SelectPostList Class Reference
A postlist parent class for classes which only return selected docs from a source postlist (e.g. More...
#include <selectpostlist.h>
Public Member Functions | |
| PostList * | next (Xapian::weight w_min) |
| Advance the current position to the next document in the postlist. | |
| PostList * | skip_to (Xapian::docid did, Xapian::weight w_min) |
| Skip forward to the specified docid. | |
| PostList * | check (Xapian::docid did, Xapian::weight w_min, bool &valid) |
| Check if the specified docid occurs in this postlist. | |
| Xapian::doccount | get_termfreq_max () const |
| Get an upper bound on the number of documents indexed by this term. | |
| Xapian::doccount | get_termfreq_min () const |
| Get a lower bound on the number of documents indexed by this term. | |
| Xapian::weight | get_maxweight () const |
| Return an upper bound on what get_weight() can return. | |
| Xapian::docid | get_docid () const |
| Return the current docid. | |
| Xapian::weight | get_weight () const |
| Return the weight contribution for the current position. | |
| Xapian::termcount | get_doclength () const |
| Return the length of current document. | |
| Xapian::weight | recalc_maxweight () |
| Recalculate the upper bound on what get_weight() can return. | |
| PositionList * | read_position_list () |
| Read the position list for the term in the current document and return a pointer to it (owned by the PostList). | |
| PositionList * | open_position_list () const |
| Read the position list for the term in the current document and return a pointer to it (not owned by the PostList). | |
| bool | at_end () const |
| Return true if the current position is past the last entry in this list. | |
| Xapian::termcount | count_matching_subqs () const |
| Count the number of leaf subqueries which match at the current position. | |
| std::string | get_description () const |
| Return a string description of this object. | |
| SelectPostList (PostList *source_) | |
| ~SelectPostList () | |
Protected Member Functions | |
| virtual bool | test_doc ()=0 |
| Subclasses should override test_doc() with a method which returns true if a document meets the appropriate criterion, false in not. | |
Protected Attributes | |
| PostList * | source |
Private Member Functions | |
| SelectPostList (const SelectPostList &) | |
| SelectPostList & | operator= (const SelectPostList &) |
Detailed Description
A postlist parent class for classes which only return selected docs from a source postlist (e.g.NEAR and PHRASE)
Definition at line 30 of file selectpostlist.h.
Constructor & Destructor Documentation
| SelectPostList::SelectPostList | ( | const SelectPostList & | ) | [private] |
| SelectPostList::SelectPostList | ( | PostList * | source_ | ) | [inline] |
Definition at line 66 of file selectpostlist.h.
| SelectPostList::~SelectPostList | ( | ) | [inline] |
Member Function Documentation
| bool SelectPostList::at_end | ( | ) | const [inline, virtual] |
Return true if the current position is past the last entry in this list.
Implements Xapian::PostingIterator::Internal.
Definition at line 58 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::at_end(), and source.
Referenced by PhrasePostList::do_test(), NearPostList::do_test(), PhrasePostList::test_doc(), NearPostList::test_doc(), and ExactPhrasePostList::test_doc().
| PostList * SelectPostList::check | ( | Xapian::docid | did, | |
| Xapian::weight | w_min, | |||
| bool & | valid | |||
| ) | [virtual] |
Check if the specified docid occurs in this postlist.
The caller is required to ensure that the specified docid actually exists in the database.
This method acts like skip_to() if that can be done at little extra cost, in which case it then sets valid to true.
Otherwise it simply checks if a particular docid is present. If it is, valid is set to true. If it isn't, it sets valid to false, and leaves the position unspecified (and hence the result of calling methods which depends on the current position, such as get_docid(), are also unspecified). In this state, next() will advance to the first matching position after docid, and skip_to() will act as it would if the position was the first matching position after docid.
The default implementation calls skip_to().
Reimplemented from Xapian::PostingIterator::Internal.
Definition at line 56 of file selectpostlist.cc.
References Assert, Xapian::PostingIterator::Internal::at_end(), Xapian::PostingIterator::Internal::check(), LOGCALL, RETURN, source, and test_doc().
| Xapian::termcount SelectPostList::count_matching_subqs | ( | ) | const [inline, virtual] |
Count the number of leaf subqueries which match at the current position.
Reimplemented from Xapian::PostingIterator::Internal.
Definition at line 60 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::count_matching_subqs(), and source.
| std::string SelectPostList::get_description | ( | ) | const [inline, virtual] |
Return a string description of this object.
Implements Xapian::PostingIterator::Internal.
Reimplemented in ExactPhrasePostList, NearPostList, and PhrasePostList.
Definition at line 71 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_description(), and source.
| Xapian::docid SelectPostList::get_docid | ( | ) | const [inline, virtual] |
Return the current docid.
Implements Xapian::PostingIterator::Internal.
Definition at line 52 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_docid(), and source.
Referenced by PhrasePostList::do_test(), NearPostList::do_test(), and skip_to().
| Xapian::termcount SelectPostList::get_doclength | ( | ) | const [inline, virtual] |
Return the length of current document.
