Better unified piece abstractions using a tiny bit of unsafe

crates/pallet-subspace/src/mock.rs

@@ -41,7 +41,7 @@ use subspace_archiving::archiver::{ArchivedSegment, Archiver};
 use subspace_core_primitives::crypto::kzg::{embedded_kzg_settings, Kzg, Witness};
 use subspace_core_primitives::crypto::{blake2b_256_254_hash_to_scalar, kzg, ScalarLegacy};
 use subspace_core_primitives::{
-    ArchivedBlockProgress, Blake2b256Hash, LastArchivedBlock, Piece, Randomness, RecordsRoot,
+    ArchivedBlockProgress, Blake2b256Hash, LastArchivedBlock, PieceArray, Randomness, RecordsRoot,
     RootBlock, SegmentIndex, Solution, SolutionRange, PIECE_SIZE, RECORDED_HISTORY_SEGMENT_SIZE,
 };
 use subspace_solving::{create_chunk_signature, derive_global_challenge, REWARD_SIGNING_CONTEXT};
@@ -362,7 +362,7 @@ pub fn create_signed_vote(
     parent_hash: <Block as BlockT>::Hash,
     slot: Slot,
     global_randomnesses: &Randomness,
-    piece: Piece,
+    piece: &PieceArray,
     reward_address: <Test as frame_system::Config>::AccountId,
 ) -> SignedVote<u64, <Block as BlockT>::Hash, <Test as frame_system::Config>::AccountId> {
     let reward_signing_context = schnorrkel::signing_context(REWARD_SIGNING_CONTEXT);
@@ -382,8 +382,8 @@ pub fn create_signed_vote(
             sector_index: 0,
             total_pieces: NonZeroU64::new(1).unwrap(),
             piece_offset: 0,
-            piece_record_hash: blake2b_256_254_hash_to_scalar(&piece.record()),
-            piece_witness: Witness::try_from_bytes(&piece.witness()).unwrap(),
+            piece_record_hash: blake2b_256_254_hash_to_scalar(piece.record().as_ref()),
+            piece_witness: Witness::try_from_bytes(piece.witness()).unwrap(),
             chunk_offset: 0,
             chunk,
             chunk_signature: create_chunk_signature(keypair, &chunk.to_bytes()),

crates/pallet-subspace/src/tests.rs

@@ -44,7 +44,6 @@ use sp_runtime::transaction_validity::{
 use sp_runtime::DispatchError;
 use std::assert_matches::assert_matches;
 use std::collections::BTreeMap;
-use subspace_core_primitives::Piece;
 use subspace_runtime_primitives::{FindBlockRewardAddress, FindVotingRewardAddresses};
 use subspace_solving::REWARD_SIGNING_CONTEXT;
 use subspace_verification::Error as VerificationError;
@@ -628,7 +627,7 @@ fn vote_block_listed() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         BlockList::<Test>::insert(
             FarmerPublicKey::unchecked_from(keypair.public.to_bytes()),
@@ -658,7 +657,7 @@ fn vote_after_genesis() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         // Can't submit vote right after genesis block
         let signed_vote = create_signed_vote(
@@ -683,7 +682,7 @@ fn vote_too_low_height() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 1, 1);
 
@@ -696,7 +695,7 @@ fn vote_too_low_height() {
                 <Test as frame_system::Config>::Hash::default(),
                 Subspace::current_slot() + 1,
                 &Subspace::global_randomnesses().current,
-                piece.clone(),
+                piece,
                 1,
             );
 
@@ -713,7 +712,7 @@ fn vote_past_future_height() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 4, 1);
 
@@ -725,7 +724,7 @@ fn vote_past_future_height() {
                 <Test as frame_system::Config>::Hash::default(),
                 Subspace::current_slot() + 1,
                 &Subspace::global_randomnesses().current,
-                piece.clone(),
+                piece,
                 1,
             );
 
@@ -760,7 +759,7 @@ fn vote_wrong_parent() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 
@@ -787,7 +786,7 @@ fn vote_past_future_slot() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         RecordsRoot::<Test>::insert(
             archived_segment.root_block.segment_index(),
@@ -809,7 +808,7 @@ fn vote_past_future_slot() {
                 frame_system::Pallet::<Test>::block_hash(2),
                 2.into(),
                 &Subspace::global_randomnesses().current,
-                piece.clone(),
+                piece,
                 1,
             );
 
