Revert "capacity can be different from len"

This reverts commit deccb8b.

bindings/c/include/opendal.h

@@ -99,10 +99,6 @@ typedef struct opendal_bytes {
    * The length of the byte array
    */
   uintptr_t len;
-  /**
-   * The capacity of the byte array
-   */
-  uintptr_t capacity;
 } opendal_bytes;
 
 /**

bindings/c/src/error.rs

@@ -121,7 +121,7 @@ impl opendal_error {
                 drop(Vec::from_raw_parts(
                     data_mut,
                     (*message_ptr).len,
-                    (*message_ptr).capacity,
+                    (*message_ptr).len,
                 ));
             }
 

bindings/c/src/types.rs

@@ -34,8 +34,6 @@ pub struct opendal_bytes {
     pub data: *const u8,
     /// The length of the byte array
     pub len: usize,
-    /// The capacity of the byte array
-    pub capacity: usize,
 }
 
 impl opendal_bytes {
@@ -44,21 +42,16 @@ impl opendal_bytes {
         let vec = buf.to_vec();
         let data = vec.as_ptr();
         let len = vec.len();
-        let capacity = vec.capacity();
         std::mem::forget(vec);
-        Self {
-            data,
-            len,
-            capacity,
-        }
+        Self { data, len }
     }
 
     /// \brief Frees the heap memory used by the opendal_bytes
     #[no_mangle]
     pub unsafe extern "C" fn opendal_bytes_free(ptr: *mut opendal_bytes) {
         if !ptr.is_null() {
             let data_mut = (*ptr).data as *mut u8;
-            drop(Vec::from_raw_parts(data_mut, (*ptr).len, (*ptr).capacity));
+            drop(Vec::from_raw_parts(data_mut, (*ptr).len, (*ptr).len));
             drop(Box::from_raw(ptr));
         }
     }