Class TSTLookup
- java.lang.Object
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- org.apache.lucene.search.suggest.Lookup
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- org.apache.lucene.search.suggest.tst.TSTLookup
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- All Implemented Interfaces:
Accountable
public class TSTLookup extends Lookup
Suggest implementation based on a Ternary Search Tree- See Also:
TSTAutocomplete
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.lucene.search.suggest.Lookup
Lookup.LookupPriorityQueue, Lookup.LookupResult
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Field Summary
Fields Modifier and Type Field Description (package private) TSTAutocomplete
autocomplete
private long
count
Number of entries the lookup was built withprivate static byte
EQ_KID
private static byte
HAS_TOKEN
private static byte
HAS_VALUE
private static byte
HI_KID
private static byte
LO_KID
(package private) TernaryTreeNode
root
private Directory
tempDir
private java.lang.String
tempFileNamePrefix
private static java.util.Comparator<BytesRef>
utf8SortedAsUTF16SortOrder
TST uses UTF-16 sorting, so we need a suitable BytesRef comparator to do this.-
Fields inherited from class org.apache.lucene.search.suggest.Lookup
CHARSEQUENCE_COMPARATOR
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Fields inherited from interface org.apache.lucene.util.Accountable
NULL_ACCOUNTABLE
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
add(java.lang.CharSequence key, java.lang.Object value)
Adds a new node ifkey
already exists, otherwise replaces its value.void
build(InputIterator iterator)
Builds up a new internalLookup
representation based on the givenInputIterator
.private static boolean
charSeqEquals(java.lang.CharSequence left, java.lang.CharSequence right)
java.lang.Object
get(java.lang.CharSequence key)
Returns the value for the specified key, or null if the key does not exist.long
getCount()
Get the number of entries the lookup was built withboolean
load(DataInput input)
Discard current lookup data and load it from a previously saved copy.java.util.List<Lookup.LookupResult>
lookup(java.lang.CharSequence key, java.util.Set<BytesRef> contexts, boolean onlyMorePopular, int num)
Look up a key and return possible completion for this key.long
ramBytesUsed()
Returns byte size of the underlying TSTprivate void
readRecursively(DataInput in, TernaryTreeNode node)
boolean
store(DataOutput output)
Persist the constructed lookup data to a directory.private void
writeRecursively(DataOutput out, TernaryTreeNode node)
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Methods inherited from class org.apache.lucene.search.suggest.Lookup
build, load, lookup, lookup, store
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface org.apache.lucene.util.Accountable
getChildResources
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Field Detail
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root
TernaryTreeNode root
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autocomplete
TSTAutocomplete autocomplete
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count
private long count
Number of entries the lookup was built with
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tempDir
private final Directory tempDir
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tempFileNamePrefix
private final java.lang.String tempFileNamePrefix
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utf8SortedAsUTF16SortOrder
private static final java.util.Comparator<BytesRef> utf8SortedAsUTF16SortOrder
TST uses UTF-16 sorting, so we need a suitable BytesRef comparator to do this.
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LO_KID
private static final byte LO_KID
- See Also:
- Constant Field Values
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EQ_KID
private static final byte EQ_KID
- See Also:
- Constant Field Values
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HI_KID
private static final byte HI_KID
- See Also:
- Constant Field Values
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HAS_TOKEN
private static final byte HAS_TOKEN
- See Also:
- Constant Field Values
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HAS_VALUE
private static final byte HAS_VALUE
- See Also:
- Constant Field Values
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Constructor Detail
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TSTLookup
public TSTLookup()
Creates a new TSTLookup with an empty Ternary Search Tree.- See Also:
build(InputIterator)
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TSTLookup
public TSTLookup(Directory tempDir, java.lang.String tempFileNamePrefix)
Creates a new TSTLookup, for building.- See Also:
build(InputIterator)
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Method Detail
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build
public void build(InputIterator iterator) throws java.io.IOException
Description copied from class:Lookup
Builds up a new internalLookup
representation based on the givenInputIterator
. The implementation might re-sort the data internally.
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add
public boolean add(java.lang.CharSequence key, java.lang.Object value)
Adds a new node ifkey
already exists, otherwise replaces its value.This method always returns true.
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get
public java.lang.Object get(java.lang.CharSequence key)
Returns the value for the specified key, or null if the key does not exist.
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charSeqEquals
private static boolean charSeqEquals(java.lang.CharSequence left, java.lang.CharSequence right)
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lookup
public java.util.List<Lookup.LookupResult> lookup(java.lang.CharSequence key, java.util.Set<BytesRef> contexts, boolean onlyMorePopular, int num)
Description copied from class:Lookup
Look up a key and return possible completion for this key.- Specified by:
lookup
in classLookup
- Parameters:
key
- lookup key. Depending on the implementation this may be a prefix, misspelling, or even infix.contexts
- contexts to filter the lookup by, or null if all contexts are allowed; if the suggestion contains any of the contexts, it's a matchonlyMorePopular
- return only more popular resultsnum
- maximum number of results to return- Returns:
- a list of possible completions, with their relative weight (e.g. popularity)
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readRecursively
private void readRecursively(DataInput in, TernaryTreeNode node) throws java.io.IOException
- Throws:
java.io.IOException
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writeRecursively
private void writeRecursively(DataOutput out, TernaryTreeNode node) throws java.io.IOException
- Throws:
java.io.IOException
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store
public boolean store(DataOutput output) throws java.io.IOException
Description copied from class:Lookup
Persist the constructed lookup data to a directory. Optional operation.- Specified by:
store
in classLookup
- Parameters:
output
-DataOutput
to write the data to.- Returns:
- true if successful, false if unsuccessful or not supported.
- Throws:
java.io.IOException
- when fatal IO error occurs.
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load
public boolean load(DataInput input) throws java.io.IOException
Description copied from class:Lookup
Discard current lookup data and load it from a previously saved copy. Optional operation.
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ramBytesUsed
public long ramBytesUsed()
Returns byte size of the underlying TST
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