starting FieldMatcher cleaning

3 files changed, 39 insertions, 5 deletions

diff --git a/db/query.h b/db/query.h
index 2b597fff9f3..e4ba08d33a9 100644
--- a/db/query.h
+++ b/db/query.h
@@ -293,7 +293,7 @@ namespace mongo {
             if ( fields.isEmpty() )
                 return;
             _fields.reset( new FieldMatcher() );
-            _fields->add( fields );
+            _fields->init( fields );
         }
 
         ParsedQuery( const ParsedQuery& other ){
diff --git a/db/queryutil.cpp b/db/queryutil.cpp
index 2b6322ecbc3..3500852f6a6 100644
--- a/db/queryutil.cpp
+++ b/db/queryutil.cpp
@@ -794,7 +794,7 @@ namespace mongo {
     // FieldMatcher //
     ///////////////////
     
-    void FieldMatcher::add( const BSONObj& o ){
+    void FieldMatcher::init( const BSONObj& o ){
         massert( 10371 , "can only add to FieldMatcher once", _source.isEmpty());
         _source = o;
 
@@ -854,7 +854,8 @@ namespace mongo {
     void FieldMatcher::add(const string& field, bool include){
         if (field.empty()){ // this is the field the user referred to
             _include = include;
-        } else {
+        } 
+        else {
             _include = !include;
 
             const size_t dot = field.find('.');
@@ -892,6 +893,15 @@ namespace mongo {
         return _source;
     }
 
+    BSONObj FieldMatcher::transform( const BSONObj& in ) const {
+        BSONObjBuilder b;
+        BSONObjIterator i(in);
+        while ( i.more() )
+            append( b , i.next() );
+        return b.obj();
+    }
+    
+
     //b will be the value part of an array-typed BSONElement
     void FieldMatcher::appendArray( BSONObjBuilder& b , const BSONObj& a , bool nested) const {
         int skip  = nested ?  0 : _skip;
diff --git a/db/queryutil.h b/db/queryutil.h
index e73c0c5d9c5..763cc7a6cd5 100644
--- a/db/queryutil.h
+++ b/db/queryutil.h
@@ -553,12 +553,35 @@ namespace mongo {
             , _limit(-1)
         {}
         
-        void add( const BSONObj& o );
+        /**
+         * called once per lifetime
+         */
+        void init( const BSONObj& spec );
+        
+        /**
+         * @return the spec init was called with
+         */
+        BSONObj getSpec() const;
 
+        /**
+         * appends e to b if user wants it
+         * will descend into e if needed
+         */
         void append( BSONObjBuilder& b , const BSONElement& e ) const;
 
-        BSONObj getSpec() const;
+
+        /**
+         * transforms in according to spec
+         * NOTE: this will stricy obey _id, which is not true 
+         *       for normal queries
+         */
+        BSONObj transform( const BSONObj& in ) const;
+
+        /**
+         * @return if _id should be returned
+         */
         bool includeID() { return _includeID; }
+
     private:
 
         void add( const string& field, bool include );
@@ -567,6 +590,7 @@ namespace mongo {
 
         bool _include; // true if default at this level is to include
         bool _special; // true if this level can't be skipped or included without recursing
+
         //TODO: benchmark vector<pair> vs map
         typedef map<string, boost::shared_ptr<FieldMatcher> > FieldMap;
         FieldMap _fields;