xapian-core  1.4.19
Public Member Functions | Private Member Functions | Private Attributes | List of all members
MyOddPostingSource Class Reference
+ Inheritance diagram for MyOddPostingSource:
+ Collaboration diagram for MyOddPostingSource:

Public Member Functions

 MyOddPostingSource (const Xapian::Database &db)
 
PostingSourceclone () const
 Clone the posting source. More...
 
void init (const Xapian::Database &)
 Set this PostingSource to the start of the list of postings. More...
 
Xapian::doccount get_termfreq_min () const
 A lower bound on the number of documents this object can return. More...
 
Xapian::doccount get_termfreq_est () const
 An estimate of the number of documents this object can return. More...
 
Xapian::doccount get_termfreq_max () const
 An upper bound on the number of documents this object can return. More...
 
void next (double wt)
 Advance the current position to the next matching document. More...
 
void skip_to (Xapian::docid to_did, double wt)
 Advance to the specified docid. More...
 
bool at_end () const
 Return true if the current position is past the last entry in this list. More...
 
Xapian::docid get_docid () const
 Return the current docid. More...
 
string get_description () const
 Return a string describing this object. More...
 
- Public Member Functions inherited from Xapian::PostingSource
 PostingSource ()
 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
 Return the currently set upper bound on what get_weight() can return. More...
 
virtual double get_weight () const
 Return the weight contribution for the current document. 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...
 
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

 MyOddPostingSource (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 39 of file api_postingsource.cc.

Constructor & Destructor Documentation

◆ MyOddPostingSource() [1/2]

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

Definition at line 46 of file api_postingsource.cc.

◆ MyOddPostingSource() [2/2]

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

Definition at line 52 of file api_postingsource.cc.

Member Function Documentation

◆ at_end()

bool MyOddPostingSource::at_end ( ) const
inlinevirtual

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 79 of file api_postingsource.cc.

◆ clone()

PostingSource* MyOddPostingSource::clone ( ) const
inlinevirtual

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

Reimplemented from Xapian::PostingSource.

Definition at line 56 of file api_postingsource.cc.

◆ get_description()

string MyOddPostingSource::get_description ( ) const
inlinevirtual

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 86 of file api_postingsource.cc.

◆ get_docid()

Xapian::docid MyOddPostingSource::get_docid ( ) const
inlinevirtual

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 84 of file api_postingsource.cc.

◆ get_termfreq_est()

Xapian::doccount MyOddPostingSource::get_termfreq_est ( ) const
inlinevirtual

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 63 of file api_postingsource.cc.

◆ get_termfreq_max()

Xapian::doccount MyOddPostingSource::get_termfreq_max ( ) const
inlinevirtual

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 65 of file api_postingsource.cc.

◆ get_termfreq_min()

Xapian::doccount MyOddPostingSource::get_termfreq_min ( ) const
inlinevirtual

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 61 of file api_postingsource.cc.

◆ init()

void MyOddPostingSource::init ( const Xapian::Database db)
inlinevirtual

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
dbThe database which the PostingSource should iterate through.

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 58 of file api_postingsource.cc.

◆ next()

void MyOddPostingSource::next ( double  min_wt)
inlinevirtual

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 init() 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 67 of file api_postingsource.cc.

◆ skip_to()

void MyOddPostingSource::skip_to ( Xapian::docid  did,
double  min_wt 
)
inlinevirtual

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
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 73 of file api_postingsource.cc.

Member Data Documentation

◆ did

Xapian::docid MyOddPostingSource::did
private

Definition at line 44 of file api_postingsource.cc.

◆ last_docid

Xapian::doccount MyOddPostingSource::last_docid
private

Definition at line 42 of file api_postingsource.cc.

◆ num_docs

Xapian::doccount MyOddPostingSource::num_docs
private

Definition at line 40 of file api_postingsource.cc.


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