com.google.common.hash.HashCode.bits()方法的使用及代码示例
本文整理了Java中com.google.common.hash.HashCode.bits()方法的一些代码示例，展示了HashCode.bits()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。HashCode.bits()方法的具体详情如下：
包路径：com.google.common.hash.HashCode
类名称：HashCode
方法名：bits
HashCode.bits介绍
[英]Returns the number of bits in this hash code; a positive multiple of 8.
[中]返回此哈希代码中的位数；8的正倍数。
代码示例
代码示例来源：origin: google/guava
/**
* Returns {@code true} if {@code object} is a {@link HashCode} instance with the identical byte
* representation to this hash code.
*
* <p><b>Security note:</b> this method uses a constant-time (not short-circuiting) implementation
* to protect against <a href="http://en.wikipedia.org/wiki/Timing_attack">timing attacks</a>.
*/
@Override
public final boolean equals(@Nullable Object object) {
if (object instanceof HashCode) {
HashCode that = (HashCode) object;
return bits() == that.bits() && equalsSameBits(that);
}
return false;
}代码示例来源：origin: google/guava
/**
* Returns a hash code, having the same bit length as each of the input hash codes, that combines
* the information of these hash codes in an unordered fashion. That is, whenever two equal hash
* codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
* was computed from the <i>same</i> input hash codes in <i>some</i> order.
*
* @throws IllegalArgumentException if {@code hashCodes} is empty, or the hash codes do not all
* have the same bit length
*/
public static HashCode combineUnordered(Iterable<HashCode> hashCodes) {
Iterator<HashCode> iterator = hashCodes.iterator();
checkArgument(iterator.hasNext(), "Must be at least 1 hash code to combine.");
byte[] resultBytes = new byte[iterator.next().bits() / 8];
for (HashCode hashCode : hashCodes) {
byte[] nextBytes = hashCode.asBytes();
checkArgument(
nextBytes.length == resultBytes.length, "All hashcodes must have the same bit length.");
for (int i = 0; i < nextBytes.length; i++) {
resultBytes[i] += nextBytes[i];
}
}
return HashCode.fromBytesNoCopy(resultBytes);
}代码示例来源：origin: google/guava
/**
* Returns a hash code, having the same bit length as each of the input hash codes, that combines
* the information of these hash codes in an ordered fashion. That is, whenever two equal hash
* codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
* was computed from the <i>same</i> input hash codes in the <i>same</i> order.
*
* @throws IllegalArgumentException if {@code hashCodes} is empty, or the hash codes do not all
* have the same bit length
*/
public static HashCode combineOrdered(Iterable<HashCode> hashCodes) {
Iterator<HashCode> iterator = hashCodes.iterator();
checkArgument(iterator.hasNext(), "Must be at least 1 hash code to combine.");
int bits = iterator.next().bits();
byte[] resultBytes = new byte[bits / 8];
for (HashCode hashCode : hashCodes) {
byte[] nextBytes = hashCode.asBytes();
checkArgument(
nextBytes.length == resultBytes.length, "All hashcodes must have the same bit length.");
for (int i = 0; i < nextBytes.length; i++) {
resultBytes[i] = (byte) (resultBytes[i] * 37 ^ nextBytes[i]);
}
}
return HashCode.fromBytesNoCopy(resultBytes);
}代码示例来源：origin: google/j2objc
/**
* Returns {@code true} if {@code object} is a {@link HashCode} instance with the identical byte
* representation to this hash code.
*
* <p><b>Security note:</b> this method uses a constant-time (not short-circuiting) implementation
* to protect against <a href="http://en.wikipedia.org/wiki/Timing_attack">timing attacks</a>.
