feat: add metadata method to puffin reader (#5501)

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

src/puffin/src/puffin_manager.rs

@@ -21,6 +21,7 @@ pub mod stager;
 mod tests;
 
 use std::path::PathBuf;
+use std::sync::Arc;
 
 use async_trait::async_trait;
 use common_base::range_read::RangeReader;
@@ -28,6 +29,7 @@ use futures::AsyncRead;
 
 use crate::blob_metadata::CompressionCodec;
 use crate::error::Result;
+use crate::file_metadata::FileMetadata;
 
 /// The `PuffinManager` trait provides a unified interface for creating `PuffinReader` and `PuffinWriter`.
 #[async_trait]
@@ -79,6 +81,9 @@ pub trait PuffinReader {
 
     fn with_file_size_hint(self, file_size_hint: Option<u64>) -> Self;
 
+    /// Returns the metadata of the Puffin file.
+    async fn metadata(&self) -> Result<Arc<FileMetadata>>;
+
     /// Reads a blob from the Puffin file.
     ///
     /// The returned `BlobGuard` is used to access the blob data.

src/puffin/src/puffin_manager/fs_puffin_manager/reader.rs

@@ -87,6 +87,15 @@ where
         self
     }
 
+    async fn metadata(&self) -> Result<Arc<FileMetadata>> {
+        let reader = self
+            .puffin_file_accessor
+            .reader(&self.puffin_file_name)
+            .await?;
+        let mut file = PuffinFileReader::new(reader);
+        self.get_puffin_file_metadata(&mut file).await
+    }
+
     async fn blob(&self, key: &str) -> Result<Self::Blob> {
         let mut reader = self
             .puffin_file_accessor