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/*
* Copyright (C) 2018 "IoT.bzh"
* 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.
*/
/******************************************************************************/
/******************************************************************************/
/* IMPLEMENTATION OF QUEUE OF DATABASE MODIFIERS */
/******************************************************************************/
/******************************************************************************/
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "data.h"
#include "db.h"
#define DROP 0
#define SET 1
/**
* Queue
*/
struct queue
{
/** read index within queue */
uint32_t read;
/** write index within queue */
uint32_t write;
/** capacity of the queue */
uint32_t capacity;
/** the memory of the queue */
void *queue;
};
typedef struct queue queue_t;
/** the queue */
static queue_t queue;
/**
* Read data from the queue
*
* @param data where to store the data
* @param length length of the data to read
* @return true on success or false on error
*/
static
bool
qread(
void *data,
uint32_t length
) {
if (queue.read + length > queue.write)
return false;
memcpy(data, queue.queue + queue.read, length);
queue.read += length;
return true;
}
/**
* Get a time from the queue
*
* @param value where to store the time
* @return true on success or false on error
*/
static
bool
qget_time(
time_t *value
) {
return qread(value, sizeof *value);
}
/**
* Get a string from the queue
*
* @param text where to store the string
* @return true on success or false on error
*/
static
bool
qget_string(
const char **text
) {
char *p = queue.queue + queue.read;
uint32_t length = (uint32_t)strlen(p);
if (queue.read + length >= queue.write)
return false;
*text = p;
queue.read += length + 1;
return true;
}
/**
* Write the data to the queue
*
* @param data data to write
* @param length length of the data
* @return true on success or false on error
*/
static
bool
qwrite(
const void *data,
uint32_t length
) {
uint32_t c;
void *b;
c = queue.capacity;
while (c < queue.write + length)
c += 4096;
if (c != queue.capacity) {
b = realloc(queue.queue, c);
if (b == NULL)
return false;
queue.queue = b;
queue.capacity = c;
}
memcpy(queue.queue + queue.write, data, length);
queue.write += length;
return true;
}
/**
* Put the time in the queue
*
* @param value the value to put
* @return true on success or false on error
*/
static
bool
qput_time(
time_t value
) {
return qwrite(&value, sizeof value);
}
/**
* Put the text in the queue
*
* @param text the text to put
*
* @return true on success or false on error
*/
static
bool
qput_string(
const char *text
) {
size_t len;
text = text ?: "";
/* check length */
len = strnlen(text, MAX_NAME_LENGTH + 1);
if (len > MAX_NAME_LENGTH)
return false;
return qwrite(text, 1 + (uint32_t)len);
}
/* see queue.h */
int
queue_drop(
const data_key_t *key
) {
return qput_string(key->client)
&& qput_string(key->session)
&& qput_string(key->user)
&& qput_string(key->permission)
&& qput_string(NULL)
? 0 : -(errno = ENOMEM);
}
/* see queue.h */
int
queue_set(
const data_key_t *key,
const data_value_t *value
) {
return qput_string(key->client)
&& qput_string(key->session)
&& qput_string(key->user)
&& qput_string(key->permission)
&& qput_string(value->value)
&& qput_time(value->expire)
? 0 : -(errno = ENOMEM);
}
/* see queue.h */
void
queue_clear(
) {
queue.write = 0;
}
/* see queue.h */
int
queue_play(
) {
int rc, rc2;
data_key_t key;
data_value_t value;
rc = 0;
queue.read = 0;
while (queue.read < queue.write) {
rc2 = -EINVAL;
if (qget_string(&key.client)
&& qget_string(&key.session)
&& qget_string(&key.user)
&& qget_string(&key.permission)
&& qget_string(&value.value)) {
if (!value.value[0])
rc2 = db_drop(&key);
else {
if (qget_time(&value.expire))
rc2 = db_set(&key, &value);
}
}
if (rc2 != 0 && rc == 0)
rc = rc2;
}
return rc;
}
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