From: chris mikkelson <chris@mikk.net>
Date: Thu, 15 Apr 2010 21:02:33 +0000 (-0500)
Subject: Added inter-module communication "channels" API.  Modules can
X-Git-Url: https://git.mikk.net/?a=commitdiff_plain;h=993804158efc5e88cbc79c5d78d43aed11b8fcf6;p=smtpsink

Added inter-module communication "channels" API.  Modules can
register callbacks to named channels with ssm_subscribe() and
publish to named channels with ssm_publish().
---

diff --git a/module_api.c b/module_api.c
index e050374..a2dcd1d 100644
--- a/module_api.c
+++ b/module_api.c
@@ -73,3 +73,79 @@ ssm_setpriv(struct smtpsink_module *m, struct conn *c, void *data)
 	assert(c->priv_data);
 	c->priv_data[m->ssm_module_index] = data;
 }
+
+struct sub {
+	void (*cb)(struct conn *, void *);
+	SLIST_ENTRY(sub) sub_list;
+};
+
+struct channel {
+	const char *name;
+	unsigned np;
+	SLIST_ENTRY(channel) chan_list;
+	SLIST_HEAD(,sub) subscribers;
+};
+
+SLIST_HEAD(,channel) channels = SLIST_HEAD_INITIALIZER(channels);
+
+void
+ssm_subscribe(const char *chan, void (*cb)(struct conn *, void *))
+{
+	struct sub *s = malloc(sizeof(struct sub));
+	struct channel *ch;
+
+	s->cb = cb;
+	SLIST_FOREACH(ch, &channels, chan_list) {
+		if (!strcmp(ch->name, chan)) {
+			SLIST_INSERT_HEAD(&ch->subscribers, s, sub_list);
+			return;
+		}
+	}
+	ch = malloc(sizeof(struct channel));
+	ch->name = chan;
+	SLIST_INIT(&ch->subscribers);
+	SLIST_INSERT_HEAD(&ch->subscribers, s, sub_list);
+	SLIST_INSERT_HEAD(&channels, ch, chan_list);
+}
+
+int
+ssm_nproviders(const char *chan)
+{
+	struct channel *ch;
+	SLIST_FOREACH(ch, &channels, chan_list) {
+		if (!strcmp(ch->name, chan))
+			return ch->np;
+	}
+	return 0;
+}
+
+void
+ssm_provide(const char *chan)
+{
+	struct channel *ch;
+	SLIST_FOREACH(ch, &channels, chan_list) {
+		if (!strcmp(ch->name, chan)) {
+			ch->np++;
+			return;
+		}
+	}
+        ch = malloc(sizeof(struct channel));
+        ch->name = chan;
+	ch->np = 1;
+        SLIST_INIT(&ch->subscribers);
+	SLIST_INSERT_HEAD(&channels, ch, chan_list);
+}
+
+void
+ssm_publish(const char *chan, struct conn *c, void *data)
+{
+	struct sub *s;
+	struct channel *ch;
+	SLIST_FOREACH(ch, &channels, chan_list) {
+		if (!strcmp(ch->name, chan)) {
+			SLIST_FOREACH(s, &ch->subscribers, sub_list) {
+				s->cb(c, data);
+			}
+		}
+	}
+}
diff --git a/smtpsink.h b/smtpsink.h
index a0302f6..11bb671 100644
--- a/smtpsink.h
+++ b/smtpsink.h
@@ -88,3 +88,14 @@ struct smtpsink_module {
 
 void *ssm_getpriv(struct smtpsink_module *, struct conn *);
 void ssm_setpriv(struct smtpsink_module *, struct conn *, void *);
+
+/* inter-module communication */
+int ssm_nproviders(const char *);
+void ssm_provide(const char *);
+void ssm_publish(const char *, struct conn *, void *);
+void ssm_subscribe(const char *, void (*)(struct conn *, void *));
+
+struct message_body {
+	char *body;
+	size_t blen;
+};