From 2ec351f20e3ea1e23c186550687e304f46d0f46c Mon Sep 17 00:00:00 2001
From: DecDuck <declanahofmeyr@gmail.com>
Date: Fri, 25 Oct 2024 10:28:58 +1100
Subject: [PATCH] fixed multi-chunk downloads

---
 src-tauri/Cargo.lock                        |  1 +
 src-tauri/Cargo.toml                        |  1 +
 src-tauri/src/downloads/download_logic.rs   | 14 ++++++++------
 src-tauri/src/downloads/download_manager.rs | 13 +++++++++----
 src-tauri/src/downloads/manifest.rs         |  3 ++-
 5 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/src-tauri/Cargo.lock b/src-tauri/Cargo.lock
index 622e924..8e498ad 100644
--- a/src-tauri/Cargo.lock
+++ b/src-tauri/Cargo.lock
@@ -1028,6 +1028,7 @@ dependencies = [
  "rayon",
  "reqwest",
  "rustbreak",
+ "rustix",
  "serde",
  "serde_json",
  "structured-logger",
diff --git a/src-tauri/Cargo.toml b/src-tauri/Cargo.toml
index edbcbbb..21ada3f 100644
--- a/src-tauri/Cargo.toml
+++ b/src-tauri/Cargo.toml
@@ -40,6 +40,7 @@ http = "1.1.0"
 tokio = { version = "1.40.0", features = ["rt", "tokio-macros"] }
 versions = { version = "6.3.2", features = ["serde"] }
 urlencoding = "2.1.3"
+rustix = "0.38.37"
 
 [dependencies.uuid]
 version = "1.10.0"
diff --git a/src-tauri/src/downloads/download_logic.rs b/src-tauri/src/downloads/download_logic.rs
index fa64f1c..cf999bf 100644
--- a/src-tauri/src/downloads/download_logic.rs
+++ b/src-tauri/src/downloads/download_logic.rs
@@ -3,8 +3,8 @@ use crate::db::DatabaseImpls;
 use crate::downloads::manifest::DropDownloadContext;
 use crate::DB;
 use log::info;
+use std::{fs::OpenOptions, io::{BufWriter, Seek, SeekFrom, Write}};
 use urlencoding::encode;
-use std::io::{BufWriter, Seek, SeekFrom, Write};
 
 pub fn download_game_chunk(ctx: DropDownloadContext) {
     let base_url = DB.fetch_base_url();
@@ -14,7 +14,10 @@ pub fn download_game_chunk(ctx: DropDownloadContext) {
         .join(&format!(
             "/api/v1/client/chunk?id={}&version={}&name={}&chunk={}",
             // Encode the parts we don't trust
-            ctx.game_id, encode(&ctx.version), encode(&ctx.file_name), ctx.index
+            ctx.game_id,
+            encode(&ctx.version),
+            encode(&ctx.file_name),
+            ctx.index
         ))
         .unwrap();
 
@@ -26,16 +29,15 @@ pub fn download_game_chunk(ctx: DropDownloadContext) {
         .send()
         .unwrap();
 
-    let mut file_lock = ctx.file.lock().unwrap();
+    let mut file = OpenOptions::new().write(true).open(ctx.path).unwrap();
 
     if ctx.offset != 0 {
-        file_lock
+        file
             .seek(SeekFrom::Start(ctx.offset))
             .expect("Failed to seek to file offset");
     }
 
-    let mut stream = BufWriter::with_capacity(1024 * 1024, file_lock.try_clone().unwrap());
-    drop(file_lock);
+    let mut stream = BufWriter::with_capacity(1024 * 1024, file);
 
     response.copy_to(&mut stream).unwrap();
 }
diff --git a/src-tauri/src/downloads/download_manager.rs b/src-tauri/src/downloads/download_manager.rs
index 50af71d..0d0662a 100644
--- a/src-tauri/src/downloads/download_manager.rs
+++ b/src-tauri/src/downloads/download_manager.rs
@@ -5,6 +5,7 @@ use crate::downloads::manifest::{DropDownloadContext, DropManifest};
 use crate::downloads::progress::ProgressChecker;
 use crate::{AppState, DB};
 use log::info;
+use rustix::fs::{fallocate, FallocateFlags};
 use serde::{Deserialize, Serialize};
 use std::fs::{create_dir_all, File};
 use std::path::Path;
@@ -64,7 +65,7 @@ impl GameDownloadManager {
         }
         self.ensure_manifest_exists().await
     }
-    
+
     pub fn begin_download(
         &self,
         max_threads: usize,
@@ -143,7 +144,7 @@ pub fn generate_job_contexts(
         let container = path.parent().unwrap();
         create_dir_all(container).unwrap();
 
-        let file = Arc::new(Mutex::new(File::create(path).unwrap()));
+        let file = File::create(path.clone()).unwrap();
         let mut running_offset = 0;
 
         for i in 0..chunk.ids.len() {
@@ -153,10 +154,12 @@ pub fn generate_job_contexts(
                 offset: running_offset,
                 index: i,
                 game_id: game_id.to_string(),
-                file: file.clone(),
+                path: path.clone(),
             });
             running_offset += chunk.lengths[i] as u64;
         }
+
+        fallocate(file, FallocateFlags::empty(), 0, running_offset);
     }
     contexts
 }
@@ -184,7 +187,9 @@ pub async fn start_game_download(
 
     let contexts = generate_job_contexts(&local_manifest, game_version.clone(), game_id);
 
-    let _ = download_manager.begin_download(max_threads, contexts);
+    download_manager
+        .begin_download(max_threads, contexts)
+        .unwrap();
 
     Ok(())
 }
diff --git a/src-tauri/src/downloads/manifest.rs b/src-tauri/src/downloads/manifest.rs
index 7feb45c..f03a706 100644
--- a/src-tauri/src/downloads/manifest.rs
+++ b/src-tauri/src/downloads/manifest.rs
@@ -1,5 +1,6 @@
 use std::collections::HashMap;
 use std::fs::File;
+use std::path::PathBuf;
 use std::sync::{Arc, Mutex};
 use serde::{Deserialize, Serialize};
 
@@ -19,5 +20,5 @@ pub struct DropDownloadContext {
     pub index: usize,
     pub offset: u64,
     pub game_id: String,
-    pub file: Arc<Mutex<File>>
+    pub path: PathBuf
 }
\ No newline at end of file