Add set_len

src/downloader/downloader.rs

@@ -54,9 +54,20 @@ pub trait GetTargetFileName {
     }
 }
 
+/// Truncates or extends the underlying file, updating the size of this file.
+pub trait SetLen {
+    /// Truncates or extends the underlying file, updating the size of this file to become `size`.
+    ///
+    /// If the `size` is less than the current file’s size, then the file will be shrunk.
+    /// If it is greater than the current file’s size, then the file will be extended to `size` and have all of the intermediate data filled in with 0s.
+    fn set_len(&mut self, size: u64) -> Result<(), DownloaderError>;
+}
+
 #[derive(Debug)]
 /// A file downloader
-pub struct DownloaderInternal<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName> {
+pub struct DownloaderInternal<
+    T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName + SetLen,
+> {
     /// The webclient
     pub client: Arc<WebClient>,
     /// The download status
@@ -185,7 +196,7 @@ impl DownloaderInternal<LocalFile> {
     }
 }
 
-impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName> DownloaderInternal<T> {
+impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName + SetLen> DownloaderInternal<T> {
     /// Add a new task to tasks
     /// * `task` - Task
     pub fn add_task(&self, task: JoinHandle<Result<(), DownloaderError>>) {
@@ -395,6 +406,19 @@ impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName> DownloaderIn
         self.dropped.qstore(true);
     }
 
+    #[inline]
+    /// Truncates or extends the underlying file, updating the size of this file to become `size`.
+    ///
+    /// If the `size` is less than the current file’s size, then the file will be shrunk.
+    /// If it is greater than the current file’s size, then the file will be extended to `size` and have all of the intermediate data filled in with 0s.
+    pub fn set_len(&self, size: u64) -> Result<(), DownloaderError> {
+        match self.file.get_mut().deref_mut() {
+            Some(f) => f.set_len(size)?,
+            None => {}
+        }
+        Ok(())
+    }
+
     #[inline]
     /// Set the downloader is panic and set the error.
     /// * `err` - Error
@@ -491,7 +515,7 @@ impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName> DownloaderIn
 ///
 /// When dropping downloader, the downloader need some times to let all threads exited.
 /// This process is handled after [Drop].
-pub struct Downloader<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName> {
+pub struct Downloader<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName + SetLen> {
     /// internal type
     downloader: Arc<DownloaderInternal<T>>,
 }
@@ -553,7 +577,9 @@ macro_rules! define_downloader_fn {
     }
 }
 
-impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName + 'static> Downloader<T> {
+impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName + SetLen + 'static>
+    Downloader<T>
+{
     /// Start download if download not started.
     ///
     /// Returns the status of the Downloader
@@ -703,7 +729,9 @@ impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName + 'static> Do
     define_downloader_fn!(is_panic, bool, "Returns true if the downloader is panic.");
 }
 
-impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName> Drop for Downloader<T> {
+impl<T: Write + Seek + Send + Sync + ClearFile + GetTargetFileName + SetLen> Drop
+    for Downloader<T>
+{
     fn drop(&mut self) {
         self.downloader.set_dropped();
         #[cfg(test)]

src/downloader/local_file.rs

@@ -1,7 +1,9 @@
 use super::downloader::GetTargetFileName;
+use super::downloader::SetLen;
 use crate::ext::io::ClearFile;
 use std::fs::remove_file;
 use std::fs::File;
+use std::fs::OpenOptions;
 use std::io::Seek;
 use std::io::Write;
 use std::ops::Deref;
@@ -22,7 +24,12 @@ impl LocalFile {
     /// This function will create a file if it does not exist, and will truncate it if it does.
     pub fn create<P: AsRef<Path>>(path: P) -> std::io::Result<Self> {
         let p = path.as_ref().to_owned();
-        let f = File::create(&p)?;
+        let f = OpenOptions::new()
+            .create(true)
+            .read(true)
+            .write(true)
+            .truncate(true)
+            .open(&p)?;
         Ok(Self {
             file: Some(f),
             path: p,
@@ -32,7 +39,11 @@ impl LocalFile {
     /// Attempts to open a file in read-only mode.
     pub fn open<P: AsRef<Path>>(path: P) -> std::io::Result<Self> {
         let p = path.as_ref().to_owned();
-        let f = File::open(&p)?;
+        let f = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .truncate(true)
+            .open(&p)?;
         Ok(Self {
             file: Some(f),
             path: p,
@@ -72,6 +83,13 @@ impl Seek for LocalFile {
     }
 }
 
