Class FieldComparer

Inheritance

System.Object

FieldComparer

FieldComparer<T>

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Lucene.Net.Search

Assembly: Lucene.Net.dll

Syntax

public abstract class FieldComparer

Properties

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Item[Int32]

Return the actual value in the slot. LUCENENET NOTE: This was value(int) in Lucene.

Declaration

public abstract IComparable this[int slot] { get; }

Parameters

Type	Name	Description
System.Int32	slot	The value

Property Value

Type	Description
System.IComparable	Value in this slot

Methods

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Compare(Int32, Int32)

Compare hit at slot1 with hit at slot2.

Declaration

public abstract int Compare(int slot1, int slot2)

Parameters

Type	Name	Description
System.Int32	slot1	first slot to compare
System.Int32	slot2	second slot to compare

Returns

Type	Description
System.Int32	any N < 0 if `slot2`'s value is sorted after `slot1`, any N > 0 if the `slot2`'s value is sorted before `slot1` and 0 if they are equal

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CompareBottom(Int32)

Compare the bottom of the queue with this doc. This will only invoked after setBottom has been called. This should return the same result as Compare(Int32, Int32) as if bottom were slot1 and the new document were slot 2.

For a search that hits many results, this method will be the hotspot (invoked by far the most frequently).

Declaration

public abstract int CompareBottom(int doc)

Parameters

Type	Name	Description
System.Int32	doc	Doc that was hit

Returns

Type	Description
System.Int32	Any N < 0 if the doc's value is sorted after the bottom entry (not competitive), any N > 0 if the doc's value is sorted before the bottom entry and 0 if they are equal.

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CompareTop(Int32)

Compare the top value with this doc. This will only invoked after SetTopValue(Object) has been called. This should return the same result as Compare(Int32, Int32) as if topValue were slot1 and the new document were slot 2. This is only called for searches that use SearchAfter (deep paging).

Declaration

public abstract int CompareTop(int doc)

Parameters

Type	Name	Description
System.Int32	doc	Doc that was hit

Returns

Type	Description
System.Int32	Any N < 0 if the doc's value is sorted after the bottom entry (not competitive), any N > 0 if the doc's value is sorted before the bottom entry and 0 if they are equal.

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CompareValues(Object, Object)

Declaration

public abstract int CompareValues(object first, object second)

Parameters

Type	Name	Description
System.Object	first
System.Object	second

Returns

Type	Description
System.Int32

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Copy(Int32, Int32)

This method is called when a new hit is competitive. You should copy any state associated with this document that will be required for future comparisons, into the specified slot.

Declaration

public abstract void Copy(int slot, int doc)

Parameters

Type	Name	Description
System.Int32	slot	Which slot to copy the hit to
System.Int32	doc	DocID relative to current reader

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SetBottom(Int32)

Set the bottom slot, ie the "weakest" (sorted last) entry in the queue. When CompareBottom(Int32) is called, you should compare against this slot. This will always be called before CompareBottom(Int32).

Declaration

public abstract void SetBottom(int slot)

Parameters

Type	Name	Description
System.Int32	slot	The currently weakest (sorted last) slot in the queue

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SetNextReader(AtomicReaderContext)

Set a new AtomicReaderContext. All subsequent docIDs are relative to the current reader (you must add docBase if you need to map it to a top-level docID).

Declaration

public abstract FieldComparer SetNextReader(AtomicReaderContext context)

Parameters

Type	Name	Description
AtomicReaderContext	context	Current reader context

Returns

Type	Description
FieldComparer	The comparer to use for this segment; most comparers can just return "this" to reuse the same comparer across segments

Exceptions

Type	Condition
System.IO.IOException	if there is a low-level IO error

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SetScorer(Scorer)

Sets the Scorer to use in case a document's score is needed.

Declaration

public virtual void SetScorer(Scorer scorer)

Parameters

Type	Name	Description
Scorer	scorer	Scorer instance that you should use to obtain the current hit's score, if necessary.

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SetTopValue(Object)

Record the top value, for future calls to CompareTop(Int32). This is only called for searches that use SearchAfter (deep paging), and is called before any calls to SetNextReader(AtomicReaderContext).

Declaration

public abstract void SetTopValue(object value)

Parameters

Type	Name	Description
System.Object	value