From cd307d16713f2552f8cf9c1116e860de3aa2cec6 Mon Sep 17 00:00:00 2001
From: "@syxhe" <https://t.me/syxhe>
Date: Fri, 4 Apr 2025 20:16:27 -0500
Subject: Add some documentation to arena.h, fix simplearena_clear not being
 declared

---
 src/arena.c |  6 ++----
 src/arena.h | 28 ++++++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 6 deletions(-)

(limited to 'src')

diff --git a/src/arena.c b/src/arena.c
index de3523b..07c28dc 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -51,6 +51,8 @@ arenanode * arenanode_init(size_t bytes) {
 arena * arena_init(size_t bytes) {
     if(!ISPOWOF2(MEM_ALIGN_BYTES))
         XALLOC_EXIT("<arena_init> \"MEM_ALIGN_BYTES\" is not a power of 2. Refusing to create a new arena", );
+    if(bytes < 1)
+        RETURNWERR(EINVAL, NULL);
 
     arena *a = VALLOC(1, sizeof(arena));
     if(!a)
@@ -142,10 +144,6 @@ int arena_clear(arena **arena) {
 
 
 
-// Simple Arena is an arena that can't expand whenever allocating memory, meaning what you originally allocated is what you get
-
-typedef arena simplearena;
-
 simplearena * simplearena_init(size_t bytes) {
     return arena_init(bytes);
 }
diff --git a/src/arena.h b/src/arena.h
index 331bbb1..1377fa1 100644
--- a/src/arena.h
+++ b/src/arena.h
@@ -7,21 +7,45 @@
 // enables XALLOC functionality
 #define ___VXGG___USE_XALLOC_FOR_ARENAS___ 1
 
+// Normal arena. Can expand in size beyond original allocation
 typedef struct arena arena;
+
+// A wrapper for the normal arena struct. Can not expand in size
 typedef arena simplearena;
 
+// Bitwise operation to check if a number is a power of 2
 #define ISPOWOF2(x) (((x) & ((x) - 1)) == 0)
-static const size_t MEM_ALIGN_BYTES = (2 * sizeof(void*)); // Hey, the static keyword did something for once!
+
+// Variable for memory alignment
+static const size_t MEM_ALIGN_BYTES = (2 * sizeof(void*));
+
+// Macro to get the remaining bytes necessary to be on a power of 2
 #define MEM_ALIGN(x) ((x) + (((x) & (MEM_ALIGN_BYTES - 1)) != 0) * (MEM_ALIGN_BYTES - ((x) & (MEM_ALIGN_BYTES - 1))))
 
+
+// Initialize an arena with `bytes` bytes of pre-allocated memory. Exits / returns NULL on error depending on the value of `___VXGG___USE_XALLOC_FOR_ARENAS___`
 arena * arena_init(size_t bytes);
+
+// Take `bytes` bytes of memory from `arena`'s memory pool. Exits / returns NULL on error depending on the value of `___VXGG___USE_XALLOC_FOR_ARENAS___`
 void * arena_alloc(arena * const arena, size_t bytes);
+
+// Free an arena its memory pool(s). Returns -1 and sets `errno` if the given arena is NULL 
 int arena_free(arena **arena);
+
+// Clear an arena of its contents (frees and inits an arena in 1). Returns -1 and sets `errno` if the given arena is NULL
 int arena_clear(arena **arena);
 
+
+// Initializes a simple arena. 
 simplearena * simplearena_init(size_t bytes);
+
+// Grabs some memory from the simple arena's pool. Exits / returns NULL on error depending on the value of `___VXGG___USE_XALLOC_FOR_ARENAS___`
 void * simplearena_alloc(simplearena * const a, size_t bytes);
+
+// Free a simple arena. Exits / returns -1 on error depending on the value of `___VXGG___USE_XALLOC_FOR_ARENAS___`
 int simplearena_free(simplearena **a);
-int simplearena_free(simplearena **a);
+
+// Clear a simple arena and its memory pool (frees and inits a simple arena in 1). Exits / returns -1 on error depending on the value of `___VXGG___USE_XALLOC_FOR_ARENAS___`
+int simplearena_clear(simplearena **a);
 
 #endif
\ No newline at end of file
-- 
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