Core: remove MAX_CYLINDERS restriction

Instead of using fixed size arrays, use a new cylinder_table structure.
The code copies the weightsystem code, but is significantly more complex
because cylinders are such an integral part of the core.

Two functions to access the cylinders were added:
get_cylinder() and get_or_create_cylinder()
The former does a simple array access and supposes that the cylinder
exists. The latter is used by the parser(s) and if a cylinder with
the given id does not exist, cylinders up to that id are generated.

One point will make C programmers cringe: the cylinder structure is
passed by value. This is due to the way the table-macros work. A
refactoring of the table macros is planned. It has to be noted that
the size of a cylinder_t is 64 bytes, i.e. 8 long words on a 64-bit
architecture, so passing on the stack is probably not even significantly
slower than passing as reference.

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

1 files changed, 29 insertions, 29 deletions

diff --git a/core/libdivecomputer.c b/core/libdivecomputer.c
index 9787ab826..d3e5a115d 100644
--- a/core/libdivecomputer.c
+++ b/core/libdivecomputer.c
@@ -112,7 +112,9 @@ static int parse_gasmixes(device_data_t *devdata, struct dive *dive, dc_parser_t
 	}
 	bool no_volume = true;
 
-	for (i = 0; i < MAX_CYLINDERS && (i < ngases || i < ntanks); i++) {
+	clear_cylinder_table(&dive->cylinders);
+	for (i = 0; i < ngases || i < ntanks; i++) {
+		cylinder_t cyl = { 0 };
 		if (i < ngases) {
 			dc_gasmix_t gasmix = { 0 };
 			int o2, he;
@@ -139,27 +141,22 @@ static int parse_gasmixes(device_data_t *devdata, struct dive *dive, dc_parser_t
 				}
 				he = 0;
 			}
-			dive->cylinder[i].gasmix.o2.permille = o2;
-			dive->cylinder[i].gasmix.he.permille = he;
-		} else {
-			dive->cylinder[i].gasmix.o2.permille = 0;
-			dive->cylinder[i].gasmix.he.permille = 0;
+			cyl.gasmix.o2.permille = o2;
+			cyl.gasmix.he.permille = he;
 		}
 
 		if (i < ntanks) {
 			dc_tank_t tank = { 0 };
 			rc = dc_parser_get_field(parser, DC_FIELD_TANK, i, &tank);
 			if (rc == DC_STATUS_SUCCESS) {
-				cylinder_t *cyl = dive->cylinder + i;
-
-				cyl->type.size.mliter = lrint(tank.volume * 1000);
-				cyl->type.workingpressure.mbar = lrint(tank.workpressure * 1000);
+				cyl.type.size.mliter = lrint(tank.volume * 1000);
+				cyl.type.workingpressure.mbar = lrint(tank.workpressure * 1000);
 
-				cyl->cylinder_use = OC_GAS;
+				cyl.cylinder_use = OC_GAS;
 				if (tank.type & DC_TANKINFO_CC_O2)
-					cyl->cylinder_use = OXYGEN;
+					cyl.cylinder_use = OXYGEN;
 				if (tank.type & DC_TANKINFO_CC_DILUENT)
-					cyl->cylinder_use = DILUENT;
+					cyl.cylinder_use = DILUENT;
 