Implements Xapian::PostingIterator::Internal.
Definition at line 54 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_doclength(), and source.
| Xapian::weight SelectPostList::get_maxweight | ( | ) | const [inline, virtual] |
Return an upper bound on what get_weight() can return.
Implements Xapian::PostingIterator::Internal.
Definition at line 51 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_maxweight(), and source.
| Xapian::doccount SelectPostList::get_termfreq_max | ( | ) | const [inline, virtual] |
Get an upper bound on the number of documents indexed by this term.
Implements Xapian::PostingIterator::Internal.
Definition at line 49 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_termfreq_max(), and source.
| Xapian::doccount SelectPostList::get_termfreq_min | ( | ) | const [inline, virtual] |
Get a lower bound on the number of documents indexed by this term.
Implements Xapian::PostingIterator::Internal.
Definition at line 50 of file selectpostlist.h.
| Xapian::weight SelectPostList::get_weight | ( | ) | const [inline, virtual] |
Return the weight contribution for the current position.
Implements Xapian::PostingIterator::Internal.
Definition at line 53 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_weight(), and source.
| PostList * SelectPostList::next | ( | Xapian::weight | w_min | ) | [virtual] |
Advance the current position to the next document in the postlist.
The list starts before the first entry in the list, so next() must be called before any methods which need the context of the current position.
- Parameters:
-
w_min The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore).
- Returns:
- If a non-NULL pointer is returned, then the caller should substitute the returned pointer for its pointer to us, and then delete us. This "pruning" can only happen for a non-leaf subclass of this class.
Implements Xapian::PostingIterator::Internal.
Definition at line 30 of file selectpostlist.cc.
References Assert, Xapian::PostingIterator::Internal::at_end(), LOGCALL, Xapian::PostingIterator::Internal::next(), RETURN, source, and test_doc().
| PositionList* SelectPostList::open_position_list | ( | ) | const [inline, virtual] |
Read the position list for the term in the current document and return a pointer to it (not owned by the PostList).
The default implementation throws Xapian::UnimplementedError.
Reimplemented from Xapian::PostingIterator::Internal.
Definition at line 57 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::open_position_list(), and source.
| SelectPostList& SelectPostList::operator= | ( | const SelectPostList & | ) | [private] |
| PositionList* SelectPostList::read_position_list | ( | ) | [inline, virtual] |
Read the position list for the term in the current document and return a pointer to it (owned by the PostList).
The default implementation throws Xapian::UnimplementedError.
Reimplemented from Xapian::PostingIterator::Internal.
Definition at line 56 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::read_position_list(), and source.
| Xapian::weight SelectPostList::recalc_maxweight | ( | ) | [inline, virtual] |
Recalculate the upper bound on what get_weight() can return.
If the tree has pruned, get_maxweight() may use cached values. Calling this method instead forces a full recalculation.
Note that this method may be called after the postlist has reached the end. In this situation, the method should return 0.
Implements Xapian::PostingIterator::Internal.
Definition at line 55 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::recalc_maxweight(), and source.
| PostList * SelectPostList::skip_to | ( | Xapian::docid | , | |
| Xapian::weight | w_min | |||
| ) | [virtual] |
Skip forward 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).
- Parameters:
-
w_min The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore).
- Returns:
- If a non-NULL pointer is returned, then the caller should substitute the returned pointer for its pointer to us, and then delete us. This "pruning" can only happen for a non-leaf subclass of this class.
Implements Xapian::PostingIterator::Internal.
Definition at line 42 of file selectpostlist.cc.
References Assert, Xapian::PostingIterator::Internal::at_end(), get_docid(), LOGCALL, Xapian::PostingIterator::Internal::next(), RETURN, Xapian::PostingIterator::Internal::skip_to(), source, and test_doc().
| virtual bool SelectPostList::test_doc | ( | ) | [protected, pure virtual] |
Subclasses should override test_doc() with a method which returns true if a document meets the appropriate criterion, false in not.
Implemented in ExactPhrasePostList, NearPostList, and PhrasePostList.
Member Data Documentation
PostList* SelectPostList::source [protected] |
Definition at line 37 of file selectpostlist.h.
Referenced by at_end(), check(), count_matching_subqs(), get_description(), PhrasePostList::get_description(), NearPostList::get_description(), ExactPhrasePostList::get_description(), get_docid(), get_doclength(), get_maxweight(), PhrasePostList::get_termfreq_est(), NearPostList::get_termfreq_est(), ExactPhrasePostList::get_termfreq_est(), PhrasePostList::get_termfreq_est_using_stats(), NearPostList::get_termfreq_est_using_stats(), ExactPhrasePostList::get_termfreq_est_using_stats(), get_termfreq_max(), get_weight(), next(), open_position_list(), read_position_list(), recalc_maxweight(), skip_to(), and ~SelectPostList().
The documentation for this class was generated from the following files:
- matcher/selectpostlist.h
- matcher/selectpostlist.cc