public class RelationScan extends SourceOperator
tupleCounter| Constructor and Description |
|---|
RelationScan(StorageManager sm,
Relation relation,
java.lang.String filename)
Constructs a new relation scan operator
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| Modifier and Type | Method and Description |
|---|---|
java.lang.String |
getFileName()
Fetch the filename that is to be scanned.
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protected java.util.List<Tuple> |
innerGetNext()
Inner method to retrieve the next tuple(s).
|
protected java.util.List<Tuple> |
innerProcessTuple(Tuple tuple,
int inOp)
Inner processing of a tuple (never called, but made idempotent
for safety because I'm kinda stupid.)
|
static void |
main(java.lang.String[] args)
Debug main
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protected Relation |
setOutputRelation()
Sets the output relation of this relation scan.
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protected void |
setup()
Sets up the relation scan.
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protected java.lang.String |
toStringSingle()
Textual representation.
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allDone, cleanup, getInputOperator, getMultiNext, getNext, getNumberOfInputs, getOutputRelation, prefix, processTuple, setInputs, toString, toString, tuplespublic RelationScan(StorageManager sm, Relation relation, java.lang.String filename) throws EngineException
sm - this scanner's storage manager.relation - the relation this scanner scans.filename - the filename of the file that stores the
relation.EngineException - thrown whenever the relation scanner
cannot be properly initialised.public java.lang.String getFileName()
protected void setup()
throws EngineException
setup in class OperatorEngineException - whenever the relation scan cannot be
set up.protected java.util.List<Tuple> innerGetNext() throws EngineException
innerGetNext in class OperatorEngineException - whenever the next tuple(s) cannot be
retrieved.protected java.util.List<Tuple> innerProcessTuple(Tuple tuple, int inOp) throws EngineException
innerProcessTuple in class Operatortuple - the tuple to be processed.inOp - the source of this tuple.EngineException - never thrown by default (legacy call)protected Relation setOutputRelation() throws EngineException
setOutputRelation in class OperatorEngineException - thrown whenever the output relation
cannot be set.protected java.lang.String toStringSingle()
toStringSingle in class Operatorpublic static void main(java.lang.String[] args)
args - arguments