co.cask.tephra

Class Transaction

java.lang.Object

co.cask.tephra.Transaction

public class Transaction
extends Object

Transaction details

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Transaction.VisibilityLevel Defines the possible visibility levels for read operations.

Field Summary

Fields

Modifier and Type	Field and Description
static Transaction	ALL_VISIBLE_LATEST
static long	NO_TX_IN_PROGRESS

Constructor Summary

Constructors

Constructor and Description
Transaction(long readPointer, long txId, long[] invalids, long[] inProgress, long firstShortInProgress) Creates a new short transaction.
Transaction(long readPointer, long txId, long[] invalids, long[] inProgress, long firstShortInProgress, TransactionType type) Creates a new transaction.
Transaction(long readPointer, long txId, long writePointer, long[] invalids, long[] inProgress, long firstShortInProgress, TransactionType type, long[] checkpointPointers, Transaction.VisibilityLevel visibilityLevel) Creates a new transaction.
Transaction(Transaction toCopy, long writePointer, long[] checkpointPointers) Creates a new transaction for a checkpoint operation, copying all members from the original transaction, with the updated checkpoint write pointers.

Method Summary

Methods

Modifier and Type	Method and Description
int	excludesSize()
long[]	getCheckpointWritePointers() Returns any prior write pointers used in the current transaction.
long	getFirstInProgress()
long	getFirstShortInProgress()
long[]	getInProgress()
long[]	getInvalids()
long	getReadPointer()
long	getTransactionId() Returns the initial write pointer assigned to the transaction.
TransactionType	getType()
Transaction.VisibilityLevel	getVisibilityLevel() Returns the currently set visibility level.
long	getVisibilityUpperBound()
long	getWritePointer() Returns the write pointer to be used in persisting any changes.
boolean	hasExcludes()
boolean	isCheckpoint(long version) Returns true if the the given version corresponds to one of the checkpoint versions in the current transaction.
boolean	isExcluded(long version) Returns true if the given version is present in one of the arrays of excluded versions (in-progress and invalid transactions).
boolean	isInProgress(long version) Returns true if the given version corresponds to a transaction that was in-progress at the time this transaction started.
boolean	isVisible(long version) Returns whether or not the given version should be visible to the current transaction.
void	setVisibility(Transaction.VisibilityLevel level) Sets the visibility level for read operations.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

NO_TX_IN_PROGRESS

public static final long NO_TX_IN_PROGRESS

See Also:

Constant Field Values

ALL_VISIBLE_LATEST

public static final Transaction ALL_VISIBLE_LATEST

Constructor Detail

Transaction

public Transaction(long readPointer,
           long txId,
           long[] invalids,
           long[] inProgress,
           long firstShortInProgress)

Creates a new short transaction.

Parameters:

readPointer - read pointer for transaction

txId - unique identifier for the transaction

invalids - list of invalid transactions to exclude while reading

inProgress - list of in-progress transactions to exclude while reading

firstShortInProgress - earliest in-progress short transaction

Transaction

public Transaction(long readPointer,
           long txId,
           long[] invalids,
           long[] inProgress,
           long firstShortInProgress,
           TransactionType type)

Creates a new transaction.

Parameters:

readPointer - read pointer for transaction

txId - unique identifier for the transaction

invalids - list of invalid transactions to exclude while reading

inProgress - list of in-progress transactions to exclude while reading

firstShortInProgress - earliest in-progress short transaction

type - transaction type

Transaction

public Transaction(long readPointer,
           long txId,
           long writePointer,
           long[] invalids,
           long[] inProgress,
           long firstShortInProgress,
           TransactionType type,
           long[] checkpointPointers,
           Transaction.VisibilityLevel visibilityLevel)

Creates a new transaction.

Parameters:

readPointer - read pointer for transaction

txId - unique identifier for the transaction

writePointer - the current pointer to be used for any writes. For new transactions, this will be the same as txId. For checkpointed transactions, this will be the most recent write pointer issued.

invalids - list of invalid transactions to exclude while reading

inProgress - list of in-progress transactions to exclude while reading

firstShortInProgress - earliest in-progress short transaction

type - transaction type

checkpointPointers - the list of writer pointers added from checkpoints on the transaction

visibilityLevel - the visibility level to use for transactional reads

Transaction

public Transaction(Transaction toCopy,
           long writePointer,
           long[] checkpointPointers)

Creates a new transaction for a checkpoint operation, copying all members from the original transaction, with the updated checkpoint write pointers.

Parameters:

toCopy - the original transaction containing the state to copy

writePointer - the new write pointer to use for the transaction

checkpointPointers - the list of write pointers added from checkpoints on the transaction

Method Detail

getReadPointer

public long getReadPointer()

getTransactionId

public long getTransactionId()

Returns the initial write pointer assigned to the transaction. This will remain the same for the life of the transaction, and uniquely identifies it with the transaction service. This value should be provided to identify the transaction when calling any transaction lifecycle methods on the transaction service.

getWritePointer

public long getWritePointer()

Returns the write pointer to be used in persisting any changes. After a checkpoint is performed, this will differ from getTransactionId(). This method should always be used when setting the timestamp for writes in order to ensure that the correct value is used.

getInvalids

public long[] getInvalids()

getInProgress

public long[] getInProgress()

getFirstInProgress

public long getFirstInProgress()

getType

public TransactionType getType()

getVisibilityUpperBound

public long getVisibilityUpperBound()

Returns:

transaction id X such that any of the transactions newer than X may be invisible to this

NOTE: the returned tx id can be invalid.

getFirstShortInProgress

public long getFirstShortInProgress()

isInProgress

public boolean isInProgress(long version)

Returns true if the given version corresponds to a transaction that was in-progress at the time this transaction started.

isExcluded

public boolean isExcluded(long version)

Returns true if the given version is present in one of the arrays of excluded versions (in-progress and invalid transactions).

isCheckpoint

public boolean isCheckpoint(long version)

Returns true if the the given version corresponds to one of the checkpoint versions in the current transaction.

isVisible

public boolean isVisible(long version)

Returns whether or not the given version should be visible to the current transaction. A version will be visible if it was successfully committed prior to the current transaction starting, or was written by the current transaction (using either the current write pointer or the write pointer from a prior checkpoint).

Parameters:

version - the data version to check for visibility

Returns:

true if the version is visible, false if it should be hidden (filtered)

See Also:

to control whether the current write pointer is visible.

setVisibility

public void setVisibility(Transaction.VisibilityLevel level)

Sets the visibility level for read operations.

getVisibilityLevel

public Transaction.VisibilityLevel getVisibilityLevel()

Returns the currently set visibility level.

hasExcludes

public boolean hasExcludes()

excludesSize

public int excludesSize()

getCheckpointWritePointers

public long[] getCheckpointWritePointers()

Returns any prior write pointers used in the current transaction. A new write pointer is issued when the TransactionContext.checkpoint(Transaction) operation is called, and the prior write pointer is added to the array of checkpoint write pointers. `

toString

public String toString()

Overrides:

toString in class Object