@@ -845,7 +844,7 @@ fn vote_past_future_slot() {
         // in that context it is valid
         {
             let keypair = Keypair::generate();
-            let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+            let piece = &archived_segment.pieces[0];
 
             let signed_vote = create_signed_vote(
                 &keypair,
@@ -885,7 +884,7 @@ fn vote_same_slot() {
         // Same time slot in the vote as in the block is fine if height is the same (pre-dispatch)
         {
             let keypair = Keypair::generate();
-            let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+            let piece = &archived_segment.pieces[0];
             let signed_vote = create_signed_vote(
                 &keypair,
                 3,
@@ -903,7 +902,7 @@ fn vote_same_slot() {
         // (pre-dispatch)
         {
             let keypair = Keypair::generate();
-            let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+            let piece = &archived_segment.pieces[0];
             let signed_vote = create_signed_vote(
                 &keypair,
                 2,
@@ -927,7 +926,7 @@ fn vote_bad_reward_signature() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 
@@ -956,7 +955,7 @@ fn vote_unknown_records_root() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 
@@ -983,7 +982,7 @@ fn vote_outside_of_solution_range() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 
@@ -1017,7 +1016,7 @@ fn vote_invalid_solution_signature() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 
@@ -1070,7 +1069,7 @@ fn vote_correct_signature() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 
@@ -1104,7 +1103,7 @@ fn vote_randomness_update() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         RecordsRoot::<Test>::insert(
             archived_segment.root_block.segment_index(),
@@ -1141,7 +1140,7 @@ fn vote_equivocation_current_block_plus_vote() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 
@@ -1192,7 +1191,7 @@ fn vote_equivocation_parent_block_plus_vote() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 
@@ -1252,7 +1251,7 @@ fn vote_equivocation_parent_block_plus_vote() {
 fn vote_equivocation_current_voters_duplicate() {
     new_test_ext().execute_with(|| {
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&Keypair::generate(), 2, 1);
 
@@ -1332,7 +1331,7 @@ fn vote_equivocation_parent_voters_duplicate() {
     new_test_ext().execute_with(|| {
         let keypair = Keypair::generate();
         let archived_segment = create_archived_segment();
-        let piece = Piece::from(archived_segment.pieces.as_pieces().next().unwrap());
+        let piece = &archived_segment.pieces[0];
 
         progress_to_block(&keypair, 2, 1);
 

crates/sc-consensus-subspace/src/tests.rs

@@ -549,7 +549,7 @@ async fn run_one_test(mutator: impl Fn(&mut TestHeader, Stage) + Send + Sync + '
                 .await
                 .unwrap()
                 .iter()
-                .flat_map(|flat_pieces| flat_pieces.as_pieces())
+                .flat_map(|flat_pieces| flat_pieces.iter())
                 .enumerate()
                 .choose(&mut thread_rng())
                 .map(|(piece_index, piece)| (piece_index as u64, Piece::from(piece)))

crates/sp-lightclient/src/tests.rs

@@ -91,7 +91,7 @@ impl Farmer {
         let kzg = Kzg::new(kzg::embedded_kzg_settings());
         let archived_segment = archived_segment(kzg.clone());
         let root_block = archived_segment.root_block;
-        let total_pieces = NonZeroU64::new(archived_segment.pieces.count() as u64).unwrap();
+        let total_pieces = NonZeroU64::new(archived_segment.pieces.len() as u64).unwrap();
         let mut sector = vec![0u8; PLOT_SECTOR_SIZE as usize];
         let mut sector_metadata = vec![0u8; SectorMetadata::encoded_size()];
         let sector_index = 0;
@@ -150,7 +150,7 @@ impl PieceGetter for TestPieceGetter {
         Ok(self
             .archived_segment
             .pieces
-            .as_pieces()
+            .iter()
             .nth(piece_index as usize)
             .map(Piece::from))
     }

crates/subspace-archiving/src/archiver.rs

@@ -35,7 +35,7 @@ use subspace_core_primitives::objects::{
     BlockObject, BlockObjectMapping, PieceObject, PieceObjectMapping,
 };
 use subspace_core_primitives::{
-    ArchivedBlockProgress, Blake2b256Hash, BlockNumber, FlatPieces, LastArchivedBlock, PieceRef,
+    ArchivedBlockProgress, Blake2b256Hash, BlockNumber, FlatPieces, LastArchivedBlock, PieceArray,
     RecordsRoot, RootBlock, RECORDED_HISTORY_SEGMENT_SIZE, RECORD_SIZE,
 };
 
