Refactor the blockstore

fvm/src/blockstore/buffered.rs

@@ -5,30 +5,33 @@
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::io::{Cursor, Read, Seek};
+use std::marker::PhantomData;
 
 use anyhow::{anyhow, Result};
 use byteorder::{BigEndian, ByteOrder, ReadBytesExt};
 use cid::Cid;
-use fvm_ipld_blockstore::{Blockstore, Buffered};
+use fvm_ipld_blockstore::{Block, Blockstore, Buffered};
 use fvm_ipld_encoding::{CBOR, DAG_CBOR};
 use fvm_shared::commcid::{FIL_COMMITMENT_SEALED, FIL_COMMITMENT_UNSEALED};
 
 /// Wrapper around `Blockstore` to limit and have control over when values are written.
 /// This type is not threadsafe and can only be used in synchronous contexts.
 #[derive(Debug)]
-pub struct BufferedBlockstore<BS> {
+pub struct BufferedBlockstore<BS, C = multihash::Code> {
     base: BS,
     write: RefCell<HashMap<Cid, Vec<u8>>>,
+    _marker: PhantomData<fn() -> C>,
 }
 
-impl<BS> BufferedBlockstore<BS>
+impl<BS, C> BufferedBlockstore<BS, C>
 where
     BS: Blockstore,
 {
     pub fn new(base: BS) -> Self {
         Self {
             base,
             write: Default::default(),
+            _marker: Default::default(),
         }
     }
 
@@ -37,6 +40,20 @@ where
     }
 }
 
+impl<BS, C> BufferedBlockstore<BS, C>
+where
+    C: multihash::MultihashDigest<64>,
+    anyhow::Error: From<C::Error>,
+{
+    fn cid_of(&self, mh_code: u64, block: &dyn Block) -> Result<Cid> {
+        let mh_code = C::try_from(mh_code)?;
+        let data = block.data();
+        let codec = block.codec();
+        let digest = mh_code.digest(data);
+        Ok(Cid::new_v1(codec, digest))
+    }
+}
+
 impl<BS> Buffered for BufferedBlockstore<BS>
 where
     BS: Blockstore,
@@ -229,9 +246,11 @@ fn copy_rec<'a>(
     Ok(())
 }
 
-impl<BS> Blockstore for BufferedBlockstore<BS>
+impl<BS, C> Blockstore for BufferedBlockstore<BS, C>
 where
     BS: Blockstore,
+    C: multihash::MultihashDigest<64>,
+    anyhow::Error: From<C::Error>,
 {
     fn get(&self, cid: &Cid) -> Result<Option<Vec<u8>>> {
         Ok(if let Some(data) = self.write.borrow().get(cid) {
@@ -241,6 +260,12 @@ where
         })
     }
 
+    fn put(&self, mh_code: u64, block: &dyn fvm_ipld_blockstore::Block) -> Result<Cid> {
+        let k = self.cid_of(mh_code, block)?;
+        self.put_keyed(&k, block.data())?;
+        Ok(k)
+    }
+
     fn put_keyed(&self, cid: &Cid, buf: &[u8]) -> Result<()> {
         self.write.borrow_mut().insert(*cid, Vec::from(buf));
         Ok(())

fvm/src/blockstore/discard.rs

@@ -1,22 +1,67 @@
 // Copyright 2021-2023 Protocol Labs
 // SPDX-License-Identifier: Apache-2.0, MIT
 
+use std::marker::PhantomData;
+
 use cid::Cid;
 use fvm_ipld_blockstore::Blockstore;
 
 // A blockstore that accepts but discards all insertions, and returns errors on reads.
 // Useful for when the FVM needs to stage ephemeral data structures without persisting them,
 // like the events AMT.
-pub struct DiscardBlockstore;
+#[derive(Copy, Clone)]
+pub struct DiscardBlockstore<C = multihash::Code>(PhantomData<fn() -> C>);
+
+impl Default for DiscardBlockstore {
+    fn default() -> Self {
+        DiscardBlockstore(Default::default())
+    }
+}
 