 				if (tank.type & DC_TANKINFO_IMPERIAL) {
 					if (same_string(devdata->model, "Suunto EON Steel")) {
@@ -169,13 +166,13 @@ static int parse_gasmixes(device_data_t *devdata, struct dive *dive, dc_parser_t
 						 * First, the pressures are off by a constant factor. WTF?
 						 * Then we can round the wet sizes so we get to multiples of 10
 						 * for cuft sizes (as that's all that you can enter) */
-						dive->cylinder[i].type.workingpressure.mbar = lrint(
-							dive->cylinder[i].type.workingpressure.mbar * 206.843 / 206.7 );
+						cyl.type.workingpressure.mbar = lrint(
+							cyl.type.workingpressure.mbar * 206.843 / 206.7 );
 						char name_buffer[17];
-						int rounded_size = lrint(ml_to_cuft(gas_volume(&dive->cylinder[i],
-							dive->cylinder[i].type.workingpressure)));
+						int rounded_size = lrint(ml_to_cuft(gas_volume(&cyl,
+							cyl.type.workingpressure)));
 						rounded_size = (int)((rounded_size + 5) / 10) * 10;
-						switch (dive->cylinder[i].type.workingpressure.mbar) {
+						switch (cyl.type.workingpressure.mbar) {
 						case 206843:
 							snprintf(name_buffer, sizeof(name_buffer), "AL%d", rounded_size);
 							break;
@@ -192,9 +189,9 @@ static int parse_gasmixes(device_data_t *devdata, struct dive *dive, dc_parser_t
 							snprintf(name_buffer, sizeof(name_buffer), "%d cuft", rounded_size);
 							break;
 						}
-						dive->cylinder[i].type.description = copy_string(name_buffer);
-						dive->cylinder[i].type.size.mliter = lrint(cuft_to_l(rounded_size) * 1000 /
-											mbar_to_atm(dive->cylinder[i].type.workingpressure.mbar));
+						cyl.type.description = copy_string(name_buffer);
+						cyl.type.size.mliter = lrint(cuft_to_l(rounded_size) * 1000 /
+											mbar_to_atm(cyl.type.workingpressure.mbar));
 					}
 				}
 				if (tank.gasmix != i) { // we don't handle this, yet
@@ -213,22 +210,24 @@ static int parse_gasmixes(device_data_t *devdata, struct dive *dive, dc_parser_t
 			// rest of the code treats this as if they were valid values
 			if (!IS_FP_SAME(tank.beginpressure, 0.0)) {
 				if (!IS_FP_SAME(tank.endpressure, 0.0)) {
-					dive->cylinder[i].start.mbar = lrint(tank.beginpressure * 1000);
-					dive->cylinder[i].end.mbar = lrint(tank.endpressure * 1000);
+					cyl.start.mbar = lrint(tank.beginpressure * 1000);
+					cyl.end.mbar = lrint(tank.endpressure * 1000);
 				} else if (same_string(devdata->vendor, "Uwatec")) {
-					dive->cylinder[i].start.mbar = lrint(tank.beginpressure * 1000 + 30000);
-					dive->cylinder[i].end.mbar = 30000;
+					cyl.start.mbar = lrint(tank.beginpressure * 1000 + 30000);
+					cyl.end.mbar = 30000;
 				}
 			}
 		}
 		if (no_volume) {
 			/* for the first tank, if there is no tanksize available from the
 			 * dive computer, fill in the default tank information (if set) */
-			fill_default_cylinder(dive, i);
+			fill_default_cylinder(dive, &cyl);
 		}
 		/* whatever happens, make sure there is a name for the cylinder */
-		if (empty_string(dive->cylinder[i].type.description))
-			dive->cylinder[i].type.description = strdup(translate("gettextFromC", "unknown"));
+		if (empty_string(cyl.type.description))
+			cyl.type.description = strdup(translate("gettextFromC", "unknown"));
+
+		add_to_cylinder_table(&dive->cylinders, dive->cylinders.nr, cyl);
 	}
 	return DC_STATUS_SUCCESS;
 }
@@ -294,7 +293,8 @@ static void handle_event(struct divecomputer *dc, struct sample *sample, dc_samp
 
 static void handle_gasmix(struct divecomputer *dc, struct sample *sample, int idx)
 {
-	if (idx < 0 || idx >= MAX_CYLINDERS)
+	/* TODO: Verify that index is not higher than the number of cylinders */
+	if (idx < 0)
 		return;
 	add_event(dc, sample->time.seconds, SAMPLE_EVENT_GASCHANGE2, idx+1, 0, "gaschange");
 	current_gas_index = idx;