remove dead code from zebra-chain (#5464)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

zebra-chain/src/block/commitment.rs

@@ -125,7 +125,7 @@ impl Commitment {
     }
 
     /// Returns the serialized bytes for this Commitment.
-    #[allow(dead_code)]
+    #[cfg(test)]
     pub(super) fn to_bytes(self) -> [u8; 32] {
         use Commitment::*;
 
@@ -220,7 +220,7 @@ impl ChainHistoryBlockTxAuthCommitmentHash {
 /// all possible verification failures enumerates the consensus rules we
 /// implement, and ensures that we don't reject blocks or transactions
 /// for a non-enumerated reason.
-#[allow(dead_code, missing_docs)]
+#[allow(missing_docs)]
 #[derive(Error, Debug, PartialEq, Eq)]
 pub enum CommitmentError {
     #[error(

zebra-chain/src/block/error.rs

@@ -2,7 +2,7 @@
 
 use thiserror::Error;
 
-#[allow(dead_code, missing_docs)]
+#[allow(missing_docs)]
 #[derive(Error, Debug, PartialEq, Eq)]
 pub enum BlockError {
     #[error("transaction has wrong consensus branch id for block network upgrade")]

zebra-chain/src/orchard/keys.rs

@@ -2,7 +2,6 @@
 //!
 //! <https://zips.z.cash/protocol/nu5.pdf#orchardkeycomponents>
 #![allow(clippy::fallible_impl_from)]
-#![allow(dead_code)]
 
 #[cfg(test)]
 mod tests;
@@ -76,27 +75,6 @@ pub fn prf_expand(sk: [u8; 32], t: Vec<&[u8]>) -> [u8; 64] {
     *state.finalize().as_array()
 }
 
-/// Used to derive the outgoing cipher key _ock_ used to encrypt an encrypted
-/// output note from an Action.
-///
-/// PRF^ock(ovk, cv, cm_x, ephemeralKey) := BLAKE2b-256(“Zcash_Orchardock”, ovk || cv || cm_x || ephemeralKey)
-///
-/// <https://zips.z.cash/protocol/nu5.pdf#concreteprfs>
-/// <https://zips.z.cash/protocol/nu5.pdf#concretesym>
-fn prf_ock(ovk: [u8; 32], cv: [u8; 32], cm_x: [u8; 32], ephemeral_key: [u8; 32]) -> [u8; 32] {
-    let hash = blake2b_simd::Params::new()
-        .hash_length(32)
-        .personal(b"Zcash_Orchardock")
-        .to_state()
-        .update(&ovk)
-        .update(&cv)
-        .update(&cm_x)
-        .update(&ephemeral_key)
-        .finalize();
-
-    hash.as_bytes().try_into().expect("32 byte array")
-}
-
 /// Used to derive a diversified base point from a diversifier value.
 ///
 /// DiversifyHash^Orchard(d) := {︃ GroupHash^P("z.cash:Orchard-gd",""), if P = 0_P

zebra-chain/src/orchard/note.rs

@@ -1,7 +1,6 @@
 //! Orchard notes
 
 #![allow(clippy::unit_arg)]
-#![allow(dead_code)]
 
 use group::{ff::PrimeField, GroupEncoding};
 use halo2::{arithmetic::FieldExt, pasta::pallas};

zebra-chain/src/orchard/note/nullifiers.rs

@@ -1,5 +1,4 @@
 #![allow(clippy::unit_arg)]
-#![allow(dead_code)]
 
 use std::{
     convert::TryFrom,

zebra-chain/src/orchard/tests/vectors/key_components.rs

@@ -4,7 +4,6 @@
 //! Produced by <https://github.com/zcash-hackworks/zcash-test-vectors/blob/ec5fe3abef5219d0f8c9edbc93bb4038f1729dfe/orchard_key_components.py>
 
 #![allow(dead_code)]
-
 pub struct TestVector {
     pub(crate) sk: [u8; 32],
     pub(crate) ask: [u8; 32],

zebra-chain/src/primitives/zcash_history.rs

@@ -2,7 +2,6 @@
 //! librustzcash.
 
 // TODO: remove after this module gets to be used
-#![allow(dead_code)]
 #![allow(missing_docs)]
 
 mod tests;
@@ -210,26 +209,6 @@ impl<V: Version> Tree<V> {
         }
         Ok(new_nodes)
     }
-
-    /// Append multiple blocks to the tree.
-    fn append_leaf_iter(
-        &mut self,
-        vals: impl Iterator<Item = (Arc<Block>, sapling::tree::Root, orchard::tree::Root)>,
-    ) -> Result<Vec<Entry>, zcash_history::Error> {
-        let mut new_nodes = Vec::new();
-        for (block, sapling_root, orchard_root) in vals {
-            new_nodes.append(&mut self.append_leaf(block, &sapling_root, &orchard_root)?);
-        }
-        Ok(new_nodes)
-    }
-
-    /// Remove the last leaf (block) from the tree.
-    ///
-    /// Returns the number of nodes removed from the tree after the operation.
-    fn truncate_leaf(&mut self) -> Result<u32, zcash_history::Error> {
-        self.inner.truncate_leaf()
-    }
-
     /// Return the root hash of the tree, i.e. `hashChainHistoryRoot`.
     pub fn hash(&self) -> ChainHistoryMmrRootHash {
         // Both append_leaf() and truncate_leaf() leave a root node, so it should

zebra-chain/src/sapling/commitment/test_vectors.rs

@@ -9,8 +9,6 @@
 // librustzcash, they match their Display impl to match the Python hex strings
 // and that's what they compare in their unit tests, not the bytes.
 
