refactor: call stack item cleanup

yarn-project/acir-simulator/src/acvm/serialize.ts

@@ -50,6 +50,7 @@ export function toACVMField(
  * are empty since this is just an execution request, so we don't send them to the circuit.
  * @param item - The public call stack item to serialize to be passed onto Noir.
  * @returns The fields expected by the enqueue_public_function_call_oracle Aztec.nr function.
+ * TODO(#4380): Nuke this and replace it with PublicCallRequest.toFields()
  */
 export function toAcvmEnqueuePublicFunctionResult(item: PublicCallRequest): ACVMField[] {
   return [

yarn-project/circuits.js/src/structs/index.ts

@@ -2,7 +2,6 @@ export * from '@aztec/foundation/eth-address';
 export * from './aggregation_object.js';
 export * from './call_context.js';
 export * from './call_request.js';
-export * from './call_stack_item.js';
 export * from './complete_address.js';
 export * from './contract_deployment_data.js';
 export * from './contract_storage_read.js';
@@ -20,9 +19,11 @@ export * from './kernel/public_inputs_final.js';
 export * from './kernel/public_kernel.js';
 export * from './membership_witness.js';
 export * from './nullifier_key_validation_request.js';
+export * from './private_call_stack_item.js';
 export * from './private_circuit_public_inputs.js';
 export * from './proof.js';
 export * from './public_call_request.js';
+export * from './public_call_stack_item.js';
 export * from './public_circuit_public_inputs.js';
 export * from './read_request_membership_witness.js';
 export * from './rollup/append_only_tree_snapshot.js';

yarn-project/circuits.js/src/structs/kernel/private_kernel.test.ts

@@ -77,15 +77,6 @@ describe('CallRequest', () => {
   });
 });
 
-describe('PrivateCallStackcItem', () => {
-  it('convert to and from buffer', () => {
-    const fad = makePrivateCallStackItem(0);
-
-    const buf = fad.toBuffer();
-    expect(PrivateCallStackItem.fromBuffer(buf)).toEqual(fad);
-  });
-});
-
 describe('Private Circuit Public Inputs', () => {
   it('convert to and from buffer', () => {
     const pkpi = makePrivateCircuitPublicInputs();

yarn-project/circuits.js/src/structs/kernel/private_kernel.ts

@@ -14,14 +14,14 @@ import {
 } from '../../constants.gen.js';
 import { GrumpkinPrivateKey } from '../../types/grumpkin_private_key.js';
 import { CallRequest } from '../call_request.js';
-import { PrivateCallStackItem } from '../call_stack_item.js';
 import { MembershipWitness } from '../membership_witness.js';
 import { Proof } from '../proof.js';
 import { ReadRequestMembershipWitness } from '../read_request_membership_witness.js';
 import { SideEffect, SideEffectLinkedToNoteHash } from '../side_effects.js';
 import { TxRequest } from '../tx_request.js';
 import { VerificationKey } from '../verification_key.js';
 import { PreviousKernelData } from './previous_kernel_data.js';
+import { PrivateCallStackItem } from '../private_call_stack_item.js';
 
 /**
  * Private call data.

yarn-project/circuits.js/src/structs/kernel/public_kernel.ts

@@ -9,10 +9,10 @@ import {
   PUBLIC_DATA_TREE_HEIGHT,
 } from '../../constants.gen.js';
 import { CallRequest } from '../call_request.js';
-import { PublicCallStackItem } from '../call_stack_item.js';
 import { MembershipWitness } from '../membership_witness.js';
 import { Proof } from '../proof.js';
 import { PreviousKernelData } from './previous_kernel_data.js';
+import { PublicCallStackItem } from '../public_call_stack_item.js';
 
 /**
  * Inputs to the public kernel circuit.

yarn-project/circuits.js/src/structs/call_stack_item.test.ts → yarn-project/circuits.js/src/structs/private_call_stack_item.test.ts

@@ -1,5 +1,5 @@
 import { makePrivateCallStackItem } from '../tests/factories.js';
-import { PrivateCallStackItem } from './call_stack_item.js';
+import { PrivateCallStackItem } from './private_call_stack_item.js';
 
 describe('PrivateCallStackItem', () => {
   it('serializes to buffer and deserializes it back', () => {

yarn-project/circuits.js/src/structs/call_stack_item.ts → yarn-project/circuits.js/src/structs/private_call_stack_item.ts

@@ -1,12 +1,12 @@
 import { AztecAddress } from '@aztec/foundation/aztec-address';
 import { Fr } from '@aztec/foundation/fields';
-import { BufferReader, FieldReader, serializeToBuffer } from '@aztec/foundation/serialize';
+import { BufferReader, FieldReader, serializeToBuffer, serializeToFields } from '@aztec/foundation/serialize';
+import { FieldsOf } from '@aztec/foundation/types';
 
