org.apache.beam.sdk.io.gcp.spanner.changestreams.dao

Class PartitionMetadataDao

java.lang.Object

org.apache.beam.sdk.io.gcp.spanner.changestreams.dao.PartitionMetadataDao

public class PartitionMetadataDao
extends java.lang.Object

Data access object for the Connector metadata tables.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PartitionMetadataDao.InTransactionContext Represents the execution of a read / write transaction in Cloud Spanner.
static class	PartitionMetadataDao.TransactionResult<T> Represents a result from executing a Cloud Spanner read / write transaction.

Method Summary

Modifier and Type	Method and Description
com.google.cloud.spanner.Struct	getPartition(java.lang.String partitionToken) Fetches the partition metadata row data for the given partition token.
com.google.cloud.spanner.ResultSet	getPartitionsInState(PartitionMetadata.State state) Fetches all the partitions from the partition metadata table that are in the given state and returns them ordered by the PartitionMetadataAdminDao.COLUMN_START_TIMESTAMP column in ascending order.
com.google.cloud.Timestamp	getUnfinishedMinWatermark() Fetches the earliest partition watermark from the partition metadata table that is not in a PartitionMetadata.State.FINISHED state.
com.google.cloud.Timestamp	insert(PartitionMetadata row) Inserts the partition metadata.
<T> PartitionMetadataDao.TransactionResult<T>	runInTransaction(java.util.function.Function<PartitionMetadataDao.InTransactionContext,T> callable) Runs a given function in a transaction context.
com.google.cloud.Timestamp	updateToFinished(java.lang.String partitionToken) Updates a partition row to PartitionMetadata.State.FINISHED state.
com.google.cloud.Timestamp	updateToRunning(java.lang.String partitionToken) Updates a partition row to PartitionMetadata.State.RUNNING state.
com.google.cloud.Timestamp	updateToScheduled(java.lang.String partitionToken) Updates a partition row to PartitionMetadata.State.SCHEDULED state.
void	updateWatermark(java.lang.String partitionToken, com.google.cloud.Timestamp watermark) Update the partition watermark to the given timestamp.

Methods inherited from class java.lang.Object

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

Method Detail

getPartition

@Nullable
public com.google.cloud.spanner.Struct getPartition(java.lang.String partitionToken)

Fetches the partition metadata row data for the given partition token.

Parameters:

partitionToken - the partition unique identifier

Returns:

the partition metadata for the given token if it exists as a struct. Otherwise, it returns null.

getPartitionsInState

public com.google.cloud.spanner.ResultSet getPartitionsInState(PartitionMetadata.State state)

Fetches all the partitions from the partition metadata table that are in the given state and returns them ordered by the PartitionMetadataAdminDao.COLUMN_START_TIMESTAMP column in ascending order.

Parameters:

state - the PartitionMetadata.State to fetch all the partitions

Returns:

a ResultSet with the partition rows fetched

getUnfinishedMinWatermark

@Nullable
public com.google.cloud.Timestamp getUnfinishedMinWatermark()

Fetches the earliest partition watermark from the partition metadata table that is not in a PartitionMetadata.State.FINISHED state.

Returns:

the earliest partition watermark which is not in a PartitionMetadata.State.FINISHED state.

insert

public com.google.cloud.Timestamp insert(PartitionMetadata row)

Inserts the partition metadata.

Parameters:

row - the partition metadata to be inserted

Returns:

the commit timestamp of the read / write transaction

updateToScheduled

public com.google.cloud.Timestamp updateToScheduled(java.lang.String partitionToken)

Updates a partition row to PartitionMetadata.State.SCHEDULED state.

Parameters:

partitionToken - the partition unique identifier

Returns:

the commit timestamp of the read / write transaction

updateToRunning

public com.google.cloud.Timestamp updateToRunning(java.lang.String partitionToken)

Updates a partition row to PartitionMetadata.State.RUNNING state.

Parameters:

partitionToken - the partition unique identifier

Returns:

the commit timestamp of the read / write transaction

updateToFinished

public com.google.cloud.Timestamp updateToFinished(java.lang.String partitionToken)

Updates a partition row to PartitionMetadata.State.FINISHED state.

Parameters:

partitionToken - the partition unique identifier

Returns:

the commit timestamp of the read / write transaction

updateWatermark

public void updateWatermark(java.lang.String partitionToken,
                            com.google.cloud.Timestamp watermark)

Update the partition watermark to the given timestamp.

Parameters:

partitionToken - the partition unique identifier

watermark - the new partition watermark

runInTransaction

public <T> PartitionMetadataDao.TransactionResult<T> runInTransaction(java.util.function.Function<PartitionMetadataDao.InTransactionContext,T> callable)

Runs a given function in a transaction context. The transaction object is given as the parameter to the input function. If the function returns successfully, it will be committed. If the function throws an exception it will be rolled back.

Type Parameters:

T - the return type to be returned from the input transactional function

Parameters:

callable - the function to be executed within the transaction context

Returns:

a transaction result containing the result from the function and a commit timestamp for the read / write transaction