/**
* mds — A micro-display server
* Copyright © 2014, 2015, 2016, 2017 Mattias Andrée (maandree@kth.se)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "client-list.h"
#include "macros.h"
#include <string.h>
#include <errno.h>
/**
* The default initial capacity
*/
#ifndef CLIENT_LIST_DEFAULT_INITIAL_CAPACITY
# define CLIENT_LIST_DEFAULT_INITIAL_CAPACITY 8
#endif
/**
* Computes the nearest, but higher, power of two,
* but only if the current value is not a power of two
*
* @param value The value to be rounded up to a power of two
* @return The nearest, but not smaller, power of two
*/
static size_t __attribute__((const))
to_power_of_two(size_t value)
{
value -= 1;
value |= value >> 1;
value |= value >> 2;
value |= value >> 4;
value |= value >> 8;
value |= value >> 16;
#if SIZE_MAX == UINT64_MAX
value |= value >> 32;
#endif
return value + 1;
}
/**
* Create a client list
*
* @param this Memory slot in which to store the new client list
* @param capacity The minimum initial capacity of the client list, 0 for default
* @return Non-zero on error, `errno` will have been set accordingly
*/
int
client_list_create(client_list_t *restrict this, size_t capacity)
{
/* Use default capacity of zero is specified. */
if (!capacity)
capacity = CLIENT_LIST_DEFAULT_INITIAL_CAPACITY;
/* Initialise the client list. */
this->capacity = capacity = to_power_of_two(capacity);
this->size = 0;
this->clients = NULL;
fail_if (xmalloc(this->clients, capacity, uint64_t));
return 0;
fail:
return -1;
}
/**
* Release all resources in a client list, should
* be done even if `client_list_create` fails
*
* @param this The client list
*/
void
client_list_destroy(client_list_t *restrict this)
{
free(this->clients);
this->clients = NULL;
}
/**
* Clone a client list
*
* @param this The client list to clone
* @param out Memory slot in which to store the new client list
* @return Non-zero on error, `errno` will have been set accordingly
*/
int
client_list_clone(const client_list_t *restrict this, client_list_t *restrict out)
{
fail_if (xmemdup(out->clients, this->clients, this->capacity, uint64_t));
out->capacity = this->capacity;
out->size = this->size;
return 0;
fail:
return -1;
}
/**
* Add a client to the list
*
* @param this The list
* @param client The client to add
* @return Non-zero on error, `errno` will be set accordingly
*/
int
client_list_add(client_list_t *restrict this, uint64_t client)
{
uint64_t* old;
if (this->size == this->capacity) {
old = this->clients;
if (xrealloc(old, this->capacity <<= 1, uint64_t)) {
this->capacity >>= 1;
this->clients = old;
fail_if (1);
}
}
this->clients[this->size++] = client;
return 0;
fail:
return -1;
}
/**
* Remove a client from the list, once
*
* @param this The list
* @param client The client to remove
*/
void
client_list_remove(client_list_t *restrict this, uint64_t client)
{
size_t i, n;
uint64_t *old;
for (i = 0; i < this->size; i++) {
if (this->clients[i] == client) {
n = (--(this->size) - i) * sizeof(uint64_t);
memmove(this->clients + i, this->clients + i + 1, n);
if (this->size << 1 <= this->capacity) {
old = this->clients;
if (xrealloc(old, this->capacity >>= 1, uint64_t)) {
this->capacity <<= 1;
this->clients = old;
}
}
return;
}
}
}
/**
* Calculate the buffer size need to marshal a client list
*
* @param this The list
* @return The number of bytes to allocate to the output buffer
*/
size_t
client_list_marshal_size(const client_list_t *restrict this)
{
return 2 * sizeof(size_t) + this->size * sizeof(uint64_t) + sizeof(int);
}
/**
* Marshals a client list
*
* @param this The list
* @param data Output buffer for the marshalled data
*/
void
client_list_marshal(const client_list_t *restrict this, char *restrict data)
{
buf_set_next(data, int, CLIENT_LIST_T_VERSION);
buf_set_next(data, size_t, this->capacity);
buf_set_next(data, size_t, this->size);
memcpy(data, this->clients, this->size * sizeof(uint64_t));
}
/**
* Unmarshals a client list
*
* @param this Memory slot in which to store the new client list
* @param data In buffer with the marshalled data
* @return Non-zero on error, `errno` will be set accordingly.
* Destroy the list on error.
*/
int
client_list_unmarshal(client_list_t *restrict this, char *restrict data)
{
/* buf_get(data, int, 0, CLIENT_LIST_T_VERSION); */
buf_next(data, int, 1);
this->clients = NULL;
buf_get_next(data, size_t, this->capacity);
buf_get_next(data, size_t, this->size);
fail_if (xmalloc(this->clients, this->capacity, uint64_t));
memcpy(this->clients, data, this->size * sizeof(uint64_t));
return 0;
fail:
return -1;
}
