Package com.scurrilous.circe.impl

Class AbstractIncrementalIntHash

java.lang.Object
com.scurrilous.circe.impl.AbstractIncrementalIntHash
All Implemented Interfaces:
Hash, IncrementalIntHash, StatelessHash, StatelessIntHash
Direct Known Subclasses:
AbstractIntCrc, Sse42Crc32C
public abstract class AbstractIncrementalIntHash extends Object implements IncrementalIntHash
Base implementation for incremental stateless integer hash functions.

  • Constructor Summary

    Constructors
    Constructor
    Description
    AbstractIncrementalIntHash()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    calculate(byte[] input)
    Evaluates this hash function for the entire given input array.
    int
    calculate(byte[] input, int index, int length)
    Evaluates this hash function for the given range of the given input array.
    int
    calculate(long address, long length)
    Evaluates this hash function for the memory with the given address and length.
    int
    calculate(ByteBuffer input)
    Evaluates this hash function with the remaining contents of the given input buffer.
    StatefulIntHash
    createStateful()
    Returns a new instance of stateful version of this hash function.
    protected abstract int
    initial()
    The initial state of the hash function, which is the same as the output value for an empty input sequence.
    int
    resume(int current, byte[] input)
    Evaluates this hash function as if the entire given input array were appended to the previously hashed input.
    int
    resume(int current, byte[] input, int index, int length)
    Evaluates this hash function as if the given range of the given input array were appended to the previously hashed input.
    int
    resume(int current, long address, long length)
    Evaluates this hash function as if the memory with the given address and length were appended to the previously hashed input.
    int
    resume(int current, ByteBuffer input)
    Evaluates this hash function as if the remaining contents of the given input buffer were appended to the previously hashed input.
    protected abstract int
    resumeUnchecked(int current, byte[] input, int index, int length)
    Evaluates this hash function as if the given range of the given input array were appended to the previously hashed input.
    boolean
    supportsUnsafe()
    Returns whether this hash function supports unsafe access to arbitrary memory addresses using methods such as StatefulHash.update(long, long), StatelessIntHash.calculate(long, long), or IncrementalIntHash.resume(int, long, long).

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface com.scurrilous.circe.Hash

    algorithm, length

  • Constructor Details

    • AbstractIncrementalIntHash

      public AbstractIncrementalIntHash()

  • Method Details

    • supportsUnsafe

      public boolean supportsUnsafe()
      Description copied from interface: Hash
      Returns whether this hash function supports unsafe access to arbitrary memory addresses using methods such as StatefulHash.update(long, long), StatelessIntHash.calculate(long, long), or IncrementalIntHash.resume(int, long, long). Such functions are generally implemented in native code.
      Specified by:
      supportsUnsafe in interface Hash
      Returns:
      true if unsafe access is supported, false if not

    • createStateful

      public StatefulIntHash createStateful()
      Description copied from interface: StatelessIntHash
      Returns a new instance of stateful version of this hash function.
      Specified by:
      createStateful in interface StatelessHash
      Specified by:
      createStateful in interface StatelessIntHash
      Returns:
      the stateful version of this hash function

    • calculate

      public int calculate(byte[] input)
      Description copied from interface: StatelessIntHash
      Evaluates this hash function for the entire given input array.
      Specified by:
      calculate in interface StatelessIntHash
      Parameters:
      input - the input array
      Returns:
      the output of the hash function

    • calculate

      public int calculate(byte[] input, int index, int length)
      Description copied from interface: StatelessIntHash
      Evaluates this hash function for the given range of the given input array.
      Specified by:
      calculate in interface StatelessIntHash
      Parameters:
      input - the input array
      index - the starting index of the first input byte
      length - the length of the input range
      Returns:
      the output of the hash function

    • calculate

      public int calculate(ByteBuffer input)
      Description copied from interface: StatelessIntHash
      Evaluates this hash function with the remaining contents of the given input buffer. This method leaves the buffer position at the limit.
      Specified by:
      calculate in interface StatelessIntHash
      Parameters:
      input - the input buffer
      Returns:
      the output of the hash function

    • calculate

      public int calculate(long address, long length)
      Description copied from interface: StatelessIntHash
      Evaluates this hash function for the memory with the given address and length. The arguments are generally not checked in any way and will likely lead to a VM crash or undefined results if invalid.
      Specified by:
      calculate in interface StatelessIntHash
      Parameters:
      address - the base address of the input
      length - the length of the input
      Returns:
      the output of the hash function
      See Also:

    • resume

      public int resume(int current, byte[] input)
      Description copied from interface: IncrementalIntHash
      Evaluates this hash function as if the entire given input array were appended to the previously hashed input.
      Specified by:
      resume in interface IncrementalIntHash
      Parameters:
      current - the hash output for input hashed so far
      input - the input array
      Returns:
      the output of the hash function for the concatenated input

    • resume

      public int resume(int current, byte[] input, int index, int length)
      Description copied from interface: IncrementalIntHash
      Evaluates this hash function as if the given range of the given input array were appended to the previously hashed input.
      Specified by:
      resume in interface IncrementalIntHash
      Parameters:
      current - the hash output for input hashed so far
      input - the input array
      index - the starting index of the first input byte
      length - the length of the input range
      Returns:
      the output of the hash function for the concatenated input

    • resume

      public int resume(int current, ByteBuffer input)
      Description copied from interface: IncrementalIntHash
      Evaluates this hash function as if the remaining contents of the given input buffer were appended to the previously hashed input. This method leaves the buffer position at the limit.
      Specified by:
      resume in interface IncrementalIntHash
      Parameters:
      current - the hash output for input hashed so far
      input - the input buffer
      Returns:
      the output of the hash function for the concatenated input

    • resume

      public int resume(int current, long address, long length)
      Description copied from interface: IncrementalIntHash
      Evaluates this hash function as if the memory with the given address and length were appended to the previously hashed input. The arguments are generally not checked in any way and will likely lead to a VM crash or undefined results if invalid.
      Specified by:
      resume in interface IncrementalIntHash
      Parameters:
      current - the hash output for input hashed so far
      address - the base address of the input
      length - the length of the input
      Returns:
      the output of the hash function for the concatenated input
      See Also:

    • initial

      protected abstract int initial()
      The initial state of the hash function, which is the same as the output value for an empty input sequence.
      Returns:
      the initial hash state/output

    • resumeUnchecked

      protected abstract int resumeUnchecked(int current, byte[] input, int index, int length)
      Evaluates this hash function as if the given range of the given input array were appended to the previously hashed input. The index and length parameters have already been validated.
      Parameters:
      current - the hash output for input hashed so far
      input - the input array
      index - the starting index of the first input byte
      length - the length of the input range
      Returns:
      the output of the hash function for the concatenated input