container.h

一个不错的fastdb使用例子

//-< CONTAINER.H >---------------------------------------------------*--------*
// FastDB                    Version 1.0         (c) 1999  GARRET    *     ?  *
// (Main Memory Database Management System)                          *   /\|  *
//                                                                   *  /  \  *
//                          Created:     05-Nov-2002  K.A. Knizhnik  * / [] \ *
//                          Last update: 05-Nov-2002  K.A. Knizhnik  * GARRET *
//-------------------------------------------------------------------*--------*
// T-Tree object container
//-------------------------------------------------------------------*--------*

#ifndef __CONTAINER_H__
#define __CONTAINER_H__

/**
 * Base class for all containers.
 * Container are implemented using T-Tree
 */

class FASTDB_DLL_ENTRY dbAnyContainer : public dbAnyReference
{

protected:
  dbFieldDescriptor* fd;

  void create(dbDatabase& db);
  void purge(dbDatabase& db);
  void free(dbDatabase& db);

  void add
    (dbDatabase& db, dbAnyReference const& ref);

  void remove
    (dbDatabase& db, dbAnyReference const& ref);

  int  search(dbAnyCursor& cursor, void const* from, void const* till);

  dbAnyContainer(char const* fieldName, dbTableDescriptor& desc);
};


/**
 * Template of container for particular table
 */

template<class T>

class dbContainer : public dbAnyContainer
{

public:
  /**
   * Search records matching search criteria (between, less or equal, great or equal)
   * @param cursor cursor to iterate through selected resords
   * @param from inclusive low bound for the search key, if <code>NULL</code> then there is no low bound
   * @param till inclusive high bound for the search key,  if <code>NULL</code> then there is no high bound
   * @return number of selected records
   */
  int search(dbCursor<T>& cursor, void const* from, void const* till)
  {
    return dbAnyContainer::search(cursor, from, till);
  }

  /**
   * Select records with sepcified value of the key
   * @param cursor cursor to iterate through selected resords
   * @param key searched value of the key
   * @return number of selected records
   */
  int search(dbCursor<T>& cursor, void const* key)
  {
    return dbAnyContainer::search(cursor, key, key);
  }

  /**
   * Select all records in the container
   * @param cursor cursor to iterate through selected resords
   * @return number of selected records
   */
  int search(dbCursor<T>& cursor)
  {
    return dbAnyContainer::search(cursor, NULL, NULL);
  }

  /**
   * Create new container.
   */
  void create()
  {
    dbAnyContainer::create(T::dbDescriptor.db);
  }

  /**
   * Clear the container
   */
  void purge()
  {
    dbAnyContainer::purge(T::dbDescriptor.db);
  }

  /**
   * Deallocate container
   */
  void free()
  {
    dbAnyContainer::free(T::dbDescriptor.db);
  }

  /**
   * Add new record to container
   * @param ref reference to the record added to the container
   */

  void add
    (dbReference<T> const& ref)
  {

    dbAnyContainer::add
      (T::dbDescriptor.db, ref);
  }

  /**
   * Remove record from the container
   * @param ref reference to the record deleted from the container
   */
  void remove
    (dbReference<T> const& ref)
  {

    dbAnyContainer::remove
      (T::dbDescriptor.db, ref);
  }

  /**
   * Constructor of the contanier reference
   * @param fieldName name of the key field used by container
   */
  dbContainer(const char* fieldName) : dbAnyContainer(fieldName, T::dbDescriptor)
{}

}

;

#endif