From cfaffd0ac27e7db7c13f35c64f5a4c7a61816e96 Mon Sep 17 00:00:00 2001
From: Christof Petig <christof.petig@arcor.de>
Date: Sun, 18 Jun 2023 19:38:00 +0200
Subject: [PATCH] implement up to two slices in write_bytes (gather)

---
 common/state/src/plugin/memory_manager.rs | 24 +++++++++++++++--------
 common/state/src/plugin/module.rs         | 22 +--------------------
 2 files changed, 17 insertions(+), 29 deletions(-)

diff --git a/common/state/src/plugin/memory_manager.rs b/common/state/src/plugin/memory_manager.rs
index f811bd7818..e6332a702a 100644
--- a/common/state/src/plugin/memory_manager.rs
+++ b/common/state/src/plugin/memory_manager.rs
@@ -147,7 +147,10 @@ impl MemoryManager {
             store,
             memory,
             allocator,
-            &bincode::serialize(object).map_err(PluginModuleError::Encoding)?,
+            (
+                &bincode::serialize(object).map_err(PluginModuleError::Encoding)?,
+                &[],
+            ),
         )
     }
 
@@ -184,7 +187,7 @@ impl MemoryManager {
             <MemoryModel as wasmer::MemorySize>::Offset,
             WasmPtr<u8, MemoryModel>,
         >,
-        bytes: &[u8],
+        bytes: (&[u8], &[u8]),
     ) -> Result<
         (
             WasmPtr<u8, MemoryModel>,
@@ -192,15 +195,22 @@ impl MemoryManager {
         ),
         PluginModuleError,
     > {
-        let len = bytes.len() as <MemoryModel as wasmer::MemorySize>::Offset;
+        let len = (bytes.0.len() + bytes.1.len()) as <MemoryModel as wasmer::MemorySize>::Offset;
         let ptr = self
             .get_pointer(store, len, allocator)
             .map_err(PluginModuleError::MemoryAllocation)?;
         ptr.slice(
             &memory.view(store),
-            bytes.len() as <MemoryModel as wasmer::MemorySize>::Offset,
+            len as <MemoryModel as wasmer::MemorySize>::Offset,
         )
-        .and_then(|s| s.write_slice(bytes))
+        .and_then(|s| {
+            if !bytes.1.is_empty() {
+                s.subslice(0..bytes.0.len() as u64).write_slice(bytes.0)?;
+                s.subslice(bytes.0.len() as u64..len).write_slice(bytes.1)
+            } else {
+                s.write_slice(bytes.0)
+            }
+        })
         .map_err(|_| PluginModuleError::InvalidPointer)?;
         Ok((ptr, len))
     }
@@ -221,9 +231,7 @@ impl MemoryManager {
         bytes: &[u8],
     ) -> Result<WasmPtr<u8, MemoryModel>, PluginModuleError> {
         let len = bytes.len() as <MemoryModel as wasmer::MemorySize>::Offset;
-        let new_bytes = [&len.to_le_bytes(), bytes].concat();
-        // TODO: could make write_bytes take an IntoIterator to avoid this concat?
-        self.write_bytes(store, memory, allocator, &new_bytes)
+        self.write_bytes(store, memory, allocator, (&len.to_le_bytes(), &bytes))
             .map(|val| val.0)
     }
 }
diff --git a/common/state/src/plugin/module.rs b/common/state/src/plugin/module.rs
index b1a471fc76..54a1533068 100644
--- a/common/state/src/plugin/module.rs
+++ b/common/state/src/plugin/module.rs
@@ -223,7 +223,7 @@ fn execute_raw(
         &mut module.store.as_store_mut(),
         &module.memory,
         &module.allocator,
-        bytes,
+        (bytes, &[]),
     )?;
 
     // This gets the event function from module exports
@@ -270,26 +270,6 @@ fn execute_raw(
         result_len,
     )?;
     Ok(bytes)
-    // Waiting for `multi-value` to be added to LLVM. So we encode a pointer to
-    // a u128 that represent [u64; 2]
-
-    // let u128_pointer = from_i64(
-    //     function_result[0]
-    //         .i64()
-    //         .ok_or_else(PluginModuleError::InvalidArgumentType)?,
-    // );
-
-    // let bytes = memory_manager::read_bytes(&module.memory, u128_pointer, 16);
-
-    // We read the return object and deserialize it
-
-    // The first 8 bytes are encoded as le and represent the pointer to the data
-    // The next 8 bytes are encoded as le and represent the length of the data
-    // Ok(memory_manager::read_bytes(
-    //     &module.memory,
-    //     u64::from_le_bytes(bytes[0..8].try_into().unwrap()),
-    //     u64::from_le_bytes(bytes[8..16].try_into().unwrap()),
-    // ))
 }
 
 fn retrieve_action(