public interface Hasher
put(int), put(long), etc) to bytes in
little-endian order.
Warning: The result of calling any methods after calling hash() is undefined.
Warning: Using a specific character encoding when hashing a CharSequence with
put(CharSequence, Charset) is generally only useful for cross-language
compatibility (otherwise prefer #putUnencodedChars). However, the character encodings
must be identical across languages. Also beware that Charset definitions may occasionally
change between Java releases.
Warning: Chunks of data that are put into the Hasher are not delimited. The
resulting HashCode is dependent only on the bytes inserted, and the order in which they
were inserted, not how those bytes were chunked into discrete put() operations. For example, the
following three expressions all generate colliding hash codes:
newHasher().putByte(b1).putByte(b2).putByte(b3).hash()
newHasher().putByte(b1).putBytes(new byte[] { b2, b3 }).hash()
newHasher().putBytes(new byte[] { b1, b2, b3 }).hash()
If you wish to avoid this, you should either prepend or append the size of each chunk. Keep in
mind that when dealing with char sequences, the encoded form of two concatenated char sequences
is not equivalent to the concatenation of their encoded form. Therefore,
put(CharSequence, Charset) should only be used consistently with complete
sequences and not broken into chunks.
| Modifier and Type | Method and Description |
|---|---|
HashCode |
hash()
Computes a hash code based on the data that have been provided to this hasher.
|
Hasher |
put(boolean b)
Equivalent to
putByte(b ? (byte) 1 : (byte) 0). |
Hasher |
put(byte b) |
Hasher |
put(byte[] bytes) |
Hasher |
put(byte[] bytes,
int off,
int len) |
Hasher |
put(char c) |
Hasher |
put(char[] chars) |
Hasher |
put(char[] chars,
int off,
int len) |
Hasher |
put(CharSequence charSequence)
Equivalent to processing each
char value in the CharSequence, in order. |
Hasher |
put(CharSequence charSequence,
Charset charset)
Equivalent to
putBytes(charSequence.toString().getBytes(charset)). |
Hasher |
put(double d)
Equivalent to
putLong(Double.doubleToRawLongBits(d)). |
Hasher |
put(float f)
Equivalent to
putInt(Float.floatToRawIntBits(f)). |
Hasher |
put(int i) |
Hasher |
put(long l) |
Hasher |
put(short s) |
<T> Hasher |
put(T instance,
BiConsumer<? super T,? super Hasher> funnel)
A simple convenience for
funnel.funnel(object, this). |
Hasher put(byte b)
b - Hasher put(byte[] bytes)
bytes - Hasher put(byte[] bytes, int off, int len)
bytes - off - len - Hasher put(short s)
s - Hasher put(int i)
i - Hasher put(long l)
l - Hasher put(float f)
putInt(Float.floatToRawIntBits(f)).f - Hasher put(double d)
putLong(Double.doubleToRawLongBits(d)).d - Hasher put(boolean b)
putByte(b ? (byte) 1 : (byte) 0).b - Hasher put(char c)
c - Hasher put(char[] chars)
chars - Hasher put(char[] chars, int off, int len)
chars - off - len - Hasher put(CharSequence charSequence)
char value in the CharSequence, in order. In
other words, no character encoding is performed; the low byte and high byte of each char are hashed directly (in that order). The input must not be updated while this method is
in progress.
Warning: This method will produce different output than most other languages do when
running the same hash function on the equivalent input. For cross-language compatibility, use
#putString, usually with a charset of UTF-8. For other use cases, use putUnencodedChars.
charSequence - Hasher put(CharSequence charSequence, Charset charset)
putBytes(charSequence.toString().getBytes(charset)).
Warning: This method, which reencodes the input before hashing it, is useful only for
cross-language compatibility. For other use cases, prefer #putUnencodedChars, which is
faster, produces the same output across Java releases, and hashes every char in the
input, even if some are invalid.
charSequence - charset - <T> Hasher put(T instance, BiConsumer<? super T,? super Hasher> funnel)
funnel.funnel(object, this).T - instance - funnel - HashCode hash()
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