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
ResultSet	getAllPartitionsCreatedAfter(com.google.cloud.Timestamp timestamp) Fetches all partitions with a PartitionMetadataAdminDao.COLUMN_CREATED_AT less than the given timestamp.
Struct	getPartition(java.lang.String partitionToken) Fetches the partition metadata row data for the given partition token.
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.
boolean	tableExists() Checks whether the metadata table already exists in the database.
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.util.List<java.lang.String> partitionTokens) Updates multiple 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

tableExists

public boolean tableExists()

Checks whether the metadata table already exists in the database.

Returns:

true if the table exists, false if the table does not exist.

getPartition

@Nullable
public 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.

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.

getAllPartitionsCreatedAfter

public ResultSet getAllPartitionsCreatedAfter(com.google.cloud.Timestamp timestamp)

Fetches all partitions with a PartitionMetadataAdminDao.COLUMN_CREATED_AT less than the given timestamp. The results are ordered by the PartitionMetadataAdminDao.COLUMN_CREATED_AT and PartitionMetadataAdminDao.COLUMN_START_TIMESTAMP columns in ascending order.

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.util.List<java.lang.String> partitionTokens)

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

Parameters:

partitionTokens - the partitions' unique identifiers

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