1 files changed, 30 insertions, 0 deletions
diff --git a/src/memory.c b/src/memory.c
new file mode 100644
index 0000000..63acb39
--- /dev/null
+++ b/src/memory.c
@@ -0,0 +1,30 @@
+#include <assert.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../include/memory.h"
+#include "../include/types.h"
+
+Arena Arena_new(size cap) {
+    Arena a = {0};
+    a.cap = cap;
+    a.beg = malloc(cap);
+    a.end = a.beg ? a.beg + cap : 0;
+    return a;
+}
+
+// Magic to allow optimisation __attribute((malloc, alloc_size(2, 4),
+// alloc_align(3)))
+void *alloc(Arena *a, size count, size tsize, size align) {
+    size padding = -(uptr)a->beg & (align - 1);
+    byte *beg = a->beg + padding;
+    size alloc_size = count * tsize;
+    assert(beg + alloc_size < a->end);
+    a->beg = beg + alloc_size;
+    return memset(beg, 0, count * tsize);
+}
+
+void Arena_reset(Arena *a) { a->beg = a->end - a->cap; }
+
+size Arena_get_used(Arena a) { return a.cap - (a.end - a.beg); }