array |
| * @return - hashcode |
| */ |
| public static int hash32(byte[] data) { |
| return hash32(data, 0, data.length, DEFAULT_SEED); |
| } |
| |
| /** |
| * Murmur3 32-bit variant. |
| * |
| * @param data - input byte array |
| * @param length - length of array |
| * @return - hashcode |
| */ |
| public static int hash32(byte[] data, int length) { |
| return hash32(data, 0, length, DEFAULT_SEED); |
| } |
| |
| /** |
| * Murmur3 32-bit variant. |
| * |
| * @param data - input byte array |
| * @param length - length of array |
| * @param seed - seed. (default 0) |
| * @return - hashcode |
| */ |
| public static int hash32(byte[] data, int length, int seed) { |
| return hash32(data, 0, length, seed); |
| } |
| |
| /** |
| * Murmur3 32-bit variant. |
| * |
| * @param data - input byte array |
| * @param offset - offset of data |
| * @param length - length of array |
| * @param seed - seed. (default 0) |
| * @return - hashcode |
| */ |
| public static int hash32(byte[] data, int offset, int length, int seed) { |
| int hash = seed; |
| final int nblocks = length >> 2; |
| |
| // body |
| for (int i = 0; i < nblocks; i++) { |
| int i_4 = i << 2; |
| int k = (data[offset + i_4] & 0xff) |
| | ((data[offset + i_4 + 1] & 0xff) << 8) |
| | ((data[offset + i_4 + 2] & 0xff) << 16) |
| | ((data[offset + i_4 + 3] & 0xff) << 24); |
| |
| // mix functions |
| k *= C1_32; |
| k = Integer.rotateLeft(k, R1_32); |
| k *= C2_32; |
| hash ^= k; |
| hash = Integer.rotateLeft(hash, R2_32) * M_32 + N_32; |
| } |
| |
| // tail |
| int idx = nblocks << 2; |
| int k1 = 0; |
| switch (length - idx) { |
| case 3: |
| k1 ^= data[offset + idx + 2] << 16; |
| case 2: |
| k1 ^= data[offset + idx + 1] << 8; |
| case 1: |
| k1 ^= data[offset + idx]; |
| |
| // mix functions |
| k1 *= C1_32; |
| k1 = Integer.rotateLeft(k1, R1_32); |
| k1 *= C2_32; |
| hash ^= k1; |
| } |
| |
| // finalization |
| hash ^= length; |
| hash ^= (hash >>> 16); |
| hash *= 0x85ebca6b; |
| hash ^= (hash >>> 13); |
| hash *= 0xc2b2ae35; |
| hash ^= (hash >>> 16); |
| |
| return hash; |
| } |
| |
| public static int hash32(ByteBuf data, int offset, int length, int seed) { |
| int hash = seed; |
| final int nblocks = length >> 2; |
| |
| // body |
| for (int i = 0; i < nblocks; i++) { |
| int i_4 = i << 2; |
| int k = (data.getByte(offset + i_4) & 0xff) |
| | ((data.getByte(offset + i_4 + 1) & 0xff) << 8) |
| | ((data.getByte(offset + i_4 + 2) & 0xff) << 16) |
| | ((data.getByte(offset + i_4 + 3) & 0xff) << 24); |
| |
| // mix functions |
| k *= C1_32; |
| k = Integer.rotateLeft(k, R1_32); |
| k *= C2_32; |
| hash ^= k; |
| hash = Integer.rotateLeft(hash, R2_32) * M_32 + N_32; |
| } |
| |
| // tail |
| int idx = nblocks << 2; |
| int k1 = 0; |
| switch (length - idx) { |
| case 3: |
| k1 ^= data.getByte(offset + idx + 2) << 16; |
| case 2: |
| k1 ^= data.getByte(offset + idx + 1) << 8; |
| case 1: |
| k1 ^= data.getByte(offset + idx); |
| |
| // mix functions |
| k1 *= C1_32; |
| k1 = Integer.rotateLeft(k1, R1_32); |
| k1 *= C2_32; |
| hash ^= k1; |
| } |
| |
| // finalization |
| hash ^= length; |
| hash ^= (hash >>> 16); |
| hash *= 0x85ebca6b; |
| hash ^= (hash >>> 13); |
| hash *= 0xc2b2ae35; |
| hash ^= (hash >>> 16); |
| |
| return hash; |
| } |
| |
| /** |
| * Murmur3 128-bit variant. |
| * |
| * @param data - input byte array |
| * @return - hashcode (2 longs) |
| */ |
| public static long[] hash128(byte[] data) { |
| return hash128(data, 0, data.length, DEFAULT_SEED); |
| } |
| |
| /** |
| * Murmur3 128-bit variant. |
