feat: add malloc&free 1

__internal/memory/README.md

@@ -1,3 +1,4 @@
 
 Reference:
 * https://radu-matei.com/blog/practical-guide-to-wasm-memory/
+* https://github.com/alec-deason/wasm_plugin/blob/main/guest/src/lib.rs

__internal/memory/src/main.rs

@@ -1,5 +1,16 @@
 #[no_mangle]
 pub unsafe fn malloc_1(len: usize) -> *mut u8 {
+    let mut buffer: std::mem::ManuallyDrop<Vec<u8>> = std::mem::ManuallyDrop::new(Vec::with_capacity(len as usize));
+    buffer.as_mut_ptr() as *mut u8
+}
+
+#[no_mangle]
+pub unsafe fn free_1(ptr: *mut u8, len: usize) {
+    std::mem::drop(Vec::from_raw_parts(ptr as *mut u8, 0, len as usize))
+}
+
+#[no_mangle]
+pub unsafe fn malloc_2(len: usize) -> *mut u8 {
     let mut buf = Vec::with_capacity(len);
     let ptr = buf.as_mut_ptr();
     std::mem::forget(buf);
@@ -7,20 +18,20 @@ pub unsafe fn malloc_1(len: usize) -> *mut u8 {
 }
 
 #[no_mangle]
-pub unsafe fn free_1(ptr: *mut u8, len: usize) {
+pub unsafe fn free_2(ptr: *mut u8, len: usize) {
     let data = Vec::from_raw_parts(ptr, len, len);
     std::mem::drop(data);
 }
 
 #[no_mangle]
-pub unsafe fn malloc_2(len: usize) -> *mut u8 {
+pub unsafe fn malloc_3(len: usize) -> *mut u8 {
     let align = std::mem::align_of::<usize>();
     let layout = std::alloc::Layout::from_size_align_unchecked(len, align);
     std::alloc::alloc(layout)
 }
 
 #[no_mangle]
-pub unsafe fn free_2(ptr: *mut u8, len: usize) {
+pub unsafe fn free_3(ptr: *mut u8, len: usize) {
     let align = std::mem::align_of::<usize>();
     let layout = std::alloc::Layout::from_size_align_unchecked(len, align);
     std::alloc::dealloc(ptr, layout)
@@ -28,14 +39,16 @@ pub unsafe fn free_2(ptr: *mut u8, len: usize) {
 
 fn main() {
     unsafe {
-        println!("Malloc-1");
+        println!("Malloc & Free - 1");
         let p = malloc_1(1024);
-        println!("Free-1");
         free_1(p, 1024);
 
-        println!("Malloc-2");
+        println!("Malloc & Free - 2");
         let p = malloc_2(1024);
-        println!("Free-2");
         free_2(p, 1024);
+
+        println!("Malloc & Free - 3");
+        let p = malloc_3(1024);
+        free_3(p, 1024);
     }
 }