- All Implemented Interfaces:
org.apache.jena.atlas.lib.Closeable
,DatasetGraph
,Transactional
DatasetGraph
backed by an QuadTable
. By default, this is a
HexTable
designed for high-speed in-memory operation.-
Nested Class Summary
Nested classes/interfaces inherited from interface org.apache.jena.sparql.core.Transactional
Transactional.Promote
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Constructor Summary
ConstructorDescriptionDefault constructor. -
Method Summary
Modifier and TypeMethodDescriptionvoid
abort()
Abort a transaction - finish the transaction and undo any changes (if a "write" transaction)void
addGraph
(org.apache.jena.graph.Node graphName, org.apache.jena.graph.Graph graph) Add the given graph to the dataset.void
Start a transaction.
READ or WRITE transactions start in that state and do not change for the lifetime of the transaction.void
clear()
Remove everything - remove all named graphs, clear the default graphvoid
close()
Close the datasetvoid
commit()
Commit a transaction - finish the transaction and make any changes permanent (if a "write" transaction)void
end()
Finish the transaction - if a write transaction and commit() has not been called, then abortorg.apache.jena.graph.Graph
Get the default graph as a Jena Graphorg.apache.jena.graph.Graph
getGraph
(org.apache.jena.graph.Node graphNode) Get the graph named by graphNode : returns null when there is no such graph.org.apache.jena.graph.Graph
Return aGraph
that is the union of all named graphs in this dataset.boolean
Say whether inside a transaction.Iterator<org.apache.jena.graph.Node>
Iterate over all names of named graphsprefixes()
Prefixes for this DatasetGraphboolean
promote
(Transactional.Promote promoteMode) Attempt to promote a transaction from "read" mode to "write" and the transaction.void
removeGraph
(org.apache.jena.graph.Node graphName) Remove all data associated with the named graph.long
size()
Get the size (number of named graphs) - may be -1 for unknownboolean
Declare whetherTransactional.abort()
is supported.boolean
ADatasetGraph
supports transactions if it providesTransactional.begin()
/Transactional.commit()
/Transactional.end()
.Return the current mode of the transaction - "read" or "write".Return the transaction type used inbegin(TxnType)
.Methods inherited from class org.apache.jena.sparql.core.DatasetGraphTriplesQuads
add, add, delete, delete
Methods inherited from class org.apache.jena.sparql.core.DatasetGraphBaseFind
find, findInUnionGraph, findNG, findQuadsInUnionGraph
Methods inherited from class org.apache.jena.sparql.core.DatasetGraphBase
contains, contains, containsGraph, deleteAny, deleteAny, find, find, getContext, getLock, isEmpty, toString
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.apache.jena.sparql.core.DatasetGraph
addAll, stream, stream
Methods inherited from interface org.apache.jena.sparql.core.Transactional
begin, begin, calc, calculate, calculateRead, calculateWrite, exec, execute, executeRead, executeWrite, promote
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Constructor Details
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DatasetGraphInMemory
public DatasetGraphInMemory()Default constructor. -
DatasetGraphInMemory
- Parameters:
i
- a table in which to store quadst
- a table in which to store triples
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Method Details
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isInTransaction
public boolean isInTransaction()Description copied from interface:Transactional
Say whether inside a transaction.- Specified by:
isInTransaction
in interfaceTransactional
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transactionMode
Description copied from interface:Transactional
Return the current mode of the transaction - "read" or "write". If the caller is not in a transaction, this method returns null.- Specified by:
transactionMode
in interfaceTransactional
- Returns:
- the current mode of the transaction in progress
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transactionType
Description copied from interface:Transactional
Return the transaction type used inbegin(TxnType)
. If the caller is not in a transaction, this method returns null.- Specified by:
transactionType
in interfaceTransactional
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supportsTransactions
public boolean supportsTransactions()Description copied from interface:DatasetGraph
ADatasetGraph
supports transactions if it providesTransactional.begin()
/Transactional.commit()
/Transactional.end()
. The core storageDatasetGraph
s provide fully serialized transactions. ADatasetGraph
that provides functionality across independent systems can not provide such strong guarantees. For example, it may use MRSW locking and some isolation control. Specifically, it would not necessarily provideTransactional.abort()
.See
DatasetGraph.supportsTransactionAbort()
forTransactional.abort()
. In addition, check details of a specific implementation.- Specified by:
supportsTransactions
in interfaceDatasetGraph
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supportsTransactionAbort
public boolean supportsTransactionAbort()Description copied from interface:DatasetGraph
Declare whetherTransactional.abort()
is supported. This goes along with clearing up after exceptions inside application transaction code.- Specified by:
supportsTransactionAbort
in interfaceDatasetGraph
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begin
Description copied from interface:Transactional
Start a transaction.