-import { computePrivateCallStackItemHash, computePublicCallStackItemHash } from '../abis/abis.js';
+import { computePrivateCallStackItemHash } from '../abis/abis.js';
 import { CallRequest, CallerContext } from './call_request.js';
 import { FunctionData } from './function_data.js';
 import { PrivateCircuitPublicInputs } from './private_circuit_public_inputs.js';
-import { PublicCircuitPublicInputs } from './public_circuit_public_inputs.js';
 
 /**
  * Call stack item on a private call.
@@ -35,17 +35,16 @@ export class PrivateCallStackItem {
     }
   }
 
+  static getFields(fields: FieldsOf<PrivateCallStackItem>) {
+    return [fields.contractAddress, fields.functionData, fields.publicInputs, fields.isExecutionRequest] as const;
+  }
+
   toBuffer() {
-    return serializeToBuffer(this.contractAddress, this.functionData, this.publicInputs, this.isExecutionRequest);
+    return serializeToBuffer(...PrivateCallStackItem.getFields(this));
   }
 
   toFields(): Fr[] {
-    return [
-      this.contractAddress.toField(),
-      ...this.functionData.toFields(),
-      ...this.publicInputs.toFields(),
-      new Fr(this.isExecutionRequest),
-    ];
+    return serializeToFields(...PrivateCallStackItem.getFields(this));
   }
 
   /**
@@ -116,74 +115,3 @@ export class PrivateCallStackItem {
     return new CallRequest(this.hash(), callContext.msgSender, callerContext, Fr.ZERO, Fr.ZERO);
   }
 }
-
-/**
- * Call stack item on a public call.
- * @see cpp/src/aztec3/circuits/abis/call_stack_item.hpp.
- */
-export class PublicCallStackItem {
-  constructor(
-    /**
-     * Address of the contract on which the function is invoked.
-     */
-    public contractAddress: AztecAddress,
-    /**
-     * Data identifying the function being called.
-     */
-    public functionData: FunctionData,
-    /**
-     * Public inputs to the public kernel circuit.
-     */
-    public publicInputs: PublicCircuitPublicInputs,
-    /**
-     * Whether the current callstack item should be considered a public fn execution request.
-     */
-    public isExecutionRequest: boolean,
-  ) {}
-
-  toBuffer() {
-    return serializeToBuffer(this.contractAddress, this.functionData, this.publicInputs, this.isExecutionRequest);
-  }
-
-  /**
-   * Returns a new instance of PublicCallStackItem with zero contract address, function data and public inputs.
-   * @returns A new instance of PublicCallStackItem with zero contract address, function data and public inputs.
-   */
-  public static empty(): PublicCallStackItem {
-    return new PublicCallStackItem(
-      AztecAddress.ZERO,
-      FunctionData.empty({ isPrivate: false }),
-      PublicCircuitPublicInputs.empty(),
-      false,
-    );
-  }
-
-  isEmpty() {
-    return this.contractAddress.isZero() && this.functionData.isEmpty() && this.publicInputs.isEmpty();
-  }
-
-  /**
-   * Computes this call stack item hash.
-   * @returns Hash.
-   */
-  public hash() {
-    return computePublicCallStackItemHash(this);
-  }
-
-  /**
-   * Creates a new CallRequest with values of the calling contract.
-   * @returns A CallRequest instance with the contract address, caller context, and the hash of the call stack item.
-   */
-  public toCallRequest() {
-    if (this.isEmpty()) {
-      return CallRequest.empty();
-    }
-
-    const callContext = this.publicInputs.callContext;
-    const callerContext = callContext.isDelegateCall
-      ? new CallerContext(callContext.msgSender, callContext.storageContractAddress)
-      : CallerContext.empty();
-    // todo: populate side effect counters correctly
-    return new CallRequest(this.hash(), callContext.msgSender, callerContext, Fr.ZERO, Fr.ZERO);
-  }
-}

yarn-project/circuits.js/src/structs/public_call_stack_item.test.ts

@@ -0,0 +1,28 @@
+import { makePublicCallStackItem } from '../tests/factories.js';
+import { PublicCallStackItem } from './public_call_stack_item.js';
+
+describe('PublicCallStackItem', () => {
+  it('serializes to buffer and deserializes it back', () => {
+    const randomInt = Math.floor(Math.random() * 1000);
+    const expected = makePublicCallStackItem(randomInt);
+    const buffer = expected.toBuffer();
+    const res = PublicCallStackItem.fromBuffer(buffer);
+    expect(res).toEqual(expected);
+  });
+
+  it('serializes to field array and deserializes it back', () => {
+    const randomInt = Math.floor(Math.random() * 1000);
+    const expected = makePublicCallStackItem(randomInt);
+
+    const fieldArray = expected.toFields();
+    const res = PublicCallStackItem.fromFields(fieldArray);
+    expect(res).toEqual(expected);
+  });
+
+  it('computes hash', () => {
+    const seed = 9870243;
+    const PublicCallStackItem = makePublicCallStackItem(seed);
+    const hash = PublicCallStackItem.hash();
+    expect(hash).toMatchSnapshot();
+  });
+});

