ring/ring.odin

@@ -16,11 +16,17 @@ Ring_Soa :: struct($E: typeid) {
 	next_write_index, len: int,
 }
 
-destroy_aos :: #force_inline proc(ring: ^Ring($E)) -> runtime.Allocator_Error {
+destroy_aos :: #force_inline proc(
+	ring: ^Ring($E),
+	allocator := context.allocator,
+) -> runtime.Allocator_Error {
 	return delete(ring.data)
 }
 
-destroy_soa :: #force_inline proc(ring: ^Ring_Soa($E)) -> runtime.Allocator_Error {
+destroy_soa :: #force_inline proc(
+	ring: ^Ring_Soa($E),
+	allocator := context.allocator,
+) -> runtime.Allocator_Error {
 	return delete(ring.data)
 }
 
@@ -53,6 +59,7 @@ create_soa :: #force_inline proc(
 	return ring, err
 }
 
+// All contents of `data` will be completely ignored, `data` is treated as an empty slice.
 init_from_slice_aos :: #force_inline proc(ring: ^Ring($E), data: $T/[]E) {
 	ring.data = data
 	ring.len = 0
@@ -60,6 +67,7 @@ init_from_slice_aos :: #force_inline proc(ring: ^Ring($E), data: $T/[]E) {
 	return
 }
 
