MyOddPostingSource Class Reference

Inheritance diagram for MyOddPostingSource:

Collaboration diagram for MyOddPostingSource:

List of all members.

Public Member Functions

MyOddPostingSource (const Xapian::Database &db)

PostingSource * clone () const

Clone the posting source.

void init (const Xapian::Database &)

Set this PostingSource to the start of the list of postings.

Xapian::doccount get_termfreq_min () const

A lower bound on the number of documents this object can return.

Xapian::doccount get_termfreq_est () const

An estimate of the number of documents this object can return.

Xapian::doccount get_termfreq_max () const

An upper bound on the number of documents this object can return.

void next (Xapian::weight wt)

Advance the current position to the next matching document.

void skip_to (Xapian::docid to_did, Xapian::weight wt)

Advance to the specified docid.

bool at_end () const

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

Xapian::docid get_docid () const

Return the current docid.

string get_description () const

Return a string describing this object.

Private Member Functions

MyOddPostingSource (Xapian::doccount num_docs_, Xapian::doccount last_docid_)

Private Attributes

Xapian::doccount num_docs

Xapian::doccount last_docid

Xapian::docid did

Detailed Description

Definition at line 37 of file api_postingsource.cc.

Constructor & Destructor Documentation

MyOddPostingSource::MyOddPostingSource	(	Xapian::doccount	num_docs_,
		Xapian::doccount	last_docid_
	)			`[inline, private]`

Definition at line 44 of file api_postingsource.cc.

Referenced by clone().

MyOddPostingSource::MyOddPostingSource ( const Xapian::Database & db ) [inline]

Definition at line 50 of file api_postingsource.cc.

Member Function Documentation

bool MyOddPostingSource::at_end ( ) const [inline, virtual]

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

At least one of next(), skip_to() or check() will be called before this method is first called.

Implements Xapian::PostingSource.

Definition at line 77 of file api_postingsource.cc.

References did, and last_docid.

PostingSource* MyOddPostingSource::clone ( ) const [inline, virtual]

Clone the posting source.

The clone should inherit the configuration of the parent, but need not inherit the state. ie, the clone does not need to be in the same iteration position as the original: the matcher will always call init() on the clone before attempting to move the iterator, or read the information about the current position of the iterator.

This may return NULL to indicate that cloning is not supported. In this case, the PostingSource may only be used with a single-database search.

The default implementation returns NULL.

Note that the returned object will be deallocated by Xapian after use with "delete". If you want to handle the deletion in a special way (for example when wrapping the Xapian API for use from another language) then you can define a static operator delete method in your subclass as shown here: http://trac.xapian.org/ticket/554#comment:1

Reimplemented from Xapian::PostingSource.

Definition at line 54 of file api_postingsource.cc.

References last_docid, MyOddPostingSource(), and num_docs.

string MyOddPostingSource::get_description ( ) const [inline, virtual]

Return a string describing this object.

This default implementation returns a generic answer. This default it provided to avoid forcing those deriving their own PostingSource subclass from having to implement this (they may not care what get_description() gives for their subclass).

Reimplemented from Xapian::PostingSource.

Definition at line 84 of file api_postingsource.cc.

Xapian::docid MyOddPostingSource::get_docid ( ) const [inline, virtual]

Return the current docid.

This method may assume that it will only be called when there is a "current document". See get_weight() for details.

Note: in the case of a multi-database search, the returned docid should be in the single subdatabase relevant to this posting source. See the init() method for details.

Implements Xapian::PostingSource.

Definition at line 82 of file api_postingsource.cc.

References did.

Xapian::doccount MyOddPostingSource::get_termfreq_est ( ) const [inline, virtual]

An estimate of the number of documents this object can return.

It must always be true that:

get_termfreq_min() <= get_termfreq_est() <= get_termfreq_max()

Xapian will always call init() on a PostingSource before calling this for the first time.

Implements Xapian::PostingSource.

Definition at line 61 of file api_postingsource.cc.

References num_docs.

Xapian::doccount MyOddPostingSource::get_termfreq_max ( ) const [inline, virtual]

An upper bound on the number of documents this object can return.

Xapian will always call init() on a PostingSource before calling this for the first time.

Implements Xapian::PostingSource.

