/*
* 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.
*/
/**
* @page tutorial_stringshare_page Stringshare Tutorial
*
* to be written...
*
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include
#include
#include
#ifdef HAVE_EVIL
# include
#endif
#include "eina_stringshare.h"
#include "eina_hash.h"
#include "eina_rbtree.h"
#include "eina_error.h"
#include "eina_private.h"
#include "eina_magic.h"
/*============================================================================*
* Local *
*============================================================================*/
/**
* @cond LOCAL
*/
#define EINA_STRINGSHARE_BUCKETS 256
#define EINA_STRINGSHARE_MASK 0xFF
#define EINA_MAGIC_CHECK_STRINGSHARE_HEAD(d) \
do { \
if (!EINA_MAGIC_CHECK((d), EINA_MAGIC_STRINGSHARE_HEAD)) \
EINA_MAGIC_FAIL((d), EINA_MAGIC_STRINGSHARE_HEAD); \
} while (0);
#define EINA_MAGIC_CHECK_STRINGSHARE_NODE(d) \
do { \
if (!EINA_MAGIC_CHECK((d), EINA_MAGIC_STRINGSHARE_NODE)) \
EINA_MAGIC_FAIL((d), EINA_MAGIC_STRINGSHARE_NODE); \
} while (0);
typedef struct _Eina_Stringshare Eina_Stringshare;
typedef struct _Eina_Stringshare_Node Eina_Stringshare_Node;
typedef struct _Eina_Stringshare_Head Eina_Stringshare_Head;
struct _Eina_Stringshare
{
Eina_Stringshare_Head *buckets[EINA_STRINGSHARE_BUCKETS];
EINA_MAGIC;
};
struct _Eina_Stringshare_Head
{
EINA_RBTREE;
EINA_MAGIC;
int hash;
#ifdef EINA_STRINGSHARE_USAGE
int population;
#endif
Eina_Stringshare_Node *head;
};
struct _Eina_Stringshare_Node
{
EINA_MAGIC;
Eina_Stringshare_Node *next;
int length;
int references;
Eina_Bool begin : 1;
};
static Eina_Stringshare *share = NULL;
static int _eina_stringshare_init_count = 0;
static const char _eina_stringshare_single[512] = {
0,0,1,0,2,0,3,0,4,0,5,0,6,0,7,0,8,0,9,0,10,0,11,0,12,0,13,0,14,0,15,0,
16,0,17,0,18,0,19,0,20,0,21,0,22,0,23,0,24,0,25,0,26,0,27,0,28,0,29,0,30,0,
31,0,32,0,33,0,34,0,35,0,36,0,37,0,38,0,39,0,40,0,41,0,42,0,43,0,44,0,45,0,
46,0,47,0,48,0,49,0,50,0,51,0,52,0,53,0,54,0,55,0,56,0,57,0,58,0,59,0,60,0,
61,0,62,0,63,0,64,0,65,0,66,0,67,0,68,0,69,0,70,0,71,0,72,0,73,0,74,0,75,0,
76,0,77,0,78,0,79,0,80,0,81,0,82,0,83,0,84,0,85,0,86,0,87,0,88,0,89,0,90,0,
91,0,92,0,93,0,94,0,95,0,96,0,97,0,98,0,99,0,100,0,101,0,102,0,103,0,104,0,105,0,
106,0,107,0,108,0,109,0,110,0,111,0,112,0,113,0,114,0,115,0,116,0,117,0,118,0,119,0,120,0,
121,0,122,0,123,0,124,0,125,0,126,0,127,0,128,0,129,0,130,0,131,0,132,0,133,0,134,0,135,0,
136,0,137,0,138,0,139,0,140,0,141,0,142,0,143,0,144,0,145,0,146,0,147,0,148,0,149,0,150,0,
151,0,152,0,153,0,154,0,155,0,156,0,157,0,158,0,159,0,160,0,161,0,162,0,163,0,164,0,165,0,
166,0,167,0,168,0,169,0,170,0,171,0,172,0,173,0,174,0,175,0,176,0,177,0,178,0,179,0,180,0,
181,0,182,0,183,0,184,0,185,0,186,0,187,0,188,0,189,0,190,0,191,0,192,0,193,0,194,0,195,0,
196,0,197,0,198,0,199,0,200,0,201,0,202,0,203,0,204,0,205,0,206,0,207,0,208,0,209,0,210,0,
211,0,212,0,213,0,214,0,215,0,216,0,217,0,218,0,219,0,220,0,221,0,222,0,223,0,224,0,225,0,
226,0,227,0,228,0,229,0,230,0,231,0,232,0,233,0,234,0,235,0,236,0,237,0,238,0,239,0,240,0,
241,0,242,0,243,0,244,0,245,0,246,0,247,0,248,0,249,0,250,0,251,0,252,0,253,0,254,0,255,0
};
#ifdef EINA_STRINGSHARE_USAGE
typedef struct _Eina_Stringshare_Population Eina_Stringshare_Population;
struct _Eina_Stringshare_Population
{
int count;
int max;
};
static Eina_Stringshare_Population population = { 0, 0 };
static Eina_Stringshare_Population population_group[5] =
{
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
{ 0, 0 }
};
static int max_node_population = 0;
#endif
static int
_eina_stringshare_cmp(const Eina_Stringshare_Head *ed, const int *hash, __UNUSED__ int length, __UNUSED__ void *data)
{
EINA_MAGIC_CHECK_STRINGSHARE_HEAD(ed);
return ed->hash - *hash;
}
static Eina_Rbtree_Direction
