PureJavaCrc32 (Hadoop 1.2.1 API)
Date: 2013-07-22

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## org.apache.hadoop.util
Class PureJavaCrc32

    java.lang.Object
      org.apache.hadoop.util.PureJavaCrc32

All Implemented Interfaces:
  Checksum

    public class PureJavaCrc32

extends Object
implements Checksum

A pure-java implementation of the CRC32 checksum that uses the same polynomial as the built-in native CRC32. This is to avoid the JNI overhead for certain uses of Checksumming where many small pieces of data are checksummed in succession. The current version is ~10x to 1.8x as fast as Sun's native java.util.zip.CRC32 in Java 1.6

See Also:
  `CRC32`

Constructor Summary
`PureJavaCrc32()`

Method Summary
`long` | `getValue()`
`void` | `reset()`
`void` | `update(byte[] b, int off, int len)`
`void` | `update(int b)`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### PureJavaCrc32

    public PureJavaCrc32()

Method Detail

### getValue

    public long getValue()

  Specified by:
    `getValue` in interface `Checksum`

### reset

    public void reset()

  Specified by:
    `reset` in interface `Checksum`

### update

    public void update(byte[] b,
                       int off,
                       int len)

  Specified by:
    `update` in interface `Checksum`

### update

    public final void update(int b)

  Specified by:
    `update` in interface `Checksum`

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