READ or WRITE transactions start in that state and do not change for the lifetime of the transaction.WRITE
: this guarantees a WRITE will complete ifcommit()
is called. The same asbegin(ReadWrite.WRITE)
.READ
: the transaction can not promote to WRITE,ensuring read-only access to the data. The same asbegin(ReadWrite.READ)
.READ_PROMOTE
: the transaction will go from "read" to "write" if an update is attempted and if the dataset has not been changed by another write transaction. See alsoTransactional.promote()
.READ_COMMITTED_PROMOTE
: Use this with care. The promotion will succeed but changes from other transactions become visible.
begin
). IfREAD_PROMOTE
, the dataset must not have changed; ifREAD_COMMITTED_PROMOTE
any intermediate changes are visible but the application can not assume any data it has read in the transaction is the same as it was at the point the transaction started.This operation is optional and some implementations may throw a
JenaTransactionException
exception for some or allTxnType
values.See
Transactional.begin(ReadWrite)
for a form that is required of implementations.- Specified by:
begin
in interfaceTransactional
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promote
Description copied from interface:Transactional
Attempt to promote a transaction from "read" mode to "write" and the transaction. This method allows the form of promotion to be specified. The transaction must not have been started withREAD
, which is read-only.An argument of
READ_PROMOTE
treats the promotion as if the transaction was started withREAD_PROMOTE
(any other writer commiting since the transaction started blocks promotion) andREAD_COMMITTED_PROMOTE
treats the promotion as if the transaction was started withREAD_COMMITTED_PROMOTE
(intemediate writer commits become visible).Returns "true" if the transaction is in write mode after the call. The method always succeeds of the transaction is already "write".
This method returns true if a
READ_PROMOTE
orREAD_COMMITTED_PROMOTE
is promoted.This method returns false if a
READ_PROMOTE
can't be promoted - the transaction is still valid and in "read" mode.This method throws an exception if there is an attempt to promote a
READ
transaction.- Specified by:
promote
in interfaceTransactional
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commit
public void commit()Description copied from interface:Transactional
Commit a transaction - finish the transaction and make any changes permanent (if a "write" transaction)- Specified by:
commit
in interfaceTransactional
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abort
public void abort()Description copied from interface:Transactional
Abort a transaction - finish the transaction and undo any changes (if a "write" transaction)- Specified by:
abort
in interfaceTransactional
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close
public void close()Description copied from interface:DatasetGraph
Close the dataset- Specified by:
close
in interfaceorg.apache.jena.atlas.lib.Closeable
- Specified by:
close
in interfaceDatasetGraph
- Overrides:
close
in classDatasetGraphBase
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end
public void end()Description copied from interface:Transactional
Finish the transaction - if a write transaction and commit() has not been called, then abort- Specified by:
end
in interfaceTransactional
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listGraphNodes
Description copied from interface:DatasetGraph
Iterate over all names of named graphs- Specified by:
listGraphNodes
in interfaceDatasetGraph
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getGraph
public org.apache.jena.graph.Graph getGraph(org.apache.jena.graph.Node graphNode) Description copied from interface:DatasetGraph
Get the graph named by graphNode : returns null when there is no such graph. NB Whether a dataset contains a graph if there are no triples is not defined - see the specific implementation. Some datasets are "open" - they have all graphs even if no triples.- Specified by:
getGraph
in interfaceDatasetGraph
- Specified by:
getGraph
in classDatasetGraphBase
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getDefaultGraph
public org.apache.jena.graph.Graph getDefaultGraph()Description copied from interface:DatasetGraph
Get the default graph as a Jena Graph- Specified by:
getDefaultGraph
in interfaceDatasetGraph
- Specified by:
getDefaultGraph
in classDatasetGraphBase
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getUnionGraph
public org.apache.jena.graph.Graph getUnionGraph()Description copied from interface:DatasetGraph
Return aGraph
that is the union of all named graphs in this dataset. This union graph is read-only (its prefix mapping in the current JVM may be changed but that may not persist).- Specified by:
getUnionGraph
in interfaceDatasetGraph
- Overrides:
getUnionGraph
in classDatasetGraphBase
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addGraph
public void addGraph(org.apache.jena.graph.Node graphName, org.apache.jena.graph.Graph graph) Description copied from interface:DatasetGraph
Add the given graph to the dataset. Replaces any existing data for the named graph; to add data, get the graph and add triples to it, or add quads to the dataset. Do not assume that the same Java object is returned byDatasetGraph.getGraph(org.apache.jena.graph.Node)
- Specified by:
addGraph
in interfaceDatasetGraph
- Overrides:
addGraph
in classDatasetGraphTriplesQuads
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removeGraph
public void removeGraph(org.apache.jena.graph.Node graphName) Description copied from interface:DatasetGraph
Remove all data associated with the named graph. This will include prefixes associated with the graph.- Specified by:
removeGraph
in interfaceDatasetGraph
- Overrides:
removeGraph
in classDatasetGraphTriplesQuads
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prefixes
Description copied from interface:DatasetGraph
Prefixes for this DatasetGraph- Specified by:
prefixes
in interfaceDatasetGraph
- Returns:
- the prefixes in use in this dataset
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size
public long size()Description copied from interface:DatasetGraph
Get the size (number of named graphs) - may be -1 for unknown- Specified by:
size
in interfaceDatasetGraph
- Overrides:
size
in classDatasetGraphBase
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clear
public void clear()Description copied from interface:DatasetGraph
Remove everything - remove all named graphs, clear the default graph- Specified by:
clear
in interfaceDatasetGraph
- Overrides:
clear
in classDatasetGraphBase
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