classxapian_1_1mset.tex

xapian 是一个“Xapian 是一个开源概率论信息检索库

\subsubsection[empty]{\setlength{\rightskip}{0pt plus 5cm}bool Xapian::MSet::empty () const}}
\label{classXapian_1_1MSet_fdd5c88361d0b83fc007a0aef92363b9}


Test if this \hyperlink{classXapian_1_1MSet}{MSet} is empty. 

\hypertarget{classXapian_1_1MSet_8fbd9cc68354f519f8773b35d121144b}{
\index{Xapian::MSet@{Xapian::MSet}!end@{end}}
\index{end@{end}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[end]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{classXapian_1_1MSetIterator}{MSet\-Iterator} Xapian::MSet::end () const}}
\label{classXapian_1_1MSet_8fbd9cc68354f519f8773b35d121144b}


End iterator corresponding to \hyperlink{classXapian_1_1MSet_4c5ef6da9fd73cede679081be26df41e}{begin()}. 

\hypertarget{classXapian_1_1MSet_fd639440abc4d569a48b8ff2a88c6e6a}{
\index{Xapian::MSet@{Xapian::MSet}!fetch@{fetch}}
\index{fetch@{fetch}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[fetch]{\setlength{\rightskip}{0pt plus 5cm}void Xapian::MSet::fetch () const}}
\label{classXapian_1_1MSet_fd639440abc4d569a48b8ff2a88c6e6a}


Fetch all the items in the \hyperlink{classXapian_1_1MSet}{MSet}. 

\hypertarget{classXapian_1_1MSet_367ce5b6d717042d9baf3c4285272add}{
\index{Xapian::MSet@{Xapian::MSet}!fetch@{fetch}}
\index{fetch@{fetch}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[fetch]{\setlength{\rightskip}{0pt plus 5cm}void Xapian::MSet::fetch (const \hyperlink{classXapian_1_1MSetIterator}{MSet\-Iterator} \& {\em item}) const}}
\label{classXapian_1_1MSet_367ce5b6d717042d9baf3c4285272add}


Fetch the single item specified. 

\hypertarget{classXapian_1_1MSet_52d96c2df7e63c3fd674e234c0a7c009}{
\index{Xapian::MSet@{Xapian::MSet}!fetch@{fetch}}
\index{fetch@{fetch}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[fetch]{\setlength{\rightskip}{0pt plus 5cm}void Xapian::MSet::fetch (const \hyperlink{classXapian_1_1MSetIterator}{MSet\-Iterator} \& {\em begin}, const \hyperlink{classXapian_1_1MSetIterator}{MSet\-Iterator} \& {\em end}) const}}
\label{classXapian_1_1MSet_52d96c2df7e63c3fd674e234c0a7c009}


Fetch the the document info for a set of items in the \hyperlink{classXapian_1_1MSet}{MSet}. 

This method causes the documents in the range specified by the iterators to be fetched from the database, and cached in the \hyperlink{classXapian_1_1MSet}{Xapian::MSet} object. This has little effect when performing a search across a local database, but will greatly speed up subsequent access to the document contents when the documents are stored in a remote database.

The iterators must be over this \hyperlink{classXapian_1_1MSet}{Xapian::MSet}: undefined behaviour will result otherwise.

\begin{Desc}
\item[Parameters:]
\begin{description}
\item[{\em begin}]\hyperlink{classXapian_1_1MSetIterator}{MSet\-Iterator} for first item to fetch. \item[{\em end}]\hyperlink{classXapian_1_1MSetIterator}{MSet\-Iterator} for item after last item to fetch. \end{description}
\end{Desc}
\hypertarget{classXapian_1_1MSet_78297ec3345af21e915eb061cddca80c}{
\index{Xapian::MSet@{Xapian::MSet}!get_description@{get\_\-description}}
\index{get_description@{get\_\-description}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-description]{\setlength{\rightskip}{0pt plus 5cm}std::string Xapian::MSet::get\_\-description () const}}
\label{classXapian_1_1MSet_78297ec3345af21e915eb061cddca80c}


Returns a string representing the mset. 

Introspection method. \hypertarget{classXapian_1_1MSet_a347db8d918c7e3b1f2f9e256807229f}{
\index{Xapian::MSet@{Xapian::MSet}!get_firstitem@{get\_\-firstitem}}
\index{get_firstitem@{get\_\-firstitem}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-firstitem]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_b4166dca4ac15d88c933bbb8e0d55d23}{Xapian::doccount} Xapian::MSet::get\_\-firstitem () const}}
\label{classXapian_1_1MSet_a347db8d918c7e3b1f2f9e256807229f}


The index of the first item in the result which was put into the \hyperlink{classXapian_1_1MSet}{MSet}. 

