1 files changed, 182 insertions, 0 deletions
diff --git a/src/afb-token.c b/src/afb-token.c
new file mode 100644
index 00000000..b81a87df
--- /dev/null
+++ b/src/afb-token.c
@@ -0,0 +1,182 @@
+/*
+ * 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);
+	}
+}
+
+/**
+ * Check whether the token is valid or not
+ *
+ * @param token the token to check
+ * @return a boolean value: 0 if not valid, 1 if valid
+ */
+int afb_token_check(struct afb_token *token)
+{
+	/* TODO */
+	return 1;
+}
+
+/**
+ * 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;
+}