com.thinkaurelius.titan.diskstorage

Class BackendTransaction

java.lang.Object

com.thinkaurelius.titan.diskstorage.BackendTransaction

All Implemented Interfaces:

BaseTransaction, LoggableTransaction

public class BackendTransaction
extends Object
implements LoggableTransaction

Bundles all storage/index transactions and provides a proxy for some of their methods for convenience. Also increases robustness of read call by attempting read calls multiple times on failure.

Author:

Matthias Broecheler (me@matthiasb.com)

Field Summary

Fields

Modifier and Type	Field and Description
static StaticBuffer	EDGESTORE_MAX_KEY
static StaticBuffer	EDGESTORE_MIN_KEY
static int	MIN_TASKS_TO_PARALLELIZE

Constructor Summary

Constructors

Constructor and Description
BackendTransaction(CacheTransaction storeTx, BaseTransactionConfig txConfig, StoreFeatures features, KCVSCache edgeStore, KCVSCache indexStore, Duration maxReadTime, Map<String,IndexTransaction> indexTx, Executor threadPool)

Method Summary

Methods

Modifier and Type	Method and Description
void	acquireEdgeLock(StaticBuffer key, Entry entry)
void	acquireEdgeLock(StaticBuffer key, StaticBuffer column) Acquires a lock for the key-column pair on the edge store which ensures that nobody else can take a lock on that respective entry for the duration of this lock (but somebody could potentially still overwrite the key-value entry without taking a lock).
void	acquireIndexLock(StaticBuffer key, Entry entry)
void	acquireIndexLock(StaticBuffer key, StaticBuffer column) Acquires a lock for the key-column pair on the property index which ensures that nobody else can take a lock on that respective entry for the duration of this lock (but somebody could potentially still overwrite the key-value entry without taking a lock).
void	commit() Commits the transaction and persists all modifications to the backend.
Map<String,Throwable>	commitIndexes()
void	commitStorage()
KeyIterator	edgeStoreKeys(KeyRangeQuery range)
KeyIterator	edgeStoreKeys(SliceQuery sliceQuery)
Map<StaticBuffer,EntryList>	edgeStoreMultiQuery(List<StaticBuffer> keys, SliceQuery query)
EntryList	edgeStoreQuery(KeySliceQuery query)
BaseTransactionConfig	getBaseTransactionConfig()
IndexTransaction	getIndexTransaction(String index)
StoreTransaction	getStoreTransaction()
EntryList	indexQuery(KeySliceQuery query)
List<String>	indexQuery(String index, IndexQuery query)
void	logMutations(DataOutput out)
void	mutateEdges(StaticBuffer key, List<Entry> additions, List<Entry> deletions) Applies the specified insertion and deletion mutations on the edge store to the provided key.
void	mutateIndex(StaticBuffer key, List<Entry> additions, List<Entry> deletions) Applies the specified insertion and deletion mutations on the property index to the provided key.
Iterable<RawQuery.Result<String>>	rawQuery(String index, RawQuery query)
void	rollback() Rolls back all transactions and makes sure that this does not get cut short by exceptions.

Methods inherited from class java.lang.Object

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

Field Detail

MIN_TASKS_TO_PARALLELIZE

public static final int MIN_TASKS_TO_PARALLELIZE

See Also:

Constant Field Values

EDGESTORE_MIN_KEY

public static final StaticBuffer EDGESTORE_MIN_KEY

EDGESTORE_MAX_KEY

public static final StaticBuffer EDGESTORE_MAX_KEY

Constructor Detail

BackendTransaction

public BackendTransaction(CacheTransaction storeTx,
                  BaseTransactionConfig txConfig,
                  StoreFeatures features,
                  KCVSCache edgeStore,
                  KCVSCache indexStore,
                  Duration maxReadTime,
                  Map<String,IndexTransaction> indexTx,
                  Executor threadPool)

Method Detail

getStoreTransaction

public StoreTransaction getStoreTransaction()

getBaseTransactionConfig

public BaseTransactionConfig getBaseTransactionConfig()

getIndexTransaction

public IndexTransaction getIndexTransaction(String index)

commitStorage

public void commitStorage()
                   throws StorageException

Throws:

StorageException

commitIndexes

public Map<String,Throwable> commitIndexes()

commit

public void commit()
            throws StorageException

Description copied from interface: BaseTransaction

Commits the transaction and persists all modifications to the backend. Call either this method or BaseTransaction.rollback() at most once per instance.

