From 53a16d10e0596d114f0f35ad35ebff3a369e4fba Mon Sep 17 00:00:00 2001
From: Archit Gupta <archigup@amazon.com>
Date: Tue, 29 Oct 2024 18:04:16 -0700
Subject: [PATCH] Add helper to allocate rest of a GglArena

---
 ggl-lib/include/ggl/arena.h | 3 +++
 ggl-lib/src/arena.c         | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/ggl-lib/include/ggl/arena.h b/ggl-lib/include/ggl/arena.h
index 50df1dd4c..589031b68 100644
--- a/ggl-lib/include/ggl/arena.h
+++ b/ggl-lib/include/ggl/arena.h
@@ -46,4 +46,7 @@ GglError ggl_arena_resize_last(
 /// Returns true if arena's mem contains ptr.
 bool ggl_arena_owns(const GglArena *arena, const void *ptr);
 
+/// Allocates remaining space into a buffer.
+GglBuffer ggl_arena_alloc_rest(GglArena *arena);
+
 #endif
diff --git a/ggl-lib/src/arena.c b/ggl-lib/src/arena.c
index eeefa188f..da96d594c 100644
--- a/ggl-lib/src/arena.c
+++ b/ggl-lib/src/arena.c
@@ -3,6 +3,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include "ggl/arena.h"
+#include "ggl/buffer.h"
 #include "ggl/error.h"
 #include "ggl/log.h"
 #include <assert.h>
@@ -93,3 +94,10 @@ bool ggl_arena_owns(const GglArena *arena, const void *ptr) {
     uintptr_t ptr_int = (uintptr_t) ptr;
     return (ptr_int >= mem_int) && (ptr_int < mem_int + arena->CAPACITY);
 }
+
+GglBuffer ggl_arena_alloc_rest(GglArena *arena) {
+    GglBuffer rest = { .data = arena->MEM + arena->index,
+                       .len = arena->CAPACITY - arena->index };
+    arena->index = arena->CAPACITY;
+    return rest;
+}