From f6dda8af9998eba76ff377c91cb69593c086b8c0 Mon Sep 17 00:00:00 2001
From: Imogen Thoms <alcove@posteo.com>
Date: Thu, 30 Jan 2025 21:35:11 +0000
Subject: added mogi_arena allocator

Signed-off-by: Imogen Thoms <alcove@posteo.com>
---
 inc/arena.h | 24 ++++++++++++++++++++++++
 makefile    |  2 +-
 src/arena.c | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 1 deletion(-)
 create mode 100644 inc/arena.h
 create mode 100644 src/arena.c

diff --git a/inc/arena.h b/inc/arena.h
new file mode 100644
index 0000000..dda105b
--- /dev/null
+++ b/inc/arena.h
@@ -0,0 +1,24 @@
+/*
+ * arena.h
+ * arena allocator i wrote during a meeting in 30 mins
+ * imogen sorindeia thoms 2025
+ * */
+
+#ifndef MOGI_ARENA_H
+#define MOGI_ARENA_H
+
+#include <stdlib.h>
+#include <stdint.h>
+
+struct _mogi_arena_s {
+	char *buffer;
+	size_t posn;
+	size_t capacity;
+};
+typedef struct _mogi_arena_s mogi_arena_t;
+
+mogi_arena_t mogi_arena_init(size_t size);
+void mogi_arena_dispose(mogi_arena_t *a);
+uintptr_t mogi_arena_allocate(mogi_arena_t *a, size_t size);
+
+#endif /* MOGI_ARENA_H */
diff --git a/makefile b/makefile
index 26595fd..8ac6378 100644
--- a/makefile
+++ b/makefile
@@ -13,7 +13,7 @@ endif
 
 INCLUDES=-Iinc/
 
-OBJECTS=obj/salloc.o
+OBJECTS=obj/salloc.o obj/arena.o
 
 .PHONY: all
 all: build/lib/libspicy.so build/lib/static/libspicy.a includes
diff --git a/src/arena.c b/src/arena.c
new file mode 100644
index 0000000..e38ad20
--- /dev/null
+++ b/src/arena.c
@@ -0,0 +1,38 @@
+/*
+ * arena.c
+ * arena allocator i wrote during a meeting in 30 mins
+ * imogen sorindeia thoms 2025
+ * */
+
+#include <stdlib.h>
+#include <stdint.h>
+
+#include "arena.h"
+
+/* initialize an arena with given capacity */
+mogi_arena_t mogi_arena_init(size_t size) {
+	mogi_arena_t a = {
+			.buffer = calloc(size, 1),
+			.capacity = size
+	};
+	return a;
+}
+
+/* get rid of entire arena */
+void mogi_arena_dispose(mogi_arena_t *a) {
+	if(NULL != a->buffer) {
+		free(a->buffer);
+	}
+}
+
+/* allocate space on arena
+ * TODO: alignment l m f a o
+ */
+uintptr_t mogi_arena_allocate(mogi_arena_t *a, size_t size) {
+	if((NULL == a->buffer) || ((a->posn + size) > a->capacity)) {
+		return (uintptr_t)0;
+	}
+	uintptr_t p = (uintptr_t)(a->buffer + a->posn);
+	a->posn += (uintptr_t)size;
+	return p;
+}
-- 
cgit 1.4.1-2-gfad0