fix: no memory allocation in StableContainer Profile hashTreeRootInto()

ChainSafe · Oct 14, 2024 · 79152c4 · 79152c4
1 parent f17019e
commit 79152c4
Show file tree

Hide file tree

Showing 4 changed files with 17 additions and 13 deletions.
diff --git a/packages/ssz/src/type/composite.ts b/packages/ssz/src/type/composite.ts
@@ -240,6 +240,7 @@ export abstract class CompositeType<V, TV, TVDU> extends Type<V> {
     const merkleBytes = this.getChunkBytes(value);
     merkleizeInto(merkleBytes, this.maxChunkCount, output, offset);
     if (this.cachePermanentRootStruct) {
+      // Buffer.prototype.slice does not copy memory, Enforce Uint8Array usage https://github.com/nodejs/node/issues/28087
       const cachedRoot = Uint8Array.prototype.slice.call(output, offset, offset + 32);
       (value as ValueWithCachedPermanentRoot)[symbolCachedPermanentRoot] = cachedRoot;
     }

diff --git a/packages/ssz/src/type/listComposite.ts b/packages/ssz/src/type/listComposite.ts
@@ -207,7 +207,12 @@ export class ListCompositeType<
     merkleizeInto(this.mixInLengthChunkBytes, chunkCount, output, offset);
 
     if (this.cachePermanentRootStruct) {
-      (value as ValueWithCachedPermanentRoot)[symbolCachedPermanentRoot] = output.slice(offset, offset + 32);
+      // Buffer.prototype.slice does not copy memory, Enforce Uint8Array usage https://github.com/nodejs/node/issues/28087
+      (value as ValueWithCachedPermanentRoot)[symbolCachedPermanentRoot] = Uint8Array.prototype.slice.call(
+        output,
+        offset,
+        offset + 32
+      );
     }
   }
 

diff --git a/packages/ssz/src/type/profile.ts b/packages/ssz/src/type/profile.ts
@@ -34,7 +34,6 @@ import {Case} from "../util/strings";
 import {BitArray} from "../value/bitArray";
 import {mixInActiveFields, setActiveFields} from "./stableContainer";
 import {NonOptionalFields, isOptionalType, toNonOptionalType} from "./optional";
-import {allocUnsafe} from "@chainsafe/as-sha256";
 /* eslint-disable @typescript-eslint/member-ordering */
 
 type BytesRange = {start: number; end: number};
@@ -89,6 +88,8 @@ export class ProfileType<Fields extends Record<string, Type<unknown>>> extends C
   protected readonly TreeView: ContainerTreeViewTypeConstructor<Fields>;
   protected readonly TreeViewDU: ContainerTreeViewDUTypeConstructor<Fields>;
   private optionalFieldsCount: number;
+  // temporary root to avoid memory allocation
+  private tempRoot = new Uint8Array(32);
 
   constructor(readonly fields: Fields, activeFields: BitArray, readonly opts?: ProfileOptions<Fields>) {
     super();
@@ -378,13 +379,11 @@ export class ProfileType<Fields extends Record<string, Type<unknown>>> extends C
     }
 
     const merkleBytes = this.getChunkBytes(value);
-    const root = allocUnsafe(32);
-    merkleizeInto(merkleBytes, this.maxChunkCount, root, 0);
-    mixInActiveFields(root, this.activeFields, root, 0);
-    output.set(root, offset);
+    merkleizeInto(merkleBytes, this.maxChunkCount, this.tempRoot, 0);
+    mixInActiveFields(this.tempRoot, this.activeFields, output, offset);
 
     if (this.cachePermanentRootStruct) {
-      (value as ValueWithCachedPermanentRoot)[symbolCachedPermanentRoot] = root;
+      (value as ValueWithCachedPermanentRoot)[symbolCachedPermanentRoot] = this.tempRoot.slice();
     }
   }
 

diff --git a/packages/ssz/src/type/stableContainer.ts b/packages/ssz/src/type/stableContainer.ts
@@ -38,7 +38,6 @@ import {
 import {Case} from "../util/strings";
 import {isOptionalType, toNonOptionalType, NonOptionalFields} from "./optional";
 import {BitArray} from "../value/bitArray";
-import {allocUnsafe} from "@chainsafe/as-sha256";
 /* eslint-disable @typescript-eslint/member-ordering */
 
 type BytesRange = {start: number; end: number};
@@ -94,6 +93,8 @@ export class StableContainerType<Fields extends Record<string, Type<unknown>>> e
   protected readonly TreeView: ContainerTreeViewTypeConstructor<Fields>;
   protected readonly TreeViewDU: ContainerTreeViewDUTypeConstructor<Fields>;
   private padActiveFields: boolean[];
+  // temporary root to avoid memory allocation
+  private tempRoot = new Uint8Array(32);
 
   constructor(fields: Fields, readonly maxFields: number, readonly opts?: StableContainerOptions<Fields>) {
     super();
@@ -351,18 +352,16 @@ export class StableContainerType<Fields extends Record<string, Type<unknown>>> e
     }
 
     const merkleBytes = this.getChunkBytes(value);
-    const root = allocUnsafe(32);
-    merkleizeInto(merkleBytes, this.maxChunkCount, root, 0);
+    merkleizeInto(merkleBytes, this.maxChunkCount, this.tempRoot, 0);
     // compute active field bitvector
     const activeFields = BitArray.fromBoolArray([
       ...this.fieldsEntries.map(({fieldName}) => value[fieldName] != null),
       ...this.padActiveFields,
     ]);
-    mixInActiveFields(root, activeFields, root, 0);
-    output.set(root, offset);
+    mixInActiveFields(this.tempRoot, activeFields, output, offset);
 
     if (this.cachePermanentRootStruct) {
-      (value as ValueWithCachedPermanentRoot)[symbolCachedPermanentRoot] = root;
+      (value as ValueWithCachedPermanentRoot)[symbolCachedPermanentRoot] = this.tempRoot.slice();
     }
   }