$mod operator

6 files changed, 47 insertions, 2 deletions

diff --git a/db/jsobj.cpp b/db/jsobj.cpp
index bf44e9370cc..b872239310e 100644
--- a/db/jsobj.cpp
+++ b/db/jsobj.cpp
@@ -411,6 +411,8 @@ namespace mongo {
                 if ( fn[1] == 'n' && fn[3] == 0 )
                     return BSONObj::NE;
             }
+            else if ( fn[1] == 'm' && fn[2] == 'o' && fn[3] == 'd' && fn[4] == 0 )
+                return BSONObj::opMOD;
             else if ( fn[1] == 'i' && fn[2] == 'n' && fn[3] == 0 )
                 return BSONObj::opIN;
             else if ( fn[1] == 'n' && fn[2] == 'i' && fn[3] == 'n' && fn[4] == 0 )
diff --git a/db/jsobj.h b/db/jsobj.h
index 9fd2a1b88ec..711c539a2a7 100644
--- a/db/jsobj.h
+++ b/db/jsobj.h
@@ -901,6 +901,7 @@ namespace mongo {
             opALL = 0x0B,
             NIN = 0x0C,
             opEXISTS = 0x0D,
+            opMOD = 0x0E
         };        
     };
     ostream& operator<<( ostream &s, const BSONObj &o );
diff --git a/db/matcher.cpp b/db/matcher.cpp
index bc6792c7e67..fac352a1d60 100644
--- a/db/matcher.cpp
+++ b/db/matcher.cpp
@@ -246,6 +246,11 @@ namespace mongo {
                             basics.push_back( BasicMatcher( e , BSONObj::opIN , fe.embeddedObject() ) );
                             ok = true;
                         }
+                        else if ( fn[1] == 'm' && fn[2] == 'o' && fn[3] == 'd' && fn[4] == 0 && fe.type() == Array ) {
+                            // $mod
+                            basics.push_back( BasicMatcher( e , BSONObj::opMOD ) );
+                            ok = true;
+                        }
                         else if ( fn[1] == 'n' && fn[2] == 'i' && fn[3] == 'n' && fn[4] == 0 && fe.type() == Array ) {
                             // $nin
                             basics.push_back( BasicMatcher( e , BSONObj::NIN , fe.embeddedObject() ) );
@@ -315,7 +320,14 @@ namespace mongo {
             }
             return count == r.number();
         }
-                
+        
+        if ( op == BSONObj::opMOD ){
+            if ( ! l.isNumber() )
+                return false;
+            
+            return l.numberLong() % bm.mod == bm.modm;
+        }
+
         /* check LT, GTE, ... */
         if ( !( l.isNumber() && r.isNumber() ) && ( l.type() != r.type() ) )
             return false;
diff --git a/db/matcher.h b/db/matcher.h
index c814fe3c2cb..03b5b335845 100644
--- a/db/matcher.h
+++ b/db/matcher.h
@@ -57,9 +57,17 @@ namespace mongo {
         }
         
         BasicMatcher( BSONElement _e , int _op ) : toMatch( _e ) , compareOp( _op ){
+            if ( _op == BSONObj::opMOD ){
+                BSONObj o = _e.embeddedObject().firstElement().embeddedObject();
+                mod = o["0"].numberInt();
+                modm = o["1"].numberInt();
+                
+                uassert( "mod can't be 0" , mod );
+                uassert( "mod eq can't be 0" , modm );
+            }
         }
 
-
+        
         BasicMatcher( BSONElement _e , int _op , const BSONObj& array ) : toMatch( _e ) , compareOp( _op ){
             
             myset.reset( new set<BSONElement,element_lt>() );
@@ -74,6 +82,9 @@ namespace mongo {
         BSONElement toMatch;
         int compareOp;
         shared_ptr< set<BSONElement,element_lt> > myset;
+
+        int mod;
+        int modm;
     };
 
 // SQL where clause equivalent
diff --git a/db/queryutil.cpp b/db/queryutil.cpp
index 2f7a2acf79a..a4d44f9e965 100644
--- a/db/queryutil.cpp
+++ b/db/queryutil.cpp
@@ -65,6 +65,9 @@ namespace mongo {
             }
             break;
 	    }
+        case BSONObj::opMOD: {
+            break;
+        }
 	    case BSONObj::opIN: {
             massert( "$in requires array", e.type() == Array );
             BSONElement max = minKey.firstElement();
diff --git a/jstests/mod1.js b/jstests/mod1.js
new file mode 100644
index 00000000000..c77b5091e89
--- /dev/null
+++ b/jstests/mod1.js
@@ -0,0 +1,16 @@
+
+t = db.mod1;
+t.drop();
+
+t.save( { a : 1 } );
+t.save( { a : 2 } );
+t.save( { a : 11 } );
+
+assert.eq( 2 , t.find( "this.a % 10 == 1" ).itcount() , "A" );
+assert.eq( 2 , t.find( { a : { $mod : [ 10 , 1 ] } } ).itcount() , "B" );
+
+t.ensureIndex( { a : 1 } );
+
+assert.eq( 2 , t.find( "this.a % 10 == 1" ).itcount() , "C" );
+assert.eq( 2 , t.find( { a : { $mod : [ 10 , 1 ] } } ).itcount() , "D" );
+