use std::collections::VecDeque;
use crate::{
blobservice::BlobService,
chunkservice::{read_all_and_chunk, update_hasher, ChunkService},
Error,
};
use data_encoding::BASE64;
use tokio::{sync::mpsc::channel, task};
use tokio_stream::{wrappers::ReceiverStream, StreamExt};
use tonic::{async_trait, Request, Response, Status, Streaming};
use tracing::{debug, instrument, warn};
pub struct GRPCBlobServiceWrapper<BS: BlobService, CS: ChunkService> {
blob_service: BS,
chunk_service: CS,
}
impl<BS: BlobService, CS: ChunkService> GRPCBlobServiceWrapper<BS, CS> {
pub fn new(blob_service: BS, chunk_service: CS) -> Self {
Self {
blob_service,
chunk_service,
}
}
// upload the chunk to the chunk service, and return its digest (or an error) when done.
#[instrument(skip(chunk_service))]
fn upload_chunk(chunk_service: CS, chunk_data: Vec<u8>) -> Result<Vec<u8>, Error> {
let mut hasher = blake3::Hasher::new();
update_hasher(&mut hasher, &chunk_data);
let digest = hasher.finalize();
if chunk_service.has(digest.as_bytes())? {
debug!("already has chunk, skipping");
}
let digest_resp = chunk_service.put(chunk_data)?;
assert_eq!(&digest_resp, digest.as_bytes());
Ok(digest.as_bytes().to_vec())
}
}
#[async_trait]
impl<
BS: BlobService + Send + Sync + Clone + 'static,
CS: ChunkService + Send + Sync + Clone + 'static,
> super::blob_service_server::BlobService for GRPCBlobServiceWrapper<BS, CS>
{
type ReadStream = ReceiverStream<Result<super::BlobChunk, Status>>;
#[instrument(skip(self))]
async fn stat(
&self,
request: Request<super::StatBlobRequest>,
) -> Result<Response<super::BlobMeta>, Status> {
let rq = request.into_inner();
match self.blob_service.stat(&rq) {
Ok(None) => Err(Status::not_found(format!(
"blob {} not found",
BASE64.encode(&rq.digest)
))),
Ok(Some(blob_meta)) => Ok(Response::new(blob_meta)),
Err(e) => Err(e.into()),
}
}
#[instrument(skip(self))]
async fn read(
&self,
request: Request<super::ReadBlobRequest>,
) -> Result<Response<Self::ReadStream>, Status> {
let req = request.into_inner();
let (tx, rx) = channel(5);
let req_digest: [u8; 32] = req
.digest
.try_into()
.map_err(|_e| Status::invalid_argument("invalid digest length"))?;
// query the chunk service for more detailed blob info
let stat_resp = self.blob_service.stat(&super::StatBlobRequest {
digest: req_digest.to_vec(),
include_chunks: true,
..Default::default()
})?;
match stat_resp {
None => {
// If the stat didn't return any blobmeta, the client might
// still have asked for a single chunk to be read.
// Check the chunkstore.
if let Some(data) = self.chunk_service.get(&req_digest)? {
// We already know the hash matches, and contrary to
// iterating over a blobmeta, we can't know the size,
// so send the contents of that chunk over,
// as the first (and only) element of the stream.
task::spawn(async move {
let res = Ok(super::BlobChunk { data });
// send the result to the client. If the client already left, that's also fine.
if (tx.send(res).await).is_err() {
debug!("receiver dropped");
}
});
} else {
return Err(Status::not_found(format!(
"blob {} not found",
BASE64.encode(&req_digest),
)));
}
}
Some(blobmeta) => {
let chunk_client = self.chunk_service.clone();
// TODO: use BlobReader?
// But then we might not be able to send compressed chunks as-is.
// Might require implementing https://docs.rs/futures-core/latest/futures_core/stream/trait.Stream.html for it
// first, so we can .next().await in here.
task::spawn(async move {
for chunkmeta in blobmeta.chunks {
// request chunk.
// We don't need to validate the digest again, as
// that's required for all implementations of ChunkService.
// TODO: handle error
let chunkmeta_digest = &chunkmeta.digest.try_into().unwrap();
let res = match chunk_client.get(&chunkmeta_digest) {
Err(e) => Err(e.into()),
// TODO: make this a separate error type
Ok(None) => Err(Error::StorageError(format!(
"consistency error: chunk {} for blob {} not found",
BASE64.encode(chunkmeta_digest),
BASE64.encode(&req_digest),
))
.into()),
Ok(Some(data)) => {
// We already know the hash matches, but also
// check the size matches what chunkmeta said.
if data.len() as u32 != chunkmeta.size {
Err(Error::StorageError(format!(
"consistency error: chunk {} for blob {} has wrong size, expected {}, got {}",
BASE64.encode(chunkmeta_digest),
BASE64.encode(&req_digest),
chunkmeta.size,
data.len(),
)).into())
} else {
// send out the current chunk
// TODO: we might want to break this up further if too big?
Ok(super::BlobChunk { data })
}
}
};
// send the result to the client
if (tx.send(res).await).is_err() {
debug!("receiver dropped");
break;
}
}
});
}
}
let receiver_stream = ReceiverStream::new(rx);
Ok(Response::new(receiver_stream))
}
#[instrument(skip(self))]
async fn put(
&self,
request: Request<Streaming<super::BlobChunk>>,
) -> Result<Response<super::PutBlobResponse>, Status> {
let req_inner = request.into_inner();
let data_stream = req_inner.map(|x| {
x.map(|x| VecDeque::from(x.data))
.map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, e))
});
let data_reader = tokio_util::io::StreamReader::new(data_stream);
// TODO: can we get rid of this clone?
let chunk_service = self.chunk_service.clone();
let (blob_digest, blob_meta) =
task::spawn_blocking(move || -> Result<(Vec<u8>, super::BlobMeta), Error> {
// feed read_all_and_chunk a (sync) reader to the data retrieved from the stream.
read_all_and_chunk(
&chunk_service,
tokio_util::io::SyncIoBridge::new(data_reader),
)
})
.await
.map_err(|e| Status::internal(e.to_string()))??;
// upload blobmeta if not there yet
if self
.blob_service
.stat(&super::StatBlobRequest {
digest: blob_digest.to_vec(),
include_chunks: false,
include_bao: false,
})?
.is_none()
{
// upload blobmeta
self.blob_service.put(&blob_digest, blob_meta)?;
}
// return to client.
Ok(Response::new(super::PutBlobResponse {
digest: blob_digest,
}))
}
}
