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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