Merge branch 'tomas+brentstone/common-read-storage-trait' (#324)

* tomas+brentstone/common-read-storage-trait:
  fixup! rustdoc: fix more broken links
  rustdoc: fix more broken links
  rustdoc: resolve ambiguous link
  changelog: add #324
  update wasm checksums
  ledger/pos: implement PosReadOnly using StorageRead trait
  ledger/tx: inherit StorageRead in TxEnv
  ledger/storage: impl StorageRead for Storage
  ledger/vp: impl StorageRead for WASM VPs pre and post state
  ledger/native_vp: implement StorageRead for pre and post state
  ledger: add StorageRead trait with extensible error type

.changelog/unreleased/improvements/324-common-read-storage-trait.md

@@ -0,0 +1,3 @@
+- Added a StorageRead trait for a common interface for VPs prior and posterior
+  state, transactions and direct storage access for protocol and RPC handlers
+  ([#324](https://github.com/anoma/namada/pull/324))

apps/src/lib/node/ledger/shell/mod.rs

@@ -2,7 +2,7 @@
 //!
 //! Any changes applied before [`Shell::finalize_block`] might have to be
 //! reverted, so any changes applied in the methods `Shell::prepare_proposal`
-//! (ABCI++), [`Shell::process_and_decode_proposal`] must be also reverted
+//! (ABCI++), [`Shell::process_proposal`] must be also reverted
 //! (unless we can simply overwrite them in the next block).
 //! More info in <https://github.com/anoma/anoma/issues/362>.
 mod finalize_block;

apps/src/lib/node/ledger/shell/prepare_proposal.rs

@@ -1,4 +1,4 @@
-//! Implementation of the [`PrepareProposal`] ABCI++ method for the Shell
+//! Implementation of the [`RequestPrepareProposal`] ABCI++ method for the Shell
 
 use tendermint_proto::abci::TxRecord;
 

shared/src/ledger/mod.rs

@@ -8,6 +8,7 @@ pub mod native_vp;
 pub mod parameters;
 pub mod pos;
 pub mod storage;
+pub mod storage_api;
 pub mod treasury;
 pub mod tx_env;
 pub mod vp_env;

shared/src/ledger/native_vp.rs

@@ -3,6 +3,7 @@
 use std::cell::RefCell;
 use std::collections::BTreeSet;
 
+use super::storage_api::{self, ResultExt, StorageRead};
 pub use super::vp_env::VpEnv;
 use crate::ledger::gas::VpGasMeter;
 use crate::ledger::storage::write_log::WriteLog;
@@ -72,6 +73,30 @@ where
     pub cache_access: std::marker::PhantomData<CA>,
 }
 
