xapian-core  2.0.0
Public Member Functions | Private Member Functions | Private Attributes | List of all members
MyOddWeightingPostingSource Class Reference
+ Inheritance diagram for MyOddWeightingPostingSource:
+ Collaboration diagram for MyOddWeightingPostingSource:

Public Member Functions

 MyOddWeightingPostingSource (const Xapian::Database &db)
 
PostingSourceclone () const override
 Clone the posting source. More...
 
void init (const Xapian::Database &) override
 Older method which did the same job as reset(). More...
 
double get_weight () const override
 Return the weight contribution for the current document. More...
 
Xapian::doccount get_termfreq_min () const override
 A lower bound on the number of documents this object can return. More...
 
Xapian::doccount get_termfreq_est () const override
 An estimate of the number of documents this object can return. More...
 
Xapian::doccount get_termfreq_max () const override
 An upper bound on the number of documents this object can return. More...
 
void next (double wt) override
 Advance the current position to the next matching document. More...
 
void skip_to (Xapian::docid to_did, double wt) override
 Advance to the specified docid. More...
 
bool at_end () const override
 Return true if the current position is past the last entry in this list. More...
 
Xapian::docid get_docid () const override
 Return the current docid. More...
 
string get_description () const override
 Return a string describing this object. More...
 
- Public Member Functions inherited from Xapian::PostingSource
 PostingSource () noexcept
 Allow subclasses to be instantiated. More...
 
virtual ~PostingSource ()
 
void set_maxweight (double max_weight)
 Specify an upper bound on what get_weight() will return from now on. More...
 
double get_maxweight () const noexcept
 Return the currently set upper bound on what get_weight() can return. More...
 
virtual bool check (Xapian::docid did, double min_wt)
 Check if the specified docid occurs. More...
 
virtual std::string name () const
 Name of the posting source class. More...
 
virtual std::string serialise () const
 Serialise object parameters into a string. More...
 
virtual PostingSourceunserialise (const std::string &serialised) const
 Create object given string serialisation returned by serialise(). More...
 
virtual PostingSourceunserialise_with_registry (const std::string &serialised, const Registry &registry) const
 Create object given string serialisation returned by serialise(). More...
 
virtual void reset (const Database &db, Xapian::doccount shard_index)
 Set this PostingSource to the start of the list of postings. More...
 
PostingSourcerelease ()
 Start reference counting this object. More...
 
const PostingSourcerelease () const
 Start reference counting this object. More...
 
- Public Member Functions inherited from Xapian::Internal::opt_intrusive_base
 opt_intrusive_base (const opt_intrusive_base &)
 
opt_intrusive_baseoperator= (const opt_intrusive_base &)
 
 opt_intrusive_base ()
 Construct object which is initially not reference counted. More...
 
virtual ~opt_intrusive_base ()
 
void ref () const
 
void unref () const
 

Private Member Functions

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

Private Attributes

Xapian::doccount num_docs
 
Xapian::doccount last_docid
 
Xapian::docid did
 

Additional Inherited Members

- Public Attributes inherited from Xapian::Internal::opt_intrusive_base
unsigned _refs
 Reference count. More...
 
- Protected Member Functions inherited from Xapian::Internal::opt_intrusive_base
void release () const
 Start reference counting. More...
 

Detailed Description

Definition at line 138 of file api_postingsource.cc.

Constructor & Destructor Documentation

◆ MyOddWeightingPostingSource() [1/2]

MyOddWeightingPostingSource::MyOddWeightingPostingSource ( Xapian::doccount  num_docs_,
Xapian::doccount  last_docid_ 
)
inlineprivate

Definition at line 145 of file api_postingsource.cc.

◆ MyOddWeightingPostingSource() [2/2]

MyOddWeightingPostingSource::MyOddWeightingPostingSource ( const Xapian::Database db)
inline

Definition at line 153 of file api_postingsource.cc.

