fix(clippy): Resolve some lifetime and reference lints

zebra-chain/src/orchard/tree.rs

@@ -335,7 +335,8 @@ impl NoteCommitmentTree {
  .cached_root
  .write()
  .expect("a thread that previously held exclusive lock access panicked");
- match *write_root {
+ let read_root = write_root.as_ref().cloned();
+ match read_root {
  // Another thread got write access first, return cached root.
  Some(root) => root,
  None => {

zebra-chain/src/sapling/tree.rs

@@ -340,7 +340,8 @@ impl NoteCommitmentTree {
  .cached_root
  .write()
  .expect("a thread that previously held exclusive lock access panicked");
- match *write_root {
+ let read_root = write_root.as_ref().cloned();
+ match read_root {
  // Another thread got write access first, return cached root.
  Some(root) => root,
  None => {

zebra-chain/src/sprout/tree.rs

@@ -274,7 +274,8 @@ impl NoteCommitmentTree {
  .cached_root
  .write()
  .expect("a thread that previously held exclusive lock access panicked");
- match *write_root {
+ let read_root = write_root.as_ref().cloned();
+ match read_root {
  // Another thread got write access first, return cached root.
  Some(root) => root,
  None => {

zebra-chain/src/transparent/serialize.rs

@@ -98,7 +98,7 @@ pub(crate) fn parse_coinbase_height(
  mut data: Vec<u8>,
 ) -> Result<(block::Height, CoinbaseData), SerializationError> {
  use block::Height;
- match (data.get(0), data.len()) {
+ match (data.first(), data.len()) {
  // Blocks 1 through 16 inclusive encode block height with OP_N opcodes.
  (Some(op_n @ 0x51..=0x60), len) if len >= 1 => Ok((
  Height((op_n - 0x50) as u32),

zebra-state/src/service/chain_tip.rs

@@ -195,12 +195,18 @@ impl ChainTipSender {
  // a read-lock being created and living beyond the `self.sender.send(..)` call. If that
  // happens, the `send` method will attempt to obtain a write-lock and will dead-lock.
  // Without the binding, the guard is dropped at the end of the expression.
- let needs_update = match (new_tip.as_ref(), self.sender.borrow().as_ref()) {
+ let active_hash = self
+ .sender
+ .borrow()
+ .as_ref()
+ .map(|active_value| active_value.hash);
+
+ let needs_update = match (new_tip.as_ref(), active_hash) {
  // since the blocks have been contextually validated,
  // we know their hashes cover all the block data
- (Some(new_tip), Some(active_value)) => new_tip.hash != active_value.hash,
+ (Some(new_tip), Some(active_hash)) => new_tip.hash != active_hash,
  (Some(_new_tip), None) => true,
- (None, _active_value) => false,
+ (None, _active_value_hash) => false,
  };
 
  if needs_update {

zebra-state/src/service/finalized_state/disk_format.rs

@@ -73,7 +73,7 @@ where
  type Bytes = T::Bytes;
 
  fn as_bytes(&self) -> Self::Bytes {
- T::as_bytes(&*self)
+ T::as_bytes(self)
  }
 }