fix(cli): read exact chunk len (#7777)

crates/net/downloaders/src/file_client.rs

@@ -16,9 +16,11 @@ use thiserror::Error;
 use tokio::{fs::File, io::AsyncReadExt};
 use tokio_stream::StreamExt;
 use tokio_util::codec::FramedRead;
-use tracing::{trace, warn};
+use tracing::{debug, trace, warn};
 
-/// Byte length of chunk to read from chain file.
+/// Default byte length of chunk to read from chain file.
+///
+/// Default is 1 GB.
 pub const DEFAULT_BYTE_LEN_CHUNK_CHAIN_FILE: u64 = 1_000_000_000;
 
 /// Front-end API for fetching chain data from a file.
@@ -70,7 +72,7 @@ impl FileClient {
         let file_len = metadata.len();
 
         let mut reader = vec![];
-        file.read_to_end(&mut reader).await.unwrap();
+        file.read_to_end(&mut reader).await?;
 
         Ok(Self::from_reader(&reader[..], file_len).await?.0)
     }
@@ -87,9 +89,15 @@ impl FileClient {
         let mut hash_to_number = HashMap::new();
         let mut bodies = HashMap::new();
 
-        // use with_capacity to make sure the internal buffer contains the entire file
+        // use with_capacity to make sure the internal buffer contains the entire chunk
         let mut stream = FramedRead::with_capacity(reader, BlockFileCodec, num_bytes as usize);
 
+        trace!(target: "downloaders::file",
+            target_num_bytes=num_bytes,
+            capacity=stream.read_buffer().capacity(),
+            "init decode stream"
+        );
+
         let mut remaining_bytes = vec![];
 
         let mut log_interval = 0;
@@ -98,7 +106,12 @@ impl FileClient {
         while let Some(block_res) = stream.next().await {
             let block = match block_res {
                 Ok(block) => block,
-                Err(FileClientError::Rlp(_err, bytes)) => {
+                Err(FileClientError::Rlp(err, bytes)) => {
+                    trace!(target: "downloaders::file",
+                        %err,
+                        bytes_len=bytes.len(),
+                        "partial block returned from decoding chunk"
+                    );
                     remaining_bytes = bytes;
                     break
                 }
@@ -135,7 +148,7 @@ impl FileClient {
             log_interval += 1;
         }
 
-        trace!(blocks = headers.len(), "Initialized file client");
+        trace!(target: "downloaders::file", blocks = headers.len(), "Initialized file client");
 
         Ok((Self { headers, hash_to_number, bodies }, remaining_bytes))
     }
@@ -204,6 +217,16 @@ impl FileClient {
         }
         self
     }
+
+    /// Returns the current number of headers in the client.
+    pub fn headers_len(&self) -> usize {
+        self.headers.len()
+    }
+
+    /// Returns the current number of bodies in the client.
+    pub fn bodies_len(&self) -> usize {
+        self.bodies.len()
+    }
 }
 
 impl HeadersClient for FileClient {
@@ -297,8 +320,8 @@ impl DownloadClient for FileClient {
 pub struct ChunkedFileReader {
     /// File to read from.
     file: File,
-    /// Current file length.
+    /// Current file byte length.
-    file_len: u64,
+    file_byte_len: u64,
     /// Bytes that have been read.
     chunk: Vec<u8>,
     /// Max bytes per chunk.
@@ -322,20 +345,20 @@ impl ChunkedFileReader {
     pub async fn from_file(file: File, chunk_byte_len: u64) -> Result<Self, FileClientError> {
         // get file len from metadata before reading
         let metadata = file.metadata().await?;
-        let file_len = metadata.len();
+        let file_byte_len = metadata.len();
 
-        Ok(Self { file, file_len, chunk: vec![], chunk_byte_len })
+        Ok(Self { file, file_byte_len, chunk: vec![], chunk_byte_len })
     }
 
     /// Calculates the number of bytes to read from the chain file. Returns a tuple of the chunk
     /// length and the remaining file length.
     fn chunk_len(&self) -> u64 {
-        let Self { chunk_byte_len, file_len, .. } = *self;
+        let Self { chunk_byte_len, file_byte_len, .. } = *self;
-        let file_len = file_len + self.chunk.len() as u64;
+        let file_byte_len = file_byte_len + self.chunk.len() as u64;
 
-        if chunk_byte_len > file_len {
+        if chunk_byte_len > file_byte_len {
             // last chunk
-            file_len
+            file_byte_len
         } else {
             chunk_byte_len
         }
@@ -343,37 +366,52 @@ impl ChunkedFileReader {
 
     /// Read next chunk from file. Returns [`FileClient`] containing decoded chunk.
     pub async fn next_chunk(&mut self) -> Result<Option<FileClient>, FileClientError> {
-        if self.file_len == 0 && self.chunk.is_empty() {
+        if self.file_byte_len == 0 && self.chunk.is_empty() {
             // eof
             return Ok(None)
         }
 
-        let chunk_len = self.chunk_len();
+        let chunk_target_len = self.chunk_len();
         let old_bytes_len = self.chunk.len() as u64;
 
         // calculate reserved space in chunk
-        let new_bytes_len = chunk_len - old_bytes_len;
+        let new_read_bytes_target_len = chunk_target_len - old_bytes_len;
 
         // read new bytes from file
-        let mut reader = BytesMut::with_capacity(new_bytes_len as usize);
+        let mut reader = BytesMut::zeroed(new_read_bytes_target_len as usize);
-        self.file.read_buf(&mut reader).await?;
+        // actual bytes that have been read
+        let new_read_bytes_len = self.file.read_exact(&mut reader).await? as u64;
 
         // update remaining file length
-        self.file_len -= new_bytes_len;
+        self.file_byte_len -= new_read_bytes_len;
 
-        trace!(target: "downloaders::file",
+        let prev_read_bytes_len = self.chunk.len();
-            max_chunk_byte_len=self.chunk_byte_len,
-            prev_read_bytes_len=self.chunk.len(),
-            new_bytes_len,
-            remaining_file_byte_len=self.file_len,
-            "new bytes were read from file"
-        );
 
         // read new bytes from file into chunk
         self.chunk.extend_from_slice(&reader[..]);
+        let next_chunk_byte_len = self.chunk.len();
+
+        debug!(target: "downloaders::file",
+            max_chunk_byte_len=self.chunk_byte_len,
+            prev_read_bytes_len,
+            new_read_bytes_target_len,
+            new_read_bytes_len,
+            reader_capacity=reader.capacity(),
+            next_chunk_byte_len,
+            remaining_file_byte_len=self.file_byte_len,
+            "new bytes were read from file"
+        );
 
         // make new file client from chunk
-        let (file_client, bytes) = FileClient::from_reader(&self.chunk[..], chunk_len).await?;
+        let (file_client, bytes) =
+            FileClient::from_reader(&self.chunk[..], next_chunk_byte_len as u64).await?;
+
+        debug!(target: "downloaders::file",
+            headers_len=file_client.headers.len(),
+            bodies_len=file_client.bodies.len(),
+            remaining_bytes_len=bytes.len(),
+            "parsed blocks that were read from file"
+        );
 
         // save left over bytes
         self.chunk = bytes;