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121 lines
3.3 KiB
C++
121 lines
3.3 KiB
C++
// cursors.cpp
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/*
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* Copyright (C) 2010 10gen Inc.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License, version 3,
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "stdafx.h"
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#include "cursors.h"
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#include "../client/connpool.h"
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#include "../db/queryutil.h"
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namespace mongo {
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// -------- ShardedCursor -----------
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ShardedClientCursor::ShardedClientCursor( QueryMessage& q , ClusteredCursor * cursor ){
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assert( cursor );
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_cursor = cursor;
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_skip = q.ntoskip;
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_ntoreturn = q.ntoreturn;
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_totalSent = 0;
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_done = false;
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do {
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// TODO: only create _id when needed
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_id = security.getNonce();
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} while ( _id == 0 );
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}
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ShardedClientCursor::~ShardedClientCursor(){
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assert( _cursor );
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delete _cursor;
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_cursor = 0;
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}
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bool ShardedClientCursor::sendNextBatch( Request& r , int ntoreturn ){
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uassert( 10191 , "cursor already done" , ! _done );
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int maxSize = 1024 * 1024;
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if ( _totalSent > 0 )
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maxSize *= 3;
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BufBuilder b(32768);
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int num = 0;
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bool sendMore = true;
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while ( _cursor->more() ){
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BSONObj o = _cursor->next();
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b.append( (void*)o.objdata() , o.objsize() );
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num++;
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if ( b.len() > maxSize ){
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break;
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}
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if ( num == ntoreturn ){
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// soft limit aka batch size
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break;
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}
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if ( ntoreturn != 0 && ( -1 * num + _totalSent ) == ntoreturn ){
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// hard limit - total to send
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sendMore = false;
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break;
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}
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}
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bool hasMore = sendMore && _cursor->more();
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log(6) << "\t hasMore:" << hasMore << " wouldSendMoreIfHad: " << sendMore << " id:" << _id << " totalSent: " << _totalSent << endl;
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replyToQuery( 0 , r.p() , r.m() , b.buf() , b.len() , num , _totalSent , hasMore ? _id : 0 );
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_totalSent += num;
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_done = ! hasMore;
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return hasMore;
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}
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CursorCache::CursorCache(){
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}
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CursorCache::~CursorCache(){
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// TODO: delete old cursors?
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}
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ShardedClientCursor* CursorCache::get( long long id ){
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map<long long,ShardedClientCursor*>::iterator i = _cursors.find( id );
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if ( i == _cursors.end() ){
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OCCASIONALLY log() << "Sharded CursorCache missing cursor id: " << id << endl;
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return 0;
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}
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return i->second;
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}
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void CursorCache::store( ShardedClientCursor * cursor ){
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_cursors[cursor->getId()] = cursor;
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}
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void CursorCache::remove( long long id ){
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_cursors.erase( id );
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}
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CursorCache cursorCache;
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}
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