Replace push macro with da_append from tsoding

1 files changed, 21 insertions, 10 deletions

diff --git a/lib/arena.h b/lib/arena.h
index 1ddddac..7535f8a 100644
--- a/lib/arena.h
+++ b/lib/arena.h
@@ -1,3 +1,5 @@
+// Most of the code is from https://github.com/tsoding/arena
+
 #ifndef ARENA_H_
 #define ARENA_H_
 
@@ -19,22 +21,31 @@ struct region {
 typedef struct {
   region *beg;
   region *end;
+  size_t region_cap;
 } arena;
 
+arena arena_init_cap(size_t cap);
 void *arena_alloc(arena *a, size_t size);
 void arena_free(arena *a);
-void grow_da(void *slice, size_t size, arena *arena);
-
+void *arena_realloc(arena *a, void *oldptr, size_t oldsz, size_t newsz);
 
 #define new(a, t, c) (t *)arena_alloc(a, sizeof(t)*c)
 
-#define ARENA_REGION_DEFAULT_CAPACITY (8*1024);
-
-// from nullprogram
-#define push(slice, arena) \
-  ((slice)->len >= (slice)->cap \
-	? grow_da(slice, sizeof(*(slice)->data), arena), \
-	  (slice)->data + (slice)->len++ \
-	: (slice)->data + (slice)->len++)
+#define ARENA_REGION_DEFAULT_CAPACITY (8*1024)
+#define ARENA_DA_INIT_CAP (2)
+
+#define arena_da_append(a, da, item)												\
+    do {																			\
+        if ((da)->len >= (da)->cap) {												\
+            size_t new_cap = (da)->cap == 0 ? ARENA_DA_INIT_CAP : (da)->cap*2;		\
+            (da)->data = arena_realloc(												\
+                (a), (da)->data,													\
+                (da)->cap*sizeof(*(da)->data),										\
+                new_cap*sizeof(*(da)->data));										\
+            (da)->cap = new_cap;													\
+        }																			\
+																					\
+        (da)->data[(da)->len++] = (item);											\
+    } while (0)
 
 #endif //ARENA_H_