From c191b15809aa234516e48de5b5af305035423d4e Mon Sep 17 00:00:00 2001
From: Steffen Vogel <post@steffenvogel.de>
Date: Mon, 17 Aug 2020 17:01:36 +0200
Subject: [PATCH] path: add UUID

---
 include/villas/path.h | 11 +++++++----
 lib/path.cpp          | 22 +++++++++++++++++++---
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/include/villas/path.h b/include/villas/path.h
index 72348d6f8..5cd3a2b1c 100644
--- a/include/villas/path.h
+++ b/include/villas/path.h
@@ -31,6 +31,7 @@
 
 #include <bitset>
 
+#include <uuid/uuid.h>
 #include <pthread.h>
 #include <jansson.h>
 
@@ -59,6 +60,8 @@ struct vpath {
 
 	enum PathMode mode;		/**< Determines when this path is triggered. */
 
+	uuid_t uuid;
+
 	struct {
 		int nfds;
 		struct pollfd *pfds;
@@ -79,10 +82,10 @@ struct vpath {
 	double rate;			/**< A timeout for */
 	int enabled;			/**< Is this path enabled. */
 	int poll;			/**< Weather or not to use poll(2). */
-	int reverse;			/**< This path as a matching reverse path. */
+	int reverse;			/**< This path has a matching reverse path. */
 	int builtin;			/**< This path should use built-in hooks by default. */
-	int original_sequence_no;       /**< Use original source sequence number when multiplexing */
-	unsigned queuelen;			/**< The queue length for each path_destination::queue */
+	int original_sequence_no;	/**< Use original source sequence number when multiplexing */
+	unsigned queuelen;		/**< The queue length for each path_destination::queue */
 
 	char *_name;			/**< Singleton: A string which is used to print this path to screen. */
 
@@ -92,7 +95,7 @@ struct vpath {
 	villas::Logger logger;
 
 	std::bitset<MAX_SAMPLE_LENGTH> mask;		/**< A mask of path_sources which are enabled for poll(). */
-	std::bitset<MAX_SAMPLE_LENGTH> received;		/**< A mask of path_sources for which we already received samples. */
+	std::bitset<MAX_SAMPLE_LENGTH> received;	/**< A mask of path_sources for which we already received samples. */
 };
 
 /** Initialize internal data structures. */
diff --git a/lib/path.cpp b/lib/path.cpp
index 2babe99a7..fcef417f7 100644
--- a/lib/path.cpp
+++ b/lib/path.cpp
@@ -27,6 +27,7 @@
 
 #include <unistd.h>
 #include <poll.h>
+#include <openssl/md5.h>
 
 #include <villas/node/config.h>
 #include <villas/utils.hpp>
@@ -323,12 +324,12 @@ int path_parse(struct vpath *p, json_t *cfg, struct vlist *nodes)
 	json_t *json_hooks = nullptr;
 	json_t *json_mask = nullptr;
 
-	const char *mode = nullptr;
+	const char *mode = nullptr, *uuid = nullptr;
 
 	struct vlist destinations;
 	vlist_init(&destinations);
 
-	ret = json_unpack_ex(cfg, &err, 0, "{ s: o, s?: o, s?: o, s?: b, s?: b, s?: b, s?: i, s?: s, s?: b, s?: F, s?: o, s?: b}",
+	ret = json_unpack_ex(cfg, &err, 0, "{ s: o, s?: o, s?: o, s?: b, s?: b, s?: b, s?: i, s?: s, s?: b, s?: F, s?: o, s?: b, s?: s}",
 		"in", &json_in,
 		"out", &json_out,
 		"hooks", &json_hooks,
@@ -340,7 +341,8 @@ int path_parse(struct vpath *p, json_t *cfg, struct vlist *nodes)
 		"poll", &p->poll,
 		"rate", &p->rate,
 		"mask", &json_mask,
-		"original_sequence_no", &p->original_sequence_no
+		"original_sequence_no", &p->original_sequence_no,
+		"uuid", &uuid
 	);
 	if (ret)
 		jerror(&err, "Failed to parse path configuration");
@@ -364,6 +366,20 @@ int path_parse(struct vpath *p, json_t *cfg, struct vlist *nodes)
 		}
 	}
 
+	if (uuid) {
+		ret = uuid_parse(uuid, p->uuid);
+		if (ret)
+			throw ConfigError(cfg, "node-config-path-uuid", "Failed to parse UUID: {}", uuid);
+	}
+	else {
+		/* Generate UUID from hashed config */
+		char *json_str = json_dumps(cfg, JSON_COMPACT | JSON_SORT_KEYS);
+
+		MD5((unsigned char*) json_str, strlen(json_str), (unsigned char*) &p->uuid);
+
+		free(json_str);
+	}
+
 	/* Output node(s) */
 	if (json_out) {
 		ret = node_list_parse(&destinations, json_out, nodes);