public class JpaTokenStore extends Object implements TokenStore
TokenEntry
entities.Constructor and Description |
---|
JpaTokenStore(EntityManagerProvider entityManagerProvider,
Serializer serializer)
Initializes a token store with given
entityManagerProvider and serializer . |
JpaTokenStore(EntityManagerProvider entityManagerProvider,
Serializer serializer,
TemporalAmount claimTimeout,
String nodeId)
Initialize the JpaTokenStore with given resources.
|
Modifier and Type | Method and Description |
---|---|
void |
extendClaim(String processorName,
int segment)
Extends the claim on the current token held by the this node for the given
processorName and
segment . |
int[] |
fetchSegments(String processorName)
Returns an array of known
segments for a given processorName . |
TrackingToken |
fetchToken(String processorName,
int segment)
|
void |
initializeTokenSegments(String processorName,
int segmentCount)
Initializes the given
segmentCount number of segments for the given processorName to track its
tokens. |
protected TokenEntry |
loadOrCreateToken(String processorName,
int segment,
javax.persistence.EntityManager entityManager)
Loads an existing
TokenEntry or creates a new one using the given entityManager for given processorName and segment . |
void |
releaseClaim(String processorName,
int segment)
Release a claim of the token for given
processorName and segment . |
void |
storeToken(TrackingToken token,
String processorName,
int segment)
Stores the given
token in the store. |
public JpaTokenStore(EntityManagerProvider entityManagerProvider, Serializer serializer)
entityManagerProvider
and serializer
.entityManagerProvider
- The provider of the entity managerserializer
- The serializer used to serialize tokenspublic JpaTokenStore(EntityManagerProvider entityManagerProvider, Serializer serializer, TemporalAmount claimTimeout, String nodeId)
claimTimeout
is used to 'steal' any claim
that has not been updated since that amount of time.entityManagerProvider
- provides the EntityManager to access the underlying databaseserializer
- The serializer to serialize tokens withclaimTimeout
- The timeout after which this process will force a claimnodeId
- The identifier to identify ownership of the tokenspublic void initializeTokenSegments(String processorName, int segmentCount) throws UnableToClaimTokenException
TokenStore
segmentCount
number of segments for the given processorName
to track its
tokens. This method should only be invoked when no tokens have been stored for the given processor, yet.
This method will initialize the tokens, but no claim them. It will create the segments ranging from 0
until segmentCount - 1
.
The exact behavior when this method is called while tokens were already present, is undefined in case the token already present is not owned by the initializing process.
initializeTokenSegments
in interface TokenStore
processorName
- The name of the processor to initialize segments forsegmentCount
- The number of segments to initializeUnableToClaimTokenException
- when a segment has already been createdpublic void storeToken(TrackingToken token, String processorName, int segment)
TokenStore
token
in the store. The token marks the current position of the process with given
processorName
and segment
. The given token
may be null
.
Any claims made by the current process have their timestamp updated.storeToken
in interface TokenStore
token
- The token to store for a given process and segment. May be null
.processorName
- The name of the process for which to store the tokensegment
- The index of the segment for which to store the tokenpublic void releaseClaim(String processorName, int segment)
TokenStore
processorName
and segment
. If no such claim existed,
nothing happens.
The caller must ensure not to use any streams opened based on the token for which the claim is released.
releaseClaim
in interface TokenStore
processorName
- The name of the process owning the token (e.g. a TrackingEventProcessor name)segment
- the segment for which a token was obtainedpublic TrackingToken fetchToken(String processorName, int segment)
TokenStore
token
for the given processorName
and segment
.
Returns null
if the store holds no token or if the stored token for the given process and segment is
null
.
The token will be claimed by the current process (JVM instance), preventing access by other instances. To release
the claim, use TokenStore.releaseClaim(String, int)
fetchToken
in interface TokenStore
processorName
- The process name for which to fetch the tokensegment
- The segment index for which to fetch the tokennull
if the store holds no token for given process and segmentpublic void extendClaim(String processorName, int segment) throws UnableToClaimTokenException
TokenStore
processorName
and
segment
.extendClaim
in interface TokenStore
processorName
- The process name for which to fetch the tokensegment
- The segment index for which to fetch the tokenUnableToClaimTokenException
- if there is no token for given processorName
and segment
, or
if it has been claimed by another process.public int[] fetchSegments(String processorName)
TokenStore
segments
for a given processorName
.
The segments returned are segments for which a token has been stored previously. When the TokenStore
is
empty, an empty array is returned.
fetchSegments
in interface TokenStore
processorName
- The process name for which to fetch the segmentsprotected TokenEntry loadOrCreateToken(String processorName, int segment, javax.persistence.EntityManager entityManager)
TokenEntry
or creates a new one using the given entityManager
for given processorName
and segment
.processorName
- the name of the event processorsegment
- the segment of the event processorentityManager
- the entity manager instance to use for the queryUnableToClaimTokenException
- if there is a token for given processorName
and segment
, but
it is claimed by another process.Copyright © 2010–2017. All rights reserved.