/*
* vim:ts=8:sw=3:sts=8:noexpandtab:cino=>5n-3f0^-2{2
*/
/* EINA - EFL data type library
* Copyright (C) 2002-2008 Carsten Haitzler, Jorge Luis Zapata Muga, Cedric Bail
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library;
* if not, see .
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright (C) 2008 Peter Wehrfritz
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies of the Software and its Copyright notices. In addition publicly
* documented acknowledgment must be given that this software has been used if no
* source code of this software is made available publicly. This includes
* acknowledgments in either Copyright notices, Manuals, Publicity and Marketing
* documents or any documentation provided with any product containing this
* software. This License does not apply to any software that links to the
* libraries provided by this software (statically or dynamically), but only to
* the software provided.
*
* Please see the OLD-COPYING.PLAIN for a plain-english explanation of this notice
* and it's intent.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include
#include
#include
#include "eina_stringshare.h"
#include "eina_hash.h"
#include "eina_rbtree.h"
#include "eina_error.h"
#include "eina_private.h"
/*============================================================================*
* Local *
*============================================================================*/
typedef struct _Eina_Stringshare Eina_Stringshare;
typedef struct _Eina_Stringshare_Node Eina_Stringshare_Node;
struct _Eina_Stringshare
{
Eina_Stringshare_Node *buckets[1024];
};
struct _Eina_Stringshare_Node
{
Eina_Rbtree node;
int references;
};
static Eina_Stringshare *share = NULL;
static int eina_stringshare_init_count = 0;
static int
_eina_stringshare_cmp(const Eina_Stringshare_Node *node, const char *key, int length, __UNUSED__ void *data)
{
const char *el_str;
el_str = (const char *) (node + 1);
return strncmp(el_str, key, length);
}
static Eina_Rbtree_Direction
_eina_stringshare_node(const Eina_Stringshare_Node *left, const Eina_Stringshare_Node *right, __UNUSED__ void *data)
{
if (!left) return EINA_RBTREE_RIGHT;
if (!right) return EINA_RBTREE_LEFT;
if (strcmp((const char*) (left + 1), (const char*) (right + 1)) < 0)
return EINA_RBTREE_LEFT;
return EINA_RBTREE_RIGHT;
}
/*============================================================================*
* Global *
*============================================================================*/
/*============================================================================*
* API *
*============================================================================*/
/**
* @addtogroup Eina_Stringshare_Group String Instance Functions
*
* These functions allow you to store one copy of a string, and use it
* throughout your program.
*
* This is a method to reduce the number of duplicated strings kept in
* memory. It's pretty common for the same strings to be dynamically
* allocated repeatedly between applications and libraries, especially in
* circumstances where you could have multiple copies of a structure that
* allocates the string. So rather than duplicating and freeing these
* strings, you request a read-only pointer to an existing string and
* only incur the overhead of a hash lookup.
*
* It sounds like micro-optimizing, but profiling has shown this can have
* a significant impact as you scale the number of copies up. It improves
* string creation/destruction speed, reduces memory use and decreases
* memory fragmentation, so a win all-around.
*
* @{
*/
/**
* Initialize the eina stringshare internal structure.
* @return Zero on failure, non-zero on successful initialization.
*/
EAPI int
eina_stringshare_init()
{
/*
* No strings have been loaded at this point, so create the hash
* table for storing string info for later.
*/
if (!eina_stringshare_init_count)
{
share = calloc(1, sizeof(Eina_Stringshare));
if (!share)
return 0;
eina_error_init();
}
eina_stringshare_init_count++;
return 1;
}
/**
* Retrieves an instance of a string for use in a program.
* @param str The string to retrieve an instance of.
* @return A pointer to an instance of the string on success.
* @c NULL on failure.
*/
EAPI const char *
eina_stringshare_add(const char *str)
{
Eina_Stringshare_Node *el;
char *el_str;
int hash_num, slen;
if (!str) return NULL;
slen = strlen(str) + 1;
hash_num = eina_hash_superfast(str, slen) & 0x3FF;
el = (Eina_Stringshare_Node*) eina_rbtree_inline_lookup((Eina_Rbtree*) share->buckets[hash_num], str, slen, EINA_RBTREE_CMP_KEY_CB(_eina_stringshare_cmp), NULL);
if (el)
{
el->references++;
return (const char*) (el + 1);
}
el = malloc(sizeof (Eina_Stringshare_Node) + slen + 1);
if (!el) return NULL;
el->references = 1;
el_str = (char*) (el + 1);
memcpy(el_str, str, slen + 1);
share->buckets[hash_num] = (Eina_Stringshare_Node*) eina_rbtree_inline_insert((Eina_Rbtree*) share->buckets[hash_num], &el->node, EINA_RBTREE_CMP_NODE_CB(_eina_stringshare_node), NULL);
return el_str;
}
/**
* Notes that the given string has lost an instance.
*
* It will free the string if no other instances are left.
*
* @param str string The given string.
*/
EAPI void
eina_stringshare_del(const char *str)
{
Eina_Stringshare_Node *el;
int hash_num, slen;
if (!str) return;
slen = strlen(str) + 1;
hash_num = eina_hash_superfast(str, slen) & 0x3FF;
el = (Eina_Stringshare_Node*) eina_rbtree_inline_lookup((Eina_Rbtree*) share->buckets[hash_num], str, slen, EINA_RBTREE_CMP_KEY_CB(_eina_stringshare_cmp), NULL);
if (el)
{
el->references--;
if (el->references == 0)
{
share->buckets[hash_num] = (Eina_Stringshare_Node*) eina_rbtree_inline_remove((Eina_Rbtree*) share->buckets[hash_num], &el->node, EINA_RBTREE_CMP_NODE_CB(_eina_stringshare_node), NULL);
free(el);
}
return ;
}
EINA_ERROR_PWARN("EEEK trying to del non-shared stringshare \"%s\"\n", str);
if (getenv("EINA_ERROR_ABORT")) abort();
}
/**
* Shutdown the eina string internal structures
*/
EAPI int
eina_stringshare_shutdown()
{
--eina_stringshare_init_count;
if (!eina_stringshare_init_count)
{
int i;
/* remove any string still in the table */
for (i = 0; i < 1024; i++)
{
Eina_Rbtree *el = (Eina_Rbtree*) share->buckets[i];
Eina_Rbtree *save;
while (el)
{
save = el;
el = eina_rbtree_inline_remove(el, el, EINA_RBTREE_CMP_NODE_CB(_eina_stringshare_node), NULL);
free(save);
}
share->buckets[i] = NULL;
}
free(share);
share = NULL;
eina_error_shutdown();
}
return eina_stringshare_init_count;
}
/**
* @}
*/