bool group( string realdbname , const string& ns , const BSONObj& query ,
BSONObj keyPattern , string keyFunctionCode , string reduceCode , const char * reduceScope ,
BSONObj initial , string finalize ,
string& errmsg , BSONObjBuilder& result ) {
auto_ptr<Scope> s = globalScriptEngine->getPooledScope( realdbname );
s->localConnect( realdbname.c_str() );
if ( reduceScope )
s->init( reduceScope );
s->setObject( "$initial" , initial , true );
s->exec( "$reduce = " + reduceCode , "reduce setup" , false , true , true , 100 );
s->exec( "$arr = [];" , "reduce setup 2" , false , true , true , 100 );
ScriptingFunction f = s->createFunction(
"function(){ "
" if ( $arr[n] == null ){ "
" next = {}; "
" Object.extend( next , $key ); "
" Object.extend( next , $initial , true ); "
" $arr[n] = next; "
" next = null; "
" } "
" $reduce( obj , $arr[n] ); "
"}" );
ScriptingFunction keyFunction = 0;
if ( keyFunctionCode.size() ) {
keyFunction = s->createFunction( keyFunctionCode.c_str() );
}
double keysize = keyPattern.objsize() * 3;
double keynum = 1;
map<BSONObj,int,BSONObjCmp> map;
list<BSONObj> blah;
shared_ptr<Cursor> cursor = NamespaceDetailsTransient::getCursor(ns.c_str() , query);
ClientCursor::CleanupPointer ccPointer;
ccPointer.reset( new ClientCursor( QueryOption_NoCursorTimeout, cursor, ns ) );
while ( cursor->ok() ) {
if ( !ccPointer->yieldSometimes( ClientCursor::MaybeCovered ) ||
!cursor->ok() ) {
break;
}
if ( !cursor->currentMatches() || cursor->getsetdup( cursor->currLoc() ) ) {
cursor->advance();
continue;
}
if ( !ccPointer->yieldSometimes( ClientCursor::WillNeed ) ||
!cursor->ok() ) {
break;
}
BSONObj obj = cursor->current();
cursor->advance();
BSONObj key = getKey( obj , keyPattern , keyFunction , keysize / keynum , s.get() );
keysize += key.objsize();
keynum++;
int& n = map[key];
if ( n == 0 ) {
n = map.size();
s->setObject( "$key" , key , true );
uassert( 10043 , "group() can't handle more than 20000 unique keys" , n <= 20000 );
}
s->setObject( "obj" , obj , true );
s->setNumber( "n" , n - 1 );
if ( s->invoke( f , 0, 0 , 0 , true ) ) {
throw UserException( 9010 , (string)"reduce invoke failed: " + s->getError() );
}
}
ccPointer.reset();
if (!finalize.empty()) {
s->exec( "$finalize = " + finalize , "finalize define" , false , true , true , 100 );
ScriptingFunction g = s->createFunction(
"function(){ "
" for(var i=0; i < $arr.length; i++){ "
" var ret = $finalize($arr[i]); "
" if (ret !== undefined) "
" $arr[i] = ret; "
" } "
"}" );
s->invoke( g , 0, 0 , 0 , true );
}
result.appendArray( "retval" , s->getObject( "$arr" ) );
result.append( "count" , keynum - 1 );
result.append( "keys" , (int)(map.size()) );
s->exec( "$arr = [];" , "reduce setup 2" , false , true , true , 100 );
s->gc();
return true;
}
/**
* Run a query with a cursor provided by the query optimizer, or FindingStartCursor.
* @yields the db lock.
*/
const char *queryWithQueryOptimizer( Message &m, int queryOptions, const char *ns,
const BSONObj &jsobj, CurOp& curop,
const BSONObj &query, const BSONObj &order,
const shared_ptr<ParsedQuery> &pq_shared,
const BSONObj &oldPlan,
const ConfigVersion &shardingVersionAtStart,
Message &result ) {
const ParsedQuery &pq( *pq_shared );
shared_ptr<Cursor> cursor;
QueryPlanSummary queryPlan;
if ( pq.hasOption( QueryOption_OplogReplay ) ) {
cursor = FindingStartCursor::getCursor( ns, query, order );
}
else {
cursor =
NamespaceDetailsTransient::getCursor( ns, query, order, QueryPlanSelectionPolicy::any(),
0, pq_shared, &queryPlan );
}
verify( cursor );
QueryResponseBuilder queryResponseBuilder( pq, cursor, queryPlan, oldPlan );
bool saveClientCursor = false;
const char *exhaust = 0;
OpTime slaveReadTill;
ClientCursor::CleanupPointer ccPointer;
ccPointer.reset( new ClientCursor( QueryOption_NoCursorTimeout, cursor, ns ) );
for( ; cursor->ok(); cursor->advance() ) {
bool yielded = false;
if ( !ccPointer->yieldSometimes( ClientCursor::MaybeCovered, &yielded ) ||
!cursor->ok() ) {
cursor.reset();
queryResponseBuilder.noteYield();
// !!! TODO The queryResponseBuilder still holds cursor. Currently it will not do
// anything unsafe with the cursor in handoff(), but this is very fragile.
