fix: avoid one in memory copy for unsealing (#1401)

* fix: avoid one in memory copy for unsealing
* feat: re-factor get_unsealed_range to use mmap

unseal_range is not readily able to be converted, but we should be
able to deprecate this call from -api by having unseal call into
get_unsealed_range transparently to the caller

* fix: preserve sealed file data

Co-authored-by: nemo <nemo@protocol.ai>

filecoin-proofs/src/api/mod.rs

@@ -1,4 +1,4 @@
-use std::fs::{self, File};
+use std::fs::{self, File, OpenOptions};
 use std::io::{self, BufReader, BufWriter, Read, Write};
 use std::path::{Path, PathBuf};
 
@@ -7,6 +7,7 @@ use bincode::deserialize;
 use filecoin_hashers::Hasher;
 use fr32::{write_unpadded, Fr32Reader};
 use log::{info, trace};
+use memmap::MmapOptions;
 use merkletree::store::{DiskStore, LevelCacheStore, StoreConfig};
 use storage_proofs_core::{
     cache_key::CacheKey,
@@ -83,18 +84,15 @@ pub fn get_unsealed_range<T: Into<PathBuf> + AsRef<Path>, Tree: 'static + Merkle
 ) -> Result<UnpaddedBytesAmount> {
     info!("get_unsealed_range:start");
 
-    let f_in = File::open(&sealed_path)
-        .with_context(|| format!("could not open sealed_path={:?}", sealed_path.as_ref()))?;
-
     let f_out = File::create(&output_path)
         .with_context(|| format!("could not create output_path={:?}", output_path.as_ref()))?;
 
     let buf_f_out = BufWriter::new(f_out);
 
-    let result = unseal_range::<_, _, _, Tree>(
+    let result = unseal_range_mapped::<_, _, Tree>(
         porep_config,
         cache_path,
-        f_in,
+        sealed_path.into(),
         buf_f_out,
         prover_id,
         sector_id,
@@ -130,7 +128,7 @@ pub fn unseal_range<P, R, W, Tree>(
     porep_config: PoRepConfig,
     cache_path: P,
     mut sealed_sector: R,
-    mut unsealed_output: W,
+    unsealed_output: W,
     prover_id: ProverId,
     sector_id: SectorId,
     comm_d: Commitment,
@@ -161,10 +159,126 @@ where
     let mut data = Vec::new();
     sealed_sector.read_to_end(&mut data)?;
 