Specified by:

commit in interface BaseTransaction

Throws:

StorageException

rollback

public void rollback()
              throws StorageException

Rolls back all transactions and makes sure that this does not get cut short by exceptions. If exceptions occur, the storage exception takes priority on re-throw.

Specified by:

rollback in interface BaseTransaction

Throws:

StorageException

logMutations

public void logMutations(DataOutput out)

Specified by:

logMutations in interface LoggableTransaction

mutateEdges

public void mutateEdges(StaticBuffer key,
               List<Entry> additions,
               List<Entry> deletions)
                 throws StorageException

Applies the specified insertion and deletion mutations on the edge store to the provided key. Both, the list of additions or deletions, may be empty or NULL if there is nothing to be added and/or deleted.

Parameters:

key - Key

additions - List of entries (column + value) to be added

deletions - List of columns to be removed

Throws:

StorageException

mutateIndex

public void mutateIndex(StaticBuffer key,
               List<Entry> additions,
               List<Entry> deletions)
                 throws StorageException

Applies the specified insertion and deletion mutations on the property index to the provided key. Both, the list of additions or deletions, may be empty or NULL if there is nothing to be added and/or deleted.

Parameters:

key - Key

additions - List of entries (column + value) to be added

deletions - List of columns to be removed

Throws:

StorageException

acquireEdgeLock

public void acquireEdgeLock(StaticBuffer key,
                   StaticBuffer column)
                     throws StorageException

Acquires a lock for the key-column pair on the edge store which ensures that nobody else can take a lock on that respective entry for the duration of this lock (but somebody could potentially still overwrite the key-value entry without taking a lock). The expectedValue defines the value expected to match the value at the time the lock is acquired (or null if it is expected that the key-column pair does not exist).

If this method is called multiple times with the same key-column pair in the same transaction, all but the first invocation are ignored.

The lock has to be released when the transaction closes (commits or aborts).

Parameters:

key - Key on which to lock

column - Column the column on which to lock

Throws:

StorageException

acquireEdgeLock

public void acquireEdgeLock(StaticBuffer key,
                   Entry entry)
                     throws StorageException

Throws:

StorageException

acquireIndexLock

public void acquireIndexLock(StaticBuffer key,
                    StaticBuffer column)
                      throws StorageException

Acquires a lock for the key-column pair on the property index which ensures that nobody else can take a lock on that respective entry for the duration of this lock (but somebody could potentially still overwrite the key-value entry without taking a lock). The expectedValue defines the value expected to match the value at the time the lock is acquired (or null if it is expected that the key-column pair does not exist).

If this method is called multiple times with the same key-column pair in the same transaction, all but the first invocation are ignored.

The lock has to be released when the transaction closes (commits or aborts).

Parameters:

key - Key on which to lock

column - Column the column on which to lock

expectedValue - The expected value for the specified key-column pair on which to lock. Null if it is expected that the pair does not exist

Throws:

StorageException

acquireIndexLock

public void acquireIndexLock(StaticBuffer key,
                    Entry entry)
                      throws StorageException

Throws:

StorageException

edgeStoreQuery

public EntryList edgeStoreQuery(KeySliceQuery query)

edgeStoreMultiQuery

public Map<StaticBuffer,EntryList> edgeStoreMultiQuery(List<StaticBuffer> keys,
                                              SliceQuery query)

edgeStoreKeys

public KeyIterator edgeStoreKeys(SliceQuery sliceQuery)

edgeStoreKeys

public KeyIterator edgeStoreKeys(KeyRangeQuery range)

indexQuery

public EntryList indexQuery(KeySliceQuery query)

indexQuery

public List<String> indexQuery(String index,
                      IndexQuery query)

rawQuery

public Iterable<RawQuery.Result<String>> rawQuery(String index,
                                         RawQuery query)