| * |
| * @param data - input byte array |
| * @param offset - the first element of array |
| * @param length - length of array |
| * @param seed - seed. (default is 0) |
| * @return - hashcode (2 longs) |
| */ |
| public static long[] hash128(byte[] data, int offset, int length, long seed) { |
| long h1 = seed; |
| long h2 = seed; |
| final int nblocks = length >> 4; |
| |
| // body |
| for (int i = 0; i < nblocks; i++) { |
| final int i16 = i << 4; |
| long k1 = ((long) data[offset + i16] & 0xff) |
| | (((long) data[offset + i16 + 1] & 0xff) << 8) |
| | (((long) data[offset + i16 + 2] & 0xff) << 16) |
| | (((long) data[offset + i16 + 3] & 0xff) << 24) |
| | (((long) data[offset + i16 + 4] & 0xff) << 32) |
| | (((long) data[offset + i16 + 5] & 0xff) << 40) |
| | (((long) data[offset + i16 + 6] & 0xff) << 48) |
| | (((long) data[offset + i16 + 7] & 0xff) << 56); |
| |
| long k2 = ((long) data[offset + i16 + 8] & 0xff) |
| | (((long) data[offset + i16 + 9] & 0xff) << 8) |
| | (((long) data[offset + i16 + 10] & 0xff) << 16) |
| | (((long) data[offset + i16 + 11] & 0xff) << 24) |
| | (((long) data[offset + i16 + 12] & 0xff) << 32) |
| | (((long) data[offset + i16 + 13] & 0xff) << 40) |
| | (((long) data[offset + i16 + 14] & 0xff) << 48) |
| | (((long) data[offset + i16 + 15] & 0xff) << 56); |
| |
| // mix functions for k1 |
| k1 *= C1; |
| k1 = Long.rotateLeft(k1, R1); |
| k1 *= C2; |
| h1 ^= k1; |
| h1 = Long.rotateLeft(h1, R2); |
| h1 += h2; |
| h1 = h1 * M + N1; |
| |
| // mix functions for k2 |
| k2 *= C2; |
| k2 = Long.rotateLeft(k2, R3); |
| k2 *= C1; |
| h2 ^= k2; |
| h2 = Long.rotateLeft(h2, R1); |
| h2 += h1; |
| h2 = h2 * M + N2; |
| } |
| |
| // tail |
| long k1 = 0; |
| long k2 = 0; |
| int tailStart = nblocks << 4; |
| switch (length - tailStart) { |
| case 15: |
| k2 ^= (long) (data[offset + tailStart + 14] & 0xff) << 48; |
| case 14: |
| k2 ^= (long) (data[offset + tailStart + 13] & 0xff) << 40; |
| case 13: |
| k2 ^= (long) (data[offset + tailStart + 12] & 0xff) << 32; |
| case 12: |
| k2 ^= (long) (data[offset + tailStart + 11] & 0xff) << 24; |
| case 11: |
| k2 ^= (long) (data[offset + tailStart + 10] & 0xff) << 16; |
| case 10: |
| k2 ^= (long) (data[offset + tailStart + 9] & 0xff) << 8; |
| case 9: |
| k2 ^= (long) (data[offset + tailStart + 8] & 0xff); |
| k2 *= C2; |
| k2 = Long.rotateLeft(k2, R3); |
| k2 *= C1; |
| h2 ^= k2; |
| |
| case 8: |
| k1 ^= (long) (data[offset + tailStart + 7] & 0xff) << 56; |
| case 7: |
| k1 ^= (long) (data[offset + tailStart + 6] & 0xff) << 48; |
| case 6: |
| k1 ^= (long) (data[offset + tailStart + 5] & 0xff) << 40; |
| case 5: |
| k1 ^= (long) (data[offset + tailStart + 4] & 0xff) << 32; |
| case 4: |
| k1 ^= (long) (data[offset + tailStart + 3] & 0xff) << 24; |
| case 3: |
| k1 ^= (long) (data[offset + tailStart + 2] & 0xff) << 16; |
| case 2: |
| k1 ^= (long) (data[offset + tailStart + 1] & 0xff) << 8; |
| case 1: |
| k1 ^= (long) (data[offset + tailStart] & 0xff); |
| k1 *= C1; |
| k1 = Long.rotateLeft(k1, R1); |
| k1 *= C2; |
| h1 ^= k1; |
| } |
| |
| // finalization |
| h1 ^= length; |
| h2 ^= length; |
| |
| h1 += h2; |
| h2 += h1; |
| |
| h1 = fmix64(h1); |
| h2 = fmix64(h2); |
| |
| h1 += h2; |
| h2 += h1; |
| |
| return new long[]{h1, h2}; |
| } |
| |
| /** |
| * Murmur3 128-bit variant. |
| * |
| * @param data - input byte array |
| * @param offset - the first element of array |
| * @param length - length of array |
| * @param seed - seed. (default is 0) |
| * @return - hashcode (2 longs) |