+    let res = unseal_range_inner::<_, _, Tree>(
+        porep_config,
+        cache_path,
+        &mut data,
+        unsealed_output,
+        replica_id,
+        offset,
+        num_bytes,
+    )?;
+
+    info!("unseal_range:finish");
+
+    Ok(res)
+}
+
+/// Unseals the sector read from `sealed_sector` and returns the bytes for a
+/// piece whose first (unpadded) byte begins at `offset` and ends at `offset`
+/// plus `num_bytes`, inclusive. Note that the entire sector is unsealed each
+/// time this function is called.
+///
+/// # Arguments
+///
+/// * `porep_config` - porep configuration containing the sector size.
+/// * `cache_path` - path to the directory in which the sector data's Merkle Tree is written.
+/// * `sealed_sector` - a byte source from which we read sealed sector data.
+/// * `unsealed_output` - a byte sink to which we write unsealed, un-bit-padded sector bytes.
+/// * `prover_id` - the prover-id that sealed the sector.
+/// * `sector_id` - the sector-id of the sealed sector.
+/// * `comm_d` - the commitment to the sector's data.
+/// * `ticket` - the ticket that was used to generate the sector's replica-id.
+/// * `offset` - the byte index in the unsealed sector of the first byte that we want to read.
+/// * `num_bytes` - the number of bytes that we want to read.
+#[allow(clippy::too_many_arguments)]
+pub fn unseal_range_mapped<P, W, Tree>(
+    porep_config: PoRepConfig,
+    cache_path: P,
+    sealed_path: PathBuf,
+    unsealed_output: W,
+    prover_id: ProverId,
+    sector_id: SectorId,
+    comm_d: Commitment,
+    ticket: Ticket,
+    offset: UnpaddedByteIndex,
+    num_bytes: UnpaddedBytesAmount,
+) -> Result<UnpaddedBytesAmount>
+where
+    P: Into<PathBuf> + AsRef<Path>,
+    W: Write,
+    Tree: 'static + MerkleTreeTrait,
+{
+    info!("unseal_range_mapped:start");
+    ensure!(comm_d != [0; 32], "Invalid all zero commitment (comm_d)");
+
+    let comm_d =
+        as_safe_commitment::<<DefaultPieceHasher as Hasher>::Domain, _>(&comm_d, "comm_d")?;
+
+    let replica_id = generate_replica_id::<Tree::Hasher, _>(
+        &prover_id,
+        sector_id.into(),
+        &ticket,
+        comm_d,
+        &porep_config.porep_id,
+    );
+
+    let mapped_file = OpenOptions::new()
+        .read(true)
+        .write(true)
+        .open(&sealed_path)?;
+    let mut data = unsafe { MmapOptions::new().map_copy(&mapped_file)? };
+
+    let result = unseal_range_inner::<_, _, Tree>(
+        porep_config,
+        cache_path,
+        &mut data,
+        unsealed_output,
+        replica_id,
+        offset,
+        num_bytes,
+    );
+    info!("unseal_range_mapped:finish");
+
+    result
+}
+
+/// Unseals the sector read from `sealed_sector` and returns the bytes for a
+/// piece whose first (unpadded) byte begins at `offset` and ends at `offset`
+/// plus `num_bytes`, inclusive. Note that the entire sector is unsealed each
+/// time this function is called.
+///
+/// # Arguments
+///
+/// * `porep_config` - porep configuration containing the sector size.
+/// * `cache_path` - path to the directory in which the sector data's Merkle Tree is written.
+/// * `sealed_sector` - a byte source from which we read sealed sector data.
+/// * `unsealed_output` - a byte sink to which we write unsealed, un-bit-padded sector bytes.
+/// * `prover_id` - the prover-id that sealed the sector.
+/// * `sector_id` - the sector-id of the sealed sector.
+/// * `comm_d` - the commitment to the sector's data.
+/// * `ticket` - the ticket that was used to generate the sector's replica-id.
+/// * `offset` - the byte index in the unsealed sector of the first byte that we want to read.
+/// * `num_bytes` - the number of bytes that we want to read.
+#[allow(clippy::too_many_arguments)]
+fn unseal_range_inner<P, W, Tree>(
+    porep_config: PoRepConfig,
+    cache_path: P,
+    data: &mut [u8],
+    mut unsealed_output: W,
+    replica_id: <Tree::Hasher as Hasher>::Domain,
+    offset: UnpaddedByteIndex,
+    num_bytes: UnpaddedBytesAmount,
+) -> Result<UnpaddedBytesAmount>
+where
+    P: Into<PathBuf> + AsRef<Path>,
+    W: Write,
+    Tree: 'static + MerkleTreeTrait,
+{
+    info!("unseal_range_inner:start");
+
     let base_tree_size = get_base_tree_size::<DefaultBinaryTree>(porep_config.sector_size)?;
     let base_tree_leafs = get_base_tree_leafs::<DefaultBinaryTree>(base_tree_size)?;
-    // MT for original data is always named tree-d, and it will be
-    // referenced later in the process as such.
     let config = StoreConfig::new(
         cache_path.as_ref(),
         CacheKey::CommDTree.to_string(),
@@ -183,11 +297,10 @@ where
     let offset_padded: PaddedBytesAmount = UnpaddedBytesAmount::from(offset).into();
     let num_bytes_padded: PaddedBytesAmount = num_bytes.into();
 
-    let unsealed_all =
-        StackedDrg::<Tree, DefaultPieceHasher>::extract_all(&pp, &replica_id, &data, Some(config))?;
+    StackedDrg::<Tree, DefaultPieceHasher>::extract_all(&pp, &replica_id, data, Some(config))?;
     let start: usize = offset_padded.into();
     let end = start + usize::from(num_bytes_padded);
-    let unsealed = &unsealed_all[start..end];
+    let unsealed = &data[start..end];
 
     // If the call to `extract_range` was successful, the `unsealed` vector must
     // have a length which equals `num_bytes_padded`. The byte at its 0-index
@@ -197,7 +310,7 @@ where
 
     let amount = UnpaddedBytesAmount(written as u64);
 
-    info!("unseal_range:finish");
+    info!("unseal_range_inner:finish");
     Ok(amount)
 }
 

filecoin-proofs/tests/api.rs

@@ -12,8 +12,8 @@ use filecoin_proofs::{
     add_piece, clear_cache, compute_comm_d, fauxrep_aux, generate_fallback_sector_challenges,
     generate_piece_commitment, generate_single_vanilla_proof, generate_window_post,
     generate_window_post_with_vanilla, generate_winning_post,
-    generate_winning_post_sector_challenge, generate_winning_post_with_vanilla, seal_commit_phase1,
-    seal_commit_phase2, seal_pre_commit_phase1, seal_pre_commit_phase2, unseal_range,
+    generate_winning_post_sector_challenge, generate_winning_post_with_vanilla, get_unsealed_range,
+    seal_commit_phase1, seal_commit_phase2, seal_pre_commit_phase1, seal_pre_commit_phase2,
     validate_cache_for_commit, validate_cache_for_precommit_phase2, verify_seal,
     verify_window_post, verify_winning_post, Commitment, DefaultTreeDomain, MerkleTreeTrait,
     PaddedBytesAmount, PieceInfo, PoRepConfig, PoRepProofPartitions, PoStConfig, PoStType,
@@ -1040,11 +1040,11 @@ fn proof_and_unseal<Tree: 'static + MerkleTreeTrait>(
 
     let commit_output = seal_commit_phase2(config, phase1_output, prover_id, sector_id)?;
 
