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java.lang.Objectit.unimi.dsi.mg4j.index.Index
it.unimi.dsi.mg4j.index.SkipIndex
An abstract representation of an index with skips.
An instance of this class stores, besides the data contained in
an Index
, data related to
skipping (quantum, height, etc.).
Field Summary | |
int |
height
The parameter h (the maximum height of a skip tower). |
int |
quantum
The quantum. |
Fields inherited from class it.unimi.dsi.mg4j.index.Index |
basename, countCoding, emptyDocumentIterator, frequencyCoding, hasCounts, hasPositions, indexFile, isCaseSensitive, maxDocPos, numberOfDocuments, numberOfTerms, offsets, pointerCoding, positionCoding, properties, singletonSet, sizes, termMap |
Fields inherited from interface it.unimi.dsi.mg4j.index.CompressionFlags |
ARITH, CODING_NAME, COUNTS_DEFAULT, COUNTS_DELTA, COUNTS_GAMMA, COUNTS_SHIFT, DELTA, FREQUENCIES_DEFAULT, FREQUENCIES_DELTA, FREQUENCIES_GAMMA, FREQUENCIES_SHIFT, GAMMA, GOLOMB, INTERP, NIBBLE, NO_COUNTS, NO_POSITIONS, NONE, POINTERS_DEFAULT, POINTERS_DELTA, POINTERS_GAMMA, POINTERS_GOLOMB, POINTERS_SHIFT, POSITIONS_ARITH, POSITIONS_DEFAULT, POSITIONS_DELTA, POSITIONS_GAMMA, POSITIONS_GOLOMB, POSITIONS_INTERP, POSITIONS_SHIFT, POSITIONS_SKEWED_GOLOMB, SKEWED_GOLOMB, UNARY, ZETA |
Constructor Summary | |
protected |
SkipIndex(CharSequence basename,
TermMap termMap,
boolean loadOffsets,
ProgressMeter pm)
Creates a new skip index using the given basename. |
|
SkipIndex(String basename,
File indexFile,
Properties properties,
int numberOfDocuments,
int numberOfTerms,
int maxDocPos,
boolean isCaseSensitive,
long flags,
TermMap termMap,
LongList offsets,
IntList sizes,
int quantum,
int height)
Creates a new skip index using the given data. |
Method Summary | |
IndexReader |
getReader()
Creates and returns a new IndexReader based on this index. |
IndexReader |
getReader(int bufferSize)
Creates and returns a new IndexReader based on this index. |
Methods inherited from class it.unimi.dsi.mg4j.index.Index |
getInstance, getInstance, getInstance, getInstance, loadTermMap, main, readOffsets, readSizes, toString |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Field Detail |
public final int height
h
(the maximum height of a skip tower).
public final int quantum
Constructor Detail |
protected SkipIndex(CharSequence basename, TermMap termMap, boolean loadOffsets, ProgressMeter pm) throws IOException
basename
- the basename of the index.termMap
- the term list for this index, or null
if there is no term list.loadOffsets
- offsets are loaded only if this parameter is true
.pm
- an optional progress meter. If null
, no progress information will be displayed.public SkipIndex(String basename, File indexFile, Properties properties, int numberOfDocuments, int numberOfTerms, int maxDocPos, boolean isCaseSensitive, long flags, TermMap termMap, LongList offsets, IntList sizes, int quantum, int height) throws IOException
This constructor provides an index that is initialised exactly to the provided data.
It is mainly useful for debugging and testing purposes, in the case you are creating
an index file (for instance, as a memory-based bit stream) but you have no property
file to use with Index.getInstance(CharSequence)
.
It is usually safe to provide null
for basename
, indexFile
and properties
, but the responsibility for data consistence is up to the caller.
basename
- the basename of this index, or null
.indexFile
- the file containing this index, or null
.properties
- the properties of this index, or null
.numberOfDocuments
- the number of documents in this index.numberOfTerms
- the number of terms in this index.maxDocPos
- the maximum length of an occurrence list, or -1 if it is not known.flags
- a bit mask setting the coding techniques to be used (see CompressionFlags
).termMap
- the term list for this index, or null
if there is no term list.offsets
- the offset list; may be null
if you do not plan using IndexReader.position(int)
.sizes
- the size list; may be null
if your code does not require it.quantum
- the quantum to be used if this index has skips (0 means that this index has no skips).height
- the height (meaningless if quantum is zero).Method Detail |
public IndexReader getReader() throws IOException
IndexReader
based on this index. After that, you
can use the reader to read this index.
getReader
in class Index
SkipIndexReader
to read this index.
IOException
public IndexReader getReader(int bufferSize) throws IOException
IndexReader
based on this index. After that, you
can use the reader to read this index.
getReader
in class Index
bufferSize
- the size of the buffer to be used when opening the InputBitStream
underlying the
SkipIndexReader
that is going to be returned.
SkipIndexReader
to read this index.
IOException
|
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