+impl SetLen for LocalFile {
+    fn set_len(&mut self, size: u64) -> Result<(), super::DownloaderError> {
+        self.file.as_ref().unwrap().set_len(size)?;
+        Ok(())
+    }
+}
+
 impl Write for LocalFile {
     fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
         self.file.as_ref().unwrap().write(buf)

src/downloader/pd_file/file.rs

@@ -21,6 +21,7 @@ use std::fs::create_dir;
 use std::fs::metadata;
 use std::fs::remove_file;
 use std::fs::File;
+use std::fs::OpenOptions;
 use std::io::Read;
 use std::io::Seek;
 use std::io::SeekFrom;
@@ -392,7 +393,11 @@ impl PdFile {
     /// Returns errors or a new instance.
     pub fn read_from_file<P: AsRef<Path> + ?Sized>(path: &P) -> Result<Self, PdFileError> {
         let p = path.as_ref();
-        let mut f = File::open(p)?;
+        let mut f = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .truncate(true)
+            .open(p)?;
         f.seek(SeekFrom::Start(0))?;
         let mut buf = [0u8, 0, 0, 0];
         f.read_exact(&mut buf)?;
@@ -446,7 +451,12 @@ impl PdFile {
         if p.exists() {
             remove_file(p)?;
         }
-        let f = File::create(p)?;
+        let f = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .truncate(true)
+            .create(true)
+            .open(p)?;
         self.file.get_mut().replace(f);
         self.file_path.get_mut().replace(PathBuf::from(p));
         self.mem_only.qstore(false);
@@ -485,7 +495,14 @@ impl PdFile {
         }
         remove_file(self.file_path.get_ref().as_ref().unwrap())?;
         f.take();
-        f.replace(File::create(self.file_path.get_ref().as_ref().unwrap())?);
+        f.replace(
+            OpenOptions::new()
+                .read(true)
+                .write(true)
+                .truncate(true)
+                .create(true)
+                .open(self.file_path.get_ref().as_ref().unwrap())?,
+        );
         Ok(())
     }
 

src/downloader/tasks.rs

@@ -1,5 +1,6 @@
 use super::downloader::DownloaderInternal;
 use super::downloader::GetTargetFileName;
+use super::downloader::SetLen;
 use super::error::DownloaderError;
 use super::pd_file::PdFilePartStatus;
 use crate::concat_error;
@@ -43,7 +44,7 @@ macro_rules! check_dropped {
 
 /// Create a download tasks in simple thread mode.
 pub async fn create_download_tasks_simple<
-    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName,
+    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + SetLen,
 >(
     d: Arc<DownloaderInternal<T>>,
 ) -> Result<(), DownloaderError> {
@@ -133,6 +134,7 @@ pub async fn create_download_tasks_simple<
                 if d.enabled_progress_bar() {
                     d.set_progress_bar_length(len);
                 }
+                d.set_len(len)?;
             }
             None => {}
         }
@@ -147,7 +149,7 @@ pub async fn create_download_tasks_simple<
 
 /// Do first job when download in multiple mode.
 pub async fn create_download_tasks_multi_first<
-    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName,
+    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + SetLen,
 >(
     d: Arc<DownloaderInternal<T>>,
 ) -> Result<(), DownloaderError> {
@@ -185,6 +187,7 @@ pub async fn create_download_tasks_multi_first<
             if d.enabled_progress_bar() {
                 d.set_progress_bar_length(len);
             }
+            d.set_len(len)?;
         }
         None => {
             d.fallback_to_simp();
@@ -209,7 +212,7 @@ pub async fn create_download_tasks_multi_first<
 
 /// Create a new download task in multiple thread mode.
 pub async fn create_download_tasks_multi<
-    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName,
+    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + SetLen,
 >(
     d: Arc<DownloaderInternal<T>>,
     pd: Arc<PdFilePartStatus>,
@@ -224,7 +227,7 @@ pub async fn create_download_tasks_multi<
 
 /// Create a new download task in multiple thread mode.
 pub async fn create_download_tasks_multi_internal<
-    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName,
+    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + SetLen,
 >(
     d: Arc<DownloaderInternal<T>>,
     pd: Arc<PdFilePartStatus>,
@@ -260,7 +263,9 @@ pub async fn create_download_tasks_multi_internal<
 }
 
 /// Handle download process
-pub async fn handle_download<T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName>(
+pub async fn handle_download<
+    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + SetLen,
+>(
     d: Arc<DownloaderInternal<T>>,
     re: Response,
     pd: Option<Arc<PdFilePartStatus>>,
@@ -365,7 +370,7 @@ pub async fn handle_download<T: Seek + Write + Send + Sync + ClearFile + GetTarg
 }
 
 pub async fn add_new_multi_tasks<
-    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + 'static,
+    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + SetLen + 'static,
 >(
     d: &Arc<DownloaderInternal<T>>,
 ) -> Result<(), DownloaderError> {
@@ -395,7 +400,7 @@ pub async fn add_new_multi_tasks<
 
 /// Check tasks are completed or not. And create new tasks if needed.
 pub async fn check_tasks<
-    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + 'static,
+    T: Seek + Write + Send + Sync + ClearFile + GetTargetFileName + SetLen + 'static,
 >(
     d: Arc<DownloaderInternal<T>>,
 ) -> Result<(), DownloaderError> {