_eina_stringshare_node(const Eina_Stringshare_Head *left, const Eina_Stringshare_Head *right, __UNUSED__ void *data)
{
EINA_MAGIC_CHECK_STRINGSHARE_HEAD(left);
EINA_MAGIC_CHECK_STRINGSHARE_HEAD(right);
if (left->hash - right->hash < 0)
return EINA_RBTREE_LEFT;
return EINA_RBTREE_RIGHT;
}
static void
_eina_stringshare_head_free(Eina_Stringshare_Head *ed, __UNUSED__ void *data)
{
EINA_MAGIC_CHECK_STRINGSHARE_HEAD(ed);
while (ed->head)
{
Eina_Stringshare_Node *el = ed->head;
ed->head = ed->head->next;
if (el->begin == EINA_FALSE)
MAGIC_FREE(el);
}
MAGIC_FREE(ed);
}
/**
* @endcond
*/
/*============================================================================*
* Global *
*============================================================================*/
/*============================================================================*
* API *
*============================================================================*/
/**
* @addtogroup Eina_Data_Types_Group Data Types
*
* @{
*/
/**
* @addtogroup Eina_Stringshare_Group Stringshare
*
* 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.
*
* For more information, you can look at the @ref tutorial_stringshare_page.
*
* @{
*/
/**
* @brief Initialize the eina stringshare internal structure.
*
* @return 1 or greater on success, 0 on error.
*
* This function allocates the memory needed by the stringshare
* internal structure and sets up the error module of Eina. It is also
* called by eina_init(). It returns 0 on failure, otherwise it
* returns the number of times it has already been called.
*/
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)
{
unsigned int i;
share = calloc(1, sizeof(Eina_Stringshare));
if (!share)
return 0;
eina_error_init();
eina_magic_string_init();
eina_magic_string_set(EINA_MAGIC_STRINGSHARE,
"Eina Stringshare");
eina_magic_string_set(EINA_MAGIC_STRINGSHARE_HEAD,
"Eina Stringshare Head");
eina_magic_string_set(EINA_MAGIC_STRINGSHARE_NODE,
"Eina Stringshare Node");
EINA_MAGIC_SET(share, EINA_MAGIC_STRINGSHARE);
#ifdef EINA_STRINGSHARE_USAGE
for (i = 0; i < sizeof (population_group) / sizeof (population_group[0]); ++i)
{
population_group[i].count = 0;
population_group[i].max = 0;
}
#endif
}
return ++_eina_stringshare_init_count;
}
/**
* @brief Shut down the eina stringshare internal structures
*
* @return 0 when the stringshare module is completely shut down, 1 or
* greater otherwise.
*
* This function frees the memory allocated by eina_stringshare_init()
* and shuts down the error module. It is also called by
* eina_shutdown(). It returns 0 when it is called the same number of
* times than eina_stringshare_init().
*/
EAPI int
eina_stringshare_shutdown()
{
unsigned int i;
#ifdef EINA_STRINGSHARE_USAGE
fprintf(stderr, "eina stringshare statistic:\n");
fprintf(stderr, " * maximum shared strings : %i\n", population.max);
fprintf(stderr, " * maximum shared strings per node : %i\n", max_node_population);
for (i = 0; i < sizeof (population_group) / sizeof (population_group[0]); ++i)
fprintf(stderr, "DDD: %i strings of length %i, max strings: %i\n", population_group[i].count, i, population_group[i].max);
#endif
--_eina_stringshare_init_count;
if (!_eina_stringshare_init_count)
{
/* remove any string still in the table */
for (i = 0; i < EINA_STRINGSHARE_BUCKETS; i++)
{
eina_rbtree_delete(EINA_RBTREE_GET(share->buckets[i]), EINA_RBTREE_FREE_CB(_eina_stringshare_head_free), NULL);
share->buckets[i] = NULL;
}
MAGIC_FREE(share);
#ifdef EINA_STRINGSHARE_USAGE
max_node_population = 0;
population.count = 0;
population.max = 0;
for (i = 0; i < sizeof (population_group) / sizeof (population_group[0]); ++i)
{
population_group[i].count = 0;
population_group[i].max = 0;
}
#endif
eina_magic_string_shutdown();
eina_error_shutdown();
}
return _eina_stringshare_init_count;
}
/**
* @brief Retrieve 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.
