java.lang.Object
- com.linkedin.venice.kafka.validation.checksum.CheckSum
- - com.linkedin.venice.kafka.validation.checksum.AdHash

```
public class AdHash
extends CheckSum
```
This class AdHash is used to keep track of the checksum of the data incrementally. It adopts the idea of AdHash that: " A message x' which I want to hash may be a simple modification of a message x which I previously hashed. If I have already computed the hash f(x) of x then, rather than re-computing f(x') from scratch, I would like to just quickly 'update' the old hash value f(x) to the new value f(x'). An incremental hash function is one that permits this. " See the paper for details: A New Paradigm for Collision-free Hashing: Incrementality at Reduced Cost. (https://cseweb.ucsd.edu/~daniele/papers/IncHash.pdf) Its adoption in ZooKeeper: Verify, And Then Trust: Data Inconsistency Detection in ZooKeeper. (https://dl.acm.org/doi/abs/10.1145/3578358.3591328)

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`byte[]`	`getEncodedState()`
`byte[]`	`getFinalCheckSum()`
`CheckSumType`	`getType()`
`void`	`resetInternal()`
`void`	`updateChecksum(byte[] input, int startIndex, int length)`	Update the checksum with the input data.

Methods inherited from class com.linkedin.venice.kafka.validation.checksum.CheckSum
getCheckSum, getInstance, getInstance, reset, toString, update, update, update, update

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

Constructors
Constructor	Description
`AdHash()`
`AdHash(byte[] encodedState)`

Class AdHash