Make created dive site uuid deterministic

Having random uuids seemed like a good idea, but there are several
situations where they really cause problems. One is merging dive file
imports from V2 logfiles. Another is testing such imports.

Instead of making the uuid random we now hash the name and add the
timestamp of the first dive associated with this dive site to the hash
(first in this context is "first encountered" with no guarantee that it is
the chronologically first). This way V2 imports create deterministic uuids
but uuid conflicts are still extremely unlikely, even if the user has
multiple dive sites with the same name.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 9 insertions, 4 deletions

diff --git a/liquivision.c b/liquivision.c
index add377237..295287c15 100644
--- a/liquivision.c
+++ b/liquivision.c
@@ -101,6 +101,7 @@ static void parse_dives (int log_version, const unsigned char *buf, unsigned int
 
 	while (ptr < buf_size) {
 		int i;
+		bool found_divesite = false;
 		dive = alloc_dive();
 		primary_sensor = 0;
 		dc = &dive->dc;
@@ -148,10 +149,8 @@ static void parse_dives (int log_version, const unsigned char *buf, unsigned int
 		}
 
 		/* Store the location only if we have one */
-		if (len || place_len) {
-			dive->dive_site_uuid = find_or_create_dive_site_with_name(location);
-			free(location);
-		}
+		if (len || place_len)
+			found_divesite = true;
 
 		ptr += len + 4 + place_len;
 
@@ -183,6 +182,12 @@ static void parse_dives (int log_version, const unsigned char *buf, unsigned int
 		dive->when = array_uint32_le(buf + ptr);
 		ptr += 4;
 
+		// now that we have the dive time we can store the divesite
+		// (we need the dive time to create deterministic uuids)
+		if (found_divesite) {
+			dive->dive_site_uuid = find_or_create_dive_site_with_name(location, dive->when);
+			free(location);
+		}
 		//unsigned int end_time = array_uint32_le(buf + ptr);
 		ptr += 4;