Definition at line 63 of file api_postingsource.cc.

References num_docs.

Xapian::doccount MyOddPostingSource::get_termfreq_min ( ) const [inline, virtual]

A lower bound on the number of documents this object can return.

Xapian will always call init() on a PostingSource before calling this for the first time.

Implements Xapian::PostingSource.

Definition at line 59 of file api_postingsource.cc.

void MyOddPostingSource::init ( const Xapian::Database & db ) [inline, virtual]

Set this PostingSource to the start of the list of postings.

This is called automatically by the matcher prior to each query being processed.

If a PostingSource is used for multiple searches, init() will therefore be called multiple times, and must handle this by using the database passed in the most recent call.

Parameters:

db

The database which the PostingSource should iterate through.

Note: the database supplied to this method must not be modified: in particular, the reopen() method should not be called on it.

Note: in the case of a multi-database search, a separate PostingSource will be used for each database (the separate PostingSources will be obtained using clone()), and each PostingSource will be passed one of the sub-databases as the db parameter here. The db parameter will therefore always refer to a single database. All docids passed to, or returned from, the PostingSource refer to docids in that single database, rather than in the multi-database.

Implements Xapian::PostingSource.

Definition at line 56 of file api_postingsource.cc.

References did.

void MyOddPostingSource::next ( Xapian::weight min_wt ) [inline, virtual]

Advance the current position to the next matching document.

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

Xapian will always call init() on a PostingSource before calling this for the first time.

Parameters:

min_wt

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

Implements Xapian::PostingSource.

Definition at line 65 of file api_postingsource.cc.

References did.

void MyOddPostingSource::skip_to	(	Xapian::docid	did,
		Xapian::weight	min_wt
	)			`[inline, virtual]`

Advance 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).

If the current position is already the specified docid, this method will leave the position unmodified.

If the specified docid is earlier than the current position, the behaviour is unspecified. A sensible behaviour would be to leave the current position unmodified, but it is also reasonable to move to the specified docid.

The default implementation calls next() repeatedly, which works but skip_to() can often be implemented much more efficiently.

Xapian will always call init() on a PostingSource before calling this for the first time.

Note: in the case of a multi-database search, the docid specified is the docid in the single subdatabase relevant to this posting source. See the init() method for details.

Parameters:

	did	The document id to advance to.
	min_wt	The minimum weight contribution that is needed (this is just a hint which subclasses may ignore).

Reimplemented from Xapian::PostingSource.

Definition at line 71 of file api_postingsource.cc.

References did.

Member Data Documentation

Xapian::docid MyOddPostingSource::did [private]

Definition at line 42 of file api_postingsource.cc.

Referenced by at_end(), get_docid(), init(), next(), and skip_to().

Xapian::doccount MyOddPostingSource::last_docid [private]

Definition at line 40 of file api_postingsource.cc.

Referenced by at_end(), and clone().

Xapian::doccount MyOddPostingSource::num_docs [private]

Definition at line 38 of file api_postingsource.cc.

Referenced by clone(), get_termfreq_est(), and get_termfreq_max().

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

tests/api_postingsource.cc


Public Member Functions
	MyOddPostingSource (const Xapian::Database &db)
PostingSource *	clone () const
	Clone the posting source.
void	init (const Xapian::Database &)
	Set this PostingSource to the start of the list of postings.
Xapian::doccount	get_termfreq_min () const
	A lower bound on the number of documents this object can return.
Xapian::doccount	get_termfreq_est () const
	An estimate of the number of documents this object can return.
Xapian::doccount	get_termfreq_max () const
	An upper bound on the number of documents this object can return.
void	next (Xapian::weight wt)
	Advance the current position to the next matching document.
void	skip_to (Xapian::docid to_did, Xapian::weight wt)
	Advance to the specified docid.
bool	at_end () const
	Return true if the current position is past the last entry in this list.
Xapian::docid	get_docid () const
	Return the current docid.
string	get_description () const
	Return a string describing this object.
Private Member Functions
	MyOddPostingSource (Xapian::doccount num_docs_, Xapian::doccount last_docid_)
Private Attributes
Xapian::doccount	num_docs
Xapian::doccount	last_docid
Xapian::docid	did