a much of multicasting stuff

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

1 files changed, 156 insertions, 0 deletions

diff --git a/src/mds-server/multicast.c b/src/mds-server/multicast.c
new file mode 100644
index 0000000..9be0e8d
--- /dev/null
+++ b/src/mds-server/multicast.c
@@ -0,0 +1,156 @@
+/**
+ * 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 "multicast.h"
+
+#include "interception_condition.h"
+
+#include <libmdsserver/macros.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+
+/**
+ * Initialise a message multicast state
+ * 
+ * @param  this  The message multicast state
+ */
+void multicast_initialise(multicast_t* restrict this)
+{
+  this->interceptions = NULL;
+  this->interceptions_count = 0;
+  this->interceptions_ptr = 0;
+  this->message = NULL;
+  this->message_length = 0;
+  this->message_ptr = 0;
+  this->message_prefix = 0;
+}
+
+
+/**
+ * Destroy a message multicast state
+ * 
+ * @param  this  The message multicast state
+ */
+void multicast_destroy(multicast_t* restrict this)
+{
+  free(this->interceptions);
+  free(this->message);
+}
+
+
+/**
+ * Calculate the buffer size need to marshal a message multicast state
+ * 
+ * @param   this  The client information
+ * @return        The number of bytes to allocate to the output buffer
+ */
+size_t multicast_marshal_size(const multicast_t* restrict this)
+{
+  size_t rc = 5 * sizeof(size_t) + this->message_length * sizeof(char);
+  size_t i;
+  for (i = 0; i < this->interceptions_count; i++)
+    rc += queued_interception_marshal_size();
+  return rc;
+}
+
+
+/**
+ * Marshals a message multicast state
+ * 
+ * @param   this  The message multicast state
+ * @param   data  Output buffer for the marshalled data
+ * @return        The number of bytes that have been written (everything will be written)
+ */
+size_t multicast_marshal(const multicast_t* restrict this, char* restrict data)
+{
+  size_t rc = 5 * sizeof(size_t);
+  size_t i, n;
+  buf_set_next(data, size_t, this->interceptions_count);
+  buf_set_next(data, size_t, this->interceptions_ptr);
+  buf_set_next(data, size_t, this->message_length);
+  buf_set_next(data, size_t, this->message_ptr);
+  buf_set_next(data, size_t, this->message_prefix);
+  for (i = 0; i < this->interceptions_count; i++)
+    {
+      n = queued_interception_marshal(this->interceptions + i, data);
+      data += n / sizeof(char);
+      rc += n;
+    }
+  memcpy(data, this->message, this->message_length * sizeof(char));
+  rc += this->message_length * sizeof(char);
+  return rc;
+}
+
+
+/**
+ * Unmarshals a message multicast state
+ * 
+ * @param   this  Memory slot in which to store the new message multicast state
+ * @param   data  In buffer with the marshalled data
+ * @return        Zero on error, errno will be set accordingly, otherwise the number of read bytes.
+ *                Destroy the client information on error.
+ */
+size_t multicast_unmarshal(multicast_t* restrict this, char* restrict data)
+{
+  size_t rc = 5 * sizeof(size_t);
+  size_t i, n;
+  this->interceptions = NULL;
+  this->message = NULL;
+  buf_get_next(data, size_t, this->interceptions_count);
+  buf_get_next(data, size_t, this->interceptions_ptr);
+  buf_get_next(data, size_t, this->message_length);
+  buf_get_next(data, size_t, this->message_ptr);
+  buf_get_next(data, size_t, this->message_prefix);
+  if (xmalloc(this->interceptions, this->interceptions_count, queued_interception_t))
+    return 0;
+  for (i = 0; i < this->interceptions_count; i++)
+    {
+      n = queued_interception_unmarshal(this->interceptions + i, data);
+      data += n / sizeof(char);
+      rc += n;
+    }
+  if (xmalloc(this->message, this->message_length, char))
+    return 0;
+  memcpy(this->message, data, this->message_length * sizeof(char));
+  rc += this->message_length * sizeof(char);
+  return rc;
+}
+
+
+/**
+ * Pretend to unmarshal a message multicast state
+ * 
+ * @param   data  In buffer with the marshalled data
+ * @return        The number of read bytes
+ */
+size_t multicast_unmarshal_skip(char* restrict data)
+{
+  size_t interceptions_count = buf_cast(data, size_t, 0);
+  size_t message_length = buf_cast(data, size_t, 2);
+  size_t rc = 5 * sizeof(size_t) + message_length * sizeof(char);
+  size_t n;
+  while (interceptions_count--)
+    {
+      n = queued_interception_unmarshal_skip();
+      data += n / sizeof(char);
+      rc += n;
+    }
+  return rc;
+}
+