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Diffstat (limited to 'db/commands/group.cpp')
| -rw-r--r-- | db/commands/group.cpp | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/db/commands/group.cpp b/db/commands/group.cpp new file mode 100644 index 0000000..0cc6ab3 --- /dev/null +++ b/db/commands/group.cpp @@ -0,0 +1,202 @@ +// group.cpp + +/** +* +* 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/>. +*/ + +#include "pch.h" +#include "../commands.h" +#include "../instance.h" +#include "../queryoptimizer.h" + +namespace mongo { + + class GroupCommand : public Command { + public: + GroupCommand() : Command("group") {} + virtual LockType locktype() const { return READ; } + virtual bool slaveOk() const { return false; } + virtual bool slaveOverrideOk() { return true; } + virtual void help( stringstream &help ) const { + help << "http://www.mongodb.org/display/DOCS/Aggregation"; + } + + BSONObj getKey( const BSONObj& obj , const BSONObj& keyPattern , ScriptingFunction func , double avgSize , Scope * s ) { + if ( func ) { + BSONObjBuilder b( obj.objsize() + 32 ); + b.append( "0" , obj ); + int res = s->invoke( func , b.obj() ); + uassert( 10041 , (string)"invoke failed in $keyf: " + s->getError() , res == 0 ); + int type = s->type("return"); + uassert( 10042 , "return of $key has to be an object" , type == Object ); + return s->getObject( "return" ); + } + return obj.extractFields( keyPattern , true ); + } + + bool group( string realdbname , const string& ns , const BSONObj& query , + BSONObj keyPattern , string keyFunctionCode , string reduceCode , const char * reduceScope , + BSONObj initial , string finalize , + string& errmsg , BSONObjBuilder& result ) { + + + auto_ptr<Scope> s = globalScriptEngine->getPooledScope( realdbname ); + s->localConnect( realdbname.c_str() ); + + if ( reduceScope ) + s->init( reduceScope ); + + s->setObject( "$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 , $arr[n] ); " + "}" ); + + ScriptingFunction keyFunction = 0; + if ( keyFunctionCode.size() ) { + keyFunction = s->createFunction( keyFunctionCode.c_str() ); + } + + + double keysize = keyPattern.objsize() * 3; + double keynum = 1; + + map<BSONObj,int,BSONObjCmp> map; + list<BSONObj> blah; + + shared_ptr<Cursor> cursor = bestGuessCursor(ns.c_str() , query , BSONObj() ); + + while ( cursor->ok() ) { + if ( cursor->matcher() && ! cursor->matcher()->matchesCurrent( cursor.get() ) ) { + cursor->advance(); + continue; + } + + BSONObj obj = cursor->current(); + cursor->advance(); + + BSONObj key = getKey( obj , keyPattern , keyFunction , keysize / keynum , s.get() ); + keysize += key.objsize(); + keynum++; + + int& n = map[key]; + if ( n == 0 ) { + n = map.size(); + s->setObject( "$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 , BSONObj() , 0 , true ) ) { + throw UserException( 9010 , (string)"reduce invoke failed: " + s->getError() ); + } + } + + 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) " + " $arr[i] = ret; " + " } " + "}" ); + s->invoke( g , BSONObj() , 0 , true ); + } + + result.appendArray( "retval" , s->getObject( "$arr" ) ); + result.append( "count" , keynum - 1 ); + result.append( "keys" , (int)(map.size()) ); + s->exec( "$arr = [];" , "reduce setup 2" , false , true , true , 100 ); + s->gc(); + + return true; + } + + bool run(const string& dbname, BSONObj& jsobj, string& errmsg, BSONObjBuilder& result, bool fromRepl ) { + + /* db.$cmd.findOne( { group : <p> } ) */ + const BSONObj& p = jsobj.firstElement().embeddedObjectUserCheck(); + + BSONObj q; + if ( p["cond"].type() == Object ) + q = p["cond"].embeddedObject(); + else if ( p["condition"].type() == Object ) + q = p["condition"].embeddedObject(); + else + q = getQuery( p ); + + if ( p["ns"].type() != String ) { + errmsg = "ns has to be set"; + return false; + } + + string ns = dbname + "." + p["ns"].String(); + + BSONObj key; + string keyf; + if ( p["key"].type() == Object ) { + key = p["key"].embeddedObjectUserCheck(); + if ( ! p["$keyf"].eoo() ) { + errmsg = "can't have key and $keyf"; + return false; + } + } + else if ( p["$keyf"].type() ) { + keyf = p["$keyf"]._asCode(); + } + else { + // no key specified, will use entire object as key + } + + BSONElement reduce = p["$reduce"]; + if ( reduce.eoo() ) { + errmsg = "$reduce has to be set"; + return false; + } + + BSONElement initial = p["initial"]; + if ( initial.type() != Object ) { + errmsg = "initial has to be an object"; + return false; + } + + + string finalize; + if (p["finalize"].type()) + finalize = p["finalize"]._asCode(); + + return group( dbname , ns , q , + key , keyf , reduce._asCode() , reduce.type() != CodeWScope ? 0 : reduce.codeWScopeScopeData() , + initial.embeddedObject() , finalize , + errmsg , result ); + } + + } cmdGroup; + + +} // namespace mongo |