Theoretically adding queue support and optimistic manifest downloading (#1). Needs tests when actual functions are implemented

src-tauri/src/downloads/game_download.rs

@@ -1,3 +1,4 @@
+use std::future::Future;
 use std::sync::{Arc, Mutex};
 use std::sync::atomic::AtomicUsize;
 use serde::{Deserialize, Serialize};
@@ -5,35 +6,40 @@ use versions::Version;
 use crate::AppState;
 use crate::downloads::progress::ProgressChecker;
 
-#[derive(Serialize, Deserialize, Clone)]
+#[derive(Serialize, Deserialize)]
 #[serde(rename_all="camelCase")]
 pub struct GameDownload {
     id: String,
     version: Version,
-    progress: GameDownloadState
+    progress: Arc<AtomicUsize>,
+    state: Mutex<GameDownloadState>,
+    manifest: Option<Mutex<GameDownloadManifest>>
 }
-#[derive(Serialize, Deserialize, Clone)]
+#[derive(Serialize, Deserialize, Clone, Eq, PartialEq)]
 pub enum GameDownloadState {
     Uninitialised,
+    Queued,
     Manifest,
-    Downloading(Arc<AtomicUsize>),
+    Downloading,
     Finished,
     Stalled,
     Failed,
     Cancelled
 }
 
-#[derive(Serialize, Deserialize, Clone)]
+#[derive(Serialize, Deserialize, Clone, Eq, PartialEq)]
 pub enum GameDownloadError {
-
+    ManifestAlreadyExists,
+    ManifestDoesNotExist,
+    ManifestDownloadError,
 }
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Clone, Eq, PartialEq, Ord, PartialOrd)]
 #[serde(rename_all="camelCase")]
 pub struct GameChunkCtx {
     chunk_id: usize,
 }
 
-#[derive(Serialize, Deserialize, Clone)]
+#[derive(Serialize, Deserialize, Clone, Eq, PartialEq)]
 pub struct GameDownloadManifest {
     // TODO: Implement game manifest
 }
@@ -43,17 +49,38 @@ impl GameDownload {
         Self {
             id,
             version,
-            progress: GameDownloadState::Uninitialised
+            progress: Arc::new(AtomicUsize::new(0)),
+            state: Mutex::from(GameDownloadState::Uninitialised),
+            manifest: None
         }
     }
-    pub async fn download(&mut self, max_threads: usize, contexts: Vec<GameChunkCtx>) -> Result<(), GameDownloadError> {
+    pub async fn queue(&self) -> Result<(), GameDownloadError> {
+        self.change_state(GameDownloadState::Queued);
+        if self.manifest.is_none() {
+            return Ok(())
+        }
+        self.download_manifest().await
+    }
+    pub async fn download(&self, max_threads: usize, contexts: Vec<GameChunkCtx>) -> Result<(), GameDownloadError> {
         let progress = Arc::new(AtomicUsize::new(0));
-        self.progress = GameDownloadState::Downloading(progress.clone());
+        self.change_state(GameDownloadState::Downloading);
         let progress = ProgressChecker::new(Box::new(download_game_chunk), progress);
         progress.run_contexts_parallel_async(contexts, max_threads).await;
         Ok(())
     }
-    pub async fn download_manifest(&mut self) -> Result<GameDownloadManifest, GameDownloadError> {
+    pub async fn download_manifest(&self) -> Result<(), GameDownloadError> {
+        if self.manifest.is_some() {
+            return Err(GameDownloadError::ManifestAlreadyExists);
+        }
+        todo!() // Need to actually download the manifest
+    }
+    pub fn change_state(&self, state: GameDownloadState) {
+        let mut lock = self.state.lock().unwrap();
+        *lock = state;
+    }
+}
+impl GameDownloadManifest {
+    fn parse_to_chunks(&self) -> Vec<GameChunkCtx> {
         todo!()
     }
 }
@@ -71,18 +98,26 @@ pub async fn start_game_download(
 ) -> Result<(), GameDownloadError> {
     let mut download = Arc::new(GameDownload::new(game_id, game_version));
     let mut app_state = state.lock().unwrap();
-    app_state.game_downloads.push(download.clone());
 
-    let manifest = match download.download_manifest().await {
-        Ok(manifest) => { manifest }
-        Err(e) => { return Err(e) }
+    let tmp = download.clone();
+    let manifest = &tmp.manifest;
+
+    let Some(unlocked) = manifest else { return Err(GameDownloadError::ManifestDoesNotExist) };
+    let lock = unlocked.lock().unwrap();
+
+    let chunks = lock.parse_to_chunks();
+
+    /*
+    let manifest = match d.manifest {
+        Some(lock) => {
+            let lock = lock.lock().unwrap();
+            lock.parse_to_chunks()
+        },
+        None => { return Err(GameDownloadError::ManifestDoesNotExist) }
     };
+     */
 
-    download.download(max_threads, manifest.parse_to_chunks()).await
+    app_state.game_downloads.push(download.clone());
+    download.download(max_threads, chunks).await
 }
 
-impl GameDownloadManifest {
-    fn parse_to_chunks(self) -> Vec<GameChunkCtx> {
-        todo!()
-    }
-}