some buffer allocator progress

buffer_allocator.c

@@ -1,22 +1,43 @@
 #include "allocator.h"
 
-// TODO
+void *buffer_allocator_alloc(buffer_allocator_t *this, size_t bytes) {
+    size_t new_size = this->size + bytes;
+    if (new_size > this->capacity) {
+        return NULL;
+    }
+    void *ptr = &this->data[this->size]
+    this->size = new_size;
+    return ptr;
+}
+
+void *buffer_allocator_resize(buffer_allocator_t *this, void *old_ptr, size_t bytes) {
+    // TODO: check if the pointer is even in the buffer?
+    void *new_ptr = buffer_allocator_alloc(this, bytes);
+    if (new_ptr == NULL) {
+        return NULL;
+    }
+    // TODO: copy over data
+}
+
+void buffer_allocator_reset(buffer_allocator_t *this) {
+    this->size = 0;
+}
 
 static void *buffer_alloc(void *this, size_t bytes, const char *file, int line) {
-    (void)this;
-    (void)bytes;
     (void)file;
     (void)line;
-    return 0;
+    return buffer_allocator_alloc((buffer_allocator_t *)this, bytes);
 }
+
 static void *buffer_resize(void *this, void *old_ptr, size_t bytes, const char *file, int line) {
-    (void)this;
     (void)old_ptr;
-    (void)bytes;
     (void)file;
     (void)line;
-    return 0;
+
+    // TODO: do the concrete implementation first!
+    void *new_ptr = buffer_allocator_alloc((buffer_allocator_t *)this, bytes);
 }
+
 static void buffer_free(void *this, void *ptr, const char *file, int line) {
     (void)this;
     (void)ptr;
@@ -29,3 +50,6 @@ static const allocator_vtbl_t buffer_vtbl = {
     .resize = buffer_resize,
     .free = buffer_free,
 };
+
+allocator_t buffer_allocator_interface(buffer_allocator_t *this) {
+}