text: // string_map_internal.h
  
  
  /*    Copyright 2012 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.
   */
  
  namespace mongo {
  
      inline size_t StringMapDefaultHash::operator()( const StringData& key ) const {
          size_t mx = key.size();
          size_t hash = 7;
          for ( size_t i = 0; i < mx; i++ ) {
              hash += ( 517 * static_cast<int>(key[i]) );
              hash *= 13;
          }
          if ( hash == 0 )
              hash = -1;
          return hash;
      }
  
  
  }
  