1 files changed, 92 insertions, 0 deletions
diff --git a/src/mongo/util/embedded_builder.h b/src/mongo/util/embedded_builder.h
new file mode 100644
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+++ b/src/mongo/util/embedded_builder.h
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+// embedded_builder.h
+
+/*    Copyright 2009 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#pragma once
+
+namespace mongo {
+
+    // utility class for assembling hierarchical objects
+    class EmbeddedBuilder {
+    public:
+        EmbeddedBuilder( BSONObjBuilder *b ) {
+            _builders.push_back( make_pair( "", b ) );
+        }
+        // It is assumed that the calls to prepareContext will be made with the 'name'
+        // parameter in lex ascending order.
+        void prepareContext( string &name ) {
+            int i = 1, n = _builders.size();
+            while( i < n &&
+                    name.substr( 0, _builders[ i ].first.length() ) == _builders[ i ].first &&
+                    ( name[ _builders[i].first.length() ] == '.' || name[ _builders[i].first.length() ] == 0 )
+                 ) {
+                name = name.substr( _builders[ i ].first.length() + 1 );
+                ++i;
+            }
+            for( int j = n - 1; j >= i; --j ) {
+                popBuilder();
+            }
+            for( string next = splitDot( name ); !next.empty(); next = splitDot( name ) ) {
+                addBuilder( next );
+            }
+        }
+        void appendAs( const BSONElement &e, string name ) {
+            if ( e.type() == Object && e.valuesize() == 5 ) { // empty object -- this way we can add to it later
+                string dummyName = name + ".foo";
+                prepareContext( dummyName );
+                return;
+            }
+            prepareContext( name );
+            back()->appendAs( e, name );
+        }
+        BufBuilder &subarrayStartAs( string name ) {
+            prepareContext( name );
+            return back()->subarrayStart( name );
+        }
+        void done() {
+            while( ! _builderStorage.empty() )
+                popBuilder();
+        }
+
+        static string splitDot( string & str ) {
+            size_t pos = str.find( '.' );
+            if ( pos == string::npos )
+                return "";
+            string ret = str.substr( 0, pos );
+            str = str.substr( pos + 1 );
+            return ret;
+        }
+
+    private:
+        void addBuilder( const string &name ) {
+            shared_ptr< BSONObjBuilder > newBuilder( new BSONObjBuilder( back()->subobjStart( name ) ) );
+            _builders.push_back( make_pair( name, newBuilder.get() ) );
+            _builderStorage.push_back( newBuilder );
+        }
+        void popBuilder() {
+            back()->done();
+            _builders.pop_back();
+            _builderStorage.pop_back();
+        }
+
+        BSONObjBuilder *back() { return _builders.back().second; }
+
+        vector< pair< string, BSONObjBuilder * > > _builders;
+        vector< shared_ptr< BSONObjBuilder > > _builderStorage;
+
+    };
+
+} //namespace mongo