EmptyPostList Class Reference

A PostList which contains no entries. More...

#include <emptypostlist.h>

Inheritance diagram for EmptyPostList:

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Collaboration diagram for EmptyPostList:

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List of all members.

Public Member Functions
	EmptyPostList ()
	Constructor.
Xapian::doccount	get_termfreq_min () const
	Get a lower bound on the number of documents indexed by this term.
Xapian::doccount	get_termfreq_max () const
	Get an upper bound on the number of documents indexed by this term.
Xapian::doccount	get_termfreq_est () const
	Get an estimate of the number of documents indexed by this term.
Xapian::weight	get_maxweight () const
	Return an upper bound on what get_weight() can return.
Xapian::docid	get_docid () const
	Return the current docid.
Xapian::termcount	get_doclength () const
	Return the length of current document.
Xapian::weight	get_weight () const
	Return the weight contribution for the current position.
bool	at_end () const
	Return true if the current position is past the last entry in this list.
Xapian::weight	recalc_maxweight ()
	Recalculate the upper bound on what get_weight() can return.
PostList *	next (Xapian::weight w_min)
	Advance the current position to the next document in the postlist.
PostList *	skip_to (Xapian::docid, Xapian::weight w_min)
	Skip forward to the specified docid.
std::string	get_description () const
	Return a string description of this object.
Private Member Functions
void	operator= (const EmptyPostList &)
	Don't allow assignment.
	EmptyPostList (const EmptyPostList &)
	Don't allow copying.

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Detailed Description

A PostList which contains no entries.

Definition at line 27 of file emptypostlist.h.

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Constructor & Destructor Documentation

EmptyPostList::EmptyPostList

(

const EmptyPostList &

)

[private]

Don't allow copying.

EmptyPostList::EmptyPostList

(

)

[inline]

Constructor.

Definition at line 36 of file emptypostlist.h.

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Member Function Documentation

bool EmptyPostList::at_end

(

)

const [virtual]

Return true if the current position is past the last entry in this list.

Implements Xapian::PostingIterator::Internal.

Definition at line 74 of file emptypostlist.cc.

string EmptyPostList::get_description

(

)

const [virtual]

Return a string description of this object.

Implements Xapian::PostingIterator::Internal.

Definition at line 98 of file emptypostlist.cc.

Xapian::docid EmptyPostList::get_docid

(

)

const [virtual]

Return the current docid.

Implements Xapian::PostingIterator::Internal.

Definition at line 54 of file emptypostlist.cc.

References Assert.

Referenced by get_doclength().

Xapian::termcount EmptyPostList::get_doclength

(

)

const [virtual]

Return the length of current document.

Implements Xapian::PostingIterator::Internal.

Definition at line 61 of file emptypostlist.cc.

References get_docid().

Xapian::weight EmptyPostList::get_maxweight

(

)

const [virtual]

Return an upper bound on what get_weight() can return.

Implements Xapian::PostingIterator::Internal.

Definition at line 48 of file emptypostlist.cc.

Referenced by recalc_maxweight().

Xapian::doccount EmptyPostList::get_termfreq_est

(

)

const [virtual]

Get an estimate of the number of documents indexed by this term.

It should always be true that: get_termfreq_min() <= get_termfreq_est() <= get_termfreq_max()

Implements Xapian::PostingIterator::Internal.

Definition at line 42 of file emptypostlist.cc.

Xapian::doccount EmptyPostList::get_termfreq_max

(

)

const [virtual]

Get an upper bound on the number of documents indexed by this term.

Implements Xapian::PostingIterator::Internal.

Definition at line 36 of file emptypostlist.cc.

Xapian::doccount EmptyPostList::get_termfreq_min

(

)

const [virtual]

Get a lower bound on the number of documents indexed by this term.

Implements Xapian::PostingIterator::Internal.

Definition at line 30 of file emptypostlist.cc.

Xapian::weight EmptyPostList::get_weight

(

)

const [virtual]

Return the weight contribution for the current position.

Implements Xapian::PostingIterator::Internal.

Definition at line 67 of file emptypostlist.cc.

References Assert.

PostList * EmptyPostList::next

(

Xapian::weight

w_min

)

[virtual]

Advance the current position to the next document in the postlist.

The list starts before the first entry in the list, so next() must be called before any methods which need the context of the current position.

Parameters:

w_min

The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore).

Returns:

If a non-NULL pointer is returned, then the caller should substitute the returned pointer for its pointer to us, and then delete us. This "pruning" can only happen for a non-leaf subclass of this class.

Implements Xapian::PostingIterator::Internal.

Definition at line 86 of file emptypostlist.cc.

void EmptyPostList::operator=

(

const EmptyPostList &

)

[private]

Don't allow assignment.

Xapian::weight EmptyPostList::recalc_maxweight

(

)

[virtual]

Recalculate the upper bound on what get_weight() can return.

If the tree has pruned, get_maxweight() may use cached values. Calling this method instead forces a full recalculation.

Note that this method may be called after the postlist has reached the end. In this situation, the method should return 0.

Implements Xapian::PostingIterator::Internal.

Definition at line 80 of file emptypostlist.cc.

References get_maxweight().

PostList * EmptyPostList::skip_to	(	Xapian::docid	,
		Xapian::weight	w_min
	)			[virtual]

Skip forward to the specified docid.

If the specified docid isn't in the list, position ourselves on the first document after it (or at_end() if no greater docids are present).

Parameters:

w_min

The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore).

Returns:

If a non-NULL pointer is returned, then the caller should substitute the returned pointer for its pointer to us, and then delete us. This "pruning" can only happen for a non-leaf subclass of this class.

Implements Xapian::PostingIterator::Internal.

Definition at line 92 of file emptypostlist.cc.

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The documentation for this class was generated from the following files:

• common/emptypostlist.h
• api/emptypostlist.cc