also forgot the test file

Author: MasonProtter

test/testslab.jl

@@ -0,0 +1,38 @@
+sb = MallocSlabBuffer(;slab_size=16_384, slabs_max_length=1, custom_slabs_max_length=0)
+
+@no_escape sb begin
+    p = sb.current
+    e = sb.slab_end
+    # Allocate something that takes up almost all the room on the slab
+    x1 = @alloc(Int8, 16_384÷2 - 1)
+    x2 = @alloc(Int8, 16_384÷2 - 1)
+    @test pointer(x1) == p
+    @test pointer(x2) == pointer(x1) + 16_384÷2 - 1
+    @test sb.slabs_max_length == 1
+    @test sb.slabs_length == 1
+    for i ∈ 1:5
+        @no_escape sb begin
+            @test sb.current == p + 16_384 - 2
+            @test p <= sb.current <= e
+            # Allocate a new vector that won't fit on the old slab
+            y = @alloc(Int, 10)
+            # A new slab was allocated automatically
+            @test !(p <= sb.current <= e)
+            @test sb.slabs_length == 2
+
+            @test sb.slabs_max_length == 65
+        end
+    end
+    @test sb.custom_slabs_max_length == 0
+    # Allocate something too big to fit on any slab
+    z = @alloc(Int, 100_000)
+    @test sb.custom_slabs_max_length == 0
+    
+    # This doesn't effect sb.current
+    @test sb.current == p + 16_384 - 2
+    @test sb.current == p + 16_384 - 2
+    @test sb.slab_end == e
+    @test !(p <= pointer(z) <= e)
+    # The pointer for z is tracked in the custom_slabs field instead
+    @test pointer(z) == unsafe_load(sb.custom_slabs, sb.custom_slabs_length)
+end