xapian-core
1.4.26
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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 (double w_min) |
Advance the current position to the next document in the postlist. More... | |
PostList * | skip_to (Xapian::docid did, double w_min) |
Skip forward to the specified docid. More... | |
PostList * | check (Xapian::docid did, double w_min, bool &valid) |
Check if the specified docid occurs in this postlist. More... | |
Xapian::doccount | get_termfreq_max () const |
Get an upper bound on the number of documents indexed by this term. More... | |
Xapian::doccount | get_termfreq_min () const |
Get a lower bound on the number of documents indexed by this term. More... | |
double | get_maxweight () const |
Return an upper bound on what get_weight() can return. More... | |
Xapian::docid | get_docid () const |
Return the current docid. More... | |
double | get_weight () const |
Return the weight contribution for the current position. More... | |
Xapian::termcount | get_doclength () const |
Return the length of current document. More... | |
Xapian::termcount | get_unique_terms () const |
Return the number of unique terms in the current document. More... | |
double | recalc_maxweight () |
Recalculate the upper bound on what get_weight() can return. More... | |
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). More... | |
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). More... | |
bool | at_end () const |
Return true if the current position is past the last entry in this list. More... | |
Xapian::termcount | count_matching_subqs () const |
Count the number of leaf subqueries which match at the current position. More... | |
std::string | get_description () const |
Return a string description of this object. More... | |
SelectPostList (PostList *source_) | |
~SelectPostList () | |
Public Member Functions inherited from Xapian::PostingIterator::Internal | |
virtual | ~Internal () |
We have virtual methods and want to be able to delete derived classes using a pointer to the base class, so we need a virtual destructor. More... | |
virtual Xapian::doccount | get_termfreq_est () const =0 |
Get an estimate of the number of documents indexed by this term. More... | |
virtual TermFreqs | get_termfreq_est_using_stats (const Xapian::Weight::Internal &stats) const |
Get an estimate for the termfreq and reltermfreq, given the stats. More... | |
virtual Xapian::termcount | get_wdf () const |
Return the wdf for the document at the current position. More... | |
virtual const std::string * | get_sort_key () const |
virtual const std::string * | get_collapse_key () const |
If the collapse key is already known, return it. More... | |
Internal * | next () |
Advance the current position to the next document in the postlist. More... | |
Internal * | skip_to (Xapian::docid did) |
Skip forward to the specified docid. More... | |
virtual void | gather_position_lists (OrPositionList *orposlist) |
Gather PositionList* objects for a subtree. More... | |
Public Member Functions inherited from Xapian::Internal::intrusive_base | |
intrusive_base () | |
Construct with no references. More... | |
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. More... | |
Protected Member Functions inherited from Xapian::PostingIterator::Internal | |
Internal () | |
Only constructable as a base class for derived classes. More... | |
Protected Attributes | |
PostList * | source |
double | wt |
Private Member Functions | |
SelectPostList (const SelectPostList &) | |
SelectPostList & | operator= (const SelectPostList &) |
bool | check_weight (double w_min) |
Additional Inherited Members | |
Public Attributes inherited from Xapian::Internal::intrusive_base | |
unsigned | _refs |
Reference count. More... | |
A postlist parent class for classes which only return selected docs from a source postlist (e.g.
NEAR and PHRASE)
Definition at line 31 of file selectpostlist.h.
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private |
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inlineexplicit |
Definition at line 77 of file selectpostlist.h.
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inline |
Definition at line 78 of file selectpostlist.h.
References source.
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inlinevirtual |
Return true if the current position is past the last entry in this list.
Implements Xapian::PostingIterator::Internal.
Definition at line 69 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::at_end().
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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 depend on the current position, such as get_docid() and at_end(), 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. If valid is set to false, then NULL must be returned (pruning in this situation doesn't make sense).
The default implementation calls skip_to().
Reimplemented from Xapian::PostingIterator::Internal.
