tablejohn/src/server/web/api/stream.rs

122 lines
3.5 KiB
Rust

//! Stream gzipped tar-ed repository worktrees.
use std::{
io::{self, BufWriter, Read},
sync::Arc,
};
use axum::{body::Bytes, BoxError};
use flate2::{write::GzEncoder, Compression};
use futures::TryStream;
use gix::{
bstr::ByteSlice, objs::tree::EntryMode, prelude::ObjectIdExt, worktree::stream::Entry,
ObjectId, ThreadSafeRepository,
};
use tokio::sync::mpsc;
use tokio_stream::wrappers::ReceiverStream;
use tracing::{debug, warn};
const BLOCK_SIZE: usize = 1024 * 1024;
const COMPRESSION_LEVEL: Compression = Compression::fast();
struct SenderWriter(mpsc::Sender<Result<Bytes, BoxError>>);
impl SenderWriter {
fn new(tx: mpsc::Sender<Result<Bytes, BoxError>>) -> Self {
Self(tx)
}
fn finish(self) {}
}
impl io::Write for SenderWriter {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
match self.0.blocking_send(Ok(Bytes::copy_from_slice(buf))) {
Ok(()) => Ok(buf.len()),
Err(_) => Err(io::ErrorKind::ConnectionAborted.into()),
}
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
fn write_entry(
mut entry: Entry<'_>,
writer: &mut tar::Builder<impl io::Write>,
) -> Result<(), BoxError> {
let mut header = tar::Header::new_gnu();
header.set_entry_type(match entry.mode {
EntryMode::Tree | EntryMode::Commit => tar::EntryType::Directory,
EntryMode::Blob | EntryMode::BlobExecutable => tar::EntryType::Regular,
EntryMode::Link => tar::EntryType::Symlink,
});
header.set_mode(match entry.mode {
EntryMode::BlobExecutable => 0o755, // rwxr-xr-x
_ => 0o644, // rw-r--r--
});
if entry.mode == EntryMode::Link {
let mut buf = vec![];
entry.read_to_end(&mut buf)?;
header.set_size(0);
let path = gix::path::from_bstr(entry.relative_path());
let target = gix::path::from_bstr(buf.as_bstr());
writer.append_link(&mut header, path, target)?;
} else {
header.set_size(entry.bytes_remaining().unwrap_or(0) as u64);
let path = gix::path::from_bstr(entry.relative_path()).to_path_buf();
writer.append_data(&mut header, path, entry)?;
}
Ok(())
}
fn write_worktree(
repo: Arc<ThreadSafeRepository>,
commit_id: ObjectId,
tx: mpsc::Sender<Result<Bytes, BoxError>>,
) -> Result<(), BoxError> {
let repo = repo.to_thread_local();
let tree_id = commit_id
.attach(&repo)
.object()?
.try_into_commit()?
.tree_id()?;
let (mut stream, _) = repo.worktree_stream(tree_id)?;
let writer = SenderWriter::new(tx);
let writer = BufWriter::with_capacity(BLOCK_SIZE, writer);
let writer = GzEncoder::new(writer, COMPRESSION_LEVEL);
let mut writer = tar::Builder::new(writer);
while let Some(entry) = stream.next_entry()? {
write_entry(entry, &mut writer)?;
}
writer
.into_inner()?
.finish()?
.into_inner()
.map_err(|e| e.into_error())?
.finish();
Ok(())
}
pub fn tar_and_gzip(
repo: Arc<ThreadSafeRepository>,
id: ObjectId,
) -> impl TryStream<Ok = Bytes, Error = BoxError> {
let (tx, rx) = mpsc::channel(1);
tokio::task::spawn_blocking(move || {
if let Err(e) = write_worktree(repo, id, tx.clone()) {
warn!("Error while streaming tar:\n{e:?}");
let _ = tx.blocking_send(Err(e));
} else {
debug!("Tar streamed successfully");
}
});
ReceiverStream::new(rx)
}