Implementing deserializing from binary

lib/engine-native/src/engine.rs

@@ -4,9 +4,10 @@ use crate::NativeModule;
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::fs::File;
-use std::io::Read;
+use std::io::{Read, Write};
 use std::path::Path;
 use std::sync::Arc;
+use tempfile::NamedTempFile;
 use wasm_common::entity::PrimaryMap;
 use wasm_common::{FunctionType, LocalFunctionIndex, MemoryIndex, SignatureIndex, TableIndex};
 use wasmer_compiler::{Compilation, CompileError, FunctionBody, Target};
@@ -171,20 +172,30 @@ impl Engine for NativeEngine {
         Ok(serialized)
     }
 
-    /// Deserializes a WebAssembly module
+    /// Deserializes a WebAssembly module (binary content of a Shared Object file)
     fn deserialize(&self, bytes: &[u8]) -> Result<Arc<dyn BaseCompiledModule>, DeserializeError> {
-        unimplemented!("Deserialize from bytes not yet implemented.");
+        if !Self::is_deserializable(&bytes) {
+            return Err(DeserializeError::Incompatible(
+                "The provided bytes are not in any native format Wasmer can understand".to_string(),
+            ));
+        }
+        // Dump the bytes into a file, so we can read it with our `dlopen`
+        let named_file = NamedTempFile::new().unwrap();
+        let (mut file, path) = named_file.keep().expect("Can't persist file");
+        file.write_all(&bytes).expect("Can't write the files");
+        self.deserialize_from_file(&path)
     }
 
     /// Deserializes a WebAssembly module from a path
+    /// It should point to a Shared Object file generated by this engine.
     fn deserialize_from_file(
         &self,
         file_ref: &Path,
     ) -> Result<Arc<dyn BaseCompiledModule>, DeserializeError> {
         // TODO: Return an IoDeserializeError, so we don't need to map the error
         let mut file = File::open(&file_ref).expect("Can't open file");
-        let mut buffer = [0; 4];
-        // read up to 4 bytes
+        let mut buffer = [0; 5];
+        // read up to 5 bytes
         file.read(&mut buffer).expect("Can't read from file");
         if !Self::is_deserializable(&buffer) {
             return Err(DeserializeError::Incompatible(