This corresponds to the parameter \char`\"{}first\char`\"{} specified in \hyperlink{classXapian_1_1Enquire_edb5fb761acc0bb2249bec375883a093}{Xapian::Enquire::get\_\-mset()}. A value of 0 corresponds to the highest result being the first item in the mset. \hypertarget{classXapian_1_1MSet_eab0a82126d9f2cf0ef5321549ea9775}{
\index{Xapian::MSet@{Xapian::MSet}!get_matches_estimated@{get\_\-matches\_\-estimated}}
\index{get_matches_estimated@{get\_\-matches\_\-estimated}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-matches\_\-estimated]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_b4166dca4ac15d88c933bbb8e0d55d23}{Xapian::doccount} Xapian::MSet::get\_\-matches\_\-estimated () const}}
\label{classXapian_1_1MSet_eab0a82126d9f2cf0ef5321549ea9775}


An estimate for the number of documents in the database which match the query. 

This figure takes into account collapsing of duplicates, and weighting cutoff values.

This value is returned because there is sometimes a request to display such information. However, our experience is that presenting this value to users causes them to worry about the large number of results, rather than how useful those at the top of the result set are, and is thus undesirable. \hypertarget{classXapian_1_1MSet_50eda0fe21978d088b66e63cfb074814}{
\index{Xapian::MSet@{Xapian::MSet}!get_matches_lower_bound@{get\_\-matches\_\-lower\_\-bound}}
\index{get_matches_lower_bound@{get\_\-matches\_\-lower\_\-bound}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-matches\_\-lower\_\-bound]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_b4166dca4ac15d88c933bbb8e0d55d23}{Xapian::doccount} Xapian::MSet::get\_\-matches\_\-lower\_\-bound () const}}
\label{classXapian_1_1MSet_50eda0fe21978d088b66e63cfb074814}


A lower bound on the number of documents in the database which match the query. 

This figure takes into account collapsing of duplicates, and weighting cutoff values.

This number is usually considerably less than the actual number of documents which match the query. \hypertarget{classXapian_1_1MSet_b7c924c5f2b7e8dee83e533f7a9a7308}{
\index{Xapian::MSet@{Xapian::MSet}!get_matches_upper_bound@{get\_\-matches\_\-upper\_\-bound}}
\index{get_matches_upper_bound@{get\_\-matches\_\-upper\_\-bound}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-matches\_\-upper\_\-bound]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_b4166dca4ac15d88c933bbb8e0d55d23}{Xapian::doccount} Xapian::MSet::get\_\-matches\_\-upper\_\-bound () const}}
\label{classXapian_1_1MSet_b7c924c5f2b7e8dee83e533f7a9a7308}


An upper bound on the number of documents in the database which match the query. 

This figure takes into account collapsing of duplicates, and weighting cutoff values.

This number is usually considerably greater than the actual number of documents which match the query. \hypertarget{classXapian_1_1MSet_8964042d7eeb9e908edd160d07768531}{
\index{Xapian::MSet@{Xapian::MSet}!get_max_attained@{get\_\-max\_\-attained}}
\index{get_max_attained@{get\_\-max\_\-attained}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-max\_\-attained]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_167860ee249b702eb746dca0d245f808}{Xapian::weight} Xapian::MSet::get\_\-max\_\-attained () const}}
\label{classXapian_1_1MSet_8964042d7eeb9e908edd160d07768531}


The greatest weight which is attained by any document in the database. 

If firstitem == 0, this is the weight of the first entry in items.

If no documents are found by the query, this will be 0.

Note that calculation of max\_\-attained requires calculation of at least one result item - therefore, if no items were requested when the query was performed (by specifying maxitems = 0 in \hyperlink{classXapian_1_1Enquire_edb5fb761acc0bb2249bec375883a093}{Xapian::Enquire::get\_\-mset()}), this value will be 0. \hypertarget{classXapian_1_1MSet_8317991625dc79949cd6ae52b6dcc920}{
\index{Xapian::MSet@{Xapian::MSet}!get_max_possible@{get\_\-max\_\-possible}}
\index{get_max_possible@{get\_\-max\_\-possible}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-max\_\-possible]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_167860ee249b702eb746dca0d245f808}{Xapian::weight} Xapian::MSet::get\_\-max\_\-possible () const}}
\label{classXapian_1_1MSet_8317991625dc79949cd6ae52b6dcc920}


The maximum possible weight in the mset. 

This weight is likely not to be attained in the set of results, but represents an upper bound on the weight which a document could attain for the given query. \hypertarget{classXapian_1_1MSet_8b53e97c924c671052f14f690061d0ea}{
\index{Xapian::MSet@{Xapian::MSet}!get_termfreq@{get\_\-termfreq}}
\index{get_termfreq@{get\_\-termfreq}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-termfreq]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_b4166dca4ac15d88c933bbb8e0d55d23}{Xapian::doccount} Xapian::MSet::get\_\-termfreq (const std::string \& {\em tname}) const}}
\label{classXapian_1_1MSet_8b53e97c924c671052f14f690061d0ea}


Return the term frequency of the given query term. 

