Cleanup: simplify dive_getUniqID()

dive_getUniqID() is used to create unique dive ids, which are
stable during application lifetime. It was passed a dive, checked
that the id was not set (if it was that it is know to the application)
and set a new id (in contradiction to its name!) if it hadn't any.

There were three callers:

alloc_dive(): called the function on a zeroed dive struct.
fixup_dive(): called the function only if the dive had a 0 id.
MainWindow::setupForAddAndPlan(): called the function on a zeroed dive
struct.

Thus, in all three callers the id is guaranteed to be zero and
the whole keeping-track-of-ids logic is moot. Remove the logic,
don't pass a dive struct to dive_getUniqID() and move the function
to the C-backend.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/dive.c

@@ -454,6 +454,15 @@ double get_weight_units(unsigned int grams, int *frac, const char **units)
 	return value;
 }
 
+// we need this to be uniq. oh, and it has no meaning whatsoever
+// - that's why we have the silly initial number and increment by 3 :-)
+int dive_getUniqID()
+{
+	static int maxId = 83529;
+	maxId += 3;
+	return maxId;
+}
+
 struct dive *alloc_dive(void)
 {
 	struct dive *dive;
@@ -462,7 +471,7 @@ struct dive *alloc_dive(void)
 	if (!dive)
 		exit(1);
 	memset(dive, 0, sizeof(*dive));
-	dive->id = dive_getUniqID(dive);
+	dive->id = dive_getUniqID();
 	return dive;
 }
 
@@ -1784,7 +1793,7 @@ struct dive *fixup_dive(struct dive *dive)
 	/* we should always have a uniq ID as that gets assigned during alloc_dive(),
 	 * but we want to make sure... */
 	if (!dive->id)
-		dive->id = dive_getUniqID(dive);
+		dive->id = dive_getUniqID();
 
 	return dive;
 }

core/dive.h

@@ -757,7 +757,7 @@ extern int legacy_format_o2pressures(struct dive *dive, struct divecomputer *dc)
 extern void sort_table(struct dive_table *table);
 extern struct dive *fixup_dive(struct dive *dive);
 extern void fixup_dc_duration(struct divecomputer *dc);
-extern int dive_getUniqID(struct dive *d);
+extern int dive_getUniqID();
 extern unsigned int dc_airtemp(struct divecomputer *dc);
 extern unsigned int dc_watertemp(struct divecomputer *dc);
 extern int split_dive(struct dive *);

core/qthelper.cpp

@@ -288,31 +288,6 @@ QList<int> getDivesInTrip(dive_trip_t *trip)
 	return ret;
 }
 
-// we need this to be uniq, but also make sure
-// it doesn't change during the life time of a Subsurface session
-// oh, and it has no meaning whatsoever - that's why we have the
-// silly initial number and increment by 3 :-)
-int dive_getUniqID(struct dive *d)
-{
-	static QSet<int> ids;
-	static int maxId = 83529;
-
-	int id = d->id;
-	if (id) {
-		if (!ids.contains(id)) {
-			qDebug() << "WTF - only I am allowed to create IDs";
-			ids.insert(id);
-		}
-		return id;
-	}
-	maxId += 3;
-	id = maxId;
-	Q_ASSERT(!ids.contains(id));
-	ids.insert(id);
-	return id;
-}
-
-
 static xmlDocPtr get_stylesheet_doc(const xmlChar *uri, xmlDictPtr, int, void *, xsltLoadType)
 {
 	QFile f(QLatin1String(":/xslt/") + (const char *)uri);

desktop-widgets/mainwindow.cpp

@@ -982,7 +982,7 @@ void MainWindow::setupForAddAndPlan(const char *model)
 	// clean out the dive and give it an id and the correct dc model
 	clear_dive(&displayed_dive);
 	clear_dive_site(&displayed_dive_site);
-	displayed_dive.id = dive_getUniqID(&displayed_dive);
+	displayed_dive.id = dive_getUniqID();
 	displayed_dive.when = QDateTime::currentMSecsSinceEpoch() / 1000L + gettimezoneoffset() + 3600;
 	displayed_dive.dc.model = strdup(model); // don't translate! this is stored in the XML file
 	dc_number = 1;