| */ |
| public static long[] hash128(ByteBuf data, int offset, int length, long seed) { |
| long h1 = seed; |
| long h2 = seed; |
| final int nblocks = length >> 4; |
| |
| // body |
| for (int i = 0; i < nblocks; i++) { |
| final int i16 = i << 4; |
| long k1 = ((long) data.getByte(offset + i16) & 0xff) |
| | (((long) data.getByte(offset + i16 + 1) & 0xff) << 8) |
| | (((long) data.getByte(offset + i16 + 2) & 0xff) << 16) |
| | (((long) data.getByte(offset + i16 + 3) & 0xff) << 24) |
| | (((long) data.getByte(offset + i16 + 4) & 0xff) << 32) |
| | (((long) data.getByte(offset + i16 + 5) & 0xff) << 40) |
| | (((long) data.getByte(offset + i16 + 6) & 0xff) << 48) |
| | (((long) data.getByte(offset + i16 + 7) & 0xff) << 56); |
| |
| long k2 = ((long) data.getByte(offset + i16 + 8) & 0xff) |
| | (((long) data.getByte(offset + i16 + 9) & 0xff) << 8) |
| | (((long) data.getByte(offset + i16 + 10) & 0xff) << 16) |
| | (((long) data.getByte(offset + i16 + 11) & 0xff) << 24) |
| | (((long) data.getByte(offset + i16 + 12) & 0xff) << 32) |
| | (((long) data.getByte(offset + i16 + 13) & 0xff) << 40) |
| | (((long) data.getByte(offset + i16 + 14) & 0xff) << 48) |
| | (((long) data.getByte(offset + i16 + 15) & 0xff) << 56); |
| |
| // mix functions for k1 |
| k1 *= C1; |
| k1 = Long.rotateLeft(k1, R1); |
| k1 *= C2; |
| h1 ^= k1; |
| h1 = Long.rotateLeft(h1, R2); |
| h1 += h2; |
| h1 = h1 * M + N1; |
| |
| // mix functions for k2 |
| k2 *= C2; |
| k2 = Long.rotateLeft(k2, R3); |
| k2 *= C1; |
| h2 ^= k2; |
| h2 = Long.rotateLeft(h2, R1); |
| h2 += h1; |
| h2 = h2 * M + N2; |
| } |
| |
| // tail |
| long k1 = 0; |
| long k2 = 0; |
| int tailStart = nblocks << 4; |
| switch (length - tailStart) { |
| case 15: |
| k2 ^= (long) (data.getByte(offset + tailStart + 14) & 0xff) << 48; |
| case 14: |
| k2 ^= (long) (data.getByte(offset + tailStart + 13) & 0xff) << 40; |
| case 13: |
| k2 ^= (long) (data.getByte(offset + tailStart + 12) & 0xff) << 32; |
| case 12: |
| k2 ^= (long) (data.getByte(offset + tailStart + 11) & 0xff) << 24; |
| case 11: |
| k2 ^= (long) (data.getByte(offset + tailStart + 10) & 0xff) << 16; |
| case 10: |
| k2 ^= (long) (data.getByte(offset + tailStart + 9) & 0xff) << 8; |
| case 9: |
| k2 ^= (long) (data.getByte(offset + tailStart + 8) & 0xff); |
| k2 *= C2; |
| k2 = Long.rotateLeft(k2, R3); |
| k2 *= C1; |
| h2 ^= k2; |
| |
| case 8: |
| k1 ^= (long) (data.getByte(offset + tailStart + 7) & 0xff) << 56; |
| case 7: |
| k1 ^= (long) (data.getByte(offset + tailStart + 6) & 0xff) << 48; |
| case 6: |
| k1 ^= (long) (data.getByte(offset + tailStart + 5) & 0xff) << 40; |
| case 5: |
| k1 ^= (long) (data.getByte(offset + tailStart + 4) & 0xff) << 32; |
| case 4: |
| k1 ^= (long) (data.getByte(offset + tailStart + 3) & 0xff) << 24; |
| case 3: |
| k1 ^= (long) (data.getByte(offset + tailStart + 2) & 0xff) << 16; |
| case 2: |
| k1 ^= (long) (data.getByte(offset + tailStart + 1) & 0xff) << 8; |
| case 1: |
| k1 ^= (long) (data.getByte(offset + tailStart) & 0xff); |
| k1 *= C1; |
| k1 = Long.rotateLeft(k1, R1); |
| k1 *= C2; |
| h1 ^= k1; |
| } |
| |
| // finalization |
| h1 ^= length; |
| h2 ^= length; |
| |
| h1 += h2; |
| h2 += h1; |
| |
| h1 = fmix64(h1); |
| h2 = fmix64(h2); |
| |
| h1 += h2; |
| h2 += h1; |
| |
| return new long[]{h1, h2}; |
| } |
| |
| private static long fmix64(long h) { |
| h ^= (h >>> 33); |
| h *= 0xff51afd7ed558ccdL; |
| h ^= (h >>> 33); |
| h *= 0xc4ceb9fe1a85ec53L; |
| h ^= (h >>> 33); |
| return h; |
| } |
| |
| } |