-#![allow(dead_code)]
-
 use bitvec::prelude::*;
 use lazy_static::lazy_static;
 

zebra-chain/src/sapling/keys.rs

@@ -9,7 +9,6 @@
 //! [3.1]: https://zips.z.cash/protocol/protocol.pdf#addressesandkeys
 #![allow(clippy::unit_arg)]
 #![allow(clippy::fallible_impl_from)]
-#![allow(dead_code)]
 
 #[cfg(test)]
 mod test_vectors;
@@ -65,25 +64,6 @@ fn prf_expand(sk: [u8; 32], t: &[u8]) -> [u8; 64] {
     *hash.as_array()
 }
 
-/// Used to derive the outgoing cipher key _ock_ used to encrypt an Output ciphertext.
-///
-/// PRF^ock(ovk, cv, cm_u, ephemeralKey) := BLAKE2b-256(“Zcash_Derive_ock”, ovk || cv || cm_u || ephemeralKey)
-///
-/// <https://zips.z.cash/protocol/nu5.pdf#concreteprfs>
-fn prf_ock(ovk: [u8; 32], cv: [u8; 32], cm_u: [u8; 32], ephemeral_key: [u8; 32]) -> [u8; 32] {
-    let hash = blake2b_simd::Params::new()
-        .hash_length(32)
-        .personal(b"Zcash_Derive_ock")
-        .to_state()
-        .update(&ovk)
-        .update(&cv)
-        .update(&cm_u)
-        .update(&ephemeral_key)
-        .finalize();
-
-    <[u8; 32]>::try_from(hash.as_bytes()).expect("32 byte array")
-}
-
 /// Invokes Blake2s-256 as _CRH^ivk_, to derive the IncomingViewingKey
 /// bytes from an AuthorizingKey and NullifierDerivingKey.
 ///

zebra-chain/src/sapling/note.rs

@@ -1,7 +1,6 @@
 //! Sapling notes
 
 #![allow(clippy::unit_arg)]
-#![allow(dead_code)]
 
 mod ciphertexts;
 mod nullifiers;

zebra-chain/src/sapling/note/nullifiers.rs

@@ -1,5 +1,4 @@
 #![allow(clippy::unit_arg)]
-#![allow(dead_code)]
 
 use super::super::{
     commitment::{pedersen_hashes::mixing_pedersen_hash, NoteCommitment},

zebra-chain/src/sprout/note.rs

@@ -1,7 +1,6 @@
 //! Sprout notes
 
 #![allow(clippy::unit_arg)]
-#![allow(dead_code)]
 
 #[cfg(any(test, feature = "proptest-impl"))]
 mod arbitrary;

zebra-chain/src/sprout/note/nullifiers.rs

@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 use byteorder::{ByteOrder, LittleEndian};
 use serde::{Deserialize, Serialize};
 use sha2::digest::generic_array::{typenum::U64, GenericArray};

zebra-chain/src/transaction.rs

@@ -975,29 +975,6 @@ impl Transaction {
             .map_err(ValueBalanceError::Transparent)
     }
 
-    /// Return the transparent value balance,
-    /// the change in the value of the transaction value pool.
-    ///
-    /// The sum of the UTXOs spent by transparent inputs in `tx_in` fields,
-    /// minus the sum of the newly created outputs in `tx_out` fields.
-    ///
-    /// Positive values are added to this transaction's value pool,
-    /// and removed from the transparent chain value pool.
-    /// Negative values are removed from the transparent chain value pool,
-    /// and added to this transaction.
-    ///
-    /// <https://zebra.zfnd.org/dev/rfcs/0012-value-pools.html#definitions>
-    ///
-    /// `utxos` must contain the utxos of every input in the transaction,
-    /// including UTXOs created by earlier transactions in this block.
-    #[allow(dead_code)]
-    fn transparent_value_balance(
-        &self,
-        utxos: &HashMap<transparent::OutPoint, transparent::Utxo>,
-    ) -> Result<ValueBalance<NegativeAllowed>, ValueBalanceError> {
-        self.transparent_value_balance_from_outputs(&outputs_from_utxos(utxos.clone()))
-    }
-
     /// Modify the transparent output values of this transaction, regardless of version.
     #[cfg(any(test, feature = "proptest-impl"))]
     pub fn output_values_mut(&mut self) -> impl Iterator<Item = &mut Amount<NonNegative>> {