perf(db): use ArrayVec for StoredNibbles key encoding (paradigmxyz#21279)

Author: mattsse

Cargo.lock

@@ -40,6 +40,7 @@ serde = { workspace = true, default-features = false }
 metrics.workspace = true
 
 # misc
+arrayvec.workspace = true
 derive_more.workspace = true
 bytes.workspace = true
 

crates/storage/db-api/Cargo.toml

@@ -126,13 +126,10 @@ impl Decode for String {
 }
 
 impl Encode for StoredNibbles {
-    type Encoded = Vec<u8>;
+    type Encoded = arrayvec::ArrayVec<u8, 64>;
 
-    // Delegate to the Compact implementation
     fn encode(self) -> Self::Encoded {
-        // NOTE: This used to be `to_compact`, but all it does is append the bytes to the buffer,
-        // so we can just use the implementation of `Into<Vec<u8>>` to reuse the buffer.
-        self.0.to_vec()
+        self.0.iter().collect()
     }
 }
 

crates/storage/db-api/src/models/mod.rs

@@ -46,10 +46,40 @@ pub trait Decompress: Send + Sync + Sized + Debug {
     }
 }
 
+/// Trait for converting encoded types to `Vec<u8>`.
+///
+/// This is implemented for all `AsRef<[u8]>` types. For `Vec<u8>` this is a no-op,
+/// for other types like `ArrayVec` or fixed arrays it performs a copy.
+pub trait IntoVec: AsRef<[u8]> {
+    /// Convert to a `Vec<u8>`.
+    fn into_vec(self) -> Vec<u8>;
+}
+
+impl IntoVec for Vec<u8> {
+    #[inline]
+    fn into_vec(self) -> Vec<u8> {
+        self
+    }
+}
+
+impl<const N: usize> IntoVec for [u8; N] {
+    #[inline]
+    fn into_vec(self) -> Vec<u8> {
+        self.to_vec()
+    }
+}
+
+impl<const N: usize> IntoVec for arrayvec::ArrayVec<u8, N> {
+    #[inline]
+    fn into_vec(self) -> Vec<u8> {
+        self.to_vec()
+    }
+}
+
 /// Trait that will transform the data to be saved in the DB.
 pub trait Encode: Send + Sync + Sized + Debug {
     /// Encoded type.
-    type Encoded: AsRef<[u8]> + Into<Vec<u8>> + Send + Sync + Ord + Debug;
+    type Encoded: AsRef<[u8]> + IntoVec + Send + Sync + Ord + Debug;
 
     /// Encodes data going into the database.
     fn encode(self) -> Self::Encoded;

crates/storage/db-api/src/table.rs

@@ -1,5 +1,5 @@
 use crate::{
-    table::{Compress, Decode, Decompress, DupSort, Encode, Key, Table, Value},
+    table::{Compress, Decode, Decompress, DupSort, Encode, IntoVec, Key, Table, Value},
     DatabaseError,
 };
 use serde::{Deserialize, Serialize};
@@ -52,7 +52,7 @@ pub struct RawKey<K: Key> {
 impl<K: Key> RawKey<K> {
     /// Create new raw key.
     pub fn new(key: K) -> Self {
-        Self { key: K::encode(key).into(), _phantom: std::marker::PhantomData }
+        Self { key: K::encode(key).into_vec(), _phantom: std::marker::PhantomData }
     }
 
     /// Creates a raw key from an existing `Vec`. Useful when we already have the encoded

crates/storage/db-api/src/tables/raw.rs

@@ -11,7 +11,7 @@ use reth_db_api::{
         DbCursorRO, DbCursorRW, DbDupCursorRO, DbDupCursorRW, DupWalker, RangeWalker,
         ReverseWalker, Walker,
     },
-    table::{Compress, Decode, Decompress, DupSort, Encode, Table},
+    table::{Compress, Decode, Decompress, DupSort, Encode, IntoVec, Table},
 };
 use reth_libmdbx::{Error as MDBXError, TransactionKind, WriteFlags, RO, RW};
 use reth_storage_errors::db::{DatabaseErrorInfo, DatabaseWriteError, DatabaseWriteOperation};
@@ -268,7 +268,7 @@ impl<T: Table> DbCursorRW<T> for Cursor<RW, T> {
                             info: e.into(),
                             operation: DatabaseWriteOperation::CursorUpsert,
                             table_name: T::NAME,
-                            key: key.into(),
+                            key: key.into_vec(),
                         }
                         .into()
                     })
@@ -290,7 +290,7 @@ impl<T: Table> DbCursorRW<T> for Cursor<RW, T> {
                             info: e.into(),
                             operation: DatabaseWriteOperation::CursorInsert,
                             table_name: T::NAME,
-                            key: key.into(),
+                            key: key.into_vec(),
                         }
                         .into()
                     })
@@ -314,7 +314,7 @@ impl<T: Table> DbCursorRW<T> for Cursor<RW, T> {
                             info: e.into(),
                             operation: DatabaseWriteOperation::CursorAppend,
                             table_name: T::NAME,
-                            key: key.into(),
+                            key: key.into_vec(),
                         }
                         .into()
                     })
@@ -350,7 +350,7 @@ impl<T: DupSort> DbDupCursorRW<T> for Cursor<RW, T> {
                             info: e.into(),
                             operation: DatabaseWriteOperation::CursorAppendDup,
                             table_name: T::NAME,
-                            key: key.into(),
+                            key: key.into_vec(),
                         }
                         .into()
                     })

crates/storage/db/src/implementation/mdbx/cursor.rs

@@ -6,7 +6,7 @@ use crate::{
     DatabaseError,
 };
 use reth_db_api::{
-    table::{Compress, DupSort, Encode, Table, TableImporter},
+    table::{Compress, DupSort, Encode, IntoVec, Table, TableImporter},
     transaction::{DbTx, DbTxMut},
 };
 use reth_libmdbx::{ffi::MDBX_dbi, CommitLatency, Transaction, TransactionKind, WriteFlags, RW};
@@ -387,7 +387,7 @@ impl Tx<RW> {
                     info: e.into(),
                     operation: write_operation,
                     table_name: T::NAME,
-                    key: key.into(),
+                    key: key.into_vec(),
                 }
                 .into()
             })