From ae7a6c404f9842e67e6822eacf465fb4b482d631 Mon Sep 17 00:00:00 2001
From: Philippe PITTOLI <p.pittoli@unistra.fr>
Date: Tue, 9 Oct 2018 16:38:27 +0200
Subject: [PATCH] message.[ch] from pubsub

---
 pubsub/lib/message.c | 132 +++++++++++++++++++++++++++++++++++++++++++
 pubsub/lib/message.h |  21 +++++++
 2 files changed, 153 insertions(+)
 create mode 100644 pubsub/lib/message.c
 create mode 100644 pubsub/lib/message.h

diff --git a/pubsub/lib/message.c b/pubsub/lib/message.c
new file mode 100644
index 0000000..5e1c78a
--- /dev/null
+++ b/pubsub/lib/message.c
@@ -0,0 +1,132 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "message.h"
+#include "../../core/error.h"
+
+void pubsub_message_serialize (const struct pubsub_msg *msg, char **data, size_t *len)
+{
+    if (msg == NULL) {
+        handle_err ("pubsub_message_serialize", "msg == NULL");
+        return;
+    }
+
+    if (data == NULL) {
+        handle_err ("pubsub_message_serialize", "data == NULL");
+        return;
+    }
+
+    if (*data != NULL) {
+        handle_err ("pubsub_message_serialize", "*data != NULL");
+        return;
+    }
+
+    if (len == NULL) {
+        handle_err ("pubsub_message_serialize", "len == NULL");
+        return;
+    }
+
+    // buflen = pubsub msg type (1) + 2* size_t (16) + chan+data
+    size_t buflen = 1 + 2 * sizeof (size_t) + msg->chanlen + msg->datalen;
+
+    if (buflen > BUFSIZ) {
+        handle_err ("pubsub_message_serialize", "chanlen + datalen too high");
+        return;
+    }
+
+    char *buf = malloc (buflen);
+    memset (buf, 0, buflen);
+
+    size_t offset = 0;
+
+    // msg type
+    buf[offset++] = msg->type;
+
+    // chan
+    memcpy (buf + offset, &msg->chanlen, sizeof (size_t));
+    offset += sizeof (size_t);
+    memcpy (buf + offset, msg->chan, msg->chanlen);
+    offset += msg->chanlen;
+
+    // data
+    memcpy (buf + offset, &msg->datalen, sizeof (size_t));
+    offset += sizeof (size_t);
+    memcpy (buf + offset, msg->data, msg->datalen);
+    offset += msg->datalen;
+
+    *data = buf;
+    *len = buflen;
+}
+
+void pubsub_message_unserialize (struct pubsub_msg *msg, const char *buf, size_t mlen)
+{
+    if (msg == NULL) {
+        handle_err ("pubsub_message_unserialize", "msg == NULL");
+        return;
+    }
+
+    pubsub_message_free (msg);
+
+    if (mlen > BUFSIZ) {
+        handle_err ("pubsub_message_unserialize", "mlen > BUFSIZ");
+        return;
+    }
+
+    size_t offset = 0;
+
+    // msg type
+    msg->type = buf[offset++];
+
+    // chan
+    memcpy (&msg->chanlen, buf + offset, sizeof (size_t));
+    if (msg->chanlen > BUFSIZ) {
+        handle_err ("pubsub_message_unserialize", "chanlen > BUFSIZ");
+        return;
+    }
+    msg->chan = malloc (msg->chanlen);
+    memset (msg->chan, 0, msg->chanlen);
+    offset += sizeof (size_t);
+    memcpy (msg->chan, buf + offset, msg->chanlen);
+    offset += msg->chanlen;
+
+    // data
+    memcpy (&msg->datalen, buf + offset, sizeof (size_t));
+    if (msg->datalen > BUFSIZ) {
+        handle_err ("pubsub_message_unserialize", "datalen > BUFSIZ");
+        return;
+    }
+    msg->data = malloc (msg->datalen);
+    memset (msg->data, 0, msg->datalen);
+    offset += sizeof (size_t);
+    memcpy (msg->data, buf + offset, msg->datalen);
+    offset += msg->datalen;
+}
+
+void pubsub_message_free (struct pubsub_msg *msg)
+{
+    if (msg == NULL) {
+        handle_err ("pubsub_message_free", "msg == NULL");
+        return;
+    }
+
+    if (msg->chan) {
+        free (msg->chan);
+        msg->chan = NULL;
+    }
+    if (msg->data) {
+        free (msg->data);
+        msg->data = NULL;
+    }
+}
+
+void pubsub_message_print (const struct pubsub_msg *msg)
+{
+    if (msg == NULL) {
+        handle_err ("pubsub_message_print", "msg == NULL");
+        return;
+    }
+
+    printf ("msg: type=%d chan=%s, data=%s\n"
+            , msg->type, msg->chan, msg->data);
+}
diff --git a/pubsub/lib/message.h b/pubsub/lib/message.h
new file mode 100644
index 0000000..8154fff
--- /dev/null
+++ b/pubsub/lib/message.h
@@ -0,0 +1,21 @@
+#ifndef __PUBSUB_MSG_H__
+#define __PUBSUB_MSG_H__
+
+#define PUBSUB_MSG_TYPE_SUB         1
+#define PUBSUB_MSG_TYPE_UNSUB       2
+#define PUBSUB_MSG_TYPE_PUB         3
+
+struct pubsub_msg {
+    unsigned char type; // message type : alert, notification, …
+    char *chan;
+    size_t chanlen;
+    char *data;
+    size_t datalen;
+};
+
+void pubsub_message_serialize (const struct pubsub_msg *msg, char **data, size_t *len);
+void pubsub_message_unserialize (struct pubsub_msg *msg, const char *data, size_t len);
+void pubsub_message_free (struct pubsub_msg *msg);
+void pubsub_message_print (const struct pubsub_msg *msg);
+
+#endif