255115ee

Refine instance upload planning contract

a73x 2026-04-08 18:50

Commit message

Refine instance upload planning contract

src/renderer.zig

Old		New
@@ -319,19 +319,27 @@ const InstanceUploadRequest = struct {
319	write_len: u32,	319	write_len: u32,
320	};	320	};
321		321
		322	const InstanceUploadMode = enum {
		323	partial,
		324	full,
		325	invalid_range,
		326	};
		327
322	const InstanceUploadDecision = struct {	328	const InstanceUploadDecision = struct {
323	needed_capacity: u32,	329	needed_capacity: ?u32,
324	needs_growth: bool,	330	upload_mode: InstanceUploadMode,
325	force_full_upload: bool,
326	};	331	};
327		332
328	fn planInstanceUpload(req: InstanceUploadRequest) InstanceUploadDecision {	333	fn planInstanceUpload(req: InstanceUploadRequest) InstanceUploadDecision {
329	const needed_capacity = std.math.add(u32, req.offset_instances, req.write_len) catch std.math.maxInt(u32);	334	const needed_capacity = std.math.add(u32, req.offset_instances, req.write_len) catch {
330	const needs_growth = needed_capacity > req.current_capacity;	335	return .{
		336	.needed_capacity = null,
		337	.upload_mode = .invalid_range,
		338	};
		339	};
331	return .{	340	return .{
332	.needed_capacity = needed_capacity,	341	.needed_capacity = needed_capacity,
333	.needs_growth = needs_growth,	342	.upload_mode = if (needed_capacity > req.current_capacity) .full else .partial,
334	.force_full_upload = needs_growth,
335	};	343	};
336	}	344	}
337		345
@@ -1375,8 +1383,8 @@ test "range upload falls back to full upload when capacity must grow" {
1375	.write_len = 4,	1383	.write_len = 4,
1376	});	1384	});
1377		1385
1378	try std.testing.expect(decision.needs_growth);	1386	try std.testing.expectEqual(@as(?u32, 10), decision.needed_capacity);
1379	try std.testing.expect(decision.force_full_upload);	1387	try std.testing.expectEqual(InstanceUploadMode.full, decision.upload_mode);
1380	}	1388	}
1381		1389
1382	test "range upload stays partial when capacity is sufficient" {	1390	test "range upload stays partial when capacity is sufficient" {
@@ -1386,6 +1394,39 @@ test "range upload stays partial when capacity is sufficient" {
1386	.write_len = 3,	1394	.write_len = 3,
1387	});	1395	});
1388		1396
1389	try std.testing.expect(!decision.needs_growth);	1397	try std.testing.expectEqual(@as(?u32, 7), decision.needed_capacity);
1390	try std.testing.expect(!decision.force_full_upload);	1398	try std.testing.expectEqual(InstanceUploadMode.partial, decision.upload_mode);
		1399	}
		1400
		1401	test "range upload stays partial on an exact fit" {
		1402	const decision = planInstanceUpload(.{
		1403	.current_capacity = 7,
		1404	.offset_instances = 4,
		1405	.write_len = 3,
		1406	});
		1407
		1408	try std.testing.expectEqual(@as(?u32, 7), decision.needed_capacity);
		1409	try std.testing.expectEqual(InstanceUploadMode.partial, decision.upload_mode);
		1410	}
		1411
		1412	test "range upload allows zero-length writes without forcing growth" {
		1413	const decision = planInstanceUpload(.{
		1414	.current_capacity = 8,
		1415	.offset_instances = 8,
		1416	.write_len = 0,
		1417	});
		1418
		1419	try std.testing.expectEqual(@as(?u32, 8), decision.needed_capacity);
		1420	try std.testing.expectEqual(InstanceUploadMode.partial, decision.upload_mode);
		1421	}
		1422
		1423	test "range upload reports overflow explicitly" {
		1424	const decision = planInstanceUpload(.{
		1425	.current_capacity = std.math.maxInt(u32),
		1426	.offset_instances = std.math.maxInt(u32),
		1427	.write_len = 1,
		1428	});
		1429
		1430	try std.testing.expectEqual(@as(?u32, null), decision.needed_capacity);
		1431	try std.testing.expectEqual(InstanceUploadMode.invalid_range, decision.upload_mode);
1391	}	1432	}