allow loading multiple plugins

crates/apub/src/objects/post.rs

@@ -3,7 +3,7 @@ use crate::{
   check_apub_id_valid_with_strictness,
   local_site_data_cached,
   objects::{read_from_string_or_source_opt, verify_is_remote_object},
-  plugins::{call_plugin, load_plugins},
+  plugins::Plugins,
   protocol::{
     objects::{
       page::{Attachment, AttributedTo, Hashtag, HashtagType, Page, PageType},
@@ -51,7 +51,6 @@ use lemmy_utils::{
 };
 use std::ops::Deref;
 use stringreader::StringReader;
-use tracing::info;
 use url::Url;
 
 const MAX_TITLE_LENGTH: usize = 200;
@@ -277,25 +276,13 @@ impl Object for ApubPost {
         .build()
     };
 
-    // TODO: move this all into helper function
-    let before_plugin_hook = "federation_before_receive_post";
-    info!("Calling plugin hook {}", &before_plugin_hook);
-    if let Some(mut plugins) = load_plugins()? {
-      if plugins.function_exists(&before_plugin_hook) {
-        call_plugin(plugins, &before_plugin_hook, &mut form)?;
-      }
-    }
+    let mut plugins = Plugins::load()?;
+    plugins.call("federation_before_receive_post", &mut form)?;
 
     let timestamp = page.updated.or(page.published).unwrap_or_else(naive_now);
     let mut post = Post::insert_apub(&mut context.pool(), timestamp, &form).await?;
 
-    let after_plugin_hook = "federation_after_receive_post";
-    info!("Calling plugin hook {}", &after_plugin_hook);
-    if let Some(mut plugins) = load_plugins()? {
-      if plugins.function_exists(&after_plugin_hook) {
-        call_plugin(plugins, &after_plugin_hook, &mut post)?;
-      }
-    }
+    plugins.call("federation_after_receive_post", &mut post)?;
 
     generate_post_link_metadata(
       post.clone(),

crates/apub/src/plugins.rs

@@ -2,8 +2,14 @@ use extism::{Manifest, Plugin};
 use lemmy_utils::{error::LemmyResult, LemmyErrorType};
 use serde::{Deserialize, Serialize};
 use std::{ffi::OsStr, fs::read_dir};
+use tracing::info;
 
-pub fn load_plugins() -> LemmyResult<Option<Plugin>> {
+pub struct Plugins {
+  plugins: Vec<Plugin>,
+}
+
+impl Plugins {
+  pub fn load() -> LemmyResult<Self> {
     // TODO: make dir configurable via env var
     // TODO: should only read fs once at startup for performance
     let plugin_paths = read_dir("plugins")?;
@@ -15,25 +21,40 @@ pub fn load_plugins() -> LemmyResult<Option<Plugin>> {
         wasm_files.push(path);
       }
     }
-  if !wasm_files.is_empty() {
-    // TODO: what if theres more than one plugin for the same hook?
-    let manifest = Manifest::new(wasm_files);
-    let plugin = Plugin::new(manifest, [], true)?;
-    Ok(Some(plugin))
-  } else {
-    Ok(None)
+    let plugins = wasm_files
+      .into_iter()
+      .map(|w| {
+        let manifest = Manifest::new(vec![w]);
+        Plugin::new(manifest, [], true).unwrap()
+      })
+      .collect();
+    Ok(Self { plugins })
   }
-}
 
-pub fn call_plugin<T: Serialize + for<'de> Deserialize<'de> + Clone>(
-  mut plugins: Plugin,
+  pub fn exists(&mut self, name: &str) -> bool {
+    for p in &mut self.plugins {
+      if p.function_exists(name) {
+        return true;
+      }
+    }
+    false
+  }
+
+  pub fn call<T: Serialize + for<'de> Deserialize<'de> + Clone>(
+    &mut self,
     name: &str,
     data: &mut T,
-) -> LemmyResult<()> {
-  *data = plugins
+  ) -> LemmyResult<()> {
+    info!("Calling plugin hook {name}");
+    for p in &mut self.plugins {
+      if p.function_exists(name) {
+        *data = p
           .call::<extism_convert::Json<T>, extism_convert::Json<T>>(name, (*data).clone().into())
           .map_err(|e| LemmyErrorType::PluginError(e.to_string()))?
           .0
           .into();
+      }
+    }
     Ok(())
+  }
 }

src/plugin_middleware.rs

@@ -7,7 +7,7 @@ use actix_web::{
 };
 use core::future::Ready;
 use futures_util::future::LocalBoxFuture;
-use lemmy_apub::plugins::{call_plugin, load_plugins};
+use lemmy_apub::plugins::Plugins;
 use serde_json::Value;
 use std::{future::ready, rc::Rc};
 use tracing::info;
@@ -61,34 +61,31 @@ where
       let path = service_req.path().replace("/api/v3/", "").replace("/", "_");
       // TODO: naming can be a bit silly, `POST /api/v3/post` becomes `api_before_post_post`
       let before_plugin_hook = format!("api_before_{method}_{path}").to_lowercase();
+      let mut plugins = Plugins::load()?;
 
       info!("Calling plugin hook {}", &before_plugin_hook);
-      if let Some(mut plugins) = load_plugins()? {
-        if plugins.function_exists(&before_plugin_hook) {
+      if plugins.exists(&before_plugin_hook) {
         let payload = service_req.extract::<Bytes>().await?;
-
-          let mut json: Value = serde_json::from_slice(&payload.to_vec())?;
-          call_plugin(plugins, &before_plugin_hook, &mut json)?;
-
+        let mut json: Value = serde_json::from_slice(&payload.to_vec()).unwrap_or(Value::Null);
+        plugins.call(&before_plugin_hook, &mut json)?;
         let (_, mut new_payload) = Payload::create(true);
         new_payload.unread_data(Bytes::from(serde_json::to_vec(&json)?));
         service_req.set_payload(new_payload.into());
       }
-      }
+
       let mut res = svc.call(service_req).await?;
 
       let after_plugin_hook = format!("api_after_{method}_{path}").to_lowercase();
+
       info!("Calling plugin hook {}", &after_plugin_hook);
-      if let Some(mut plugins) = load_plugins()? {
-        if plugins.function_exists(&before_plugin_hook) {
+      if plugins.exists(&after_plugin_hook) {
         res = res.map_body(|_, body| {
           let mut json: Value =
             serde_json::from_slice(&body.try_into_bytes().unwrap().to_vec()).unwrap();
-            call_plugin(plugins, &after_plugin_hook, &mut json).unwrap();
+          plugins.call(&after_plugin_hook, &mut json).unwrap();
           BoxBody::new(Bytes::from(serde_json::to_vec(&json).unwrap()))
         });
       }
-      }
 
       Ok(res)
     })