@@ -749,20 +749,20 @@ impl Archiver {
         // Combine data and parity records back into flat vector of pieces along with corresponding
         // witnesses (Merkle proofs) created above.
         pieces
-            .as_pieces_mut()
+            .iter_mut()
             .enumerate()
             .zip(
                 record_shards
                     .as_bytes()
                     .as_ref()
                     .chunks_exact(RECORD_SIZE as usize),
             )
-            .for_each(|((position, mut piece), shard_chunk)| {
-                let (mut record, mut witness) = piece.split_mut();
+            .for_each(|((position, piece), shard_chunk)| {
+                let (record, witness) = piece.split_mut();
 
-                record.as_mut().copy_from_slice(shard_chunk);
+                record.copy_from_slice(shard_chunk);
                 // TODO: Consider batch witness creation for improved performance
-                witness.as_mut().copy_from_slice(
+                witness.copy_from_slice(
                     &self
                         .kzg
                         .create_witness(&polynomial, position as u32)
@@ -799,18 +799,18 @@ impl Archiver {
 pub fn is_piece_valid(
     kzg: &Kzg,
     num_pieces_in_segment: usize,
-    piece: PieceRef<'_>,
+    piece: &PieceArray,
     commitment: RecordsRoot,
     position: u32,
 ) -> bool {
     let (record, witness) = piece.split();
-    let witness = match Witness::try_from_bytes(&witness) {
+    let witness = match Witness::try_from_bytes(witness) {
         Ok(witness) => witness,
         _ => {
             return false;
         }
     };
-    let leaf_hash = blake2b_256_254_hash_to_scalar(&record);
+    let leaf_hash = blake2b_256_254_hash_to_scalar(record.as_ref());
 
     kzg.verify(
         &commitment,

crates/subspace-archiving/src/piece_reconstructor.rs

@@ -105,10 +105,10 @@ impl PiecesReconstructor {
         //TODO: reuse already present commitments from segment_pieces, so we don't re-derive what
         // we already have
         reconstructed_record_shards
-            .as_pieces_mut()
+            .iter_mut()
             .zip(record_commitments.iter_mut())
             .zip(shards)
-            .for_each(|((mut piece, polynomial_data), record)| {
+            .for_each(|((piece, polynomial_data), record)| {
                 let record =
                     record.expect("Reconstruction just happened and all records are present; qed");
                 let record = record.flatten();
@@ -133,20 +133,17 @@ impl PiecesReconstructor {
     ) -> Result<FlatPieces, ReconstructorError> {
         let (mut pieces, polynomial) = self.reconstruct_shards(segment_pieces)?;
 
-        pieces
-            .as_pieces_mut()
-            .enumerate()
-            .for_each(|(position, mut piece)| {
-                piece.witness_mut().as_mut().copy_from_slice(
-                    &self
-                        .kzg
-                        .create_witness(&polynomial, position as u32)
-                        // TODO: Update this proof here and in other places, we don't use Merkle
-                        //  trees anymore
-                        .expect("We use the same indexes as during Merkle tree creation; qed")
-                        .to_bytes(),
-                );
-            });
+        pieces.iter_mut().enumerate().for_each(|(position, piece)| {
+            piece.witness_mut().as_mut().copy_from_slice(
+                &self
+                    .kzg
+                    .create_witness(&polynomial, position as u32)
+                    // TODO: Update this proof here and in other places, we don't use Merkle
+                    //  trees anymore
+                    .expect("We use the same indexes as during Merkle tree creation; qed")
+                    .to_bytes(),
+            );
+        });
 
         Ok(pieces)
     }
@@ -164,14 +161,7 @@ impl PiecesReconstructor {
             return Err(ReconstructorError::IncorrectPiecePosition);
         }
 
-        let mut piece = Piece::from(
-            reconstructed_records
-                .as_pieces()
-                .nth(piece_position)
-                .expect(
-                "Piece exists at the position within segment after successful reconstruction; qed",
-            ),
-        );
+        let mut piece = Piece::from(reconstructed_records[piece_position]);
 
         piece.witness_mut().as_mut().copy_from_slice(
             &self

crates/subspace-archiving/src/reconstructor.rs

@@ -117,7 +117,7 @@ impl Reconstructor {
             .take(self.reed_solomon.data_shard_count())
             .all(|maybe_piece| {
                 if let Some(piece) = maybe_piece {
-                    segment_data.extend_from_slice(&piece.record());
+                    segment_data.extend_from_slice(piece.record().as_ref());
                     true
                 } else {
                     false