*/
@Override
public final boolean equals(@NullableDecl Object object) {
if (object instanceof HashCode) {
HashCode that = (HashCode) object;
return bits() == that.bits() && equalsSameBits(that);
}
return false;
}代码示例来源：origin: google/guava
@Override
HashCode makeHash(Hasher[] hashers) {
byte[] bytes = new byte[bits() / 8];
int i = 0;
for (Hasher hasher : hashers) {
HashCode newHash = hasher.hash();
i += newHash.writeBytesTo(bytes, i, newHash.bits() / 8);
}
return HashCode.fromBytesNoCopy(bytes);
}代码示例来源：origin: google/j2objc
/**
* Returns a hash code, having the same bit length as each of the input hash codes, that combines
* the information of these hash codes in an unordered fashion. That is, whenever two equal hash
* codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
* was computed from the <i>same</i> input hash codes in <i>some</i> order.
*
* @throws IllegalArgumentException if {@code hashCodes} is empty, or the hash codes do not all
* have the same bit length
*/
public static HashCode combineUnordered(Iterable<HashCode> hashCodes) {
Iterator<HashCode> iterator = hashCodes.iterator();
checkArgument(iterator.hasNext(), "Must be at least 1 hash code to combine.");
byte[] resultBytes = new byte[iterator.next().bits() / 8];
for (HashCode hashCode : hashCodes) {
byte[] nextBytes = hashCode.asBytes();
checkArgument(
nextBytes.length == resultBytes.length, "All hashcodes must have the same bit length.");
for (int i = 0; i < nextBytes.length; i++) {
resultBytes[i] += nextBytes[i];
}
}
return HashCode.fromBytesNoCopy(resultBytes);
}代码示例来源：origin: google/j2objc
/**
* Returns a hash code, having the same bit length as each of the input hash codes, that combines
* the information of these hash codes in an ordered fashion. That is, whenever two equal hash
* codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
* was computed from the <i>same</i> input hash codes in the <i>same</i> order.
*
* @throws IllegalArgumentException if {@code hashCodes} is empty, or the hash codes do not all
* have the same bit length
*/
public static HashCode combineOrdered(Iterable<HashCode> hashCodes) {
Iterator<HashCode> iterator = hashCodes.iterator();
checkArgument(iterator.hasNext(), "Must be at least 1 hash code to combine.");
int bits = iterator.next().bits();
byte[] resultBytes = new byte[bits / 8];
for (HashCode hashCode : hashCodes) {
byte[] nextBytes = hashCode.asBytes();
checkArgument(
nextBytes.length == resultBytes.length, "All hashcodes must have the same bit length.");
for (int i = 0; i < nextBytes.length; i++) {
resultBytes[i] = (byte) (resultBytes[i] * 37 ^ nextBytes[i]);
}
}
return HashCode.fromBytesNoCopy(resultBytes);
}代码示例来源：origin: wildfly/wildfly
/**
* Returns {@code true} if {@code object} is a {@link HashCode} instance with the identical byte
* representation to this hash code.
*
* <p><b>Security note:</b> this method uses a constant-time (not short-circuiting) implementation
* to protect against <a href="http://en.wikipedia.org/wiki/Timing_attack">timing attacks</a>.
*/
@Override
public final boolean equals(@NullableDecl Object object) {
if (object instanceof HashCode) {
HashCode that = (HashCode) object;
return bits() == that.bits() && equalsSameBits(that);
}
return false;
}代码示例来源：origin: google/guava
/**
* Returns a "Java hash code" for this {@code HashCode} instance; this is well-defined (so, for
* example, you can safely put {@code HashCode} instances into a {@code HashSet}) but is otherwise
* probably not what you want to use.
*/
@Override
public final int hashCode() {
// If we have at least 4 bytes (32 bits), just take the first 4 bytes. Since this is
// already a (presumably) high-quality hash code, any four bytes of it will do.
if (bits() >= 32) {
return asInt();
}
// If we have less than 4 bytes, use them all.
byte[] bytes = getBytesInternal();
int val = (bytes[0] & 0xFF);
for (int i = 1; i < bytes.length; i++) {
val |= ((bytes[i] & 0xFF) << (i * 8));
}
return val;
}代码示例来源：origin: wildfly/wildfly
/**
* Returns a hash code, having the same bit length as each of the input hash codes, that combines
* the information of these hash codes in an unordered fashion. That is, whenever two equal hash
* codes are produced by two calls to this method, it is <i>as likely as possible</i> that each
* was computed from the <i>same</i> input hash codes in <i>some</i> order.
