public class InMemoryKeyColumnValueStore extends Object implements KeyColumnValueStore
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.NO_ADDITIONS, NO_DELETIONS| Constructor and Description |
|---|
InMemoryKeyColumnValueStore(String name) |
| Modifier and Type | Method and Description |
|---|---|
void |
acquireLock(StaticBuffer key,
StaticBuffer column,
StaticBuffer expectedValue,
StoreTransaction txh)
Attempts to claim a lock on the value at the specified
key and
column pair. |
void |
clear() |
void |
close()
Closes this store
|
KeyIterator |
getKeys(KeyRangeQuery query,
StoreTransaction txh)
Returns a
KeyIterator over all keys that fall within the key-range specified by the given query and have one or more columns matching the column-range. |
KeyIterator |
getKeys(SliceQuery query,
StoreTransaction txh)
Returns a
KeyIterator over all keys in the store that have one or more columns matching the column-range. |
String |
getName()
Returns the name of this store.
|
EntryList |
getSlice(KeySliceQuery query,
StoreTransaction txh)
Retrieves the list of entries (i.e.
|
Map<StaticBuffer,EntryList> |
getSlice(List<StaticBuffer> keys,
SliceQuery query,
StoreTransaction txh)
Retrieves the list of entries (i.e.
|
void |
mutate(StaticBuffer key,
List<Entry> additions,
List<StaticBuffer> deletions,
StoreTransaction txh)
Verifies acquisition of locks
txh from previous calls to
KeyColumnValueStore.acquireLock(StaticBuffer, StaticBuffer, StaticBuffer, StoreTransaction)
, then writes supplied additions and/or deletions to
key in the underlying data store. |
public InMemoryKeyColumnValueStore(String name)
public EntryList getSlice(KeySliceQuery query, StoreTransaction txh) throws BackendException
KeyColumnValueStoregetSlice in interface KeyColumnValueStorequery - Query to get results fortxh - TransactionBackendException - when columnEnd < columnStartKeySliceQuerypublic Map<StaticBuffer,EntryList> getSlice(List<StaticBuffer> keys, SliceQuery query, StoreTransaction txh) throws BackendException
KeyColumnValueStoreSliceQuery for all
of the given keys together.getSlice in interface KeyColumnValueStorekeys - List of keysquery - Slicequery specifying matching entriestxh - TransactionBackendExceptionpublic void mutate(StaticBuffer key, List<Entry> additions, List<StaticBuffer> deletions, StoreTransaction txh) throws BackendException
KeyColumnValueStoretxh from previous calls to
KeyColumnValueStore.acquireLock(StaticBuffer, StaticBuffer, StaticBuffer, StoreTransaction)
, then writes supplied additions and/or deletions to
key in the underlying data store. Deletions are applied strictly
before additions. In other words, if both an addition and deletion are
supplied for the same column, then the column will first be deleted and
then the supplied Entry for the column will be added.
Implementations which don't support locking should skip the initial lock
verification step but otherwise behave as described above.mutate in interface KeyColumnValueStorekey - the key under which the columns in additions and
deletions will be writtenadditions - the list of Entry instances representing column-value pairs to
create under key, or null to add no column-value pairsdeletions - the list of columns to delete from key, or null to
delete no columnstxh - the transaction to usePermanentLockingException - if locking is supported by the implementation and at least
one lock acquisition attempted by
KeyColumnValueStore.acquireLock(StaticBuffer, StaticBuffer, StaticBuffer, StoreTransaction)
has failedBackendExceptionpublic void acquireLock(StaticBuffer key, StaticBuffer column, StaticBuffer expectedValue, StoreTransaction txh) throws BackendException
KeyColumnValueStorekey and
column pair. These locks are discretionary.
If locking fails, implementations of this method may, but are not
required to, throw PermanentLockingException.
This method is not required
to determine whether locking actually succeeded and may return without
throwing an exception even when the lock can't be acquired. Lock
acquisition is only only guaranteed to be verified by the first call to
KeyColumnValueStore.mutate(StaticBuffer, List, List, StoreTransaction) on any given
txh.
The expectedValue must match the actual value present at the
key and column pair. If the true value does not match the
expectedValue, the lock attempt fails and
LockingException is thrown. This method may check
expectedValue. The mutate() mutate is required to check
it.
When this method is called multiple times on the same key,
column, and txh, calls after the first have no effect.
Locks acquired by this method must be automatically released on
transaction commit() or rollback().
Implementations which don't support locking should throw
UnsupportedOperationException.acquireLock in interface KeyColumnValueStorekey - the key on which to lockcolumn - the column on which to lockexpectedValue - the expected value for the specified key-column pair on which
to lock (null means the pair must have no value)txh - the transaction to usePermanentLockingException - the lock could not be acquired due to contention with other
transactions or a locking-specific storage problemBackendExceptionpublic KeyIterator getKeys(KeyRangeQuery query, StoreTransaction txh) throws BackendException
KeyColumnValueStoreKeyIterator over all keys that fall within the key-range specified by the given query and have one or more columns matching the column-range.
Calling KeyIterator.getEntries() returns the list of all entries that match the column-range specified by the given query.
This method is only supported by stores which keep keys in byte-order.getKeys in interface KeyColumnValueStoreBackendExceptionpublic KeyIterator getKeys(SliceQuery query, StoreTransaction txh) throws BackendException
KeyColumnValueStoreKeyIterator over all keys in the store that have one or more columns matching the column-range. Calling KeyIterator.getEntries()
returns the list of all entries that match the column-range specified by the given query.
This method is only supported by stores which do not keep keys in byte-order.getKeys in interface KeyColumnValueStoreBackendExceptionpublic String getName()
KeyColumnValueStoregetName in interface KeyColumnValueStoreKeyColumnValueStoreManager.openDatabase(String)public void clear()
public void close()
throws BackendException
KeyColumnValueStoreclose in interface KeyColumnValueStoreBackendExceptionCopyright © 2012–2015. All rights reserved.