\begin{Desc}
\item[Parameters:]
\begin{description}
\item[{\em tname}]The term to look for.\end{description}
\end{Desc}
\begin{Desc}
\item[Exceptions:]
\begin{description}
\item[{\em Xapian::Invalid\-Argument\-Error}]is thrown if the term was not in the query. \end{description}
\end{Desc}
\hypertarget{classXapian_1_1MSet_ab7d3fbad74151431e99659b4cd0a016}{
\index{Xapian::MSet@{Xapian::MSet}!get_termweight@{get\_\-termweight}}
\index{get_termweight@{get\_\-termweight}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[get\_\-termweight]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_167860ee249b702eb746dca0d245f808}{Xapian::weight} Xapian::MSet::get\_\-termweight (const std::string \& {\em tname}) const}}
\label{classXapian_1_1MSet_ab7d3fbad74151431e99659b4cd0a016}


Return the term weight of the given query term. 

\begin{Desc}
\item[Parameters:]
\begin{description}
\item[{\em tname}]The term to look for.\end{description}
\end{Desc}
\begin{Desc}
\item[Exceptions:]
\begin{description}
\item[{\em Xapian::Invalid\-Argument\-Error}]is thrown if the term was not in the query. \end{description}
\end{Desc}
\hypertarget{classXapian_1_1MSet_44c58632455ae84fb0464eb8c1bd3682}{
\index{Xapian::MSet@{Xapian::MSet}!max_size@{max\_\-size}}
\index{max_size@{max\_\-size}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[max\_\-size]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_b4166dca4ac15d88c933bbb8e0d55d23}{Xapian::doccount} Xapian::MSet::max\_\-size () const\hspace{0.3cm}{\tt  \mbox{[}inline\mbox{]}}}}
\label{classXapian_1_1MSet_44c58632455ae84fb0464eb8c1bd3682}


Required to allow use as an STL container. 

\hypertarget{classXapian_1_1MSet_9f4ba7407c17baa32ce9b3a7cd7d3f05}{
\index{Xapian::MSet@{Xapian::MSet}!operator=@{operator=}}
\index{operator=@{operator=}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[operator=]{\setlength{\rightskip}{0pt plus 5cm}void Xapian::MSet::operator= (const \hyperlink{classXapian_1_1MSet}{MSet} \& {\em other})}}
\label{classXapian_1_1MSet_9f4ba7407c17baa32ce9b3a7cd7d3f05}


Assignment is allowed (and is cheap). 

\hypertarget{classXapian_1_1MSet_e2da2d1b79ed814652b7c3b3781c2249}{
\index{Xapian::MSet@{Xapian::MSet}!operator[]@{operator[]}}
\index{operator[]@{operator[]}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[operator[]]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{classXapian_1_1MSetIterator}{MSet\-Iterator} Xapian::MSet::operator\mbox{[}$\,$\mbox{]} (\hyperlink{types_8h_b4166dca4ac15d88c933bbb8e0d55d23}{Xapian::doccount} {\em i}) const}}
\label{classXapian_1_1MSet_e2da2d1b79ed814652b7c3b3781c2249}


This returns the document at position i in this \hyperlink{classXapian_1_1MSet}{MSet} object. 

Note that this is not the same as the document at rank i in the query, unless the \char`\"{}first\char`\"{} parameter to \hyperlink{classXapian_1_1Enquire_edb5fb761acc0bb2249bec375883a093}{Xapian::Enquire::get\_\-mset} was 0. Rather, it is the document at rank i + first.

In other words, the offset is into the documents represented by this object, not into the set of documents matching the query. \hypertarget{classXapian_1_1MSet_3b050b4734ab96ea08b4f4b396b03ff9}{
\index{Xapian::MSet@{Xapian::MSet}!size@{size}}
\index{size@{size}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[size]{\setlength{\rightskip}{0pt plus 5cm}\hyperlink{types_8h_b4166dca4ac15d88c933bbb8e0d55d23}{Xapian::doccount} Xapian::MSet::size () const}}
\label{classXapian_1_1MSet_3b050b4734ab96ea08b4f4b396b03ff9}


The number of items in this \hyperlink{classXapian_1_1MSet}{MSet}. 

\hypertarget{classXapian_1_1MSet_8fa74c8d41283fae491f46c690a455cf}{
\index{Xapian::MSet@{Xapian::MSet}!swap@{swap}}
\index{swap@{swap}!Xapian::MSet@{Xapian::MSet}}
\subsubsection[swap]{\setlength{\rightskip}{0pt plus 5cm}void Xapian::MSet::swap (\hyperlink{classXapian_1_1MSet}{MSet} \& {\em other})}}
\label{classXapian_1_1MSet_8fa74c8d41283fae491f46c690a455cf}


Swap the \hyperlink{classXapian_1_1MSet}{MSet} we point to with another. 



The documentation for this class was generated from the following file:\begin{CompactItemize}
\item 
include/xapian/\hyperlink{enquire_8h}{enquire.h}\end{CompactItemize}