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/* -*- C++ -*- */
//=============================================================================
/**
* @file PSDL_Datastore.h
*
* $Id$
*
* @author Priyanka Gontla <gontla_p@ociweb.com>
*/
//=============================================================================
#ifndef TAO_PSDL_DATASTORE_H
#define TAO_PSDL_DATASTORE_H
#include /**/ "ace/pre.h"
#include "PSDL_Code_Gen.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
// The name under which the index of naming contexts is stored in
// persistent naming service.
#if !defined (TAO_PERSISTENT_NAME_OBJ_MAP)
# define TAO_PERSISTENT_NAME_OBJ_MAP "Persistent_Name_Obj_Map"
#endif /* ! TAO_PERSISTENT_NAME_OBJ_MAP */
#include "ace/Malloc.h"
#include "ace/Hash_Map_With_Allocator_T.h"
/**
* @class TAO_PSDL_Datastore
*
* @brief This class facilitates implementation of Persistent
* Service. Helps perform the bind and find to the hash_map
**/
// Forward declarations.
class TAO_PSDL_OctetSeq;
class TAO_PSDL_String;
class TAO_PSDL_Export TAO_PSDL_Datastore
{
public:
// = Some typedefs for convenience.
/// Hash map used by Persistent Naming Context to keep its state.
typedef ACE_Hash_Map_With_Allocator<TAO_PSDL_String, TAO_PSDL_OctetSeq> NAME_OBJ_REF_MAP;
typedef ACE_Hash_Map_Entry <TAO_PSDL_String, TAO_PSDL_OctetSeq> NAME_OBJ_REF_ENTRY;
/// Allocator we will be using to make the Naming Service persistent.
typedef ACE_Allocator_Adapter <ACE_Malloc <ACE_MMAP_MEMORY_POOL, TAO_SYNCH_MUTEX>
> ALLOCATOR;
// = Initialization and termination methods.
/// Constructor.
TAO_PSDL_Datastore ();
/**
* Create ACE_Allocator, open/create memory-mapped file with the
* specified file name/base address. Find or allocate <index_>.
* Return 0 on success or -1 on failure.
*/
int open (const ACE_TCHAR *file_name,
void * base_address = ACE_DEFAULT_BASE_ADDR);
/**
* If <index_> contains no entries (i.e., was just created), create
* a root Persistent servant with table of size
* <context_size>, and make an entry for it
* in the <index_>. If <index_> contains entries, create a
* Persistent servant for each entry. Return 0 on
* success and -1 on failure.
*/
int init (size_t context_size);
/**
* Destructor. The memory mapped file that was opened/created is
* not deleted, since we want it to keep the state of the Database
* until the next run.
*/
~TAO_PSDL_Datastore (void);
// = Accessors.
int bind (const char *name,
const CORBA::OctetSeq &octetseq);
int unbind (const char *name);
int find (const char *name,
CORBA::OctetSeq &octet_seq);
/// Return allocator.
ACE_Allocator *allocator (void);
private:
/// Helper for the <init> method. Iterates over <index_>, and
/// creates a servant for each entry.
int recreate_all (void);
/// Helper for the <open> method.
int create_index (void);
/// Helper for <create_index> method: places hash table into an
/// allocated space.
int create_index_helper (void *buffer);
/// Lock to prevent multiple threads from modifying entries in the
/// <index_> simultanneously.
TAO_SYNCH_MUTEX lock_;
/**
* Allocator that deals out memory from a memory-mapped file. We
* use it whenever we
* deal with data that should be kept in persistent store.
*/
ALLOCATOR *allocator_;
/// Hash map where we keep entries for all Persistent entries
NAME_OBJ_REF_MAP *obj_ref_map_;
/// Name of the memory-mapped file used by <allocator_>.
const ACE_TCHAR *index_file_;
/// Base address for the memory-mapped file.
void *base_address_;
};
#include /**/ "ace/post.h"
#endif /* TAO_PSDL_DATASTORE_H */
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