org.janusgraph.diskstorage.inmemory

Class InMemoryKeyColumnValueStore

java.lang.Object

org.janusgraph.diskstorage.inmemory.InMemoryKeyColumnValueStore

All Implemented Interfaces:

KeyColumnValueStore

public class InMemoryKeyColumnValueStore
extends Object
implements KeyColumnValueStore

An in-memory implementation of KeyColumnValueStore. This implementation is thread-safe. All data is held in memory, which means that the capacity of this store is determined by the available heap space. No data is persisted and all data lost when the jvm terminates or store closed. The implementation also provides basic dump/restore capabilities, so that a "snapshot" of its contents can be saved to filesystem and loaded back. Finally, it provides a means to assess the fragmentation of the data across allocated memory storage, and to defragment it if required. NOTE: with usual "populate then query" and "add only" use cases, fragmentation is of no concern. Only if your application performs a lot of deletes interleaved with additions for a prolong periods of time, and if you are experiencing a "bigger than expected" memory footprint, is it worth looking at fragmentation report.

Field Summary

Fields inherited from interface org.janusgraph.diskstorage.keycolumnvalue.KeyColumnValueStore

NO_ADDITIONS, NO_DELETIONS

Constructor Summary

Constructors

Constructor and Description
InMemoryKeyColumnValueStore(String name)

Method Summary

Modifier and Type	Method and Description
void	acquireLock(StaticBuffer key, StaticBuffer column, StaticBuffer expectedValue, StoreTransaction txh)
void	clear()
void	close()
InMemoryKeyColumnValueStoreFragmentationReport	createFragmentationReport(StoreTransaction txh)
void	dumpTo(Path storePath, ForkJoinPool parallelOperationsExecutor)
KeyIterator	getKeys(KeyRangeQuery query, StoreTransaction txh)
KeySlicesIterator	getKeys(MultiSlicesQuery queries, StoreTransaction txh)
KeyIterator	getKeys(SliceQuery query, StoreTransaction txh)
String	getName()
EntryList	getSlice(KeySliceQuery query, StoreTransaction txh)
Map<StaticBuffer,EntryList>	getSlice(List<StaticBuffer> keys, SliceQuery query, StoreTransaction txh)
void	mutate(StaticBuffer key, List<Entry> additions, List<StaticBuffer> deletions, StoreTransaction txh)
void	quickDefragment(Collection<org.janusgraph.diskstorage.inmemory.InMemoryColumnValueStore> stores, StoreTransaction txh)
void	quickDefragment(StoreTransaction txh)
static InMemoryKeyColumnValueStore	readFrom(Path storePath, String name, ForkJoinPool parallelOperationsExecutor)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.janusgraph.diskstorage.keycolumnvalue.KeyColumnValueStore

getMultiSlices

Constructor Detail

InMemoryKeyColumnValueStore

public InMemoryKeyColumnValueStore(String name)

Method Detail

getSlice

public EntryList getSlice(KeySliceQuery query,
                          StoreTransaction txh)
                   throws BackendException

Specified by:

getSlice in interface KeyColumnValueStore

Throws:

BackendException

getSlice

public Map<StaticBuffer,EntryList> getSlice(List<StaticBuffer> keys,
                                            SliceQuery query,
                                            StoreTransaction txh)
                                     throws BackendException

Specified by:

getSlice in interface KeyColumnValueStore

Throws:

BackendException

mutate

public void mutate(StaticBuffer key,
                   List<Entry> additions,
                   List<StaticBuffer> deletions,
                   StoreTransaction txh)
            throws BackendException

Specified by:

mutate in interface KeyColumnValueStore

Throws:

BackendException

acquireLock

public void acquireLock(StaticBuffer key,
                        StaticBuffer column,
                        StaticBuffer expectedValue,
                        StoreTransaction txh)
                 throws BackendException

Specified by:

acquireLock in interface KeyColumnValueStore

Throws:

BackendException

getKeys

public KeyIterator getKeys(KeyRangeQuery query,
                           StoreTransaction txh)
                    throws BackendException

Specified by:

getKeys in interface KeyColumnValueStore

Throws:

BackendException

getKeys

public KeyIterator getKeys(SliceQuery query,
                           StoreTransaction txh)
                    throws BackendException

Specified by:

getKeys in interface KeyColumnValueStore

Throws:

BackendException

getKeys

public KeySlicesIterator getKeys(MultiSlicesQuery queries,
                                 StoreTransaction txh)
                          throws BackendException

Specified by:

getKeys in interface KeyColumnValueStore

Throws:

BackendException

getName

public String getName()

Specified by:

getName in interface KeyColumnValueStore

clear

public void clear()

close

public void close()
           throws BackendException

Specified by:

close in interface KeyColumnValueStore

Throws:

BackendException

createFragmentationReport

public InMemoryKeyColumnValueStoreFragmentationReport createFragmentationReport(StoreTransaction txh)
                                                                         throws BackendException

Throws:

BackendException

quickDefragment

public void quickDefragment(Collection<org.janusgraph.diskstorage.inmemory.InMemoryColumnValueStore> stores,
                            StoreTransaction txh)
                     throws BackendException

Throws:

BackendException

quickDefragment

public void quickDefragment(StoreTransaction txh)
                     throws BackendException

Throws:

BackendException

dumpTo

public void dumpTo(Path storePath,
                   ForkJoinPool parallelOperationsExecutor)

readFrom

public static InMemoryKeyColumnValueStore readFrom(Path storePath,
                                                   String name,
                                                   ForkJoinPool parallelOperationsExecutor)
                                            throws IOException

Throws:

IOException