chore: Remove references to padding txs (#11264)

In #11096 the empty padding tx was removed in favor of other circuits
(yay!). This PR removes all dangling references to padding txs.

yarn-project/circuit-types/src/interfaces/block-builder.ts

@@ -20,7 +20,6 @@ export interface BlockBuilder extends ProcessedTxHandler {
   addTxs(txs: ProcessedTx[]): Promise<void>;
 
   /**
-   * Pads the block with empty txs if it hasn't reached the declared number of txs.
    * Assembles the block and updates the archive tree.
    */
   setBlockCompleted(expectedBlockHeader?: BlockHeader): Promise<L2Block>;

yarn-project/circuit-types/src/interfaces/epoch-prover.ts

@@ -21,7 +21,7 @@ export interface EpochProver extends Omit<BlockBuilder, 'setBlockCompleted'> {
    */
   startTubeCircuits(txs: Tx[]): void;
 
-  /** Pads the block with empty txs if it hasn't reached the declared number of txs. */
+  /** Returns the block. */
   setBlockCompleted(blockNumber: number, expectedBlockHeader?: BlockHeader): Promise<L2Block>;
 
   /** Pads the epoch with empty block roots if needed and blocks until proven. Throws if proving has failed. */

yarn-project/circuit-types/src/tx/processed_tx.ts

@@ -60,10 +60,6 @@ export type ProcessedTx = {
    * Reason the tx was reverted.
    */
   revertReason: SimulationError | undefined;
-  /**
-   * Flag indicating the tx is 'empty' meaning it's a padding tx to take us to a power of 2.
-   */
-  isEmpty: boolean;
 };
 
 /**
@@ -123,7 +119,6 @@ export function makeProcessedTxFromPrivateOnlyTx(
     txEffect,
     gasUsed,
     revertReason: undefined,
-    isEmpty: false,
   };
 }
 
@@ -181,6 +176,5 @@ export function makeProcessedTxFromTxWithPublicCalls(
     txEffect,
     gasUsed,
     revertReason,
-    isEmpty: false,
   };
 }

yarn-project/end-to-end/src/e2e_block_building.test.ts

@@ -466,7 +466,7 @@ describe('e2e_block_building', () => {
     });
 
     // Regression for https://github.com/AztecProtocol/aztec-packages/issues/7918
-    it('publishes two blocks with only padding txs', async () => {
+    it('publishes two empty blocks', async () => {
       ({ teardown, pxe, logger, aztecNode } = await setup(0, {
         minTxsPerBlock: 0,
         skipProtocolContracts: true,

yarn-project/prover-client/src/block_builder/light.ts

@@ -4,7 +4,6 @@ import {
   MerkleTreeId,
   type MerkleTreeWriteOperations,
   type ProcessedTx,
-  TxHash,
   toNumBlobFields,
 } from '@aztec/circuit-types';
 import { Fr, type GlobalVariables, NUMBER_OF_L1_L2_MESSAGES_PER_ROLLUP } from '@aztec/circuits.js';
@@ -47,9 +46,7 @@ export class LightweightBlockBuilder implements BlockBuilder {
   async addTxs(txs: ProcessedTx[]): Promise<void> {
     this.spongeBlobState = SpongeBlob.init(toNumBlobFields(txs));
     for (const tx of txs) {
-      this.logger.debug(tx.hash.equals(TxHash.zero()) ? 'Adding padding tx to block' : 'Adding new tx to block', {
-        txHash: tx.hash.toString(),
-      });
+      this.logger.debug('Adding new tx to block', { txHash: tx.hash.toString() });
       this.txs.push(tx);
       await buildBaseRollupHints(tx, this.globalVariables!, this.db, this.spongeBlobState!);
     }
@@ -91,7 +88,6 @@ export class LightweightBlockBuilderFactory {
 
 /**
  * Creates a block builder under the hood with the given txs and messages and creates a block.
- * Automatically adds padding txs to get to a minimum of 2 txs in the block.
  * @param db - A db fork to use for block building.
  */
 export async function buildBlock(

yarn-project/prover-client/src/orchestrator/orchestrator.ts

@@ -270,11 +270,6 @@ export class ProvingOrchestrator implements EpochProver {
 
         logger.info(`Received transaction: ${tx.hash}`);
 
-        if (tx.isEmpty) {
-          logger.warn(`Ignoring empty transaction ${tx.hash} - it will not be added to this block`);
-          continue;
-        }
-
         const [hints, treeSnapshots] = await this.prepareTransaction(tx, provingState);
         const txProvingState = new TxProvingState(tx, hints, treeSnapshots);
         const txIndex = provingState.addNewTx(txProvingState);
@@ -528,9 +523,7 @@ export class ProvingOrchestrator implements EpochProver {
       buildBaseRollupHints(tx, provingState.globalVariables, db, provingState.spongeBlobState),
     );
 
-    if (!tx.isEmpty) {
-      this.metrics.recordBaseRollupInputs(ms);
-    }
+    this.metrics.recordBaseRollupInputs(ms);
 
     const promises = [MerkleTreeId.NOTE_HASH_TREE, MerkleTreeId.NULLIFIER_TREE, MerkleTreeId.PUBLIC_DATA_TREE].map(
       async (id: MerkleTreeId) => {
@@ -558,11 +551,7 @@ export class ProvingOrchestrator implements EpochProver {
     const { processedTx } = txProvingState;
     const { rollupType, inputs } = txProvingState.getBaseRollupTypeAndInputs();
 
-    logger.debug(
-      `Enqueuing deferred proving base rollup${
-        processedTx.isEmpty ? ' with padding tx' : ''
-      } for ${processedTx.hash.toString()}`,
-    );
+    logger.debug(`Enqueuing deferred proving base rollup for ${processedTx.hash.toString()}`);
 
     this.deferredProving(
       provingState,

yarn-project/prover-client/src/prover-client/prover-client.ts

@@ -34,10 +34,7 @@ export class ProverClient implements EpochProverManager {
     private agentClient?: ProvingJobConsumer,
     private telemetry: TelemetryClient = getTelemetryClient(),
     private log = createLogger('prover-client:tx-prover'),
-  ) {
-    // TODO(palla/prover-node): Cache the paddingTx here, and not in each proving orchestrator,
-    // so it can be reused across multiple ones and not recomputed every time.
-  }
+  ) {}
 
   public createEpochProver(): EpochProver {
     const facade = new BrokerCircuitProverFacade(this.orchestratorClient);
@@ -60,10 +57,6 @@ export class ProverClient implements EpochProverManager {
       await this.createAndStartAgents();
     }
 
-    if (!this.config.realProofs && newConfig.realProofs) {
-      // TODO(palla/prover-node): Reset padding tx here once we cache it at this class
-    }
-
     this.config = newConfig;
   }