✨ Add support for WASM transforms

render-wasm/src/mem.rs

@@ -14,7 +14,20 @@ pub extern "C" fn alloc_bytes(len: usize) -> *mut u8 {
     return ptr;
 }
 
-pub fn free_bytes() {
+pub fn write_bytes(bytes: Vec<u8>) -> *mut u8 {
+    if unsafe { BUFFERU8.is_some() } {
+        panic!("Bytes already allocated");
+    }
+
+    let mut buffer = Box::new(bytes);
+    let ptr = buffer.as_mut_ptr();
+
+    unsafe { BUFFERU8 = Some(buffer) };
+    return ptr;
+}
+
+#[no_mangle]
+pub extern "C" fn free_bytes() {
     if unsafe { BUFFERU8.is_some() } {
         let buffer = unsafe { BUFFERU8.take() }.expect("uninitialized buffer");
         std::mem::drop(buffer);
@@ -30,3 +43,31 @@ pub fn bytes() -> Vec<u8> {
     let buffer = unsafe { BUFFERU8.take() }.expect("uninitialized buffer");
     *buffer
 }
+
+pub trait SerializableResult {
+    type BytesType;
+    fn from_bytes(bytes: Self::BytesType) -> Self;
+    fn as_bytes(&self) -> Self::BytesType;
+    fn clone_to_slice(&self, slice: &mut [u8]);
+}
+
+/*
+  Returns an array in the heap. The first 4 bytes is always the size
+  of the array. Then the items are serialized one after the other
+  by the implementation of SerializableResult trait
+*/
+pub fn write_vec<T: SerializableResult>(result: Vec<T>) -> *mut u8 {
+    let elem_size = size_of::<T>();
+    let bytes_len = 4 + result.len() * elem_size;
+    let mut result_bytes = Vec::<u8>::with_capacity(bytes_len);
+
+    result_bytes.resize(bytes_len, 0);
+    result_bytes[0..4].clone_from_slice(&result.len().to_le_bytes());
+
+    for i in 0..result.len() {
+        let base = 4 + i * elem_size;
+        result[i].clone_to_slice(&mut result_bytes[base..base + elem_size]);
+    }
+
+    write_bytes(result_bytes)
+}