text: /*    Copyright 2012 10gen Inc.
   *
   *    This program is free software: you can redistribute it and/or  modify
   *    it under the terms of the GNU Affero General Public License, version 3,
   *    as published by the Free Software Foundation.
   *
   *    This program is distributed in the hope that it will be useful,
   *    but WITHOUT ANY WARRANTY; without even the implied warranty of
   *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *    GNU Affero General Public License for more details.
   *
   *    You should have received a copy of the GNU Affero General Public License
   *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
   *
   *    As a special exception, the copyright holders give permission to link the
   *    code of portions of this program with the OpenSSL library under certain
   *    conditions as described in each individual source file and distribute
   *    linked combinations including the program with the OpenSSL library. You
   *    must comply with the GNU Affero General Public License in all respects
   *    for all of the code used other than as permitted herein. If you modify
   *    file(s) with this exception, you may extend this exception to your
   *    version of the file(s), but you are not obligated to do so. If you do not
   *    wish to do so, delete this exception statement from your version. If you
   *    delete this exception statement from all source files in the program,
   *    then also delete it in the license file.
   */
  
  #pragma once
  
  #include <string>
  #include <vector>
  
  #include "mongol/base/disallow_copying.h"
  #include "mongol/base/string_data.h"
  #include "mongol/db/auth/authorization_manager.h"
  #include "mongol/db/auth/user.h"
  #include "mongol/db/auth/user_name.h"
  
  
  namespace mongol {
  
  /**
   * A collection of authenticated users.
   * This class does not do any locking/synchronization, the consumer will be responsible for
   * synchronizing access.
   */
  class UserSet {
      MONGO_DISALLOW_COPYING(UserSet);
  
  public:
      typedef std::vector<User*>::const_iterator iterator;
  
      UserSet();
      ~UserSet();
  
      /**
       * Adds a User to the UserSet.
       *
       * The UserSet does not take ownership of the User.
       *
       * As there can only be one user per database in the UserSet, if a User already exists for
       * the new User's database, the old user will be removed from the set and returned.  It is
       * the caller's responsibility to then release that user.  If no user already exists for the
       * new user's database, returns NULL.
       *
       * Invalidates any outstanding iterators or NameIterators.
       */
      User* add(User* user);
  
      /**
       * Replaces the user at "it" with "replacement."  Does not take ownership of the User.
       * Returns a pointer to the old user referenced by "it".  Does _not_ invalidate "iterator"
       * instances.
       */
      User* replaceAt(iterator it, User* replacement);
  
      /**
       * Removes the user at "it", and returns a pointer to it.  After this call, "it" remains
       * valid.  It will either equal "end()", or refer to some user between the values of "it"
       * and "end()" before this call was made.
       */
      User* removeAt(iterator it);
  
      /**
       * Removes the User whose authentication credentials came from dbname, and returns that
       * user.  It is the caller's responsibility to then release that user back to the
       * authorizationManger.  If no user exists for the given database, returns NULL;
       */
      User* removeByDBName(StringData dbname);
  
      // Returns the User with the given name, or NULL if not found.
      // Ownership of the returned User remains with the UserSet.  The pointer
      // returned is only guaranteed to remain valid until the next non-const method is called
      // on the UserSet.
      User* lookup(const UserName& name) const;
  
      // Gets the user whose authentication credentials came from dbname, or NULL if none
      // exist.  There should be at most one such user.
      User* lookupByDBName(StringData dbname) const;
  
      // Gets an iterator over the names of the users stored in the set.  The iterator is
      // valid until the next non-const method is called on the UserSet.
      UserNameIterator getNames() const;
  
      iterator begin() const {
          return _users.begin();
      }
      iterator end() const {
          return _usersEnd;
      }
  
  private:
      typedef std::vector<User*>::iterator mutable_iterator;
  
      mutable_iterator mbegin() {
          return _users.begin();
      }
      mutable_iterator mend() {
          return _usersEnd;
      }
  
      // The UserSet maintains ownership of the Users in it, and is responsible for
      // returning them to the AuthorizationManager when done with them.
      std::vector<User*> _users;
      std::vector<User*>::iterator _usersEnd;
  };
  
  }  // namespace mongol
  