[Ericsson AB]

3 IDL Specification of Mnesia (CORBA) Session

3.1 mnesia_session.idl

// ``The contents of this file are subject to the Erlang Public License,
// Version 1.1, (the "License"); you may not use this file except in
// compliance with the License. You should have received a copy of the
// Erlang Public License along with this software. If not, it can be
// retrieved via the world wide web at http://www.erlang.org/.
// 
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
// the License for the specific language governing rights and limitations
// under the License.
// 
// The Initial Developer of the Original Code is Ericsson Utvecklings AB.
// Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings
// AB. All Rights Reserved.''
// 
//     $Id$
//
//////////////////////////////////////////////////////////////////
// Mnesia Session - IDL interface to Mnesia
//////////////////////////////////////////////////////////////////

#include <erlang.idl>

// All types are enclosed by the mnesia module

module mnesia
{
  ///////////////////////////////////////////////////////////////
  // Status - a general type for keeping track of
  // the outcome of the session related functions.

  enum Status
  {
    // Success codes:
    
    ok,            // The operation was successful and
                   // the all out parameters except 'reason'
                   // contains valid data.

    end_of_table,  // End of table has been reached.
                   // This return code is only used by
                   // a few functions, such as dirty_slot/4,
                   // dirty_first/3, dirty_next/4 ...

    // Failure codes:
  
    timeout,     // This return code is only used by
                 // wait_for_table.

    error        // Miscellaneous error.
                 // Operation did not succeed and the out
                 // parameter 'reason' contains a description
                 // of the error. The other out parameters
                 // contains garbage.
        
   // In future releases we will probably expand this enum
   // with more precise error codes like no_exists, badarg etc.
  };

  // Record - an erlang record, i.e. a tagged tuple with the
  // following layout: {tab_name, key, attr_1, ... attr_N}

  typedef erlang::term Record;  
  typedef sequence <Record> Recordlist;

  // TableName - a name of a table. Note that the character '_' 
  // should be avoided if the table is intended to be used
  // via the Corba Session.

  typedef string TableName;
  typedef sequence <TableName> TableList;

  // Key - a key of a record

  typedef erlang::term Key;  
  typedef sequence <Key> KeyList;

  // Indecies - list of index positions.
  // In the sample record above, attr_1 has position 3

  typedef sequence <long> Indices;

  // AttrNames - a list of attribute names

  typedef sequence <string> AttrNames;

  // RecordName - Type information
  
  typedef string RecordName;

  // Node - an Erlang node, e.g. "name1@host[.org.country]"

  typedef string Node;
  typedef sequence <Node> NodeList;  

  // Storage - table storage type

  enum Storage {ram_copies, disc_copies, disc_only_copies};

  // SetOrBag - table type

  enum SetOrBag {set, bag};

  // AccessMode - controls the accessibility of a table

  enum AccessMode {read_only, read_write};

  // Checkpoints - a list of checkpoint names

  typedef sequence <string> Checkpoints;

  ///////////////////////////////////////////////////////////////
  // TableDef - initial specification of a table

  struct TableDef
  {
    SetOrBag type;
    AccessMode mode;
    NodeList ram_copies;
    NodeList disc_copies;
    NodeList disc_only_copies;
    Indices index_list;
    AttrNames attributes;
    RecordName record_name;  
  };

  ///////////////////////////////////////////////////////////////
  // CheckpointDef - initial specification of a checkpoint

  struct CheckpointDef
  {
    string cpName;
    TableList max;
    TableList min;
    boolean allow_remote;
    boolean ram_overrides_dump;
  };

  ///////////////////////////////////////////////////////////////
  // TableInfo - information about a table

  struct TableInfo
  {
    AccessMode mode;
    AttrNames  attributes;
    long arity;
    Checkpoints checkpoints;
    NodeList ram_copies;
    NodeList disc_copies;
    NodeList disc_only_copies;
    Indices indexlist;
    long load_order;
    boolean local_content;
    NodeList master_nodes;
    long memory;
    long size;
    Storage storage_type;
    SetOrBag type;
    Node where_to_read;
    NodeList where_to_write;
    RecordName record_name; 
     
    // Not supported: cookie, snmp, subscribers, version, wild_pattern
  };

  ///////////////////////////////////////////////////////////////
  // SystemInfo - information about the Mnesia system
  // Some info can always be determined, but 
  // other info is only valid if Mnesia is running.

  struct SystemInfo
  {
    // The following information is always determined by
    // system_info/2:

    boolean auto_repair;
    string backup_module;
    string event_module;
    NodeList db_nodes;
    string debug;
    string directory;
    boolean dump_log_load_regulation;
    long dump_log_time_threshold;
    boolean dump_log_update_in_place;
    long dump_log_write_threshold;
    NodeList extra_db_nodes;
    boolean is_running;
    string schema_location;
    boolean use_dir;
    // Not supported: log_version, protocol_version, version
        
    // The following information is only valid if Mnesia is running.
    // Check 'is_running' before the info is accessed and regard the
    // values as undefined if 'is_running' is false.

