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/* clientcursor.h */
/**
* Copyright (C) 2008 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/* Cursor -- and its derived classes -- are our internal cursors.
ClientCursor is a wrapper that represents a cursorid from our database
application's perspective.
*/
#pragma once
#include "../stdafx.h"
namespace mongo {
typedef long long CursorId; /* passed to the client so it can send back on getMore */
class Cursor; /* internal server cursor base class */
class ClientCursor;
typedef map<CursorId, ClientCursor*> CCById;
extern CCById clientCursorsById;
class ClientCursor {
DiskLoc _lastLoc; // use getter and setter not this.
static CursorId allocCursorId();
public:
ClientCursor() : cursorid( allocCursorId() ), pos(0), idleAgeMillis(0) {
clientCursorsById.insert( make_pair(cursorid, this) );
}
~ClientCursor();
const CursorId cursorid;
string ns;
auto_ptr<JSMatcher> matcher;
auto_ptr<Cursor> c;
int pos; /* # objects into the cursor so far */
DiskLoc lastLoc() const {
return _lastLoc;
}
void setLastLoc(DiskLoc);
auto_ptr< set<string> > filter; // which fields query wants returned
Message originalMessage; // this is effectively an auto ptr for data the matcher points to
unsigned idleAgeMillis; // how long has the cursor been around, relative to server idle time
/* Get rid of cursors for namespaces that begin with nsprefix.
Used by drop, deleteIndexes, dropDatabase.
*/
static void invalidate(const char *nsPrefix);
static bool erase(CursorId id) {
ClientCursor *cc = find(id);
if ( cc ) {
delete cc;
return true;
}
return false;
}
static ClientCursor* find(CursorId id, bool warn = true) {
CCById::iterator it = clientCursorsById.find(id);
if ( it == clientCursorsById.end() ) {
if ( warn )
OCCASIONALLY out() << "ClientCursor::find(): cursor not found in map " << id << " (ok after a drop)\n";
return 0;
}
return it->second;
}
/* call when cursor's location changes so that we can update the
cursorsbylocation map. if you are locked and internally iterating, only
need to call when you are ready to "unlock".
*/
void updateLocation();
void cleanupByLocation(DiskLoc loc);
};
} // namespace mongo
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