feat(svmSpokeUtils): get fill deadline buffer implementation

src/arch/svm/SpokeUtils.ts

@@ -1,6 +1,8 @@
-import { Rpc, SolanaRpcApi } from "@solana/kit";
+import { Rpc, SolanaRpcApi, Address } from "@solana/kit";
+
 import { Deposit, FillStatus, FillWithBlock, RelayData } from "../../interfaces";
 import { BigNumber, isUnsafeDepositId } from "../../utils";
+import { fetchState } from "@across-protocol/contracts/dist/src/svm/clients/SvmSpoke";
 
 type Provider = Rpc<SolanaRpcApi>;
 
@@ -46,18 +48,14 @@ export async function getTimestampForBlock(provider: Provider, blockNumber: numb
 }
 
 /**
- * Return maximum of fill deadline buffer at start and end of block range.
- * @param spokePool SpokePool contract instance
- * @param startBlock start block
- * @param endBlock end block
- * @returns maximum of fill deadline buffer at start and end block
+ * Returns the current fill deadline buffer.
+ * @param provider SVM Provider instance
+ * @param statePda Spoke Pool's State PDA
+ * @returns fill deadline buffer
  */
-export function getMaxFillDeadlineInRange(
-  _spokePool: unknown,
-  _startBlock: number,
-  _endBlock: number
-): Promise<number> {
-  throw new Error("getMaxFillDeadlineInRange: not implemented");
+export async function getFillDeadline(provider: Provider, statePda: Address): Promise<number> {
+  const state = await fetchState(provider, statePda);
+  return state.data.fillDeadlineBuffer;
 }
 
 /**

src/arch/svm/eventsClient.ts

@@ -209,4 +209,8 @@ export class SvmSpokeEventsClient {
 
     return events;
   }
+
+  public getSvmSpokeAddress(): Address {
+    return this.svmSpokeAddress;
+  }
 }

src/arch/svm/utils.ts

@@ -1,5 +1,6 @@
 import { BN, BorshEventCoder, Idl } from "@coral-xyz/anchor";
-import web3, { address, RpcTransport } from "@solana/kit";
+import web3, { address, getProgramDerivedAddress, getU64Encoder, Address, RpcTransport } from "@solana/kit";
+
 import { EventName, EventData, SVMEventNames } from "./types";
 
 /**
@@ -64,3 +65,19 @@ export function getEventName(rawName: string): EventName {
   if (Object.values(SVMEventNames).some((name) => rawName.includes(name))) return rawName as EventName;
   throw new Error(`Unknown event name: ${rawName}`);
 }
+
+/**
+ * Returns the PDA for the State account.
+ * @param programId The SpokePool program ID.
+ * @param extraSeed An optional extra seed. Defaults to 0.
+ * @returns The PDA for the State account.
+ */
+export async function getStatePda(programId: Address, extraSeed = 0): Promise<Address> {
+  const seedEncoder = getU64Encoder();
+  const encodedExtraSeed = seedEncoder.encode(extraSeed);
+  const [statePda] = await getProgramDerivedAddress({
+    programAddress: programId,
+    seeds: ["state", encodedExtraSeed],
+  });
+  return statePda;
+}

src/clients/SpokePoolClient/SVMSpokePoolClient.ts

@@ -1,10 +1,18 @@
 import winston from "winston";
-import { Rpc, SolanaRpcApiFromTransport, RpcTransport } from "@solana/kit";
+import { Address, Rpc, SolanaRpcApiFromTransport, RpcTransport } from "@solana/kit";
+
 import { BigNumber, DepositSearchResult, EventSearchConfig, MakeOptional } from "../../utils";
-import { SvmSpokeEventsClient, SVMEventNames } from "../../arch/svm";
+import {
+  SvmSpokeEventsClient,
+  SVMEventNames,
+  getFillDeadline,
+  getTimestampForBlock,
+  getStatePda,
+} from "../../arch/svm";
 import { HubPoolClient } from "../HubPoolClient";
 import { knownEventNames, SpokePoolClient, SpokePoolUpdate } from "./SpokePoolClient";
 import { RelayData, FillStatus } from "../../interfaces";
+
 /**
  * SvmSpokePoolClient is a client for the SVM SpokePool program. It extends the base SpokePoolClient
  * and implements the abstract methods required for interacting with an SVM Spoke Pool.
@@ -19,6 +27,8 @@ export class SvmSpokePoolClient extends SpokePoolClient {
     chainId: number,
     deploymentSlot: bigint, // Using slot instead of block number for SVM
     eventSearchConfig: MakeOptional<EventSearchConfig, "toBlock">,
+    protected programId: Address,
+    protected statePda: Address,
     protected svmEventsClient: SvmSpokeEventsClient,
     protected rpc: Rpc<SolanaRpcApiFromTransport<RpcTransport>>
   ) {
@@ -38,12 +48,16 @@ export class SvmSpokePoolClient extends SpokePoolClient {
     rpc: Rpc<SolanaRpcApiFromTransport<RpcTransport>>
   ): Promise<SvmSpokePoolClient> {
     const svmEventsClient = await SvmSpokeEventsClient.create(rpc);
+    const programId = svmEventsClient.getSvmSpokeAddress();
+    const statePda = await getStatePda(programId);
     return new SvmSpokePoolClient(
       logger,
       hubPoolClient,
       chainId,
       deploymentSlot,
       eventSearchConfig,
+      programId,
+      statePda,
       svmEventsClient,
       rpc
     );
@@ -150,18 +164,18 @@ export class SvmSpokePoolClient extends SpokePoolClient {
   }
 
   /**
-   * Retrieves the maximum fill deadline buffer.
-   * TODO: Implement SVM equivalent, perhaps reading from a config account.
+   * Retrieves the fill deadline buffer fetched from the State PDA.
+   * @note This function assumes that fill deadline buffer is a constant value in svm environments.
    */
-  public getMaxFillDeadlineInRange(_startSlot: number, _endSlot: number): Promise<number> {
-    throw new Error("getMaxFillDeadlineInRange not implemented for SVM");
+  public override getMaxFillDeadlineInRange(_startSlot: number, _endSlot: number): Promise<number> {
+    return getFillDeadline(this.rpc, this.statePda);
   }
 
   /**
    * Retrieves the timestamp for a given SVM slot number.
    */
-  public getTimestampForBlock(_blockNumber: number): Promise<number> {
-    throw new Error("getTimestampForBlock not implemented for SVM");
+  public override getTimestampForBlock(blockNumber: number): Promise<number> {
+    return getTimestampForBlock(this.rpc, blockNumber);
   }
 
   /**