Definition at line 62 of file selectpostlist.cc.
References Xapian::PostingIterator::Internal::at_end(), Xapian::PostingIterator::Internal::check(), check_weight(), LOGCALL, RETURN, source, test_doc(), and wt.
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inlineprivate |
Definition at line 37 of file selectpostlist.h.
References get_weight().
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inlinevirtual |
Count the number of leaf subqueries which match at the current position.
Reimplemented from Xapian::PostingIterator::Internal.
Definition at line 71 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::count_matching_subqs(), and get_description().
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inlinevirtual |
Return a string description of this object.
Implements Xapian::PostingIterator::Internal.
Definition at line 82 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_description(), and source.
Referenced by count_matching_subqs().
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inlinevirtual |
Return the current docid.
Implements Xapian::PostingIterator::Internal.
Definition at line 58 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_docid().
Referenced by skip_to().
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inlinevirtual |
Return the length of current document.
Implements Xapian::PostingIterator::Internal.
Definition at line 64 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_doclength().
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inlinevirtual |
Return an upper bound on what get_weight() can return.
Implements Xapian::PostingIterator::Internal.
Definition at line 57 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_maxweight().
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inlinevirtual |
Get an upper bound on the number of documents indexed by this term.
Implements Xapian::PostingIterator::Internal.
Definition at line 55 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_termfreq_max().
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inlinevirtual |
Get a lower bound on the number of documents indexed by this term.
Implements Xapian::PostingIterator::Internal.
Definition at line 56 of file selectpostlist.h.
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inlinevirtual |
Return the number of unique terms in the current document.
Implements Xapian::PostingIterator::Internal.
Definition at line 65 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_unique_terms().
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inlinevirtual |
Return the weight contribution for the current position.
Implements Xapian::PostingIterator::Internal.
Definition at line 59 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::get_weight(), and wt.
Referenced by check_weight().
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virtual |
Advance the current position to the next document in the postlist.
The list 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.
w_min | The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore). |
Implements Xapian::PostingIterator::Internal.
Definition at line 30 of file selectpostlist.cc.
References Xapian::PostingIterator::Internal::at_end(), check_weight(), LOGCALL, Xapian::PostingIterator::Internal::next(), RETURN, source, test_doc(), and wt.
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inlinevirtual |
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 68 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::open_position_list().
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private |
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inlinevirtual |
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 67 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::read_position_list().
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inlinevirtual |
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 66 of file selectpostlist.h.
References Xapian::PostingIterator::Internal::recalc_maxweight().
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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).
w_min | The minimum weight contribution that is needed (this is just a hint which PostList subclasses may ignore). |
Implements Xapian::PostingIterator::Internal.
Definition at line 45 of file selectpostlist.cc.
References Xapian::PostingIterator::Internal::at_end(), check_weight(), get_docid(), LOGCALL, Xapian::PostingIterator::Internal::next(), RETURN, Xapian::PostingIterator::Internal::skip_to(), source, test_doc(), and wt.
Referenced by NearPostList::test_doc(), PhrasePostList::test_doc(), and ExactPhrasePostList::test_doc().
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protectedpure 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, PhrasePostList, and NearPostList.
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protected |
Definition at line 42 of file selectpostlist.h.
Referenced by check(), NearPostList::get_description(), ExactPhrasePostList::get_description(), PhrasePostList::get_description(), get_description(), NearPostList::get_termfreq_est(), ExactPhrasePostList::get_termfreq_est(), PhrasePostList::get_termfreq_est(), NearPostList::get_termfreq_est_using_stats(), ExactPhrasePostList::get_termfreq_est_using_stats(), PhrasePostList::get_termfreq_est_using_stats(), next(), skip_to(), and ~SelectPostList().
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mutableprotected |
Definition at line 43 of file selectpostlist.h.
Referenced by check(), get_weight(), next(), and skip_to().