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/*
* Copyright (C) 2015-2019 "IoT.bzh"
* Author "Fulup Ar Foll"
* Author: José Bollo <jose.bollo@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define _GNU_SOURCE
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <errno.h>
#include "afb-token.h"
/**
* structure for recording a token
*/
struct afb_token
{
/** link to the next token of the list */
struct afb_token *next;
/** reference of the token */
uint16_t refcount;
/** local numeric id of the token */
uint16_t id;
/** string value of the token */
char text[];
};
struct tokenset
{
struct afb_token *first;
pthread_mutex_t mutex;
uint16_t idgen;
};
static struct tokenset tokenset = {
.first = 0,
.mutex = PTHREAD_MUTEX_INITIALIZER,
.idgen = 0
};
static struct afb_token *searchid(uint16_t id)
{
struct afb_token *r = tokenset.first;
while (r && r->id != id)
r = r->next;
return r;
}
/**
* Get a token for the given value
*
* @param token address to return the pointer to the gotten token
* @param tokenstring string value of the token to get
* @return 0 in case of success or a -errno like negative code
*/
int afb_token_get(struct afb_token **token, const char *tokenstring)
{
int rc;
struct afb_token *tok;
size_t length;
/* get length of the token string */
length = + strlen(tokenstring);
/* concurrency */
pthread_mutex_lock(&tokenset.mutex);
/* search the token */
tok = tokenset.first;
while (tok && memcmp(tokenstring, tok->text, length))
tok = tok->next;
/* search done */
if (tok) {
/* found */
tok = afb_token_addref(tok);
rc = 0;
} else {
/* not found, create */
tok = malloc(length + sizeof *tok);
if (!tok)
/* creation failed */
rc = -ENOMEM;
else {
while(!++tokenset.idgen || searchid(tokenset.idgen));
tok->next = tokenset.first;
tokenset.first = tok;
tok->id = tokenset.idgen;
tok->refcount = 1;
memcpy(tok->text, tokenstring, length);
rc = 0;
}
}
pthread_mutex_unlock(&tokenset.mutex);
*token = tok;
return rc;
}
/**
* Add a reference count to the given token
*
* @param token the token to reference
* @return the token with the reference added
*/
struct afb_token *afb_token_addref(struct afb_token *token)
{
if (token)
__atomic_add_fetch(&token->refcount, 1, __ATOMIC_RELAXED);
return token;
}
/**
* Remove a reference to the given token and clean the memory if needed
*
* @param token the token that is unreferenced
*/
void afb_token_unref(struct afb_token *token)
{
struct afb_token **pt;
if (token && !__atomic_sub_fetch(&token->refcount, 1, __ATOMIC_RELAXED)) {
pthread_mutex_lock(&tokenset.mutex);
pt = &tokenset.first;
while (*pt && *pt != token)
if (*pt)
*pt = token->next;
pthread_mutex_unlock(&tokenset.mutex);
free(token);
}
}
/**
* Get the string value of the token
*
* @param token the token whose string value is queried
* @return the string value of the token
*/
const char *afb_token_string(const struct afb_token *token)
{
return token->text;
}
/**
* Get the "local" numeric id of the token
*
* @param token the token whose id is queried
* @return the numeric id of the token
*/
uint16_t afb_token_id(const struct afb_token *token)
{
return token->id;
}
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