Rewrite untar to take a visitor & simplify

signature of `download_and_extract_with_filter`

Signed-off-by: Jiahao XU <Jiahao_XU@outlook.com>

src/drivers.rs

@@ -114,7 +114,7 @@ pub async fn fetch_crate_cratesio(
         Url::parse(&crate_url)?,
         TarBasedFmt::Tgz,
         &temp_dir,
-        Some(move |path: &Path| path == cargo_toml || path == main || path.starts_with(&bin)),
+        move |path: &Path| path == cargo_toml || path == main || path.starts_with(&bin),
     )
     .await?;
 

src/helpers.rs

@@ -92,7 +92,7 @@ pub async fn download_and_extract_with_filter<
     url: Url,
     fmt: TarBasedFmt,
     path: P,
-    filter: Option<Filter>,
+    filter: Filter,
 ) -> Result<(), BinstallError> {
     debug!("Downloading from: '{url}'");
 

src/helpers/async_extracter.rs

@@ -1,11 +1,14 @@
 use std::fmt::Debug;
 use std::fs;
-use std::io::{self, Seek, Write};
+use std::io::{self, Read, Seek, Write};
-use std::path::Path;
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
 
 use bytes::Bytes;
 use futures_util::stream::{Stream, StreamExt};
+use log::debug;
 use scopeguard::{guard, ScopeGuard};
+use tar::Entries;
 use tempfile::tempfile;
 use tokio::{
     sync::mpsc,
@@ -209,17 +212,42 @@ pub async fn extract_tar_based_stream_with_filter<
     stream: impl Stream<Item = Result<Bytes, E>> + Unpin,
     output: &Path,
     fmt: TarBasedFmt,
-    filter: Option<Filter>,
+    filter: Filter,
 ) -> Result<(), BinstallError>
 where
     BinstallError: From<E>,
 {
-    let path = output.to_owned();
+    struct Visitor<F>(F, Arc<PathBuf>);
+
+    impl<F: FnMut(&Path) -> bool + Send + 'static> TarEntriesVisitor for Visitor<F> {
+        fn visit<R: Read>(&mut self, entries: Entries<'_, R>) -> Result<(), BinstallError> {
+            for res in entries {
+                let mut entry = res?;
+                let entry_path = entry.path()?;
+
+                if self.0(&entry_path) {
+                    debug!("Extracting {entry_path:#?}");
+
+                    let dst = self.1.join(entry_path);
+
+                    fs::create_dir_all(dst.parent().unwrap())?;
+
+                    entry.unpack(dst)?;
+                }
+            }
+
+            Ok(())
+        }
+    }
+
+    let path = Arc::new(output.to_owned());
+
+    let visitor = Visitor(filter, path.clone());
 
     extract_impl(stream, move |mut rx| {
         fs::create_dir_all(path.parent().unwrap())?;
 
-        extract_compressed_from_readable(ReadableRx::new(&mut rx), fmt, &path, filter)
+        extract_compressed_from_readable(ReadableRx::new(&mut rx), fmt, &*path, Some(visitor))
     })
     .await
 }
@@ -232,12 +260,20 @@ pub async fn extract_tar_based_stream<E>(
 where
     BinstallError: From<E>,
 {
+    struct DummyVisitor;
+
+    impl TarEntriesVisitor for DummyVisitor {
+        fn visit<R: Read>(&mut self, _entries: Entries<'_, R>) -> Result<(), BinstallError> {
+            unimplemented!()
+        }
+    }
+
     let path = output.to_owned();
 
     extract_impl(stream, move |mut rx| {
         fs::create_dir_all(path.parent().unwrap())?;
 
