Package org.eclipse.rdf4j.rio.hdt
Class HDTTriplesSectionBitmap
java.lang.Object
org.eclipse.rdf4j.rio.hdt.HDTPart
org.eclipse.rdf4j.rio.hdt.HDTTriplesSection
org.eclipse.rdf4j.rio.hdt.HDTTriplesSectionBitmap
- All Implemented Interfaces:
Iterator<int[]>
HDT Triples section.
This part contains two levels of bitmaps and arrays.
Typically (in SPO order), the Y-level corresponds to the predicates and the Z-level to the objects.
The X (subjects) is implicit since triples are already ordered by X, and bitmap Y is used to notify when there is a new X: X will be used until a 1 is found in bitmap Y, which indicates that the next triple uses X+1.
The array contains numeric references to the predicates and objects in the HDT dictionaries, starting with the
entries in the "shared" Dictionary
These positions are counted
starting with 1, not 0.
E.g. Y-bitmap 0 1 1
and Y-array 1 2 3
results in S1-P1 S1-P2 S2-P3
Structure:
+----------+----------+---------+---------+ | Bitmap Y | Bitmap Z | Array Y | Array Z | +----------+----------+---------+---------+
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Nested Class Summary
Nested classes/interfaces inherited from class org.eclipse.rdf4j.rio.hdt.HDTPart
HDTPart.Type
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate HDTArray
private HDTArray
private HDTBitmap
private HDTBitmap
private int
private int
private int
private int
private int
Fields inherited from class org.eclipse.rdf4j.rio.hdt.HDTPart
COOKIE, name, pos, properties
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
hasNext()
int[]
next()
protected void
parse
(InputStream is) Parse from input streamprotected void
parse
(InputStream is, HDTTriples.Order order) Parse triples section and return the triple parts in the correct S,P,O order.Methods inherited from class org.eclipse.rdf4j.rio.hdt.HDTPart
checkControl, checkCRC, checkFormat, countToNull, getDebugPartStr, getIntegerProperty, getProperties, getProperties, mapProperties, readToNull
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface java.util.Iterator
forEachRemaining, remove
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Field Details
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bitmapY
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bitmapZ
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arrY
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arrZ
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sizeY
private int sizeY -
sizeZ
private int sizeZ -
posX
private int posX -
posY
private int posY -
posZ
private int posZ
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Constructor Details
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HDTTriplesSectionBitmap
HDTTriplesSectionBitmap()
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Method Details
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hasNext
public boolean hasNext() -
next
public int[] next() -
parse
Description copied from class:HDTPart
Parse from input stream- Specified by:
parse
in classHDTPart
- Parameters:
is
-- Throws:
IOException
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parse
Description copied from class:HDTTriplesSection
Parse triples section and return the triple parts in the correct S,P,O order.- Specified by:
parse
in classHDTTriplesSection
- Parameters:
is
-order
-- Throws:
IOException
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