wip

Author: Centril

crates/core/src/host/instance_env.rs

@@ -19,6 +19,7 @@ use spacetimedb_table::indexes::RowPointer;
 use spacetimedb_table::table::RowRef;
 use std::ops::DerefMut;
 use std::sync::Arc;
+use std::vec::IntoIter;
 
 #[derive(Clone)]
 pub struct InstanceEnv {
@@ -491,6 +492,33 @@ impl InstanceEnv {
 
         Ok(chunks)
     }
+
+    pub fn fill_buffer_from_iter(
+        iter: &mut IntoIter<Vec<u8>>,
+        mut buffer: &mut [u8],
+        chunk_pool: &mut ChunkPool,
+    ) -> usize {
+        let mut written = 0;
+        // Fill the buffer as much as possible.
+        while let Some(chunk) = iter.as_slice().first() {
+            let Some((buf_chunk, rest)) = buffer.split_at_mut_checked(chunk.len()) else {
+                // Cannot fit chunk into the buffer,
+                // either because we already filled it too much,
+                // or because it is too small.
+                break;
+            };
+            buf_chunk.copy_from_slice(chunk);
+            written += chunk.len();
+            buffer = rest;
+
+            // Advance the iterator, as we used a chunk.
+            // SAFETY: We peeked one `chunk`, so there must be one at least.
+            let chunk = unsafe { iter.next().unwrap_unchecked() };
+            chunk_pool.put(chunk);
+        }
+
+        written
+    }
 }
 
 impl TxSlot {

crates/core/src/host/module_common.rs

@@ -4,7 +4,9 @@
 use crate::{
     energy::EnergyMonitor,
     host::{
-        module_host::{DynModule, ModuleInfo}, wasm_common::{module_host_actor::DescribeError, DESCRIBE_MODULE_DUNDER}, Scheduler
+        module_host::{DynModule, ModuleInfo},
+        wasm_common::{module_host_actor::DescribeError, DESCRIBE_MODULE_DUNDER},
+        Scheduler,
     },
     module_host_context::ModuleCreationContext,
     replica_context::ReplicaContext,

crates/core/src/host/v8/de.rs

@@ -92,7 +92,7 @@ impl de::Error for Error<'_> {
 }
 
 /// Returns a scratch buffer to fill when deserializing strings.
-fn scratch_buf<const N: usize>() -> [MaybeUninit<u8>; N] {
+pub(crate) fn scratch_buf<const N: usize>() -> [MaybeUninit<u8>; N] {
     [const { MaybeUninit::uninit() }; N]
 }
 

crates/core/src/host/v8/error.rs

@@ -59,12 +59,12 @@ impl<'scope, M: IntoJsString> IntoException<'scope> for RangeError<M> {
 }
 
 #[derive(Debug)]
-pub(super) struct ExceptionThrown {
+pub(crate) struct ExceptionThrown {
     _priv: (),
 }
 
 /// A result where the error indicates that an exception has already been thrown in V8.
-pub(super) type ExcResult<T> = Result<T, ExceptionThrown>;
+pub(crate) type ExcResult<T> = Result<T, ExceptionThrown>;
 
 /// Indicates that the JS side had thrown an exception.
 pub(super) fn exception_already_thrown() -> ExceptionThrown {