+/// Read access to the prior storage (state before tx execution) via
+/// [`trait@StorageRead`].
+#[derive(Debug)]
+pub struct CtxPreStorageRead<'b, 'a: 'b, DB, H, CA>
+where
+    DB: storage::DB + for<'iter> storage::DBIter<'iter>,
+    H: StorageHasher,
+    CA: WasmCacheAccess,
+{
+    ctx: &'b Ctx<'a, DB, H, CA>,
+}
+
+/// Read access to the posterior storage (state after tx execution) via
+/// [`trait@StorageRead`].
+#[derive(Debug)]
+pub struct CtxPostStorageRead<'f, 'a: 'f, DB, H, CA>
+where
+    DB: storage::DB + for<'iter> storage::DBIter<'iter>,
+    H: StorageHasher,
+    CA: WasmCacheAccess,
+{
+    ctx: &'f Ctx<'a, DB, H, CA>,
+}
+
 impl<'a, DB, H, CA> Ctx<'a, DB, H, CA>
 where
     DB: 'static + storage::DB + for<'iter> storage::DBIter<'iter>,
@@ -111,6 +136,138 @@ where
     pub fn add_gas(&self, used_gas: u64) -> Result<(), vp_env::RuntimeError> {
         vp_env::add_gas(&mut *self.gas_meter.borrow_mut(), used_gas)
     }
+
+    /// Read access to the prior storage (state before tx execution)
+    /// via [`trait@StorageRead`].
+    pub fn pre<'b>(&'b self) -> CtxPreStorageRead<'b, 'a, DB, H, CA> {
+        CtxPreStorageRead { ctx: self }
+    }
+
+    /// Read access to the posterior storage (state after tx execution)
+    /// via [`trait@StorageRead`].
+    pub fn post<'b>(&'b self) -> CtxPostStorageRead<'b, 'a, DB, H, CA> {
+        CtxPostStorageRead { ctx: self }
+    }
+}
+
+impl<'f, 'a, DB, H, CA> StorageRead for CtxPreStorageRead<'f, 'a, DB, H, CA>
+where
+    DB: 'static + storage::DB + for<'iter> storage::DBIter<'iter>,
+    H: 'static + StorageHasher,
+    CA: 'static + WasmCacheAccess,
+{
+    type PrefixIter = <DB as storage::DBIter<'a>>::PrefixIter;
+
+    fn read<T: borsh::BorshDeserialize>(
+        &self,
+        key: &crate::types::storage::Key,
+    ) -> Result<Option<T>, storage_api::Error> {
+        self.ctx.read_pre(key).into_storage_result()
+    }
+
+    fn read_bytes(
+        &self,
+        key: &crate::types::storage::Key,
+    ) -> Result<Option<Vec<u8>>, storage_api::Error> {
+        self.ctx.read_bytes_pre(key).into_storage_result()
+    }
+
+    fn has_key(
+        &self,
+        key: &crate::types::storage::Key,
+    ) -> Result<bool, storage_api::Error> {
+        self.ctx.has_key_pre(key).into_storage_result()
+    }
+
+    fn iter_prefix(
+        &self,
+        prefix: &crate::types::storage::Key,
+    ) -> Result<Self::PrefixIter, storage_api::Error> {
+        self.ctx.iter_prefix(prefix).into_storage_result()
+    }
+
+    fn iter_next(
+        &self,
+        iter: &mut Self::PrefixIter,
+    ) -> Result<Option<(String, Vec<u8>)>, storage_api::Error> {
+        self.ctx.iter_pre_next(iter).into_storage_result()
+    }
+
+    fn get_chain_id(&self) -> Result<String, storage_api::Error> {
+        self.ctx.get_chain_id().into_storage_result()
+    }
+
+    fn get_block_height(&self) -> Result<BlockHeight, storage_api::Error> {
+        self.ctx.get_block_height().into_storage_result()
+    }
+
+    fn get_block_hash(&self) -> Result<BlockHash, storage_api::Error> {
+        self.ctx.get_block_hash().into_storage_result()
+    }
+
+    fn get_block_epoch(&self) -> Result<Epoch, storage_api::Error> {
+        self.ctx.get_block_epoch().into_storage_result()
+    }
+}
+
+impl<'f, 'a, DB, H, CA> StorageRead for CtxPostStorageRead<'f, 'a, DB, H, CA>
+where
+    DB: 'static + storage::DB + for<'iter> storage::DBIter<'iter>,
+    H: 'static + StorageHasher,
+    CA: 'static + WasmCacheAccess,
+{
+    type PrefixIter = <DB as storage::DBIter<'a>>::PrefixIter;
+
+    fn read<T: borsh::BorshDeserialize>(
+        &self,
+        key: &crate::types::storage::Key,
+    ) -> Result<Option<T>, storage_api::Error> {
+        self.ctx.read_post(key).into_storage_result()
+    }
+
+    fn read_bytes(
+        &self,
+        key: &crate::types::storage::Key,
+    ) -> Result<Option<Vec<u8>>, storage_api::Error> {
+        self.ctx.read_bytes_post(key).into_storage_result()
+    }
+
+    fn has_key(
+        &self,
+        key: &crate::types::storage::Key,
+    ) -> Result<bool, storage_api::Error> {
+        self.ctx.has_key_post(key).into_storage_result()
+    }
+
+    fn iter_prefix(
+        &self,
+        prefix: &crate::types::storage::Key,
+    ) -> Result<Self::PrefixIter, storage_api::Error> {
+        self.ctx.iter_prefix(prefix).into_storage_result()
+    }
+
+    fn iter_next(
+        &self,
+        iter: &mut Self::PrefixIter,
+    ) -> Result<Option<(String, Vec<u8>)>, storage_api::Error> {
+        self.ctx.iter_post_next(iter).into_storage_result()
+    }
+
+    fn get_chain_id(&self) -> Result<String, storage_api::Error> {
+        self.ctx.get_chain_id().into_storage_result()
+    }
+
+    fn get_block_height(&self) -> Result<BlockHeight, storage_api::Error> {
+        self.ctx.get_block_height().into_storage_result()
+    }
+
+    fn get_block_hash(&self) -> Result<BlockHash, storage_api::Error> {
+        self.ctx.get_block_hash().into_storage_result()
+    }
+
+    fn get_block_epoch(&self) -> Result<Epoch, storage_api::Error> {
+        self.ctx.get_block_epoch().into_storage_result()
+    }
 }
 
