diff options
Diffstat (limited to 'db/scanandorder.h')
| -rw-r--r-- | db/scanandorder.h | 168 |
1 files changed, 84 insertions, 84 deletions
diff --git a/db/scanandorder.h b/db/scanandorder.h index a3f2a613313..6a1619bae6f 100644 --- a/db/scanandorder.h +++ b/db/scanandorder.h @@ -63,92 +63,92 @@ inline bool fillQueryResultFromObj(BufBuilder& b, set<string> *filter, BSONObj& typedef multimap<BSONObj,BSONObj> BestMap; class ScanAndOrder { - BestMap best; // key -> full object - int startFrom; - int limit; // max to send back. - KeyType order; - int dir; - unsigned approxSize; - - void _add(BSONObj& k, BSONObj o) { - best.insert(make_pair(k,o)); - } - - // T may be iterator or reverse_iterator - void _addIfBetter(BSONObj& k, BSONObj o, BestMap::iterator i) { - const BSONObj& worstBestKey = i->first; - int c = worstBestKey.woCompare(k); - if( (c<0 && dir<0) || (c>0&&dir>0) ) { - // k is better, 'upgrade' - best.erase(i); - _add(k, o); - } - } + BestMap best; // key -> full object + int startFrom; + int limit; // max to send back. + KeyType order; + int dir; + unsigned approxSize; -public: - ScanAndOrder(int _startFrom, int _limit, BSONObj _order) : - startFrom(_startFrom), order(_order) { - limit = _limit > 0 ? _limit + startFrom : 0x7fffffff; - approxSize = 0; - - // todo: do order right for compound keys. this is temp. - dir = 1; - BSONElement e = order.pattern.firstElement(); - if( e.number() < 0 ) { - dir = -1; + void _add(BSONObj& k, BSONObj o) { + best.insert(make_pair(k,o)); } - } - - int size() const { return best.size(); } - - void add(BSONObj o) { - BSONObj k = order.getKeyFromObject(o); - if( (int) best.size() < limit ) { - approxSize += k.objsize(); - uassert( "too much key data for sort() with no index", approxSize < 1 * 1024 * 1024 ); - _add(k, o); - return; - } - BestMap::iterator i; - if( dir < 0 ) - i = best.begin(); - else { - assert( best.end() != best.begin() ); - i = best.end(); i--; + + // T may be iterator or reverse_iterator + void _addIfBetter(BSONObj& k, BSONObj o, BestMap::iterator i) { + const BSONObj& worstBestKey = i->first; + int c = worstBestKey.woCompare(k); + if( (c<0 && dir<0) || (c>0&&dir>0) ) { + // k is better, 'upgrade' + best.erase(i); + _add(k, o); + } } - _addIfBetter(k, o, i); - } - - template<class T> - void _fill(BufBuilder& b, set<string> *filter, int& nout, T begin, T end) { - int n = 0; - int nFilled = 0; - for( T i = begin; i != end; i++ ) { - n++; - if( n <= startFrom ) - continue; - BSONObj& o = i->second; - if( fillQueryResultFromObj(b, filter, o) ) { - nFilled++; - if( nFilled >= limit ) - goto done; - uassert( "too much data for sort() with no index", b.len() < 4000000 ); // appserver limit + +public: + ScanAndOrder(int _startFrom, int _limit, BSONObj _order) : + startFrom(_startFrom), order(_order) { + limit = _limit > 0 ? _limit + startFrom : 0x7fffffff; + approxSize = 0; + + // todo: do order right for compound keys. this is temp. + dir = 1; + BSONElement e = order.pattern.firstElement(); + if( e.number() < 0 ) { + dir = -1; + } } - } - done: - nout = nFilled; - } - - /* scanning complete. stick the query result in b for n objects. */ - void fill(BufBuilder& b, set<string> *filter, int& nout) { - // for( BestMap::iterator i = best.begin(); i != best.end(); i++ ) - // cout << " fill:" << i->first.toString() << endl; - // for( BestMap::reverse_iterator i = best.rbegin(); i != best.rend(); i++ ) - // cout << " fillr:" << i->first.toString() << endl; - if( dir > 0 ) - _fill(b, filter, nout, best.begin(), best.end()); - else - _fill(b, filter, nout, best.rbegin(), best.rend()); - } - + + int size() const { return best.size(); } + + void add(BSONObj o) { + BSONObj k = order.getKeyFromObject(o); + if( (int) best.size() < limit ) { + approxSize += k.objsize(); + uassert( "too much key data for sort() with no index", approxSize < 1 * 1024 * 1024 ); + _add(k, o); + return; + } + BestMap::iterator i; + if( dir < 0 ) + i = best.begin(); + else { + assert( best.end() != best.begin() ); + i = best.end(); i--; + } + _addIfBetter(k, o, i); + } + + template<class T> + void _fill(BufBuilder& b, set<string> *filter, int& nout, T begin, T end) { + int n = 0; + int nFilled = 0; + for( T i = begin; i != end; i++ ) { + n++; + if( n <= startFrom ) + continue; + BSONObj& o = i->second; + if( fillQueryResultFromObj(b, filter, o) ) { + nFilled++; + if( nFilled >= limit ) + goto done; + uassert( "too much data for sort() with no index", b.len() < 4000000 ); // appserver limit + } + } +done: + nout = nFilled; + } + + /* scanning complete. stick the query result in b for n objects. */ + void fill(BufBuilder& b, set<string> *filter, int& nout) { + // for( BestMap::iterator i = best.begin(); i != best.end(); i++ ) + // cout << " fill:" << i->first.toString() << endl; + // for( BestMap::reverse_iterator i = best.rbegin(); i != best.rend(); i++ ) + // cout << " fillr:" << i->first.toString() << endl; + if( dir > 0 ) + _fill(b, filter, nout, best.begin(), best.end()); + else + _fill(b, filter, nout, best.rbegin(), best.rend()); + } + }; |