Code, PoV compression and remove CompressedPoV struct (#2852)

* use compressed blob in candidate-validation

* add some tests for compressed code blobs

* remove CompressedPoV and apply compression in collation-generation

* decompress BlockData before executing

* don't produce oversized collations

* add test for PoV decompression failure

* fix tests and clean up

* fix test

* address review and fix CI

* take this )

polkadot/node/network/availability-distribution/src/error.rs

@@ -24,7 +24,6 @@ use futures::channel::oneshot;
 
 use polkadot_node_subsystem_util::Error as UtilError;
 use polkadot_primitives::v1::SessionIndex;
-use polkadot_node_primitives::CompressedPoVError;
 use polkadot_subsystem::{errors::RuntimeApiError, SubsystemError};
 
 use crate::LOG_TARGET;
@@ -79,10 +78,6 @@ pub enum Error {
 	#[error("There was no session with the given index")]
 	NoSuchSession(SessionIndex),
 
-	/// Decompressing PoV failed.
-	#[error("PoV could not be decompressed")]
-	PoVDecompression(CompressedPoVError),
-
 	/// Fetching PoV failed with `RequestError`.
 	#[error("FetchPoV request error")]
 	FetchPoV(#[source] RequestError),

polkadot/node/network/availability-distribution/src/pov_requester/mod.rs

@@ -152,9 +152,7 @@ async fn do_fetch_pov(
 {
 	let response = pending_response.await.map_err(Error::FetchPoV)?;
 	let pov = match response {
-		PoVFetchingResponse::PoV(compressed) => {
-			compressed.decompress().map_err(Error::PoVDecompression)?
-		}
+		PoVFetchingResponse::PoV(pov) => pov,
 		PoVFetchingResponse::NoSuchPoV => {
 			return Err(Error::NoSuchPoV)
 		}
@@ -244,7 +242,7 @@ mod tests {
 	use sp_core::testing::TaskExecutor;
 
 	use polkadot_primitives::v1::{CandidateHash, Hash, ValidatorIndex};
-	use polkadot_node_primitives::{BlockData, CompressedPoV};
+	use polkadot_node_primitives::BlockData;
 	use polkadot_subsystem_testhelpers as test_helpers;
 	use polkadot_subsystem::messages::{AvailabilityDistributionMessage, RuntimeApiMessage, RuntimeApiRequest};
 
@@ -315,9 +313,8 @@ mod tests {
 							reqs.pop(),
 							Some(Requests::PoVFetching(outgoing)) => {outgoing}
 						);
-						req.pending_response.send(Ok(PoVFetchingResponse::PoV(
-							CompressedPoV::compress(&pov).unwrap()).encode()
-						)).unwrap();
+						req.pending_response.send(Ok(PoVFetchingResponse::PoV(pov.clone()).encode()))
+							.unwrap();
 						break
 					},
 					msg => tracing::debug!(target: LOG_TARGET, msg = ?msg, "Received msg"),

polkadot/node/network/availability-distribution/src/responder.rs

@@ -16,11 +16,13 @@
 
 //! Answer requests for availability chunks.
 
+use std::sync::Arc;
+
 use futures::channel::oneshot;
 
 use polkadot_node_network_protocol::request_response::{request::IncomingRequest, v1};
 use polkadot_primitives::v1::{CandidateHash, ValidatorIndex};
-use polkadot_node_primitives::{AvailableData, CompressedPoV, ErasureChunk};
+use polkadot_node_primitives::{AvailableData, ErasureChunk};
 use polkadot_subsystem::{
 	messages::{AllMessages, AvailabilityStoreMessage},
 	SubsystemContext, jaeger,
@@ -100,18 +102,7 @@ where
 	let response = match av_data {
 		None => v1::PoVFetchingResponse::NoSuchPoV,
 		Some(av_data) => {
-			let pov = match CompressedPoV::compress(&av_data.pov) {
-				Ok(pov) => pov,
-				Err(error) => {
-					tracing::error!(
-						target: LOG_TARGET,
-						error = ?error,
-						"Failed to create `CompressedPov`",
-					);
-					// this should really not happen, let this request time out:
-					return Err(Error::PoVDecompression(error))
-				}
-			};
+			let pov = Arc::try_unwrap(av_data.pov).unwrap_or_else(|a| (&*a).clone());
 			v1::PoVFetchingResponse::PoV(pov)
 		}
 	};