fix context and runtime handling

Author: dignifiedquire

extism/host/src/main.rs

@@ -1,7 +1,6 @@
 use extism::*;
 
-#[tokio::main]
-async fn main() -> anyhow::Result<()> {
+fn main() -> anyhow::Result<()> {
     let tokio_rt = tokio::runtime::Builder::new_multi_thread()
         .thread_name("main-runtime")
         .worker_threads(2)
@@ -18,11 +17,10 @@ async fn main() -> anyhow::Result<()> {
     let file = Wasm::file("../plugin/target/wasm32-unknown-unknown/debug/plugin.wasm");
     let manifest = Manifest::new([file]);
 
-    let plugin = PluginBuilder::new(manifest)
-        .with_wasi(true);
+    let plugin = PluginBuilder::new(manifest).with_wasi(true);
 
-    let mut plugin = iroh_extism_host_functions::add_all_host_functions(rt, plugin, iroh)
-        .build()?;
+    let mut plugin =
+        iroh_extism_host_functions::add_all_host_functions(rt, plugin, iroh).build()?;
 
     let res = plugin
         .call::<&str, &str>("print_hai_and_get_ticket", "blobaaa54kekl2oa7yd5ro3u65kynwolq3h2msu65c3jfj44ja23fstmcajcnb2hi4dthixs65ltmuys2mjomrsxe4bonfzg62bonzsxi53pojvs4lydabefsibbyrlqbqfiirdmivybeyaeaqktotuaaaaaaaaaaaaqb7cvoah75ql4x2hvxaxxlgje2d7qy2avizyjb25pd4anc6c5ulvgpth5xq")
@@ -31,4 +29,4 @@ async fn main() -> anyhow::Result<()> {
     println!("{}", res);
 
     Ok(())
-}
+}

extism/iroh-extism-host-functions/src/lib.rs

@@ -44,34 +44,33 @@ pub async fn create_iroh(path: PathBuf) -> Result<IrohNode> {
 //     Ok(user_data.node_id().to_string())
 // });
 
-host_fn!(iroh_blob_get_ticket(user_data: IrohNode; ticket: &str) -> Vec<u8> {
-    let node = user_data.get()?;
-    let node = node.lock().unwrap();
+struct Context {
+    rt: tokio::runtime::Handle,
+    iroh: IrohNode,
+}
+
+host_fn!(iroh_blob_get_ticket(user_data: Context; ticket: &str) -> Vec<u8> {
+    let ctx = user_data.get()?;
+    let ctx = ctx.lock().unwrap();
 
     let (node_addr, hash, format) = iroh::ticket::BlobTicket::from_str(ticket).map_err(|_| anyhow!("invalid ticket"))?.into_parts();
 
     if format != iroh::rpc_protocol::BlobFormat::Raw {
         return Err(anyhow!("can only get raw bytes for now, not HashSequences (collections)"));
     }
-
-    // TODO(b5): this crashes execution because we don't have a handle to the original _tokio_ runtime :(
-    let handle = tokio::runtime::Handle::current();
-    let buf = handle.block_on(async move {
-        let mut stream = node.client()
-        .blobs
-        .download(iroh::rpc_protocol::BlobDownloadRequest {
+    let client = ctx.iroh.client();
+    let buf = ctx.rt.block_on(async move {
+        let mut stream = client.blobs.download(iroh::rpc_protocol::BlobDownloadRequest {
             hash,
             format,
             peer: node_addr,
             out: DownloadLocation::Internal,
             tag: SetTagOption::Auto,
-        })
-        .await?;
+        }).await?;
         while stream.next().await.is_some() {}
 
-        let buffer = node.client().blobs.read(hash).await?.read_to_bytes().await.map_err(|e| anyhow!("read error: {}", e))?.to_vec();
-
-        anyhow::Ok(buffer)
+        let buffer = client.blobs.read(hash).await?.read_to_bytes().await?;
+        anyhow::Ok(buffer.to_vec())
     })?;
 
     Ok(buf)
@@ -80,15 +79,18 @@ host_fn!(iroh_blob_get_ticket(user_data: IrohNode; ticket: &str) -> Vec<u8> {
 pub fn add_all_host_functions(
     rt: tokio::runtime::Handle,
     b: PluginBuilder,
-    node: IrohNode,
+    iroh: IrohNode,
 ) -> PluginBuilder {
-    let iroh = UserData::new(node);
+    let ctx = UserData::new(Context {
+        rt,
+        iroh,
+    });
 
     b.with_function(
         "iroh_blob_get_ticket",
         [PTR],
         [PTR],
-        iroh.clone(),
+        ctx,
         iroh_blob_get_ticket,
     )
 }