- All Implemented Interfaces:
org.apache.jena.atlas.lib.Closeable
,DatasetGraph
,Transactional
DatasetGraph
as an extensible set of graphs.
Subclasses need to manage any implicit graph creation.
This implementation provides copy-in, copy-out for DatasetGraphTriplesQuads.addGraph(org.apache.jena.graph.Node, org.apache.jena.graph.Graph)
.
See DatasetGraphMapLink
for a DatasetGraph
that holds graphs as provided.
- See Also:
-
Nested Class Summary
Nested classes/interfaces inherited from interface org.apache.jena.sparql.core.Transactional
Transactional.Promote
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Constructor Summary
ConstructorsConstructorDescriptionDatasetGraphMap defaulting to storage in memory.DatasetGraphMap
(org.apache.jena.graph.Graph defaultGraph) -
Method Summary
Modifier and TypeMethodDescriptionvoid
abort()
Abort a transaction - finish the transaction and undo any changes (if a "write" transaction)void
begin()
Start a transaction which is READ mode and which will switch to WRITE if an update is attempted but only if no intermediate transaction has performed an update.void
Start either a READ or WRITE transaction.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
commit()
Commit a transaction - finish the transaction and make any changes permanent (if a "write" transaction)boolean
containsGraph
(org.apache.jena.graph.Node graphNode) Does the DatasetGraph contain a specific named graph?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.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 txnType) Attempt to promote a transaction from "read" mode to "write" and the transaction.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, addGraph, delete, delete, removeGraph
Methods inherited from class org.apache.jena.sparql.core.DatasetGraphBaseFind
find, findInUnionGraph, findNG, findQuadsInUnionGraph
Methods inherited from class org.apache.jena.sparql.core.DatasetGraphBase
close, contains, contains, deleteAny, deleteAny, find, find, getContext, getLock, getUnionGraph, 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
calc, calculate, calculateRead, calculateWrite, exec, execute, executeRead, executeWrite, promote
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Constructor Details
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DatasetGraphMap
public DatasetGraphMap()DatasetGraphMap defaulting to storage in memory. -
DatasetGraphMap
public DatasetGraphMap(org.apache.jena.graph.Graph defaultGraph)
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Method Details
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begin
public void begin()Description copied from interface:Transactional
Start a transaction which is READ mode and which will switch to WRITE if an update is attempted but only if no intermediate transaction has performed an update.See
Transactional.begin(TxnType)
for more details an options.May not be implemented. See
Transactional.begin(ReadWrite)
is guaranteed to be provided. -
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. -
begin
Description copied from interface:Transactional
Start either a READ or WRITE transaction. -
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. -
commit
public void commit()Description copied from interface:Transactional
Commit a transaction - finish the transaction and make any changes permanent (if a "write" transaction) -
abort
public void abort()Description copied from interface:Transactional
Abort a transaction - finish the transaction and undo any changes (if a "write" transaction) -
isInTransaction
public boolean isInTransaction()Description copied from interface:Transactional
Say whether inside a transaction. -
end
public void end()Description copied from interface:Transactional
Finish the transaction - if a write transaction and commit() has not been called, then abort -
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. -
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. -
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. -
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. -
listGraphNodes
Description copied from interface:DatasetGraph
Iterate over all names of named graphs -
prefixes
Description copied from interface:DatasetGraph
Prefixes for this DatasetGraph -
containsGraph
public boolean containsGraph(org.apache.jena.graph.Node graphNode) Description copied from interface:DatasetGraph
Does the DatasetGraph contain a specific named graph? 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 and this returns true always.- Specified by:
containsGraph
in interfaceDatasetGraph
- Overrides:
containsGraph
in classDatasetGraphBase
- Returns:
- boolean
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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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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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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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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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