-impl Blockstore for DiscardBlockstore {
+impl<C> Blockstore for DiscardBlockstore<C>
+where
+    C: multihash::MultihashDigest<64>,
+    anyhow::Error: From<C::Error>,
+{
     fn get(&self, _: &Cid) -> anyhow::Result<Option<Vec<u8>>> {
         Err(anyhow::anyhow!(
-            "Blockstore#get not supported with DiscardBlockstore"
+            "Blockstore::get not supported with DiscardBlockstore"
         ))
     }
 
     fn put_keyed(&self, _: &Cid, _: &[u8]) -> anyhow::Result<()> {
         Ok(())
     }
+
+    fn put(&self, mh_code: u64, block: &dyn fvm_ipld_blockstore::Block) -> anyhow::Result<Cid> {
+        let mh_code = C::try_from(mh_code)?;
+        let data = block.data();
+        let codec = block.codec();
+        let digest = mh_code.digest(data);
+        Ok(Cid::new_v1(codec, digest))
+    }
+
+    fn has(&self, _: &Cid) -> anyhow::Result<bool> {
+        Err(anyhow::anyhow!(
+            "Blockstore::has not supported with DiscardBlockstore"
+        ))
+    }
+
+    fn put_many<B, I>(&self, _: I) -> anyhow::Result<()>
+    where
+        Self: Sized,
+        B: fvm_ipld_blockstore::Block,
+        I: IntoIterator<Item = (u64, B)>,
+    {
+        Ok(())
+    }
+
+    fn put_many_keyed<D, I>(&self, _: I) -> anyhow::Result<()>
+    where
+        Self: Sized,
+        D: AsRef<[u8]>,
+        I: IntoIterator<Item = (Cid, D)>,
+    {
+        Ok(())
+    }
 }

fvm/src/call_manager/default.rs

@@ -928,7 +928,7 @@ impl EventsAccumulator {
         let root = if !self.events.is_empty() {
             const EVENTS_AMT_BITWIDTH: u32 = 5;
             let root = Amt::new_from_iter_with_bit_width(
-                DiscardBlockstore,
+                DiscardBlockstore::default(),
                 EVENTS_AMT_BITWIDTH,
                 self.events.iter().cloned(),
             )

fvm/src/machine/default.rs

@@ -4,7 +4,8 @@ use std::ops::RangeInclusive;
 
 use anyhow::{anyhow, Context as _};
 use cid::Cid;
-use fvm_ipld_blockstore::{Block, Blockstore, Buffered};
+use fvm_ipld_blockstore::{Blockstore, Buffered};
+use fvm_ipld_encoding::ipld_block::IpldBlock;
 use fvm_ipld_encoding::{to_vec, CborStore, DAG_CBOR};
 use fvm_shared::version::NetworkVersion;
 use log::debug;
@@ -24,8 +25,9 @@ use crate::EMPTY_ARR_CID;
 
 lazy_static::lazy_static! {
     /// Pre-serialized block containing the empty array
-    pub static ref EMPTY_ARRAY_BLOCK: Block<Vec<u8>> = {
-        Block::new(DAG_CBOR, to_vec::<[(); 0]>(&[]).unwrap())
+    pub static ref EMPTY_ARRAY_BLOCK: IpldBlock = IpldBlock {
+        codec: DAG_CBOR,
+        data: to_vec::<[(); 0]>(&[]).unwrap(),
     };
 }
 
@@ -194,7 +196,7 @@ where
 // Helper method that puts certain "empty" types in the blockstore.
 // These types are privileged by some parts of the system (eg. as the default actor state).
 fn put_empty_blocks<B: Blockstore>(blockstore: B) -> anyhow::Result<()> {
-    let empty_arr_cid = blockstore.put(Blake2b256, &EMPTY_ARRAY_BLOCK)?;
+    let empty_arr_cid = blockstore.put(Blake2b256.into(), &*EMPTY_ARRAY_BLOCK)?;
 
     debug_assert!(
         empty_arr_cid == *EMPTY_ARR_CID,

fvm/tests/default_kernel/mod.rs

@@ -5,7 +5,7 @@ use std::rc::Rc;
 
 // test target
 use fvm::kernel::default::DefaultKernel;
-use fvm::kernel::{Block, BlockRegistry};
+use fvm::kernel::BlockRegistry;
 use fvm::Kernel;
 use multihash::Code;
 use num_traits::Zero;

fvm/tests/default_kernel/ops.rs

@@ -177,7 +177,6 @@ mod ipld {
                 "charge_gas should only be called exactly once per block_link"
             );
 
-            let expected_block = Block::new(cid.codec(), block);
             let expected_create_price = call_manager
                 .machine
                 .context()
@@ -190,7 +189,7 @@ mod ipld {
                 .price_list
                 .on_block_link(
                     SupportedHashes::try_from(cid.hash().code()).unwrap(),
-                    expected_block.size() as usize,
+                    block.len(),
                 )
                 .total();
 

ipld/blockstore/Cargo.toml

@@ -14,5 +14,10 @@ anyhow = "1.0.51"
 # depdendency is needed to enable the features of the re-export.
 multihash = { version = "0.16.1", default-features = false, features = ["multihash-impl"] }
 
+[dev-dependencies.multihash]
+version = "*"
+default-features = false
+features = ["multihash-impl", "blake2b"]
+
 [features]
 default = []