+// All contents of `data` will be completely ignored, `data` is treated as an empty slice.
 init_from_slice_soa :: #force_inline proc(ring: ^Ring_Soa($E), data: $T/#soa[]E) {
 	ring.data = data
 	ring.len = 0
@@ -291,3 +299,141 @@ test_ring_soa :: proc(t: ^testing.T) {
 	testing.expect_value(t, ring.len, 1)
 	testing.expect_value(t, get(ring, 0), Ints{1, 1})
 }
+
+@(test)
+test_ring_aos_init_from_slice :: proc(t: ^testing.T) {
+	// Stack-allocated backing with pre-existing garbage and odd capacity.
+	backing: [7]int = {99, 99, 99, 99, 99, 99, 99}
+
+	ring: Ring(int)
+	init_from_slice(&ring, backing[:])
+
+	// Empty ring invariants after init_from_slice.
+	testing.expect_value(t, ring.len, 0)
+	testing.expect_value(t, ring.next_write_index, 0)
+	testing.expect_value(t, start_index_aos(ring), 0)
+
+	// Partial fill (3 / 7).
+	for i in 1 ..= 3 do append(&ring, i)
+	testing.expect_value(t, ring.len, 3)
+	testing.expect_value(t, ring.next_write_index, 3)
+	testing.expect_value(t, start_index_aos(ring), 0)
+	testing.expect_value(t, get(ring, 0)^, 1)
+	testing.expect_value(t, get(ring, 2)^, 3)
+	testing.expect_value(t, get_last(ring)^, 3)
+
+	// Fill exactly to capacity. Pushing element 7 must make len == cap
+	// AND wrap next_write_index from 6 back to 0 in the same step.
+	for i in 4 ..= 7 do append(&ring, i)
+	testing.expect_value(t, ring.len, 7)
+	testing.expect_value(t, ring.next_write_index, 0)
+	testing.expect_value(t, start_index_aos(ring), 0)
+	testing.expect_value(t, get(ring, 0)^, 1)
+	testing.expect_value(t, get(ring, 6)^, 7)
+	testing.expect_value(t, get_last(ring)^, 7)
+
+	// First overwrite — oldest element shifts by one.
+	append(&ring, 8)
+	testing.expect_value(t, ring.len, 7)
+	testing.expect_value(t, ring.next_write_index, 1)
+	testing.expect_value(t, start_index_aos(ring), 1)
+	testing.expect_value(t, get(ring, 0)^, 2)
+	testing.expect_value(t, get(ring, 6)^, 8)
+	testing.expect_value(t, get_last(ring)^, 8)
+
+	// Stress: 3 more complete wrap cycles (21 more pushes).
+	// After 29 total pushes, ring contains the last 7 (23..=29),
+	// and next_write_index = 29 mod 7 = 1.
+	for i in 9 ..= 29 do append(&ring, i)
+	testing.expect_value(t, ring.len, 7)
+	testing.expect_value(t, ring.next_write_index, 1)
+	testing.expect_value(t, start_index_aos(ring), 1)
+	testing.expect_value(t, get(ring, 0)^, 23)
+	testing.expect_value(t, get(ring, 3)^, 26)
+	testing.expect_value(t, get(ring, 6)^, 29)
+	testing.expect_value(t, get_last(ring)^, 29)
+
+	// Clear returns ring to empty-equivalent state.
+	clear(&ring)
+	testing.expect_value(t, ring.len, 0)
+	testing.expect_value(t, ring.next_write_index, 0)
+	testing.expect_value(t, start_index_aos(ring), 0)
+
+	// Single-element edge case: get_last(len==1) routes through get(ring, 0).
+	append(&ring, 42)
+	testing.expect_value(t, ring.len, 1)
+	testing.expect_value(t, ring.next_write_index, 1)
+	testing.expect_value(t, get(ring, 0)^, 42)
+	testing.expect_value(t, get_last(ring)^, 42)
+}
+
+@(test)
+test_ring_soa_init_from_slice :: proc(t: ^testing.T) {
+	Ints :: struct {
+		x, y: int,
+	}
+
+	// Stack-allocated backing with pre-existing garbage and odd capacity.
+	backing: #soa[7]Ints = {{99, 99}, {99, 99}, {99, 99}, {99, 99}, {99, 99}, {99, 99}, {99, 99}}
+
+	ring: Ring_Soa(Ints)
+	init_from_slice(&ring, backing[:])
+
+	// Empty ring invariants after init_from_slice.
+	testing.expect_value(t, ring.len, 0)
+	testing.expect_value(t, ring.next_write_index, 0)
+	testing.expect_value(t, start_index_soa(ring), 0)
+
+	// Partial fill (3 / 7).
+	for i in 1 ..= 3 do append(&ring, Ints{i, i})
+	testing.expect_value(t, ring.len, 3)
+	testing.expect_value(t, ring.next_write_index, 3)
+	testing.expect_value(t, start_index_soa(ring), 0)
+	testing.expect_value(t, get(ring, 0), Ints{1, 1})
+	testing.expect_value(t, get(ring, 2), Ints{3, 3})
+	testing.expect_value(t, get_last(ring), Ints{3, 3})
+
+	// Fill exactly to capacity. Pushing element 7 must make len == cap
+	// AND wrap next_write_index from 6 back to 0 in the same step.
+	for i in 4 ..= 7 do append(&ring, Ints{i, i})
+	testing.expect_value(t, ring.len, 7)
+	testing.expect_value(t, ring.next_write_index, 0)
+	testing.expect_value(t, start_index_soa(ring), 0)
+	testing.expect_value(t, get(ring, 0), Ints{1, 1})
+	testing.expect_value(t, get(ring, 6), Ints{7, 7})
+	testing.expect_value(t, get_last(ring), Ints{7, 7})
+
+	// First overwrite — oldest element shifts by one.
+	append(&ring, Ints{8, 8})
+	testing.expect_value(t, ring.len, 7)
+	testing.expect_value(t, ring.next_write_index, 1)
+	testing.expect_value(t, start_index_soa(ring), 1)
+	testing.expect_value(t, get(ring, 0), Ints{2, 2})
+	testing.expect_value(t, get(ring, 6), Ints{8, 8})
+	testing.expect_value(t, get_last(ring), Ints{8, 8})
+
+	// Stress: 3 more complete wrap cycles (21 more pushes).
+	// After 29 total pushes, ring contains the last 7 (23..=29),
+	// and next_write_index = 29 mod 7 = 1.
+	for i in 9 ..= 29 do append(&ring, Ints{i, i})
+	testing.expect_value(t, ring.len, 7)
+	testing.expect_value(t, ring.next_write_index, 1)
+	testing.expect_value(t, start_index_soa(ring), 1)
+	testing.expect_value(t, get(ring, 0), Ints{23, 23})
+	testing.expect_value(t, get(ring, 3), Ints{26, 26})
+	testing.expect_value(t, get(ring, 6), Ints{29, 29})
+	testing.expect_value(t, get_last(ring), Ints{29, 29})
+
+	// Clear returns ring to empty-equivalent state.
+	clear(&ring)
+	testing.expect_value(t, ring.len, 0)
+	testing.expect_value(t, ring.next_write_index, 0)
+	testing.expect_value(t, start_index_soa(ring), 0)
+
+	// Single-element edge case: get_last(len==1) routes through get(ring, 0).
+	append(&ring, Ints{42, 42})
+	testing.expect_value(t, ring.len, 1)
+	testing.expect_value(t, ring.next_write_index, 1)
+	testing.expect_value(t, get(ring, 0), Ints{42, 42})
+	testing.expect_value(t, get_last(ring), Ints{42, 42})
+}