arena

examples/modules/std.sx

@@ -18,13 +18,52 @@ field_value_int :: ($T: Type, idx: s64) -> s64 #builtin;
 field_index :: ($T: Type, val: T) -> s64 #builtin;
 string :: []u8 #builtin;
 
+// --- Arena allocator & Context ---
+
+Arena :: struct {
+    buf: string;
+    pos: s64;
+}
+
+Context :: struct {
+    arena: *Arena;
+    data: *void;
+}
+
+context : Context = ---;
+
+arena_create :: (size: s64) -> Arena {
+    Arena.{ buf = cstring(size), pos = 0 };
+}
+
+arena_alloc :: (arena: *Arena, size: s64) -> *void {
+    aligned := (size + 7) & (0 - 8);
+    if arena.pos + aligned > arena.buf.len {
+        return malloc(aligned);
+    }
+    ptr : *void = xx @arena.buf[arena.pos];
+    arena.pos = arena.pos + aligned;
+    ptr;
+}
+
+arena_reset :: (arena: *Arena) {
+    arena.pos = 0;
+}
+
+arena_destroy :: (arena: *Arena) {
+    free(arena.buf.ptr);
+}
+
+// --- String allocation ---
+
 CString :: union {
     s: string;
     struct { ptr: *void; len: s64; };
 }
 
 cstring :: (size: s64) -> string {
-    raw := malloc(size + 1);
+    p : s64 = xx context.arena;
+    raw := if p != 0 then arena_alloc(context.arena, size + 1) else malloc(size + 1);
     memset(raw, 0, size + 1);
     rs : CString = ---;
     rs.ptr = raw;