//
// We don't fail the query since we're fine with returning partial data if the
// collection was dropped.
// NOTE see SERVER-2454.
// TODO This is wrong. The cursor could be gone if the closeAllDatabases command
// just ran.
break;
}
if ( yielded ) {
queryResponseBuilder.noteYield();
}
if ( pq.getMaxScan() && cursor->nscanned() > pq.getMaxScan() ) {
break;
}
if ( !queryResponseBuilder.addMatch() ) {
continue;
}
// Note slave's position in the oplog.
if ( pq.hasOption( QueryOption_OplogReplay ) ) {
BSONObj current = cursor->current();
BSONElement e = current["ts"];
if ( e.type() == Date || e.type() == Timestamp ) {
slaveReadTill = e._opTime();
}
}
if ( !cursor->supportGetMore() || pq.isExplain() ) {
if ( queryResponseBuilder.enoughTotalResults() ) {
break;
}
}
else if ( queryResponseBuilder.enoughForFirstBatch() ) {
// if only 1 requested, no cursor saved for efficiency...we assume it is findOne()
if ( pq.wantMore() && pq.getNumToReturn() != 1 ) {
queryResponseBuilder.finishedFirstBatch();
if ( cursor->advance() ) {
saveClientCursor = true;
}
}
break;
}
}
if ( cursor ) {
if ( pq.hasOption( QueryOption_CursorTailable ) && pq.getNumToReturn() != 1 ) {
cursor->setTailable();
}
// If the tailing request succeeded.
if ( cursor->tailable() ) {
saveClientCursor = true;
}
}
if ( shardingState.getVersion( ns ) != shardingVersionAtStart ) {
// if the version changed during the query
// we might be missing some data
// and its safe to send this as mongos can resend
// at this point
throw SendStaleConfigException( ns , "version changed during initial query", shardingVersionAtStart, shardingState.getVersion( ns ) );
}
int nReturned = queryResponseBuilder.handoff( result );
ccPointer.reset();
long long cursorid = 0;
if ( saveClientCursor ) {
// Create a new ClientCursor, with a default timeout.
ccPointer.reset( new ClientCursor( queryOptions, cursor, ns,
jsobj.getOwned() ) );
cursorid = ccPointer->cursorid();
DEV tlog(2) << "query has more, cursorid: " << cursorid << endl;
if ( cursor->supportYields() ) {
ClientCursor::YieldData data;
ccPointer->prepareToYield( data );
}
else {
ccPointer->c()->noteLocation();
}
// !!! Save the original message buffer, so it can be referenced in getMore.
ccPointer->originalMessage = m;
// Save slave's position in the oplog.
if ( pq.hasOption( QueryOption_OplogReplay ) && !slaveReadTill.isNull() ) {
ccPointer->slaveReadTill( slaveReadTill );
}
if ( !ccPointer->ok() && ccPointer->c()->tailable() ) {
DEV tlog() << "query has no more but tailable, cursorid: " << cursorid << endl;
}
if( queryOptions & QueryOption_Exhaust ) {
exhaust = ns;
curop.debug().exhaust = true;
}
// Set attributes for getMore.
ccPointer->setChunkManager( queryResponseBuilder.chunkManager() );
ccPointer->setPos( nReturned );
ccPointer->pq = pq_shared;
ccPointer->fields = pq.getFieldPtr();
ccPointer.release();
}
QueryResult *qr = (QueryResult *) result.header();
qr->cursorId = cursorid;
curop.debug().cursorid = ( cursorid == 0 ? -1 : qr->cursorId );
qr->setResultFlagsToOk();
// qr->len is updated automatically by appendData()
curop.debug().responseLength = qr->len;
qr->setOperation(opReply);
qr->startingFrom = 0;
qr->nReturned = nReturned;
int duration = curop.elapsedMillis();
bool dbprofile = curop.shouldDBProfile( duration );
if ( dbprofile || duration >= cmdLine.slowMS ) {
curop.debug().nscanned = (int)( cursor ? cursor->nscanned() : 0 );
curop.debug().ntoskip = pq.getSkip();
}
curop.debug().nreturned = nReturned;
return exhaust;
}