Core: dynamically allocate the result of get_gas_used()

get_gas_used() returns the volume of used gases. Currently,
an array with MAX_CYLINDERS is passed in. If we want to make the
number of cylinders dynamic, the function must use an arbitrarilly
sized array.

Therefore, return a dynamically allocated array and free it
in the caller.

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

5 files changed, 16 insertions, 10 deletions

diff --git a/core/qthelper.cpp b/core/qthelper.cpp
index 8082db742..700854ebc 100644
--- a/core/qthelper.cpp
+++ b/core/qthelper.cpp
@@ -388,13 +388,14 @@ QVector<QPair<QString, int>> selectedDivesGasUsed()
 	for_each_dive (i, d) {
 		if (!d->selected)
 			continue;
-		volume_t diveGases[MAX_CYLINDERS] = {};
-		get_gas_used(d, diveGases);
-		for (j = 0; j < MAX_CYLINDERS; j++)
+		volume_t *diveGases = get_gas_used(d);
+		for (j = 0; j < MAX_CYLINDERS; j++) {
 			if (diveGases[j].mliter) {
 				QString gasName = gasname(d->cylinder[j].gasmix);
 				gasUsed[gasName] += diveGases[j].mliter;
 			}
+		}
+		free(diveGases);
 	}
 	QVector<QPair<QString, int>> gasUsedOrdered;
 	gasUsedOrdered.reserve(gasUsed.size());
diff --git a/core/statistics.c b/core/statistics.c
index 6e4630d64..d5ef58955 100644
--- a/core/statistics.c
+++ b/core/statistics.c
@@ -359,10 +359,13 @@ bool is_cylinder_prot(const struct dive *dive, int idx)
 	return false;
 }
 
-void get_gas_used(struct dive *dive, volume_t gases[MAX_CYLINDERS])
+/* Returns a dynamically allocated array with MAX_CYLINDERS entries that
+ * has to be freed by the caller */
+volume_t *get_gas_used(struct dive *dive)
 {
 	int idx;
 
+	volume_t *gases = malloc(MAX_CYLINDERS * sizeof(volume_t));
 	for (idx = 0; idx < MAX_CYLINDERS; idx++) {
 		cylinder_t *cyl = &dive->cylinder[idx];
 		pressure_t start, end;
@@ -372,6 +375,8 @@ void get_gas_used(struct dive *dive, volume_t gases[MAX_CYLINDERS])
 		if (end.mbar && start.mbar > end.mbar)
 			gases[idx].mliter = gas_volume(cyl, start) - gas_volume(cyl, end);
 	}
+
+	return gases;
 }
 
 /* Quite crude reverse-blender-function, but it produces a approx result */
@@ -397,8 +402,7 @@ void selected_dives_gas_parts(volume_t *o2_tot, volume_t *he_tot)
 	for_each_dive (i, d) {
 		if (!d->selected)
 			continue;
-		volume_t diveGases[MAX_CYLINDERS] = {};
-		get_gas_used(d, diveGases);
+		volume_t *diveGases = get_gas_used(d);
 		for (j = 0; j < MAX_CYLINDERS; j++) {
 			if (diveGases[j].mliter) {
 				volume_t o2 = {}, he = {};
@@ -407,5 +411,6 @@ void selected_dives_gas_parts(volume_t *o2_tot, volume_t *he_tot)
 				he_tot->mliter += he.mliter;
 			}
 		}
+		free(diveGases);
 	}
 }
diff --git a/core/statistics.h b/core/statistics.h
index 257303e19..6e125a217 100644
--- a/core/statistics.h
+++ b/core/statistics.h
@@ -10,7 +10,6 @@
 #define STATISTICS_H
 
 #include "core/units.h"
-#include "core/dive.h"	// For MAX_CYLINDERS
 
 #define STATS_MAX_DEPTH 300	/* Max depth for stats bucket is 300m */
 #define STATS_DEPTH_BUCKET 10	/* Size of buckets for depth range */
@@ -62,7 +61,7 @@ extern void init_stats_summary(struct stats_summary *stats);
 extern void free_stats_summary(struct stats_summary *stats);
 extern void calculate_stats_summary(struct stats_summary *stats, bool selected_only);
 extern void calculate_stats_selected(stats_t *stats_selection);
-extern void get_gas_used(struct dive *dive, volume_t gases[MAX_CYLINDERS]);
+extern volume_t *get_gas_used(struct dive *dive);
 extern void selected_dives_gas_parts(volume_t *o2_tot, volume_t *he_tot);
 
 #ifdef __cplusplus
diff --git a/desktop-widgets/tab-widgets/TabDiveInformation.cpp b/desktop-widgets/tab-widgets/TabDiveInformation.cpp
index 273bf4525..e6bb7c581 100644
--- a/desktop-widgets/tab-widgets/TabDiveInformation.cpp
+++ b/desktop-widgets/tab-widgets/TabDiveInformation.cpp
@@ -53,8 +53,7 @@ void TabDiveInformation::updateProfile()
 	ui->maximumDepthText->setText(get_depth_string(current_dive->maxdepth, true));
 	ui->averageDepthText->setText(get_depth_string(current_dive->meandepth, true));
 
-	volume_t gases[MAX_CYLINDERS] = {};
-	get_gas_used(current_dive, gases);
+	volume_t *gases =  get_gas_used(current_dive);
 	QString volumes;
 	int mean[MAX_CYLINDERS], duration[MAX_CYLINDERS];
 	per_cylinder_mean_depth(current_dive, select_dc(current_dive), mean, duration);
@@ -76,6 +75,7 @@ void TabDiveInformation::updateProfile()
 			SACs.append(get_volume_string(sac, true).append(tr("/min")));
 		}
 	}
+	free(gases);
 	ui->gasUsedText->setText(volumes);
 	ui->oxygenHeliumText->setText(gaslist);
 
diff --git a/qt-models/yearlystatisticsmodel.cpp b/qt-models/yearlystatisticsmodel.cpp
index 5950ffd5d..d280808e9 100644
--- a/qt-models/yearlystatisticsmodel.cpp
+++ b/qt-models/yearlystatisticsmodel.cpp
@@ -3,6 +3,7 @@
 #include "core/qthelper.h"
 #include "core/metrics.h"
 #include "core/statistics.h"
+#include "core/dive.h" // For NUM_DIVEMODE
 
 class YearStatisticsItem : public TreeItem {
 	Q_DECLARE_TR_FUNCTIONS(YearStatisticsItem)