From 1bb3a0b1963ee68a48550c718e5176c659608824 Mon Sep 17 00:00:00 2001
From: Abdelrahman Said <said.abdelrahman89@gmail.com>
Date: Sun, 31 Dec 2023 15:42:55 +0000
Subject: [PATCH] Add simple memory arena implementation

---
 mem_arena/arena.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 mem_arena/arena.h | 18 ++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 mem_arena/arena.c
 create mode 100644 mem_arena/arena.h

diff --git a/mem_arena/arena.c b/mem_arena/arena.c
new file mode 100644
index 0000000..248b643
--- /dev/null
+++ b/mem_arena/arena.c
@@ -0,0 +1,47 @@
+#include "arena.h"
+#include "../aliases.h"
+#include <stdlib.h>
+#include <string.h>
+
+bool arena_init(arena_t *arena, u64 capacity) {
+  arena->buf = (u8 *)malloc(capacity);
+  if (!(arena->buf)) {
+    return false;
+  }
+
+  arena->capacity = capacity;
+
+  arena->offset = arena->buf;
+
+  return true;
+}
+
+u8 *arena_alloc(arena_t *arena, u64 size) {
+  if (arena->offset + size >= arena->buf + arena->capacity) {
+    return NULL;
+  }
+
+  u8 *output = arena->offset;
+
+  arena->offset += size;
+
+  return output;
+}
+
+void arena_clear(arena_t *arena) {
+  memset(arena->buf, 0, arena->offset - arena->buf);
+
+  arena->offset = arena->buf;
+}
+
+void arena_free(arena_t *arena) {
+  arena->capacity = 0;
+
+  arena->offset = NULL;
+
+  if (arena->buf) {
+    free(arena->buf);
+  }
+
+  arena->buf = NULL;
+}
diff --git a/mem_arena/arena.h b/mem_arena/arena.h
new file mode 100644
index 0000000..509444e
--- /dev/null
+++ b/mem_arena/arena.h
@@ -0,0 +1,18 @@
+#ifndef ARENA_H
+#define ARENA_H
+
+#include "../aliases.h"
+#include <stdbool.h>
+
+typedef struct {
+  u64 capacity;
+  u8 *buf;
+  u8 *offset;
+} arena_t;
+
+bool arena_init(arena_t *arena, u64 capacity);
+u8 *arena_alloc(arena_t *arena, u64 size);
+void arena_clear(arena_t *arena);
+void arena_free(arena_t *arena);
+
+#endif // !ARENA_H