*
* This function retrieves an instance of @p str. If @p str is
* @c NULL, then @c NULL is returned. If @p str is already stored, it
* is just returned and its reference counter is increased. Otherwise
* it is added to the strings to be searched and a duplicated string
* of @p str is returned.
*/
EAPI const char *
eina_stringshare_add(const char *str)
{
Eina_Stringshare_Node *nel = NULL;
Eina_Stringshare_Node *tmp;
Eina_Stringshare_Head *ed;
Eina_Stringshare_Node *el;
char *el_str;
int hash_num, slen, hash;
if (!str) return NULL;
slen = strlen(str) + 1;
#ifdef EINA_STRINGSHARE_USAGE
population.count++;
if (population.count > population.max) population.max = population.count;
if (slen <= 5)
{
population_group[slen - 1].count++;
if (population_group[slen - 1].count > population_group[slen - 1].max)
population_group[slen - 1].max = population_group[slen - 1].count;
}
#endif
switch (slen)
{
case 1:
return "";
case 2:
return &(_eina_stringshare_single[(*str) << 1]);
case 3:
case 4:
default:
break;
}
hash = eina_hash_superfast(str, slen);
hash_num = hash & 0xFF;
hash = (hash >> 8) & EINA_STRINGSHARE_MASK;
ed = (Eina_Stringshare_Head*) eina_rbtree_inline_lookup((Eina_Rbtree*) share->buckets[hash_num],
&hash, 0,
EINA_RBTREE_CMP_KEY_CB(_eina_stringshare_cmp), NULL);
if (!ed)
{
ed = malloc(sizeof (Eina_Stringshare_Head) + sizeof (Eina_Stringshare_Node) + slen);
if (!ed) return NULL;
EINA_MAGIC_SET(ed, EINA_MAGIC_STRINGSHARE_HEAD);
ed->hash = hash;
ed->head = NULL;
#ifdef EINA_STRINGSHARE_USAGE
ed->population = 0;
#endif
share->buckets[hash_num] = (Eina_Stringshare_Head*) eina_rbtree_inline_insert((Eina_Rbtree*) share->buckets[hash_num],
EINA_RBTREE_GET(ed),
EINA_RBTREE_CMP_NODE_CB(_eina_stringshare_node), NULL);
nel = (Eina_Stringshare_Node*) (ed + 1);
EINA_MAGIC_SET(nel, EINA_MAGIC_STRINGSHARE_NODE);
nel->begin = EINA_TRUE;
}
EINA_MAGIC_CHECK_STRINGSHARE_HEAD(ed);
for (el = ed->head, tmp = NULL;
el && (slen != el->length || memcmp(str, (const char*) (el + 1), slen) != 0);
tmp = el, el = el->next)
;
if (el)
{
if (tmp)
{
tmp->next = el->next;
el->next = ed->head;
ed->head = el;
}
el->references++;
return (const char*) (el + 1);
}
if (!nel)
{
nel = malloc(sizeof (Eina_Stringshare_Node) + slen);
if (!nel) return NULL;
EINA_MAGIC_SET(nel, EINA_MAGIC_STRINGSHARE_NODE);
nel->begin = EINA_FALSE;
}
nel->references = 1;
nel->length = slen;
el_str = (char*) (nel + 1);
memcpy(el_str, str, slen);
nel->next = ed->head;
ed->head = nel;
#ifdef EINA_STRINGSHARE_USAGE
ed->population++;
if (ed->population > max_node_population) max_node_population = ed->population;
#endif
return el_str;
}
/**
* @brief Note that the given string has lost an instance.
*
* @param str string The given string.
*
* This function decreases the reference counter associated to @p str
* if it exists. If that counter reaches 0, the memory associated to
* @p str is freed. If @p str is NULL, the function returns
* immediatly.
