本文整理汇总了C++中BSONList类的典型用法代码示例。如果您正苦于以下问题：C++ BSONList类的具体用法？C++ BSONList怎么用？C++ BSONList使用的例子？那么, 这里精选的类代码示例或许可以为您提供帮助。
在下文中一共展示了BSONList类的4个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: finalReduce
/**
* Reduces a list of tuple object (key, value) to a single tuple {_id: key, value: val}
* Also applies a finalizer method if present.
*/
BSONObj JSReducer::finalReduce( const BSONList& tuples , Finalizer * finalizer ) {
BSONObj res;
BSONObj key;
if (tuples.size() == 1) {
// 1 obj, just use it
key = tuples[0];
BSONObjBuilder b(key.objsize());
BSONObjIterator it(key);
b.appendAs( it.next() , "_id" );
b.appendAs( it.next() , "value" );
res = b.obj();
}
else {
// need to reduce
int endSizeEstimate = 16;
_reduce( tuples , key , endSizeEstimate );
BSONObjBuilder b(endSizeEstimate);
b.appendAs( key.firstElement() , "_id" );
_func.scope()->append( b , "value" , "return" );
res = b.obj();
}
if ( finalizer ) {
res = finalizer->finalize( res );
}
return res;
}示例2: reduce
/**
* Reduces a list of tuple objects (key, value) to a single tuple {"0": key, "1": value}
*/
BSONObj JSReducer::reduce( const BSONList& tuples ) {
if (tuples.size() <= 1)
return tuples[0];
BSONObj key;
int endSizeEstimate = 16;
_reduce( tuples , key , endSizeEstimate );
BSONObjBuilder b(endSizeEstimate);
b.appendAs( key.firstElement() , "0" );
_func.scope()->append( b , "1" , "return" );
return b.obj();
}示例3: uassert
/**
* actually applies a reduce, to a list of tuples (key, value).
* After the call, tuples will hold a single tuple {"0": key, "1": value}
*/
void JSReducer::_reduce( const BSONList& tuples , BSONObj& key , int& endSizeEstimate ) {
uassert( 10074 , "need values" , tuples.size() );
int sizeEstimate = ( tuples.size() * tuples.begin()->getField( "value" ).size() ) + 128;
// need to build the reduce args: ( key, [values] )
BSONObjBuilder reduceArgs( sizeEstimate );
boost::scoped_ptr<BSONArrayBuilder> valueBuilder;
int sizeSoFar = 0;
unsigned n = 0;
for ( ; n<tuples.size(); n++ ) {
BSONObjIterator j(tuples[n]);
BSONElement keyE = j.next();
if ( n == 0 ) {
reduceArgs.append( keyE );
key = keyE.wrap();
sizeSoFar = 5 + keyE.size();
valueBuilder.reset(new BSONArrayBuilder( reduceArgs.subarrayStart( "tuples" ) ));
}
BSONElement ee = j.next();
uassert( 13070 , "value too large to reduce" , ee.size() < ( BSONObjMaxUserSize / 2 ) );
if ( sizeSoFar + ee.size() > BSONObjMaxUserSize ) {
assert( n > 1 ); // if not, inf. loop
break;
}
valueBuilder->append( ee );
sizeSoFar += ee.size();
}
assert(valueBuilder);
valueBuilder->done();
BSONObj args = reduceArgs.obj();
Scope * s = _func.scope();
s->invokeSafe( _func.func() , args );
if ( s->type( "return" ) == Array ) {
uasserted( 10075 , "reduce -> multiple not supported yet");
return;
}
endSizeEstimate = key.objsize() + ( args.objsize() / tuples.size() );
if ( n == tuples.size() )
return;
// the input list was too large, add the rest of elmts to new tuples and reduce again
// note: would be better to use loop instead of recursion to avoid stack overflow
BSONList x;
for ( ; n < tuples.size(); n++ ) {
x.push_back( tuples[n] );
}
BSONObjBuilder temp( endSizeEstimate );
temp.append( key.firstElement() );
s->append( temp , "1" , "return" );
x.push_back( temp.obj() );
_reduce( x , key , endSizeEstimate );
}示例4: run
bool run(const char *ns, BSONObj& cmdObj, string& errmsg, BSONObjBuilder& result, bool){
string dbname = cc().database()->name; // this has to come before dbtemprelease
dbtemprelease temprelease; // we don't touch the db directly
string shardedOutputCollection = cmdObj["shardedOutputCollection"].valuestrsafe();
MRSetup mr( dbname , cmdObj.firstElement().embeddedObjectUserCheck() , false );
set<ServerAndQuery> servers;
BSONObjBuilder shardCounts;
map<string,long long> counts;
BSONObj shards = cmdObj["shards"].embeddedObjectUserCheck();
vector< auto_ptr<DBClientCursor> > shardCursors;
BSONObjIterator i( shards );
while ( i.more() ){
BSONElement e = i.next();
string shard = e.fieldName();
BSONObj res = e.embeddedObjectUserCheck();
uassert( 10078 , "something bad happened" , shardedOutputCollection == res["result"].valuestrsafe() );
servers.insert( shard );
shardCounts.appendAs( res["counts"] , shard.c_str() );
BSONObjIterator j( res["counts"].embeddedObjectUserCheck() );
while ( j.more() ){
BSONElement temp = j.next();
counts[temp.fieldName()] += temp.numberLong();
}
}
BSONObj sortKey = BSON( "_id" << 1 );
ParallelSortClusteredCursor cursor( servers , dbname + "." + shardedOutputCollection ,
Query().sort( sortKey ) );
auto_ptr<Scope> s = globalScriptEngine->getPooledScope( ns );
ScriptingFunction reduceFunction = s->createFunction( mr.reduceCode.c_str() );
ScriptingFunction finalizeFunction = 0;
if ( mr.finalizeCode.size() )
finalizeFunction = s->createFunction( mr.finalizeCode.c_str() );
BSONList values;
result.append( "result" , mr.finalShort );
DBDirectClient db;
while ( cursor.more() ){
BSONObj t = cursor.next().getOwned();
if ( values.size() == 0 ){
values.push_back( t );
continue;
}
if ( t.woSortOrder( *(values.begin()) , sortKey ) == 0 ){
values.push_back( t );
continue;
}
db.insert( mr.tempLong , reduceValues( values , s.get() , reduceFunction , 1 , finalizeFunction ) );
values.clear();
values.push_back( t );
}
if ( values.size() )
db.insert( mr.tempLong , reduceValues( values , s.get() , reduceFunction , 1 , finalizeFunction ) );
long long finalCount = mr.renameIfNeeded( db );
log(0) << " mapreducefinishcommand " << mr.finalLong << " " << finalCount << endl;
for ( set<ServerAndQuery>::iterator i=servers.begin(); i!=servers.end(); i++ ){
ScopedDbConnection conn( i->_server );
conn->dropCollection( dbname + "." + shardedOutputCollection );
}
result.append( "shardCounts" , shardCounts.obj() );
{
BSONObjBuilder c;
for ( map<string,long long>::iterator i=counts.begin(); i!=counts.end(); i++ ){
c.append( i->first , i->second );
}
result.append( "counts" , c.obj() );
}
return 1;
}