-    let _ = unseal_range::<_, _, _, Tree>(
+    let _ = get_unsealed_range::<_, Tree>(
         config,
         cache_dir_path,
-        sealed_sector_file,
-        &unseal_file,
+        sealed_sector_file.path(),
+        unseal_file.path(),
         prover_id,
         sector_id,
         comm_d,

storage-proofs-porep/src/drg/vanilla.rs

@@ -496,36 +496,42 @@ where
     fn extract_all<'b>(
         pp: &'b Self::PublicParams,
         replica_id: &'b <H as Hasher>::Domain,
-        data: &'b [u8],
+        data: &'b mut [u8],
         _config: Option<StoreConfig>,
-    ) -> Result<Vec<u8>> {
+    ) -> Result<()> {
         decode(&pp.graph, replica_id, data, None)
     }
 
     fn extract(
         pp: &Self::PublicParams,
         replica_id: &<H as Hasher>::Domain,
-        data: &[u8],
+        data: &mut [u8],
         node: usize,
         _config: Option<StoreConfig>,
-    ) -> Result<Vec<u8>> {
-        Ok(decode_block(&pp.graph, replica_id, data, None, node)?.into_bytes())
+    ) -> Result<()> {
+        let block = decode_block(&pp.graph, replica_id, &data, None, node)?;
+        let start = node * NODE_SIZE;
+        let end = start + NODE_SIZE;
+        let dest = &mut data[start..end];
+        dest.copy_from_slice(AsRef::<[u8]>::as_ref(&block));
+
+        Ok(())
     }
 }
 
 pub fn decode<'a, H, G>(
     graph: &'a G,
     replica_id: &'a <H as Hasher>::Domain,
-    data: &'a [u8],
+    data: &'a mut [u8],
     exp_parents_data: Option<&'a [u8]>,
-) -> Result<Vec<u8>>
+) -> Result<()>
 where
     H: Hasher,
     G::Key: AsRef<H::Domain>,
     G: Graph<H> + Sync,
 {
     // TODO: proper error handling
-    let result = (0..graph.size())
+    let result: Vec<u8> = (0..graph.size())
         .into_par_iter()
         .flat_map(|i| {
             decode_block::<H, G>(graph, replica_id, data, exp_parents_data, i)
@@ -534,7 +540,8 @@ where
         })
         .collect();
 
-    Ok(result)
+    data.copy_from_slice(&result);
+    Ok(())
 }
 
 pub fn decode_block<'a, H, G>(

storage-proofs-porep/src/lib.rs

@@ -31,15 +31,15 @@ pub trait PoRep<'a, H: Hasher, G: Hasher>: ProofScheme<'a> {
     fn extract_all(
         pub_params: &'a Self::PublicParams,
         replica_id: &H::Domain,
-        replica: &[u8],
+        data: &mut [u8],
         config: Option<StoreConfig>,
-    ) -> Result<Vec<u8>>;
+    ) -> Result<()>;
 
     fn extract(
         pub_params: &'a Self::PublicParams,
         replica_id: &H::Domain,
-        replica: &[u8],
+        data: &mut [u8],
         node: usize,
         config: Option<StoreConfig>,
-    ) -> Result<Vec<u8>>;
+    ) -> Result<()>;
 }

storage-proofs-porep/src/stacked/vanilla/porep.rs

@@ -49,29 +49,27 @@ impl<'a, 'c, Tree: 'static + MerkleTreeTrait, G: 'static + Hasher> PoRep<'a, Tre
     fn extract_all<'b>(
         pp: &'b PublicParams<Tree>,
         replica_id: &'b <Tree::Hasher as Hasher>::Domain,
-        data: &'b [u8],
+        data: &'b mut [u8],
         config: Option<StoreConfig>,
-    ) -> Result<Vec<u8>> {
-        let mut data = data.to_vec();
-
+    ) -> Result<()> {
         Self::extract_and_invert_transform_layers(
             &pp.graph,
             &pp.layer_challenges,
             replica_id,
-            &mut data,
+            data,
             config.expect("Missing store config"),
         )?;
 
-        Ok(data)
+        Ok(())
     }
 
     fn extract(
         _pp: &PublicParams<Tree>,
         _replica_id: &<Tree::Hasher as Hasher>::Domain,
-        _data: &[u8],
+        _data: &mut [u8],
         _node: usize,
         _config: Option<StoreConfig>,
-    ) -> Result<Vec<u8>> {
+    ) -> Result<()> {
         unimplemented!();
     }
 }