-        extract_compressed_from_readable::<fn(&Path) -> bool, _>(
+        extract_compressed_from_readable::<DummyVisitor, _>(
             ReadableRx::new(&mut rx),
             fmt,
             &path,

src/helpers/extracter.rs

@@ -1,44 +1,34 @@
-use std::fs::{self, File};
+use std::fs::File;
 use std::io::{BufRead, Read};
 use std::path::Path;
 
 use flate2::bufread::GzDecoder;
 use log::debug;
-use tar::Archive;
+use tar::{Archive, Entries};
 use xz2::bufread::XzDecoder;
 use zip::read::ZipArchive;
 use zstd::stream::Decoder as ZstdDecoder;
 
 use crate::{BinstallError, TarBasedFmt};
 
-///  * `filter` - If Some, then it will pass the path of the file to it
+pub trait TarEntriesVisitor {
-///    and only extract ones which filter returns `true`.
+    fn visit<R: Read>(&mut self, entries: Entries<'_, R>) -> Result<(), BinstallError>;
-///    Note that this is a best-effort and it only works when `fmt`
+}
-///    is not `PkgFmt::Bin` or `PkgFmt::Zip`.
+
-fn untar<Filter: FnMut(&Path) -> bool>(
+///  * `f` - If Some, then this function will pass
-    dat: impl Read,
+///    the entries of the `dat` to it and let it decides
+///    what to do with the tar.
+fn untar<R: Read, V: TarEntriesVisitor>(
+    dat: R,
     path: &Path,
-    filter: Option<Filter>,
+    visitor: Option<V>,
 ) -> Result<(), BinstallError> {
     let mut tar = Archive::new(dat);
 
-    if let Some(mut filter) = filter {
+    if let Some(mut visitor) = visitor {
         debug!("Untaring with filter");
 
-        for res in tar.entries()? {
+        visitor.visit(tar.entries()?)?;
-            let mut entry = res?;
-            let entry_path = entry.path()?;
-
-            if filter(&entry_path) {
-                debug!("Extracting {entry_path:#?}");
-
-                let dst = path.join(entry_path);
-
-                fs::create_dir_all(dst.parent().unwrap())?;
-
-                entry.unpack(dst)?;
-            }
-        }
     } else {
         debug!("Untaring entire tar");
         tar.unpack(path)?;
@@ -56,11 +46,11 @@ fn untar<Filter: FnMut(&Path) -> bool>(
 ///    and only extract ones which filter returns `true`.
 ///    Note that this is a best-effort and it only works when `fmt`
 ///    is not `PkgFmt::Bin` or `PkgFmt::Zip`.
-pub(crate) fn extract_compressed_from_readable<Filter: FnMut(&Path) -> bool, R: BufRead>(
+pub(crate) fn extract_compressed_from_readable<V: TarEntriesVisitor, R: BufRead>(
     dat: R,
     fmt: TarBasedFmt,
     path: &Path,
-    filter: Option<Filter>,
+    visitor: Option<V>,
 ) -> Result<(), BinstallError> {
     use TarBasedFmt::*;
 
@@ -69,21 +59,21 @@ pub(crate) fn extract_compressed_from_readable<Filter: FnMut(&Path) -> bool, R:
             // Extract to install dir
             debug!("Extracting from tar archive to `{path:?}`");
 
-            untar(dat, path, filter)?
+            untar(dat, path, visitor)?
         }
         Tgz => {
             // Extract to install dir
             debug!("Decompressing from tgz archive to `{path:?}`");
 
             let tar = GzDecoder::new(dat);
-            untar(tar, path, filter)?;
+            untar(tar, path, visitor)?;
         }
         Txz => {
             // Extract to install dir
             debug!("Decompressing from txz archive to `{path:?}`");
 
             let tar = XzDecoder::new(dat);
-            untar(tar, path, filter)?;
+            untar(tar, path, visitor)?;
         }
         Tzstd => {
             // Extract to install dir
@@ -94,7 +84,7 @@ pub(crate) fn extract_compressed_from_readable<Filter: FnMut(&Path) -> bool, R:
             // as &[] by ZstdDecoder::new, thus ZstdDecoder::new
             // should not return any error.
             let tar = ZstdDecoder::with_buffer(dat)?;
-            untar(tar, path, filter)?;
+            untar(tar, path, visitor)?;
         }
     };