MyDontAskWeightPostingSource Class Reference
Public Member Functions | |
| MyDontAskWeightPostingSource () | |
| PostingSource * | clone () const |
| Clone the posting source. | |
| void | init (const Xapian::Database &db) |
| Set this PostingSource to the start of the list of postings. | |
| Xapian::weight | get_weight () const |
| Return the weight contribution for the current document. | |
| 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 | |
| MyDontAskWeightPostingSource (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 245 of file api_postingsource.cc.
Constructor & Destructor Documentation
| MyDontAskWeightPostingSource::MyDontAskWeightPostingSource | ( | Xapian::doccount | num_docs_, | |
| Xapian::doccount | last_docid_ | |||
| ) | [inline, private] |
Definition at line 252 of file api_postingsource.cc.
| MyDontAskWeightPostingSource::MyDontAskWeightPostingSource | ( | ) | [inline] |
Member Function Documentation
| bool MyDontAskWeightPostingSource::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 289 of file api_postingsource.cc.
References did, and last_docid.
| PostingSource* MyDontAskWeightPostingSource::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 260 of file api_postingsource.cc.
References last_docid, MyDontAskWeightPostingSource(), and num_docs.
| string MyDontAskWeightPostingSource::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 296 of file api_postingsource.cc.
| Xapian::docid MyDontAskWeightPostingSource::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 294 of file api_postingsource.cc.
References did.
| Xapian::doccount MyDontAskWeightPostingSource::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 275 of file api_postingsource.cc.
References num_docs.
| Xapian::doccount MyDontAskWeightPostingSource::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 277 of file api_postingsource.cc.
References num_docs.
| Xapian::doccount MyDontAskWeightPostingSource::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 273 of file api_postingsource.cc.
References num_docs.
| Xapian::weight MyDontAskWeightPostingSource::get_weight | ( | ) | const [inline, virtual] |
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 init() 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 268 of file api_postingsource.cc.
References FAIL_TEST.
| void MyDontAskWeightPostingSource::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: 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 262 of file api_postingsource.cc.
References did, Xapian::Database::get_doccount(), Xapian::Database::get_lastdocid(), last_docid, and num_docs.
| void MyDontAskWeightPostingSource::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 279 of file api_postingsource.cc.
References did.
| void MyDontAskWeightPostingSource::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 284 of file api_postingsource.cc.
References did.
Member Data Documentation
Definition at line 250 of file api_postingsource.cc.
Referenced by at_end(), get_docid(), init(), next(), and skip_to().
Definition at line 246 of file api_postingsource.cc.
Referenced by clone(), get_termfreq_est(), get_termfreq_max(), get_termfreq_min(), and init().
The documentation for this class was generated from the following file:
- tests/api_postingsource.cc