Reimplement Allocator API for Arena

src/core/mem/arena/mem_arena.c

@@ -1,5 +1,6 @@
 #include "mem_arena.h"
 #include "aliases.h"
+#include "mem_allocator.h"
 #include "mem_utils.h"
 #include <stdbool.h>
 #include <stdlib.h>
@@ -24,8 +25,40 @@ struct arena {
 #endif // ifdef WAPP_PLATFORM_WINDOWS
 };
 
-// PUBLIC API
+#pragma region Arena Allocator wrappers declarations
+internal inline void *mem_arena_alloc(u64 size, void *alloc_obj);
+internal inline void *mem_arena_alloc_aligned(u64 size, u64 alignment,
+                                              void *alloc_obj);
+#pragma endregion Arena Allocator wrappers declarations
 
+#pragma region Arena Allocator API definitions
+Allocator wapp_mem_arena_allocator_init_custom(u64 base_capacity,
+                                               MemAllocFlags flags,
+                                               bool zero_buffer) {
+  Allocator allocator = {0};
+  bool initialised = wapp_mem_arena_init_custom(
+      (Arena **)(&allocator.obj), base_capacity, flags, zero_buffer);
+  if (!initialised) {
+    return allocator;
+  }
+
+  allocator.alloc = mem_arena_alloc;
+  allocator.alloc_aligned = mem_arena_alloc_aligned;
+
+  return allocator;
+}
+
+void wapp_mem_arena_allocator_clear(Allocator *allocator) {
+  wapp_mem_arena_clear((Arena *)(allocator->obj));
+}
+
+void wapp_mem_arena_allocator_destroy(Allocator *allocator) {
+  wapp_mem_arena_destroy((Arena **)(&(allocator->obj)));
+  *allocator = (Allocator){0};
+}
+#pragma endregion Arena Allocator API definitions
+
+#pragma region API definitions
 bool wapp_mem_arena_init_custom(Arena **arena, u64 base_capacity,
                                 MemAllocFlags flags, bool zero_buffer) {
   if (!arena || *arena || base_capacity == 0) {
@@ -116,3 +149,17 @@ void wapp_mem_arena_destroy(Arena **arena) {
   free(*arena);
   *arena = NULL;
 }
+#pragma endregion API definitions
+
+#pragma region Arena Allocator wrappers definitions
+internal inline void *mem_arena_alloc(u64 size, void *alloc_obj) {
+  Arena *arena = (Arena *)alloc_obj;
+  return wapp_mem_arena_alloc(arena, size);
+}
+
+internal inline void *mem_arena_alloc_aligned(u64 size, u64 alignment,
+                                              void *alloc_obj) {
+  Arena *arena = (Arena *)alloc_obj;
+  return wapp_mem_arena_alloc_aligned(arena, size, alignment);
+}
+#pragma endregion Arena Allocator wrappers definitions

src/core/mem/arena/mem_arena.h

@@ -2,6 +2,7 @@
 #define MEM_ARENA_H
 
 #include "aliases.h"
+#include "mem_allocator.h"
 #include "mem_utils.h"
 #include <stdbool.h>
 
@@ -11,6 +12,41 @@ extern "C" {
 
 typedef struct arena Arena;
 
+#pragma region Allocator wrapper macros
+#define wapp_mem_arena_allocator_init(base_capacity)                           \
+  (wapp_mem_arena_allocator_init_custom(base_capacity, WAPP_MEM_ALLOC_RESERVE, \
+                                        false))
+#define wapp_mem_arena_allocator_init_commit(base_capacity)                    \
+  (wapp_mem_arena_allocator_init_custom(                                       \
+      base_capacity, WAPP_MEM_ALLOC_RESERVE | WAPP_MEM_ALLOC_COMMIT, false))
+#define wapp_mem_arena_allocator_init_zero(base_capacity)                      \
+  (wapp_mem_arena_allocator_init_custom(base_capacity, WAPP_MEM_ALLOC_RESERVE, \
+                                        true))
+#define wapp_mem_arena_allocator_init_commit_and_zero(base_capacity)           \
+  (wapp_mem_arena_allocator_init_custom(                                       \
+      base_capacity, WAPP_MEM_ALLOC_RESERVE | WAPP_MEM_ALLOC_COMMIT, true))
+#pragma endregion Arena Allocator wrapper macros
+
+#pragma region Allocator API declarations
+/**
+ * Wraps an Arena in an Allocator object. It attempts to initialise the Arena
+ * and, if successful, defines the operations supported by it to be used by the
+ * Allocator.
+ *
+ * An Arena allocator only supports normal allocation and aligned allocation.
+ * Reallocation, aligned reallocation and freeing aren't implemented.
+ *
+ * The `wapp_mem_arena_allocator_init_custom` provides the most control over how
+ * the Arena is initialised. Wrapper macros are provided for easier use.
+ */
+Allocator wapp_mem_arena_allocator_init_custom(u64 base_capacity,
+                                               MemAllocFlags flags,
+                                               bool zero_buffer);
+void wapp_mem_arena_allocator_clear(Allocator *allocator);
+void wapp_mem_arena_allocator_destroy(Allocator *allocator);
+#pragma endregion Arena Allocator API declarations
+
+#pragma region wrapper macros
 #define wapp_mem_arena_init(arena_dptr, base_capacity)                         \
   (wapp_mem_arena_init_custom(arena_dptr, base_capacity,                       \
                               WAPP_MEM_ALLOC_RESERVE, false))
@@ -25,13 +61,21 @@ typedef struct arena Arena;
   (wapp_mem_arena_init_custom(arena_dptr, base_capacity,                       \
                               WAPP_MEM_ALLOC_RESERVE | WAPP_MEM_ALLOC_COMMIT,  \
                               true))
+#pragma endregion Arena wrapper macros
 
+#pragma region Arena API declarations
+/**
+ * Arena initialisation function. `wapp_mem_arena_init_custom` provides the most
+ * control over how the Arena is initialised. Wrapper macros are provided for
+ * easier use.
+ */
 bool wapp_mem_arena_init_custom(Arena **arena, u64 base_capacity,
                                 MemAllocFlags flags, bool zero_buffer);
 void *wapp_mem_arena_alloc(Arena *arena, u64 size);
 void *wapp_mem_arena_alloc_aligned(Arena *arena, u64 size, u64 alignment);
 void wapp_mem_arena_clear(Arena *arena);
 void wapp_mem_arena_destroy(Arena **arena);
+#pragma endregion Arena API declarations
 
 #ifdef __cplusplus
 }