Package com.norswap.nanoeth.receipts

Class LogTopic

java.lang.Object

com.norswap.nanoeth.receipts.LogTopic

@Wrapper
public final class LogTopic
extends Object

Represents a 256-bit (32 bytes) log topic.

The purpose of log topics is to be a marker for certain type of events (in fact they map with Solidity events, see https://ethereum.stackexchange.com/a/12951 for more info).

Additionally, they are automatically entered into the bloom filter that is included in each block header. If a client wants to process all logs with a certain topic, this will help him skip the blocks that do not contain the topic, and hence lower network congestion as he will not have to request the logs over the network. (This is not useful if you're validating the network, in which case you have to derive the logs to validate the header anyway.)

Field Summary

Fields

Modifier and Type	Field	Description
byte[]	bytes	The bytes making up the hash.

Constructor Summary

Constructors

Constructor	Description
LogTopic(byte[] bytes)
LogTopic(String hexString)	Creates a log topic from a hex string (e.g.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
int	hashCode()
String	toFullHexString()	The hex-string representation of this hash, including leading 0 if any, as per ByteUtils.toFullHexString(byte[]).
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

bytes

public final byte[] bytes

The bytes making up the hash.

Constructor Details

LogTopic

public LogTopic(@Retained
byte[] bytes)

LogTopic

public LogTopic(String hexString)

Creates a log topic from a hex string (e.g. 0x123).

If the post-0x part of the hex string is not 64 characters long, the hash will be padded with zeroes at the start so that it is 32 bytes long.

Method Details

toFullHexString

public String toFullHexString()

The hex-string representation of this hash, including leading 0 if any, as per ByteUtils.toFullHexString(byte[]).

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object