misc

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 241 insertions, 0 deletions

diff --git a/src/libmdsserver/client-list.c b/src/libmdsserver/client-list.c
new file mode 100644
index 0000000..0e1a2ab
--- /dev/null
+++ b/src/libmdsserver/client-list.c
@@ -0,0 +1,241 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * 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 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 __WORDSIZE == 64
+  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 == 0)
+    capacity = CLIENT_LIST_DEFAULT_INITIAL_CAPACITY;
+  
+  /* Initialise the client list. */
+  this->capacity   = capacity = to_power_of_two(capacity);
+  this->size       = 0;
+  this->clients     = NULL;
+  if (xmalloc(this->clients, capacity, uint64_t))
+    return -1;
+  
+  return 0;
+}
+
+
+/**
+ * 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)
+{
+  size_t n = this->capacity * sizeof(uint64_t);
+  uint64_t* restrict new_clients = NULL;
+  
+  out->clients = NULL;
+  
+  if ((new_clients = malloc(n)) == NULL)
+    goto fail;
+  
+  out->clients = new_clients;
+  
+  out->capacity = this->capacity;
+  out->size     = this->size;
+  
+  memcpy(out->clients, this->clients, n);
+  
+  return 0;
+  
+ fail:
+  free(new_clients);
+  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)
+{
+  if (this->size == this->capacity)
+    {
+      uint64_t* old = this->clients;
+      if (xrealloc(old, this->capacity <<= 1, uint64_t))
+	{
+	  this->capacity >>= 1;
+	  this->clients = old;
+	  return -1;
+	}
+    }
+  
+  this->clients[this->size++] = client;
+  return 0;
+}
+
+
+/**
+ * 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;
+  for (i = 0; i < this->size; i++)
+    {
+      if (this->clients[i] == client)
+	{
+	  size_t n = (--(this->size) - i) * sizeof(uint64_t);
+	  memmove(this->clients + i, this->clients + i + 1, n);
+	  
+	  if (this->size << 1 <= this->capacity)
+	    {
+	      uint64_t* 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)
+{
+  size_t n;
+  
+  /* 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);
+  
+  n = this->capacity * sizeof(uint64_t);
+  
+  if ((this->clients = malloc(n)) == NULL)
+    return -1;
+  
+  n = this->size * sizeof(uint64_t);
+  
+  memcpy(this->clients, data, n);
+  
+  return 0;
+}
+