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//
// WordCursorOne.h
//
// NAME
//
// search and retrieve entries in a WordListOne object.
//
// SYNOPSIS
//
// #include <WordList.h>
//
// int callback(WordList *, WordDBCursor& , const WordReference *, Object &)
// {
// ...
// }
//
// Object* data = ...
//
// WordList *words = ...;
//
// WordCursor *search = words->Cursor(callback, data);
// WordCursor *search = words->Cursor(WordKey("word <UNDEF> <UNDEF>"));
// WordCursor *search = words->Cursor(WordKey("word <UNDEF> <UNDEF>"), callback, data);
// WordCursor *search = words->Cursor(WordKey());
//
// ...
//
// if(search->Walk() == NOTOK) bark;
// List* results = search->GetResults();
//
// search->WalkInit();
// if(search->WalkNext() == OK)
// dosomething(search->GetFound());
// search->WalkFinish();
//
// DESCRIPTION
//
// WordCursorOne is a WordCursor derived class that implements search
// in a WordListOne object. It currently is the only derived class of
// the WordCursor object. Most of its behaviour is described in the
// WordCursor manual page, only the behaviour specific to WordCursorOne
// is documented here.
//
//
// END
//
// Part of the ht://Dig package <http://www.htdig.org/>
// Copyright (c) 1999-2004 The ht://Dig Group
// For copyright details, see the file COPYING in your distribution
// or the GNU Library General Public License (LGPL) version 2 or later
// <http://www.gnu.org/copyleft/lgpl.html>
//
// $Id: WordCursorOne.h,v 1.4 2004/05/28 13:15:26 lha Exp $
//
#ifndef _WordCursorOne_h_
#define _WordCursorOne_h_
#ifndef SWIG
#include "htString.h"
#include "WordKey.h"
#include "WordDB.h"
#include "WordCursor.h"
class WordList;
class WordDBCursor;
#endif /* SWIG */
class WordCursorOne : public WordCursor
{
public:
#ifndef SWIG
//-
// Private constructor. Creator of the object must then call Initialize()
// prior to using any other methods.
//
WordCursorOne(WordList *words);
//-
// Private constructor. See WordList::Cursor method with same prototype for
// description.
//
WordCursorOne(WordList *words, wordlist_walk_callback_t callback, Object * callback_data);
//-
// Private constructor. See WordList::Cursor method with same prototype for
// description.
//
WordCursorOne(WordList *words, const WordKey &searchKey, int action = HTDIG_WORDLIST_WALKER);
//-
// Private constructor. See WordList::Cursor method with same prototype for
// description.
//
WordCursorOne(WordList *words, const WordKey &searchKey, wordlist_walk_callback_t callback, Object * callback_data);
#endif /* SWIG */
virtual ~WordCursorOne() {
if(cursor) delete cursor;
}
virtual void Clear();
virtual void ClearInternal();
virtual void ClearResult();
virtual inline int ContextSave(String& buffer) const { found.Get(buffer); return OK; }
virtual int ContextRestore(const String& buffer);
#ifndef SWIG
virtual int Walk();
#endif /* SWIG */
virtual int WalkInit();
virtual int WalkRewind();
virtual int WalkNext();
#ifndef SWIG
virtual int WalkNextStep();
#endif /* SWIG */
virtual int WalkFinish();
//
// Find out if cursor should better jump to the next possible key
// (DB_SET_RANGE) instead of sequential iterating (DB_NEXT). If it
// is decided that jump is a better move : cursor_set_flags =
// DB_SET_RANGE key = calculated next possible key Else do nothing
// Return OK if skipping successfull. Returns WORD_WALK_ATEND if no
// more possible match, reached the maximum. Returns
// WORD_WALK_FAILED on general failure, occurs if called and no
// skipping necessary.
//
int SkipUselessSequentialWalking();
virtual int Seek(const WordKey& patch);
#ifndef SWIG
virtual int Get(String& bufferout) const;
inline String Get() const { String tmp; Get(tmp); return tmp; }
protected:
int Initialize(WordList *nwords, const WordKey &nsearchKey, wordlist_walk_callback_t ncallback, Object * ncallback_data, int naction);
//
// Internal state
//
//
// The actual Berkeley DB cursor.
//
WordDBCursor* cursor;
//
// The latest retrieved key and data
//
String key;
String data;
//
// The shorted prefix key computed from searchKey
//
WordKey prefixKey;
//
// WalkNext leap is either DB_NEXT or DB_SET_RANGE.
//
int cursor_get_flags;
//
// True if search key is a prefix key
//
int searchKeyIsSameAsPrefix;
#endif /* SWIG */
};
#endif /* _WordCursorOne_h_ */
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