ValueRangePostList Class Reference

#include <valuerangepostlist.h>

Inheritance diagram for ValueRangePostList:

[legend]Collaboration diagram for ValueRangePostList:


Public Member Functions
	ValueRangePostList (const Xapian::Database::Internal *db_, Xapian::valueno valno_, const std::string &begin_, const std::string &end_)
	~ValueRangePostList ()
Xapian::doccount	get_termfreq_min () const
	Get a lower 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::doccount	get_termfreq_max () const
	Get an upper bound on 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::weight	get_weight () const
	Return the weight contribution for the current position.
Xapian::doclength	get_doclength () const
	Return the length of current document.
Xapian::weight	recalc_maxweight ()
	Recalculate the upper bound on what get_weight() can return.
PositionList *	read_position_list ()
	Read the position list for the term in the current document and return a pointer to it (owned by the PostList).
PositionList *	open_position_list () const
	Read the position list for the term in the current document and return a pointer to it (not owned by the PostList).
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.
PostList *	check (Xapian::docid did, Xapian::weight w_min, bool &valid)
	Check if the specified docid occurs in this postlist.
bool	at_end () const
	Return true if the current position is past the last entry in this list.
string	get_description () const
	Return a string description of this object.
Protected Member Functions
	ValueRangePostList (const ValueRangePostList &)
	Disallow copying.
void	operator= (const ValueRangePostList &)
	Disallow assignment.
Protected Attributes
const Xapian::Database::Internal *	db
Xapian::valueno	valno
const std::string	begin
const std::string	end
Xapian::docid	current
Xapian::doccount	db_size
LeafPostList *	alldocs_pl

Detailed Description

Definition at line 27 of file valuerangepostlist.h.

Constructor & Destructor Documentation

ValueRangePostList::ValueRangePostList ( const ValueRangePostList & ) [protected]

Disallow copying.

ValueRangePostList::ValueRangePostList	(	const Xapian::Database::Internal *	db_,
		Xapian::valueno	valno_,
		const std::string &	begin_,
		const std::string &	end_
	)			`[inline]`

Definition at line 48 of file valuerangepostlist.h.

ValueRangePostList::~ValueRangePostList ( )

Definition at line 33 of file valuerangepostlist.cc.

References alldocs_pl.

Member Function Documentation

void ValueRangePostList::operator= ( const ValueRangePostList & ) [protected]

Disallow assignment.

Xapian::doccount ValueRangePostList::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 39 of file valuerangepostlist.cc.

Xapian::doccount ValueRangePostList::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 45 of file valuerangepostlist.cc.

References AssertParanoid, db, db_size, and Xapian::Database::Internal::get_doccount().

Xapian::doccount ValueRangePostList::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 54 of file valuerangepostlist.cc.

References AssertParanoid, db, db_size, and Xapian::Database::Internal::get_doccount().

Xapian::weight ValueRangePostList::get_maxweight ( ) const [virtual]

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

Implements Xapian::PostingIterator::Internal.

Definition at line 61 of file valuerangepostlist.cc.

Xapian::docid ValueRangePostList::get_docid ( ) const [virtual]

Return the current docid.

Implements Xapian::PostingIterator::Internal.

Definition at line 67 of file valuerangepostlist.cc.

References Assert, current, and db.

Xapian::weight ValueRangePostList::get_weight ( ) const [virtual]

Return the weight contribution for the current position.

Implements Xapian::PostingIterator::Internal.

Definition at line 75 of file valuerangepostlist.cc.

References Assert, and db.

Xapian::doclength ValueRangePostList::get_doclength ( ) const [virtual]

Return the length of current document.

Implements Xapian::PostingIterator::Internal.

Definition at line 82 of file valuerangepostlist.cc.

References Assert, and db.

Xapian::weight ValueRangePostList::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.

Implements Xapian::PostingIterator::Internal.

Definition at line 89 of file valuerangepostlist.cc.

References Assert, and db.

PositionList * ValueRangePostList::read_position_list ( ) [virtual]

Read the position list for the term in the current document and return a pointer to it (owned by the PostList).

The default implementation throws Xapian::UnimplementedError.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 96 of file valuerangepostlist.cc.

References Assert, and db.

PositionList * ValueRangePostList::open_position_list ( ) const [virtual]

Read the position list for the term in the current document and return a pointer to it (not owned by the PostList).

The default implementation throws Xapian::UnimplementedError.

Reimplemented from Xapian::PostingIterator::Internal.

Definition at line 103 of file valuerangepostlist.cc.

References Assert, and db.

PostList * ValueRangePostList::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.

Reimplemented in ValueGePostList.

Definition at line 110 of file valuerangepostlist.cc.

References alldocs_pl, Assert, Xapian::PostingIterator::Internal::at_end(), begin, current, db, end, Xapian::PostingIterator::Internal::get_docid(), Xapian::PostingIterator::Internal::next(), Xapian::Database::Internal::open_document(), Xapian::Database::Internal::open_post_list(), Xapian::PostingIterator::Internal::skip_to(), and valno.

PostList * ValueRangePostList::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.

Reimplemented in ValueGePostList.

Definition at line 127 of file valuerangepostlist.cc.

References Assert, current, db, and Xapian::PostingIterator::Internal::next().

PostList * ValueRangePostList::check	(	Xapian::docid	did,
		Xapian::weight	w_min,
		bool &	valid
	)			`[virtual]`

Check if the specified docid occurs in this postlist.

The caller is required to ensure that the specified docid actually exists in the database.

This method acts like skip_to() if that can be done at little extra cost, in which case it then sets valid to true.

Otherwise it simply checks if a particular docid is present. If it is, valid is set to true. If it isn't, it sets valid to false, and leaves the position unspecified (and hence the result of calling methods which depends on the current position, such as get_docid(), are also unspecified). In this state, next() will advance to the first matching position after docid, and skip_to() will act as it would if the position was the first matching position after docid.

The default implementation calls skip_to().

Reimplemented from Xapian::PostingIterator::Internal.

Reimplemented in ValueGePostList.

Definition at line 136 of file valuerangepostlist.cc.

References Assert, AssertRelParanoid, begin, current, db, end, Xapian::Database::Internal::get_lastdocid(), Xapian::Database::Internal::open_document(), and valno.