*
* @throws IllegalArgumentException if {@code hashCodes} is empty, or the hash codes do not all
* have the same bit length
*/
public static HashCode combineUnordered(Iterable<HashCode> hashCodes) {
Iterator<HashCode> iterator = hashCodes.iterator();
checkArgument(iterator.hasNext(), "Must be at least 1 hash code to combine.");
byte[] resultBytes = new byte[iterator.next().bits() / 8];
for (HashCode hashCode : hashCodes) {
byte[] nextBytes = hashCode.asBytes();
checkArgument(
nextBytes.length == resultBytes.length, "All hashcodes must have the same bit length.");
for (int i = 0; i < nextBytes.length; i++) {
resultBytes[i] += nextBytes[i];
}
}
return HashCode.fromBytesNoCopy(resultBytes);
}代码示例来源：origin: google/guava
private static void assertReadableBytes(HashCode hashCode) {
assertTrue(hashCode.bits() >= 32); // sanity
byte[] hashBytes = hashCode.asBytes();
int totalBytes = hashCode.bits() / 8;
for (int bytes = 0; bytes < totalBytes; bytes++) {
byte[] bb = new byte[bytes];
hashCode.writeBytesTo(bb, 0, bb.length);
assertTrue(Arrays.equals(Arrays.copyOf(hashBytes, bytes), bb));
}
}代码示例来源：origin: google/j2objc
@Override
HashCode makeHash(Hasher[] hashers) {
byte[] bytes = new byte[bits() / 8];
int i = 0;
for (Hasher hasher : hashers) {
HashCode newHash = hasher.hash();
i += newHash.writeBytesTo(bytes, i, newHash.bits() / 8);
}
return HashCode.fromBytesNoCopy(bytes);
}代码示例来源：origin: google/j2objc
/**
* Returns a "Java hash code" for this {@code HashCode} instance; this is well-defined (so, for
* example, you can safely put {@code HashCode} instances into a {@code HashSet}) but is otherwise
* probably not what you want to use.
*/
@Override
public final int hashCode() {
// If we have at least 4 bytes (32 bits), just take the first 4 bytes. Since this is
// already a (presumably) high-quality hash code, any four bytes of it will do.
if (bits() >= 32) {
return asInt();
}
// If we have less than 4 bytes, use them all.
byte[] bytes = getBytesInternal();
int val = (bytes[0] & 0xFF);
for (int i = 1; i < bytes.length; i++) {
val |= ((bytes[i] & 0xFF) << (i * 8));
}
return val;
}代码示例来源：origin: wildfly/wildfly
@Override
HashCode makeHash(Hasher[] hashers) {
byte[] bytes = new byte[bits() / 8];
int i = 0;
for (Hasher hasher : hashers) {
HashCode newHash = hasher.hash();
i += newHash.writeBytesTo(bytes, i, newHash.bits() / 8);
}
return HashCode.fromBytesNoCopy(bytes);
}代码示例来源：origin: google/guava
/**
* Copies bytes from this hash code into {@code dest}.
*
* @param dest the byte array into which the hash code will be written
* @param offset the start offset in the data
* @param maxLength the maximum number of bytes to write
* @return the number of bytes written to {@code dest}
* @throws IndexOutOfBoundsException if there is not enough room in {@code dest}
*/
@CanIgnoreReturnValue
public int writeBytesTo(byte[] dest, int offset, int maxLength) {
maxLength = Ints.min(maxLength, bits() / 8);
Preconditions.checkPositionIndexes(offset, offset + maxLength, dest.length);
writeBytesToImpl(dest, offset, maxLength);
return maxLength;
}代码示例来源：origin: wildfly/wildfly
/**
* Returns a "Java hash code" for this {@code HashCode} instance; this is well-defined (so, for
* example, you can safely put {@code HashCode} instances into a {@code HashSet}) but is otherwise
* probably not what you want to use.
