org.corfudb.runtime.view.replication

Class ChainReplicationProtocol

java.lang.Object

org.corfudb.runtime.view.replication.AbstractReplicationProtocol

org.corfudb.runtime.view.replication.ChainReplicationProtocol

All Implemented Interfaces:

IReplicationProtocol

public class ChainReplicationProtocol
extends AbstractReplicationProtocol

Created by mwei on 4/6/17.

Field Summary

Fields inherited from class org.corfudb.runtime.view.replication.AbstractReplicationProtocol

holeFillPolicy

Constructor Summary

Constructors

Constructor and Description
ChainReplicationProtocol(IHoleFillPolicy holeFillPolicy)

Method Summary

Modifier and Type	Method and Description
protected void	holeFill(RuntimeLayout runtimeLayout, long globalAddress) Write a special hole filling entry using the given address.
ILogData	peek(RuntimeLayout runtimeLayout, long globalAddress) Peek data from a given address.
Map<Long,ILogData>	readAll(RuntimeLayout runtimeLayout, List<Long> addresses, boolean waitForWrite) Reads a list of global addresses from the chain of log unit servers.
void	write(RuntimeLayout runtimeLayout, ILogData data) Write data to the log at the given address.

Methods inherited from class org.corfudb.runtime.view.replication.AbstractReplicationProtocol

read

Methods inherited from class java.lang.Object

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

Constructor Detail

ChainReplicationProtocol

public ChainReplicationProtocol(IHoleFillPolicy holeFillPolicy)

Method Detail

write

public void write(RuntimeLayout runtimeLayout,
                  ILogData data)
           throws OverwriteException

Write data to the log at the given address.

This function blocks until -a- write at the global address is committed to the log.

If the write which is committed to the log was this write, the function returns normally.

If the write which was committed to the log was not the result of this call, an OverwriteException is thrown.

Parameters:

runtimeLayout - the RuntimeLayout stamped with layout to use for the write.

data - the ILogData to write to the log.

Throws:

OverwriteException - If a write was committed to the log and it was not the result of this call.

peek

public ILogData peek(RuntimeLayout runtimeLayout,
                     long globalAddress)

Peek data from a given address.

This function -may- return null if there was no entry committed at the given global address, otherwise it returns committed data at the given global address. It does not attempt to hole fill if there was no entry.

Parameters:

runtimeLayout - the RuntimeLayout stamped with layout to use for the peek.

globalAddress - the global address to peek from.

Returns:

the data that was committed at the given global address, or NULL, if there was no entry committed.

readAll

@Nonnull
public Map<Long,ILogData> readAll(RuntimeLayout runtimeLayout,
                                           List<Long> addresses,
                                           boolean waitForWrite)

Reads a list of global addresses from the chain of log unit servers. - This method optimizes for the time to wait to hole fill in case empty addresses are encountered. - If the waitForWrite flag is set to true, when an empty address is encountered, it waits for one hole to be filled. All the rest empty addresses within the list are hole filled directly and the reader does not wait. - In case the flag is set to false, none of the reads wait for write completion and the empty addresses are hole filled right away.

Parameters:

runtimeLayout - runtime layout.

addresses - list of addresses to read.

waitForWrite - flag whether wait for write is required or hole fill directly.

Returns:

Map of read addresses.

holeFill

protected void holeFill(RuntimeLayout runtimeLayout,
                        long globalAddress)

Write a special hole filling entry using the given address. When this call returns, either the hole filling write has been committed or the result of another client's write has committed (you WILL need to -read- the address to find out which write was adopted).

Specified by:

holeFill in class AbstractReplicationProtocol

globalAddress - The address to hole fill.