refactor(trie): replace SmallVec with Vec in sparse trie buffers (#21637)

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: DaniPopes <57450786+DaniPopes@users.noreply.github.com>

Cargo.lock

@@ -11255,7 +11255,6 @@ dependencies = [
  "reth-trie",
  "reth-trie-common",
  "reth-trie-db",
- "smallvec",
  "tracing",
 ]
 

crates/trie/sparse-parallel/Cargo.toml

@@ -28,8 +28,8 @@ reth-metrics = { workspace = true, optional = true }
 metrics = { workspace = true, optional = true }
 
 # misc
-smallvec.workspace = true
 rayon = { workspace = true, optional = true }
+smallvec.workspace = true
 
 [dev-dependencies]
 # reth

crates/trie/sparse-parallel/src/trie.rs

@@ -3248,9 +3248,9 @@ pub struct SparseSubtrieBuffers {
     /// Stack of RLP nodes
     rlp_node_stack: Vec<RlpNodeStackItem>,
     /// Reusable branch child path
-    branch_child_buf: SmallVec<[Nibbles; 16]>,
+    branch_child_buf: Vec<Nibbles>,
     /// Reusable branch value stack
-    branch_value_stack_buf: SmallVec<[RlpNode; 16]>,
+    branch_value_stack_buf: Vec<RlpNode>,
     /// Reusable RLP buffer
     rlp_buf: Vec<u8>,
 }

crates/trie/sparse/Cargo.toml

@@ -26,7 +26,6 @@ alloy-rlp.workspace = true
 # misc
 auto_impl.workspace = true
 rayon = { workspace = true, optional = true }
-smallvec = { workspace = true, features = ["const_new"] }
 
 # metrics
 reth-metrics = { workspace = true, optional = true }
@@ -80,7 +79,6 @@ arbitrary = [
     "alloy-trie/arbitrary",
     "reth-primitives-traits/arbitrary",
     "reth-trie-common/arbitrary",
-    "smallvec/arbitrary",
 ]
 
 [[bench]]

crates/trie/sparse/src/trie.rs

@@ -24,7 +24,6 @@ use reth_trie_common::{
     LeafNodeRef, Nibbles, ProofTrieNode, RlpNode, TrieMask, TrieNode, CHILD_INDEX_RANGE,
     EMPTY_ROOT_HASH,
 };
-use smallvec::SmallVec;
 use tracing::{debug, instrument, trace};
 
 /// The level below which the sparse trie hashes are calculated in
@@ -2003,9 +2002,9 @@ pub struct RlpNodeBuffers {
     /// Stack of RLP nodes
     rlp_node_stack: Vec<RlpNodeStackItem>,
     /// Reusable branch child path
-    branch_child_buf: SmallVec<[Nibbles; 16]>,
+    branch_child_buf: Vec<Nibbles>,
     /// Reusable branch value stack
-    branch_value_stack_buf: SmallVec<[RlpNode; 16]>,
+    branch_value_stack_buf: Vec<RlpNode>,
 }
 
 impl RlpNodeBuffers {
@@ -2018,8 +2017,8 @@ impl RlpNodeBuffers {
                 is_in_prefix_set: None,
             }],
             rlp_node_stack: Vec::new(),
-            branch_child_buf: SmallVec::<[Nibbles; 16]>::new_const(),
-            branch_value_stack_buf: SmallVec::<[RlpNode; 16]>::new_const(),
+            branch_child_buf: Vec::new(),
+            branch_value_stack_buf: Vec::new(),
         }
     }
 }