    Checkpoints checkpoints;
    boolean fallback_activated;
    TableList local_tables;
    TableList master_node_tables;
    NodeList running_db_nodes;
    TableList tables;
    long transaction_failures;
    long transaction_commits;
    long transaction_restarts;
    long transaction_log_writes;

    // Not supported: held_locks, lock_queue, communication protocol,
    //                subscribers, transactions
  };
  
///////////////////////////////////////////////////////////////
// Most of the following functions returns Status and in case of
// an error, the out parameter 'reason' contains the description
// of the cause and all other out parameters contains undefined values.
//
// If the function was successful, 'reason' contains an empty string
// and the other out parameters contains valid data.

  interface session
    {
      ///////////////////////////////////////////////////////////////
      // Dirty access functions
    
      Status dirty_write(         in  TableName tab,
                                  in  Record object,
                                  out string reason);

      Status dirty_read(          in  TableName tab,
                                  in  Key key, 
                                  out Recordlist result,
                                  out string reason);

      Status dirty_update_counter(in  TableName tab,
                                  in  Key key,
                                  in  long val, 
                                  out long newval,
                                  out string reason);

      Status dirty_delete(        in  TableName tab,
                                  in  Key key,
                                  out string reason);

      Status dirty_delete_object( in TableName tab, 
                                  in  Record object,
                                  out string reason);

      Status dirty_slot(          in  TableName tab,
                                  in  long slot,
                                  out Recordlist result,
                                  out string reason);

      Status dirty_first(         in  TableName tab,
                                  out Key next_key,
                                  out string reason);

      Status dirty_next(          in  TableName tab,
                                  in  Key key,
                                  out Key next_key,
                                  out string reason);

      Status dirty_all_keys(      in  TableName tab,
                                  out KeyList keys,
                                  out string reason);

      Status dirty_match_all(     in  TableName tab,
                                  out Recordlist result,
                                  out string reason);

      Status dirty_index_read(    in  TableName tab, 
                                  in  Key key,
                                  in  long pos,
                                  out Recordlist result,
                                  out string reason);

      ///////////////////////////////////////////////////////////////
      // Table management

      Status create_table(            in  TableName tab,
                                      in  TableDef tabDefs,
                                      out string reason);

      Status delete_table(            in  TableName tab,
                                      out string reason);

      Status add_table_copy(          in  TableName tab, 
                                      in  Node node, 
                                      in  Storage type, 
                                      out string reason);

      Status del_table_copy(          in  TableName tab,
                                      in  Node node,
                                      out string reason);

      Status move_table_copy(         in  TableName tab, 
                                      in  Node from,
                                      in  Node to,
                                      out string reason);

      Status add_table_index(         in  TableName tab,
                                      in  long attrname,
                                      out string reason); 

      Status del_table_index(         in  TableName tab, 
                                      in  long attrname,
                                      out string reason);

      Status change_table_copy_type(  in  TableName tab,
                                      in  Node node,
                                      in  Storage type,
                                      out string reason);

      Status change_table_access_mode(in  TableName tab,
                                      in  AccessMode mode, 
                                      out string reason);

      ///////////////////////////////////////////////////////////////
      // Table load
      Status wait_for_tables(        in  TableList tabs,
                                     in  long timeout, 
                                     out TableList failed_tabs,
                                     out string reason);

      Status force_load_table(       in  TableName tab,
                                     out string reason);

      Status change_table_load_order(in  TableName tab,
                                     in  long load_order,
                                     out string reason);

      Status set_master_nodes1(      in  NodeList nodes, 
                                     out string reason);

      Status set_master_nodes2(      in  TableName tab, 
                                     in  NodeList nodes,
                                     out string reason);

      ///////////////////////////////////////////////////////////////
      // Database management

      Status backup1(              in  string filename,
                                   out string reason);
   
      Status backup2(              in  erlang::term opaque,
                                   in  string modulename,
                                   out string reason); 
   
      Status install_fallback1(    in  string filename,
                                   out string reason);
   
      Status install_fallback2(    in  erlang::term opaque,
                                   in  string modulename, 
                                   out string reason);
   
      Status uninstall_fallback(   out string reason);

      Status dump_log(             out string reason);

      Status dump_tables(          in  TableList list, 
                                   out string reason);

      Status activate_checkpoint(  in  CheckpointDef cpdef, 
                                   out string reason);

      Status deactivate_checkpoint(in  string cpName, 
                                   out string reason);

      Status backup_checkpoint1(   in  string cpName,
                                   in  string filename, 
                                   out string reason);

      Status backup_checkpoint2(   in  string cpName, 
                                   in  erlang::term opaque,
                                   in  string modulename,
                                   out string reason);

      ///////////////////////////////////////////////////////////////
      // Miscellaneous

      Status load_textfile(   in  string filename,
                              out string reason);

      Status dump_to_textfile(in  string filename,
                              out string reason);
  
      Status table_info(      in  TableName tab,
                              out TableInfo info,
                              out string reason);

      Status system_info(     out SystemInfo info,
                              out string reason);

      ///////////////////////////////////////////////////////////////
      // match_object functions is not supported due to the fact that
      // erlang::term is represented as an 'any' object and can not
      // be handled in an ordinary way in corba

      Status dirty_match_object(      in  TableName Tab,
                                      in  Record pattern, 
                                      out Recordlist result,
                                      out string reason);

      Status dirty_index_match_object(in TableName Tab, 
                                      in  Record pattern, 
                                      in  long pos,
                                      out Recordlist result, 
                                      out string reason);

      ///////////////////////////////////////////////////////////////
      // Functions that deals with starting and stopping the Mnesia
      // application or operates when Mnesia is not running is not
      // supported in the corba interface due to fact that Orber
      // needs a running Mnesia in order to operate.
 
      Status create_schema(  in  NodeList nodes,
                             out string reason);

      Status delete_schema(  in  NodeList nodes,
                             out string reason);

      Status    start_mnesia(out string reason);

      Status    stop_mnesia( out string reason);
    };
  


//////////////////////////////////////////////////////////////////
// The connector process registers itself in the local Erlang node
// at startup of the Mnesia Session application

  interface connector
    {
      // Connects to Mnesia on the same Erlang node as the
      // Connector process, creates a Session process and returns
      // its process identifier.

      erlang::pid connect();

      // Disconnects from Mnesia and terminates
      // the Session process.

      void disconnect(in erlang::pid object_key);
    };

};


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