yarn-project/circuits.js/src/structs/public_call_stack_item.ts

@@ -0,0 +1,113 @@
+import { AztecAddress } from '@aztec/foundation/aztec-address';
+import { Fr } from '@aztec/foundation/fields';
+import { BufferReader, FieldReader, serializeToBuffer, serializeToFields } from '@aztec/foundation/serialize';
+import { FieldsOf } from '@aztec/foundation/types';
+
+import { computePublicCallStackItemHash } from '../abis/abis.js';
+import { CallRequest, CallerContext } from './call_request.js';
+import { FunctionData } from './function_data.js';
+import { PublicCircuitPublicInputs } from './public_circuit_public_inputs.js';
+
+/**
+ * Call stack item on a public call.
+ */
+export class PublicCallStackItem {
+  constructor(
+    /**
+     * Address of the contract on which the function is invoked.
+     */
+    public contractAddress: AztecAddress,
+    /**
+     * Data identifying the function being called.
+     */
+    public functionData: FunctionData,
+    /**
+     * Public inputs to the public kernel circuit.
+     */
+    public publicInputs: PublicCircuitPublicInputs,
+    /**
+     * Whether the current callstack item should be considered a public fn execution request.
+     */
+    public isExecutionRequest: boolean,
+  ) {}
+
+  static getFields(fields: FieldsOf<PublicCallStackItem>) {
+    return [fields.contractAddress, fields.functionData, fields.publicInputs, fields.isExecutionRequest] as const;
+  }
+
+  toBuffer() {
+    return serializeToBuffer(...PublicCallStackItem.getFields(this));
+  }
+
+  toFields(): Fr[] {
+    return serializeToFields(...PublicCallStackItem.getFields(this));
+  }
+
+  /**
+   * Deserializes from a buffer or reader.
+   * @param buffer - Buffer or reader to read from.
+   * @returns The deserialized instance.
+   */
+  static fromBuffer(buffer: Buffer | BufferReader): PublicCallStackItem {
+    const reader = BufferReader.asReader(buffer);
+    return new PublicCallStackItem(
+      reader.readObject(AztecAddress),
+      reader.readObject(FunctionData),
+      reader.readObject(PublicCircuitPublicInputs),
+      reader.readBoolean(),
+    );
+  }
+
+  static fromFields(fields: Fr[] | FieldReader): PublicCallStackItem {
+    const reader = FieldReader.asReader(fields);
+
+    const contractAddress = AztecAddress.fromFields(reader);
+    const functionData = FunctionData.fromFields(reader);
+    const publicInputs = PublicCircuitPublicInputs.fromFields(reader);
+    const isExecutionRequest = reader.readBoolean();
+
+    return new PublicCallStackItem(contractAddress, functionData, publicInputs, isExecutionRequest);
+  }
+
+  /**
+   * Returns a new instance of PublicCallStackItem with zero contract address, function data and public inputs.
+   * @returns A new instance of PublicCallStackItem with zero contract address, function data and public inputs.
+   */
+  public static empty(): PublicCallStackItem {
+    return new PublicCallStackItem(
+      AztecAddress.ZERO,
+      FunctionData.empty({ isPrivate: false }),
+      PublicCircuitPublicInputs.empty(),
+      false,
+    );
+  }
+
+  isEmpty() {
+    return this.contractAddress.isZero() && this.functionData.isEmpty() && this.publicInputs.isEmpty();
+  }
+
+  /**
+   * Computes this call stack item hash.
+   * @returns Hash.
+   */
+  public hash() {
+    return computePublicCallStackItemHash(this);
+  }
+
+  /**
+   * Creates a new CallRequest with values of the calling contract.
+   * @returns A CallRequest instance with the contract address, caller context, and the hash of the call stack item.
+   */
+  public toCallRequest() {
+    if (this.isEmpty()) {
+      return CallRequest.empty();
+    }
+
+    const callContext = this.publicInputs.callContext;
+    const callerContext = callContext.isDelegateCall
+      ? new CallerContext(callContext.msgSender, callContext.storageContractAddress)
+      : CallerContext.empty();
+    // todo: populate side effect counters correctly
+    return new CallRequest(this.hash(), callContext.msgSender, callerContext, Fr.ZERO, Fr.ZERO);
+  }
+}