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/*
* Pool for shared strings.
*
* Copyright (c) 2010 Marko Kreen, Skype Technologies OÜ
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <usual/strpool.h>
#include <usual/cbtree.h>
#include <string.h>
/*
* Put all strings into cbtree.
*/
struct StrPool {
CxMem *ca;
struct CBTree *tree;
int count;
};
/* pass key info to cbtree */
static size_t get_key(void *ctx, void *obj, const void **dst_p)
{
struct PStr *s = obj;
*dst_p = s->str;
return s->len;
}
/* free PStr obj */
static bool free_str(void *arg, void *obj)
{
struct PStr *p = obj;
struct StrPool *sp = p->pool;
memset(p, 0, offsetof(struct PStr, str) + 1);
cx_free(sp->ca, obj);
return true;
}
/* create main structure */
struct StrPool *strpool_create(CxMem *ca)
{
struct StrPool *sp;
sp = cx_alloc(ca, sizeof(*sp));
if (!sp)
return NULL;
sp->count = 0;
sp->ca = ca;
sp->tree = cbtree_create(get_key, NULL, NULL, ca);
if (!sp->tree) {
cx_free(ca, sp);
return NULL;
}
return sp;
}
/* free main structure */
void strpool_free(struct StrPool *sp)
{
if (sp) {
cbtree_walk(sp->tree, free_str, sp);
cbtree_destroy(sp->tree);
cx_free(sp->ca, sp);
}
}
/* return total count of strings in pool */
int strpool_total(struct StrPool *sp)
{
return sp->count;
}
/* get new reference to str */
struct PStr *strpool_get(struct StrPool *sp, const char *str, ssize_t len)
{
struct PStr *cstr;
bool ok;
if (len < 0)
len = strlen(str);
/* search */
cstr = cbtree_lookup(sp->tree, str, len);
if (cstr) {
cstr->refcnt++;
return cstr;
}
/* create */
cstr = cx_alloc(sp->ca, sizeof(*cstr) + len + 1);
if (!cstr)
return NULL;
cstr->pool = sp;
cstr->refcnt = 1;
cstr->len = len;
memcpy(cstr->str, str, len + 1);
/* insert */
ok = cbtree_insert(sp->tree, cstr);
if (!ok) {
cx_free(sp->ca, cstr);
return NULL;
}
sp->count++;
return cstr;
}
/* add reference */
void strpool_incref(struct PStr *s)
{
if (s)
s->refcnt++;
}
/* drop reference, free if none left */
void strpool_decref(struct PStr *s)
{
struct StrPool *sp;
if (!s)
return;
Assert(s->refcnt > 0);
s->refcnt--;
if (s->refcnt > 0)
return;
/* remove */
sp = s->pool;
sp->count--;
cbtree_delete(sp->tree, s->str, s->len);
free_str(NULL, s);
}
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