11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2011 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * in compliance with the License. You may obtain a copy of the License at 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software distributed under the License 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * or implied. See the License for the specific language governing permissions and limitations under 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * the License. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.hash; 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static com.google.common.base.Preconditions.checkState; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport static com.google.common.base.Preconditions.checkPositionIndexes; 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.primitives.Chars; 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.primitives.Ints; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.primitives.Longs; 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.primitives.Shorts; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.nio.ByteBuffer; 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.nio.ByteOrder; 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.nio.charset.Charset; 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.security.MessageDigest; 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.security.NoSuchAlgorithmException; 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@link HashFunction} adapter for {@link MessageDigest}s. 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author kevinb@google.com (Kevin Bourrillion) 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author andreou@google.com (Dimitris Andreou) 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertfinal class MessageDigestHashFunction extends AbstractStreamingHashFunction { 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final String algorithmName; 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final int bits; 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert MessageDigestHashFunction(String algorithmName) { 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.algorithmName = algorithmName; 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.bits = getMessageDigest(algorithmName).getDigestLength() * 8; 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public int bits() { 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return bits; 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static MessageDigest getMessageDigest(String algorithmName) { 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return MessageDigest.getInstance(algorithmName); 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchAlgorithmException e) { 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new AssertionError(e); 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher newHasher() { 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return new MessageDigestHasher(getMessageDigest(algorithmName)); 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static class MessageDigestHasher implements Hasher { 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final MessageDigest digest; 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final ByteBuffer scratch; // lazy convenience 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private boolean done; 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private MessageDigestHasher(MessageDigest digest) { 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.digest = digest; 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.scratch = ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN); 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putByte(byte b) { 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(b); 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putBytes(byte[] bytes) { 791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(bytes); 811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putBytes(byte[] bytes, int off, int len) { 851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkPositionIndexes(off, off + len, bytes.length); 871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(bytes, off, len); 881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putShort(short s) { 921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.putShort(s); 941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(scratch.array(), 0, Shorts.BYTES); 951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.clear(); 961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putInt(int i) { 1001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 1011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.putInt(i); 1021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(scratch.array(), 0, Ints.BYTES); 1031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.clear(); 1041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 1051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putLong(long l) { 1081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 1091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.putLong(l); 1101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(scratch.array(), 0, Longs.BYTES); 1111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.clear(); 1121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 1131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putFloat(float f) { 1161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 1171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.putFloat(f); 1181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(scratch.array(), 0, 4); 1191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.clear(); 1201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 1211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putDouble(double d) { 1241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 1251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.putDouble(d); 1261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(scratch.array(), 0, 8); 1271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.clear(); 1281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 1291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putBoolean(boolean b) { 1321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return putByte(b ? (byte) 1 : (byte) 0); 1331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putChar(char c) { 1361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 1371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.putChar(c); 1381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert digest.update(scratch.array(), 0, Chars.BYTES); 1391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert scratch.clear(); 1401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 1411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putString(CharSequence charSequence) { 1441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (int i = 0; i < charSequence.length(); i++) { 1451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert putChar(charSequence.charAt(i)); 1461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 1481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Hasher putString(CharSequence charSequence, Charset charset) { 1511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return putBytes(charSequence.toString().getBytes(charset.name())); 1531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (java.io.UnsupportedEncodingException impossible) { 1541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new AssertionError(impossible); 1551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public <T> Hasher putObject(T instance, Funnel<? super T> funnel) { 1591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkNotDone(); 1601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert funnel.funnel(instance, this); 1611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return this; 1621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private void checkNotDone() { 1651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert checkState(!done, "Cannot use Hasher after calling #hash() on it"); 1661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public HashCode hash() { 1691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert done = true; 1701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return HashCodes.fromBytes(digest.digest()); 1711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 174