#include <enquire.h>
Inheritance diagram for Xapian::Weight:
Public Member Functions | |
| Weight () | |
| virtual | ~Weight () |
| Weight * | create (const Internal *internal_, Xapian::doclength querysize_, Xapian::termcount wqf_, const std::string &tname_) const |
| Create a new weight object of the same type as this and initialise it with the specified statistics. | |
| virtual std::string | name () const=0 |
| Name of the weighting scheme. | |
| virtual std::string | serialise () const=0 |
| Serialise object parameters into a string. | |
| virtual Weight * | unserialise (const std::string &s) const=0 |
| Create object given string serialisation returned by serialise(). | |
| virtual Xapian::weight | get_sumpart (Xapian::termcount wdf, Xapian::doclength len) const=0 |
| Get a weight which is part of the sum over terms being performed. | |
| virtual Xapian::weight | get_maxpart () const=0 |
| Gets the maximum value that get_sumpart() may return. | |
| virtual Xapian::weight | get_sumextra (Xapian::doclength len) const=0 |
| Get an extra weight for a document to add to the sum calculated over the query terms. | |
| virtual Xapian::weight | get_maxextra () const=0 |
| Gets the maximum value that get_sumextra() may return. | |
| virtual bool | get_sumpart_needs_doclength () const |
| return false if the weight object doesn't need doclength | |
Protected Member Functions | |
| Weight (const Weight &) | |
Protected Attributes | |
| const Internal * | internal |
| Xapian::doclength | querysize |
| Xapian::termcount | wqf |
| std::string | tname |
Private Member Functions | |
| void | operator= (Weight &) |
| virtual Weight * | clone () const=0 |
| Return a new weight object of this type. | |
Friends | |
| class | Enquire |
| class | ::RemoteServer |
| class | ::ScaleWeight |
Classes | |
| class | Internal |
| Class to hold statistics for a given collection. More... | |
Definition at line 1051 of file enquire.h.
| Xapian::Weight::Weight | ( | const Weight & | ) | [protected] |
| void Xapian::Weight::operator= | ( | Weight & | ) | [private] |
| virtual Weight* Xapian::Weight::clone | ( | ) | const [private, pure virtual] |
Return a new weight object of this type.
A subclass called FooWeight taking parameters param1 and param2 should implement this as:
virtual FooWeight * clone() const { return new FooWeight(param1, param2); }
Implemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Referenced by ScaleWeight::clone(), create(), RemoteServer::register_weighting_scheme(), and Xapian::Enquire::set_weighting_scheme().
| Weight * Xapian::Weight::create | ( | const Internal * | internal_, | |
| Xapian::doclength | querysize_, | |||
| Xapian::termcount | wqf_, | |||
| const std::string & | tname_ | |||
| ) | const |
Create a new weight object of the same type as this and initialise it with the specified statistics.
You shouldn't call this method yourself - it's called by Enquire.
| internal_ | Object to ask for collection statistics. | |
| querysize_ | Query size. | |
| wqf_ | Within query frequency of term this object is associated with. | |
| tname_ | Term which this object is associated with. |
Definition at line 34 of file weight.cc.
References clone(), internal, querysize, tname, and wqf.
Referenced by LocalSubMatch::postlist_from_op_leaf_query().
| virtual std::string Xapian::Weight::name | ( | ) | const [pure virtual] |
Name of the weighting scheme.
If the subclass is called FooWeight, this should return "Foo".
Implemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Referenced by Xapian::Enquire::Internal::get_mset(), RemoteServer::register_weighting_scheme(), and RemoteDatabase::set_query().
| virtual std::string Xapian::Weight::serialise | ( | ) | const [pure virtual] |
Serialise object parameters into a string.
Implemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Referenced by ScaleWeight::serialise(), and RemoteDatabase::set_query().
| virtual Weight* Xapian::Weight::unserialise | ( | const std::string & | s | ) | const [pure virtual] |
Create object given string serialisation returned by serialise().
Implemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Referenced by DEFINE_TESTCASE(), and ScaleWeight::unserialise().
| virtual Xapian::weight Xapian::Weight::get_sumpart | ( | Xapian::termcount | wdf, | |
| Xapian::doclength | len | |||
| ) | const [pure virtual] |
Get a weight which is part of the sum over terms being performed.
This returns a weight for a given term and document. These weights are summed to give a total weight for the document.
| wdf | the within document frequency of the term. | |
| len | the (unnormalised) document length. |
Implemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Referenced by ScaleWeight::get_sumpart(), and LeafPostList::get_weight().
| virtual Xapian::weight Xapian::Weight::get_maxpart | ( | ) | const [pure virtual] |
Gets the maximum value that get_sumpart() may return.
This is used in optimising searches, by having the postlist tree decay appropriately when parts of it can have limited, or no, further effect.
Implemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Referenced by ScaleWeight::get_maxpart(), and LeafPostList::get_maxweight().
| virtual Xapian::weight Xapian::Weight::get_sumextra | ( | Xapian::doclength | len | ) | const [pure virtual] |
Get an extra weight for a document to add to the sum calculated over the query terms.
This returns a weight for a given document, and is used by some weighting schemes to account for influence such as document length.
| len | the (unnormalised) document length. |
Implemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Referenced by ScaleWeight::get_sumextra(), and ExtraWeightPostList::get_weight().
| virtual Xapian::weight Xapian::Weight::get_maxextra | ( | ) | const [pure virtual] |
Gets the maximum value that get_sumextra() may return.
This is used in optimising searches.
Implemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Referenced by ScaleWeight::get_maxextra().
| bool Xapian::Weight::get_sumpart_needs_doclength | ( | ) | const [virtual] |
return false if the weight object doesn't need doclength
Reimplemented in Xapian::BoolWeight, Xapian::BM25Weight, Xapian::TradWeight, ScaleWeight, and MyWeight.
Definition at line 47 of file weight.cc.
Referenced by ScaleWeight::get_sumpart_needs_doclength(), and LeafPostList::set_termweight().
friend class ::RemoteServer [friend] |
friend class ::ScaleWeight [friend] |
const Internal* Xapian::Weight::internal [protected] |
Definition at line 1074 of file enquire.h.
Referenced by Xapian::TradWeight::calc_termweight(), Xapian::BM25Weight::calc_termweight(), and create().
Xapian::doclength Xapian::Weight::querysize [protected] |
Definition at line 1075 of file enquire.h.
Referenced by create(), Xapian::BM25Weight::get_maxextra(), and Xapian::BM25Weight::get_sumextra().
Xapian::termcount Xapian::Weight::wqf [protected] |
Definition at line 1076 of file enquire.h.
Referenced by Xapian::BM25Weight::calc_termweight(), and create().
std::string Xapian::Weight::tname [protected] |