 impl<'a, DB, H, CA> VpEnv for Ctx<'a, DB, H, CA>

shared/src/ledger/pos/mod.rs

@@ -87,3 +87,139 @@ impl From<namada_proof_of_stake::types::Epoch> for Epoch {
         Epoch(epoch)
     }
 }
+
+#[macro_use]
+mod macros {
+    /// Implement `PosReadOnly` for a type that implements
+    /// [`trait@crate::ledger::storage_api::StorageRead`].
+    ///
+    /// Excuse the horrible syntax - we haven't found a better way to use this
+    /// for native_vp `CtxPreStorageRead`/`CtxPostStorageRead`, which have
+    /// generics and explicit lifetimes.
+    ///
+    /// # Examples
+    ///
+    /// ```ignore
+    /// impl_pos_read_only! { impl PosReadOnly for X }
+    /// ```
+    #[macro_export]
+    macro_rules! impl_pos_read_only {
+    (
+        // Type error type has to be declared before the impl.
+        // This error type must `impl From<storage_api::Error> for $error`.
+        type $error:tt = $err_ty:ty ;
+        // Matches anything, so that we can use lifetimes and generic types.
+        // This expects `impl(<.*>)? PoSReadOnly for $ty(<.*>)?`.
+        $( $any:tt )* )
+    => {
+        $( $any )*
+        {
+            type Address = $crate::types::address::Address;
+            // type Error = $crate::ledger::native_vp::Error;
+            type $error = $err_ty;
+            type PublicKey = $crate::types::key::common::PublicKey;
+            type TokenAmount = $crate::types::token::Amount;
+            type TokenChange = $crate::types::token::Change;
+
+            const POS_ADDRESS: Self::Address = $crate::ledger::pos::ADDRESS;
+
+            fn staking_token_address() -> Self::Address {
+                $crate::ledger::pos::staking_token_address()
+            }
+
+            fn read_pos_params(&self) -> std::result::Result<PosParams, Self::Error> {
+                let value = $crate::ledger::storage_api::StorageRead::read_bytes(self, &params_key())?.unwrap();
+                Ok($crate::ledger::storage::types::decode(value).unwrap())
+            }
+
+            fn read_validator_staking_reward_address(
+                &self,
+                key: &Self::Address,
+            ) -> std::result::Result<Option<Self::Address>, Self::Error> {
+                let value = $crate::ledger::storage_api::StorageRead::read_bytes(
+                    self,
+                    &validator_staking_reward_address_key(key),
+                )?;
+                Ok(value.map(|value| $crate::ledger::storage::types::decode(value).unwrap()))
+            }
+
+            fn read_validator_consensus_key(
+                &self,
+                key: &Self::Address,
+            ) -> std::result::Result<Option<ValidatorConsensusKeys>, Self::Error> {
+                let value =
+                    $crate::ledger::storage_api::StorageRead::read_bytes(self, &validator_consensus_key_key(key))?;
+                Ok(value.map(|value| $crate::ledger::storage::types::decode(value).unwrap()))
+            }
+
+            fn read_validator_state(
+                &self,
+                key: &Self::Address,
+            ) -> std::result::Result<Option<ValidatorStates>, Self::Error> {
+                let value = $crate::ledger::storage_api::StorageRead::read_bytes(self, &validator_state_key(key))?;
+                Ok(value.map(|value| $crate::ledger::storage::types::decode(value).unwrap()))
+            }
+
+            fn read_validator_total_deltas(
+                &self,
+                key: &Self::Address,
+            ) -> std::result::Result<Option<ValidatorTotalDeltas>, Self::Error> {
+                let value =
+                    $crate::ledger::storage_api::StorageRead::read_bytes(self, &validator_total_deltas_key(key))?;
+                Ok(value.map(|value| $crate::ledger::storage::types::decode(value).unwrap()))
+            }
+
+            fn read_validator_voting_power(
+                &self,
+                key: &Self::Address,
+            ) -> std::result::Result<Option<ValidatorVotingPowers>, Self::Error> {
+                let value =
+                    $crate::ledger::storage_api::StorageRead::read_bytes(self, &validator_voting_power_key(key))?;
+                Ok(value.map(|value| $crate::ledger::storage::types::decode(value).unwrap()))
+            }
+
+            fn read_validator_slashes(
+                &self,
+                key: &Self::Address,
+            ) -> std::result::Result<Vec<types::Slash>, Self::Error> {
+                let value = $crate::ledger::storage_api::StorageRead::read_bytes(self, &validator_slashes_key(key))?;
+                Ok(value
+                    .map(|value| $crate::ledger::storage::types::decode(value).unwrap())
+                    .unwrap_or_default())
+            }
+
+            fn read_bond(
+                &self,
+                key: &BondId,
+            ) -> std::result::Result<Option<Bonds>, Self::Error> {
+                let value = $crate::ledger::storage_api::StorageRead::read_bytes(self, &bond_key(key))?;
+                Ok(value.map(|value| $crate::ledger::storage::types::decode(value).unwrap()))
+            }
+
+            fn read_unbond(
+                &self,
+                key: &BondId,
+            ) -> std::result::Result<Option<Unbonds>, Self::Error> {
+                let value = $crate::ledger::storage_api::StorageRead::read_bytes(self, &unbond_key(key))?;
+                Ok(value.map(|value| $crate::ledger::storage::types::decode(value).unwrap()))
+            }
+
+            fn read_validator_set(
+                &self,
+            ) -> std::result::Result<ValidatorSets, Self::Error> {
+                let value =
+                    $crate::ledger::storage_api::StorageRead::read_bytes(self, &validator_set_key())?.unwrap();
+                Ok($crate::ledger::storage::types::decode(value).unwrap())
+            }
+
+            fn read_total_voting_power(
+                &self,
+            ) -> std::result::Result<TotalVotingPowers, Self::Error> {
+                let value =
+                    $crate::ledger::storage_api::StorageRead::read_bytes(self, &total_voting_power_key())?.unwrap();
+                Ok($crate::ledger::storage::types::decode(value).unwrap())
+            }
+        }
+    }
+}
+}