arena + dir reading

2 files changed, 55 insertions, 0 deletions

diff --git a/src/utils/arena.c b/src/utils/arena.c
new file mode 100644
index 0000000..ce50d24
--- /dev/null
+++ b/src/utils/arena.c
@@ -0,0 +1,38 @@
+#include "arena.h"
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+bool ArenaInit(Arena *arena, size_t capacity) {
+    arena->mem = malloc(capacity);
+    if (!arena->mem) {
+        return false;
+    }
+    arena->head = 0;
+    arena->capacity = capacity;
+    return true;
+}
+
+void *ArenaAlloc(Arena *arena, size_t size) {
+    uintptr_t current_ptr = (uintptr_t)arena->mem + arena->head;
+    // Alignment
+    uintptr_t aligned_ptr = (current_ptr + 7) & ~7;
+
+    size_t alignment_padding = aligned_ptr - current_ptr;
+    size_t total_needed = size + alignment_padding;
+    if (arena->head + total_needed > arena->capacity) {
+        return NULL;
+    }
+
+    arena->head += total_needed;
+    return (void *)aligned_ptr;
+}
+
+char *ArenaStrdup(Arena *arena, const char *str) {
+    size_t len = strlen(str) + 1; // adding a \0
+    char *ptr = ArenaAlloc(arena, len);
+    if (ptr == NULL) return NULL;
+    memcpy(ptr, str, len);
+    return ptr;
+}
diff --git a/src/utils/arena.h b/src/utils/arena.h
new file mode 100644
index 0000000..88cd17c
--- /dev/null
+++ b/src/utils/arena.h
@@ -0,0 +1,17 @@
+#include <stddef.h>
+#include <stdbool.h>
+
+#ifndef ARENA_H
+#define ARENA_H
+
+typedef struct {
+    void *mem;
+    size_t head;
+    size_t capacity;
+} Arena;
+
+bool ArenaInit(Arena *arena, size_t capacity);
+void *ArenaAlloc(Arena *arena, size_t size);
+char *ArenaStrdup(Arena *arena, const char *str);
+
+#endif // ARENA_H