Member Function Documentation

◆ at_end()

bool MyOddWeightingPostingSource::at_end ( ) const
inlineoverridevirtual

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 186 of file api_postingsource.cc.

◆ clone()

PostingSource* MyOddWeightingPostingSource::clone ( ) const
inlineoverridevirtual

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 reset() 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: https://trac.xapian.org/ticket/554#comment:1

Reimplemented from Xapian::PostingSource.

Definition at line 157 of file api_postingsource.cc.

◆ get_description()

string MyOddWeightingPostingSource::get_description ( ) const
inlineoverridevirtual

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 193 of file api_postingsource.cc.

◆ get_docid()

Xapian::docid MyOddWeightingPostingSource::get_docid ( ) const
inlineoverridevirtual

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 reset() method for details.

Implements Xapian::PostingSource.

Definition at line 191 of file api_postingsource.cc.

◆ get_termfreq_est()

Xapian::doccount MyOddWeightingPostingSource::get_termfreq_est ( ) const
inlineoverridevirtual

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 reset() on a PostingSource before calling this for the first time.

Implements Xapian::PostingSource.

Definition at line 172 of file api_postingsource.cc.

◆ get_termfreq_max()

Xapian::doccount MyOddWeightingPostingSource::get_termfreq_max ( ) const
inlineoverridevirtual

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

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

Implements Xapian::PostingSource.

Definition at line 174 of file api_postingsource.cc.

◆ get_termfreq_min()

Xapian::doccount MyOddWeightingPostingSource::get_termfreq_min ( ) const
inlineoverridevirtual

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

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

Implements Xapian::PostingSource.

Definition at line 170 of file api_postingsource.cc.

◆ get_weight()

double MyOddWeightingPostingSource::get_weight ( ) const
inlineoverridevirtual

Return the weight contribution for the current document.

This default implementation always returns 0, for convenience when implementing "weight-less" PostingSource subclasses.

This method may assume that it will only be called when there is a "current document". In detail: Xapian will always call reset() on a PostingSource before calling this for the first time. It will also only call this if the PostingSource reports that it is pointing to a valid document (ie, it will not call it before calling at least one of next(), skip_to() or check(), and will ensure that the PostingSource is not at the end by calling at_end()).

Reimplemented from Xapian::PostingSource.

Definition at line 165 of file api_postingsource.cc.

◆ init()

void MyOddWeightingPostingSource::init ( const Xapian::Database db)
inlineoverridevirtual

Older method which did the same job as reset().

Prior to 2.0.0, instead of reset() there was a method called init() taking one parameter. The default implementation of reset() calls init() to allow existing subclasses to continue to work.

A default implementation of init() is provided so that new subclasses can just override reset() (the default implementation should not actually get called, and will throw Xapian::InvalidOperationError if it is).

Reimplemented from Xapian::PostingSource.

Definition at line 163 of file api_postingsource.cc.

◆ next()

void MyOddWeightingPostingSource::next ( double  min_wt)
inlineoverridevirtual

Advance the current position to the next matching document.

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

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

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

Implements Xapian::PostingSource.

Definition at line 176 of file api_postingsource.cc.

◆ skip_to()

void MyOddWeightingPostingSource::skip_to ( Xapian::docid  did,
double  min_wt 
)
inlineoverridevirtual

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 reset() 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 reset() method for details.

Parameters
didThe document id to advance to.
min_wtThe minimum weight contribution that is needed (this is just a hint which subclasses may ignore).

Reimplemented from Xapian::PostingSource.

Definition at line 181 of file api_postingsource.cc.

Member Data Documentation

◆ did

Xapian::docid MyOddWeightingPostingSource::did
private

Definition at line 143 of file api_postingsource.cc.

◆ last_docid

Xapian::doccount MyOddWeightingPostingSource::last_docid
private

Definition at line 141 of file api_postingsource.cc.

◆ num_docs

Xapian::doccount MyOddWeightingPostingSource::num_docs
private

Definition at line 139 of file api_postingsource.cc.


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