Restructure

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 137 insertions, 0 deletions

diff --git a/src/communication.h b/src/communication.h
new file mode 100644
index 0000000..43af314
--- /dev/null
+++ b/src/communication.h
@@ -0,0 +1,137 @@
+/**
+ * coopgammad -- Cooperative gamma server
+ * Copyright (C) 2016  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/>.
+ */
+#ifndef COMMUNICATION_H
+#define COMMUNICATION_H
+
+
+#include <stdio.h>
+#include <stdlib.h>
+
+
+
+#ifndef GCC_ONLY
+# if defined(__GNUC__) && !defined(__clang__)
+#  define GCC_ONLY(...)  __VA_ARGS__
+# else
+#  define GCC_ONLY(...)  /* nothing */
+# endif
+#endif
+
+
+
+/**
+ * Construct a message
+ * 
+ * @param  bufp:char**            Output parameter for the buffer, must not have side-effects
+ * @param  np:size_t*             Output parameter for the size of the buffer sans `extra`
+ * @param  extra:size_t           The extra number for bytes to allocate to the buffer
+ * @param  format:string-literal  Message format string
+ * @param  ...                    Message formatting arguments
+ */
+#define MAKE_MESSAGE(bufp, np, extra, format, ...)		\
+  do								\
+    {								\
+      ssize_t m__;						\
+      snprintf(NULL, 0, format "%zn", __VA_ARGS__, &m__);	\
+      *(bufp) = malloc((size_t)(extra) + (size_t)m__);		\
+      if (*(bufp) == NULL)					\
+	return -1;						\
+      sprintf(*(bufp), format, __VA_ARGS__);			\
+      *(np) = (size_t)m__;					\
+    }								\
+  while (0)
+
+/**
+ * Send a custom error without an error number
+ * 
+ * @param   ...  The error description to send
+ * @return       1: Client disconnected
+ *               0: Success (possibily delayed)
+ *               -1: An error occurred
+ */
+#define send_error(...)  ((send_error)(conn, message_id, __VA_ARGS__))
+
+/**
+ * Send a standard error
+ * 
+ * @param   ...  The value of `errno`, 0 to indicate success
+ * @return       1: Client disconnected
+ *               0: Success (possibily delayed)
+ *               -1: An error occurred
+ */
+#define send_errno(...)  ((send_errno)(conn, message_id, __VA_ARGS__))
+
+
+
+/**
+ * Send a message
+ * 
+ * @param   conn  The index of the connection
+ * @param   buf   The data to send
+ * @param   n     The size of `buf`
+ * @return        Zero on success, -1 on error, 1 if disconncted
+ *                EINTR, EAGAIN, EWOULDBLOCK, and ECONNRESET count
+ *                as success (ECONNRESET cause 1 to be returned),
+ *                and are handled appropriately.
+ */
+int send_message(size_t conn, char* restrict buf, size_t n);
+
+/**
+ * Send a custom error without an error number
+ * 
+ * @param   conn        The index of the connection
+ * @param   message_id  The ID of the message to which this message is a response
+ * @param   desc        The error description to send
+ * @return              1: Client disconnected
+ *                      0: Success (possibily delayed)
+ *                      -1: An error occurred
+ */
+GCC_ONLY(__attribute__((nonnull)))
+int (send_error)(size_t conn, const char* restrict message_id, const char* restrict desc);
+
+/**
+ * Send a standard error
+ * 
+ * @param   conn        The index of the connection
+ * @param   message_id  The ID of the message to which this message is a response
+ * @param   number      The value of `errno`, 0 to indicate success
+ * @return              1: Client disconnected
+ *                      0: Success (possibily delayed)
+ *                      -1: An error occurred
+ */
+GCC_ONLY(__attribute__((nonnull)))
+int (send_errno)(size_t conn, const char* restrict message_id, int number);
+
+/**
+ * Continue sending the queued messages
+ * 
+ * @param   conn  The index of the connection
+ * @return        Zero on success, -1 on error, 1 if disconncted
+ *                EINTR, EAGAIN, EWOULDBLOCK, and ECONNRESET count
+ *                as success (ECONNRESET cause 1 to be returned),
+ *                and are handled appropriately.
+ */
+static inline int continue_send(size_t conn)
+{
+  return send_message(conn, NULL, 0);
+}
+
+
+
+#endif
+