*/
EAPI void
eina_stringshare_del(const char *str)
{
Eina_Stringshare_Head *ed;
Eina_Stringshare_Node *el;
Eina_Stringshare_Node *prev;
int hash_num, slen, hash;
if (!str) return;
slen = strlen(str) + 1;
#ifdef EINA_STRINGSHARE_USAGE
population.count--;
if (slen <= 5)
population_group[slen - 1].count--;
#endif
switch (slen)
{
case 1:
case 2:
return ;
case 3:
case 4:
default:
break;
}
hash = eina_hash_superfast(str, slen);
hash_num = hash & 0xFF;
hash = (hash >> 8) & EINA_STRINGSHARE_MASK;
ed = (Eina_Stringshare_Head*) eina_rbtree_inline_lookup(EINA_RBTREE_GET(share->buckets[hash_num]),
&hash, 0,
EINA_RBTREE_CMP_KEY_CB(_eina_stringshare_cmp), NULL);
if (!ed) goto on_error;
EINA_MAGIC_CHECK_STRINGSHARE_HEAD(ed);
for (prev = NULL, el = ed->head;
el && (const char*) (el + 1) != str;
prev = el, el = el->next)
;
if (!el) goto on_error;
EINA_MAGIC_CHECK_STRINGSHARE_NODE(el);
el->references--;
if (el->references == 0)
{
if (prev) prev->next = el->next;
else ed->head = el->next;
if (el->begin == EINA_FALSE)
MAGIC_FREE(el);
#ifdef EINA_STRINGSHARE_USAGE
ed->population--;
#endif
if (ed->head == NULL)
{
share->buckets[hash_num] = (Eina_Stringshare_Head*) eina_rbtree_inline_remove(EINA_RBTREE_GET(share->buckets[hash_num]),
EINA_RBTREE_GET(ed),
EINA_RBTREE_CMP_NODE_CB(_eina_stringshare_node),
NULL);
MAGIC_FREE(ed);
}
}
return ;
on_error:
EINA_ERROR_PWARN("EEEK trying to del non-shared stringshare \"%s\"\n", str);
if (getenv("EINA_ERROR_ABORT")) abort();
}
struct dumpinfo
{
int used, saved, dups, unique;
};
static Eina_Bool
eina_iterator_array_check(const Eina_Rbtree *rbtree __UNUSED__, Eina_Stringshare_Head *head, struct dumpinfo *fdata)
{
Eina_Stringshare_Node *node;
fdata->used += sizeof(Eina_Stringshare_Head);
for (node = head->head; node; node = node->next)
{
printf("DDD: %5i %5i ", node->length, node->references);
printf("'%s'\n", ((char *)node) + sizeof(Eina_Stringshare_Node));
fdata->used += sizeof(Eina_Stringshare_Node);
fdata->used += node->length;
fdata->saved += (node->references - 1) * node->length;
fdata->dups += node->references - 1;
fdata->unique++;
}
return EINA_TRUE;
}
/**
* @brief Dump the contents of the stringshare.
*
* This function dumps all strings in the stringshare to stdout with a
* DDD: prefix per line and a memory usage summary.
*/
EAPI void
eina_stringshare_dump(void)
{
Eina_Iterator *it;
unsigned int i;
struct dumpinfo di;
if (!share) return;
di.used = sizeof (_eina_stringshare_single);
di.saved = 0;
di.dups = 0;
di.unique = 0;
printf("DDD: len ref string\n");
printf("DDD:-------------------\n");
for (i = 0; i < EINA_STRINGSHARE_BUCKETS; i++)
{
if (!share->buckets[i]) continue;
// printf("DDD: BUCKET # %i (HEAD=%i, NODE=%i)\n", i,
// sizeof(Eina_Stringshare_Head), sizeof(Eina_Stringshare_Node));
it = eina_rbtree_iterator_prefix((Eina_Rbtree *)share->buckets[i]);
eina_iterator_foreach(it, EINA_EACH(eina_iterator_array_check), &di);
eina_iterator_free(it);
}
#ifdef EINA_STRINGSHARE_USAGE
/* One character strings are not counted in the hash. */
di.saved += population_group[0].count * sizeof(char);
di.saved += population_group[1].count * sizeof(char) * 2;
#endif
printf("DDD:-------------------\n");
printf("DDD: usage (bytes) = %i, saved = %i (%i duplicates, %i unique)\n",
di.used, di.saved, di.dups, di.unique);
#ifdef EINA_STRINGSHARE_USAGE
printf("DDD: Allocated strings: %i\n", population.count);
printf("DDD: Max allocated strings: %i\n", population.max);
for (i = 0; i < sizeof (population_group) / sizeof (population_group[0]); ++i)
fprintf(stderr, "DDD: %i strings of length %i, max strings: %i\n", population_group[i].count, i, population_group[i].max);
#endif
}
/**
* @}
*/
/**
* @}
*/