mu/lib/mu-msg-cache.h

160 lines
4.1 KiB
C

/*
** Copyright (C) 2011 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
**
** This program is free software; you can redistribute it and/or modify it
** under the terms of the GNU General Public License as published by the
** Free Software Foundation; either version 3, or (at your option) any
** later version.
**
** 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software Foundation,
** Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
**
*/
#ifndef __MU_MSG_CACHE_H__
#define __MU_MSG_CACHE_H__
#include <glib.h>
#include <mu-msg-fields.h>
/* MuMsgCache caches all values for one specific MuMsg, whether its
* backend is a MuMsgFile or MuMsgDb. The idea is to take all the
* values from the MuMsg so we can release the backend (file or db).
*
* It is specifically designed minimize memory allocations; you can
* either store dynamically-allocated strings, of which the cache will
* take ownership (and g_free in the end), *or* use strings, either
* static or owned elsewhere. In the later case, no copy will be made
* until mu_msg_cache_allocate_all is called
*
* Minimizing allocations in esp. necessary when storing
* search-results as a list of MuMsg instances
*/
G_BEGIN_DECLS
struct _MuMsgCache;
typedef struct _MuMsgCache MuMsgCache;
/**
* initialize the cache
*
* @param self ptr to a cache struct
*/
MuMsgCache *mu_msg_cache_new (void);
/**
* free the strings in the cache
*
* @param self ptr to a cache struct
*/
void mu_msg_cache_destroy (MuMsgCache *self);
/**
* add a string value to the cache; it will *not* be freed
*
* @param self a cache struc
* @param mfid the MessageFieldId
* @param str the string value to set
* @param do_free whether the cache should free this value (i.e, take ownership)
*
* @return the cached value (this is for nesting function calls)
*/
const char* mu_msg_cache_set_str (MuMsgCache *self, MuMsgFieldId mfid,
char *str, gboolean do_free);
/**
* get a string value from the cache
*
* @param self ptr to a MuMsgCache
* @param mfid the MessageFieldId for a string value
*
* @return the string, or NULL. Don't modify.
*/
const char* mu_msg_cache_str (MuMsgCache *cache, MuMsgFieldId mfid);
/**
* cache a string-list value
*
* @param self a mumsgcache
* @param mfid the MessageFieldId for a string-list value
* @param lst the list
* @param do_free whether the cache should free this value (i.e, take ownership)
*
* @return
*/
const GSList* mu_msg_cache_set_str_list (MuMsgCache *self, MuMsgFieldId mfid,
GSList *lst, gboolean do_free);
/**
* get a string-list value from the cache
*
* @param cache a MuMsgCache
* @param mfid the MessageFieldId for string-list value
*
* @return a list, which should not be modified
*/
const GSList* mu_msg_cache_str_list (MuMsgCache *cache, MuMsgFieldId mfid);
/**
* add a numeric value to the cache
*
* @param self a MuMsgCache ptr
* @param mfid the MessageFieldId for a numeric value
* @param val the value
*
* @return the cached value (this is for nesting function calls)
*
*/
gint64 mu_msg_cache_set_num (MuMsgCache *self, MuMsgFieldId mfid, gint64 val);
/**
* get a numeric value from the cache
*
* @param self a MuMsgCache ptr
* @param mfid the MessageFieldId for a numeric value
*
* @return a numeric value
*/
gint64 mu_msg_cache_num (MuMsgCache *self, MuMsgFieldId mfid);
/**
* is the value cached already?
*
* @param self a MuMsgCache ptr
* @param mfid the MessageFieldId for a numeric value
*
* @return TRUE if the value is cached, FALSE otherwise
*/
gboolean mu_msg_cache_cached (MuMsgCache *self, MuMsgFieldId mfid);
/**
* copy all data that was not already owned by the cache
*
* @param self a MuMsgCache ptr
*/
void mu_msg_cache_allocate_all (MuMsgCache *self);
G_END_DECLS
#endif /*__MU_MSG_CACHE_H__*/