*/
@Override
public final int hashCode() {
// If we have at least 4 bytes (32 bits), just take the first 4 bytes. Since this is
// already a (presumably) high-quality hash code, any four bytes of it will do.
if (bits() >= 32) {
return asInt();
}
// If we have less than 4 bytes, use them all.
byte[] bytes = getBytesInternal();
int val = (bytes[0] & 0xFF);
for (int i = 1; i < bytes.length; i++) {
val |= ((bytes[i] & 0xFF) << (i * 8));
}
return val;
}代码示例来源：origin: google/j2objc
/**
* Copies bytes from this hash code into {@code dest}.
*
* @param dest the byte array into which the hash code will be written
* @param offset the start offset in the data
* @param maxLength the maximum number of bytes to write
* @return the number of bytes written to {@code dest}
* @throws IndexOutOfBoundsException if there is not enough room in {@code dest}
*/
@CanIgnoreReturnValue
public int writeBytesTo(byte[] dest, int offset, int maxLength) {
maxLength = Ints.min(maxLength, bits() / 8);
Preconditions.checkPositionIndexes(offset, offset + maxLength, dest.length);
writeBytesToImpl(dest, offset, maxLength);
return maxLength;
}代码示例来源：origin: wildfly/wildfly
/**
* Copies bytes from this hash code into {@code dest}.
*
* @param dest the byte array into which the hash code will be written
* @param offset the start offset in the data
* @param maxLength the maximum number of bytes to write
* @return the number of bytes written to {@code dest}
* @throws IndexOutOfBoundsException if there is not enough room in {@code dest}
*/
@CanIgnoreReturnValue
public int writeBytesTo(byte[] dest, int offset, int maxLength) {
maxLength = Ints.min(maxLength, bits() / 8);
Preconditions.checkPositionIndexes(offset, offset + maxLength, dest.length);
writeBytesToImpl(dest, offset, maxLength);
return maxLength;
}代码示例来源：origin: google/guava
/**
* Checks that a Hasher returns the same HashCode when given the same input, and also that the
* collision rate looks sane.
*/
static void assertInvariants(HashFunction hashFunction) {
int objects = 100;
Set<HashCode> hashcodes = Sets.newHashSetWithExpectedSize(objects);
Random random = new Random(314159);
for (int i = 0; i < objects; i++) {
int value = random.nextInt();
HashCode hashcode1 = hashFunction.hashInt(value);
HashCode hashcode2 = hashFunction.hashInt(value);
Assert.assertEquals(hashcode1, hashcode2); // idempotent
Assert.assertEquals(hashFunction.bits(), hashcode1.bits());
Assert.assertEquals(hashFunction.bits(), hashcode1.asBytes().length * 8);
hashcodes.add(hashcode1);
}
Assert.assertTrue(hashcodes.size() > objects * 0.95); // quite relaxed test
assertHashBytesThrowsCorrectExceptions(hashFunction);
assertIndependentHashers(hashFunction);
assertShortcutsAreEquivalent(hashFunction, 512);
}代码示例来源：origin: google/guava
private static void assertExpectedHashCode(ExpectedHashCode expectedHashCode, HashCode hash) {
assertTrue(Arrays.equals(expectedHashCode.bytes, hash.asBytes()));
byte[] bb = new byte[hash.bits() / 8];
hash.writeBytesTo(bb, 0, bb.length);
assertTrue(Arrays.equals(expectedHashCode.bytes, bb));
assertEquals(expectedHashCode.asInt, hash.asInt());
if (expectedHashCode.asLong == null) {
try {
hash.asLong();
fail();
} catch (IllegalStateException expected) {
}
} else {
assertEquals(expectedHashCode.asLong.longValue(), hash.asLong());
}
assertEquals(expectedHashCode.toString, hash.toString());
assertSideEffectFree(hash);
assertReadableBytes(hash);
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