From 1b98c13095ecfec61cc08285095a73628313311f Mon Sep 17 00:00:00 2001
From: Trevor Porter <trkporter@ucdavis.edu>
Date: Tue, 3 Oct 2023 13:22:34 +0100
Subject: [PATCH] Request 1M compute units in transfer remote (#2771)

### Description

Because incremental merkle tree insertion complexity can change
depending on what the index in the merkle tree is, we ran into a
situation where the 200k default compute limit wasn't enough when trying
to perform a transfer remote on sealevel.

Normal cost for index 257, about 158k units:

https://explorer.solana.com/tx/4oB9b6PaaKvGMhrQS7XGmi7zBpX3GUW99sbVrSjFwm5AVT96emKF4NH6gn2y9cLMLep8wQJ9LqwJifG5QMpr4BAs

Index 255, about 245k units!:
https://explorer.solana.com/tx/3v6SbrT58smwnLdnrEFaMXowaEDmo6EpPmKFTUMe9aESo5FTExmJdr2uMH5QJW9hnZTqrB1mfFZe4Vmu75CCAyPs

The fix is to simply request more units. Solana tx fees don't actually
charge you more if you use more units. Txs have a global cap of 1.4M
units -- I'm just requesting 1M here as a balance between having lots of
units & not bricking ourselves if the max compute unit amount ever
decreases

### Drive-by changes

n/a

### Related issues

n/a

### Backward compatibility

Yes

### Testing

I tested a version of this in the UI - I went to the commit where we
published 1.5.1, and then published a 1.5.1-beta2 version with this
change and moved the UI over to it. Opening this now so we can get this
in main and move the UI over to a less sketchy version
---
 .../src/adapters/SealevelTokenAdapter.ts      | 20 ++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/typescript/token/src/adapters/SealevelTokenAdapter.ts b/typescript/token/src/adapters/SealevelTokenAdapter.ts
index f88758d0b..d3b8b7b12 100644
--- a/typescript/token/src/adapters/SealevelTokenAdapter.ts
+++ b/typescript/token/src/adapters/SealevelTokenAdapter.ts
@@ -6,6 +6,7 @@ import {
 } from '@solana/spl-token';
 import {
   AccountMeta,
+  ComputeBudgetProgram,
   Keypair,
   PublicKey,
   SystemProgram,
@@ -153,6 +154,14 @@ export class SealevelTokenAdapter
   }
 }
 
+// The compute limit to set for the transfer remote instruction.
+// This is typically around ~160k, but can be higher depending on
+// the index in the merkle tree, which can result in more moderately
+// more expensive merkle tree insertion.
+// Because a higher compute limit doesn't increase the fee for a transaction,
+// we generously request 1M units.
+const TRANSFER_REMOTE_COMPUTE_LIMIT = 1_000_000;
+
 export abstract class SealevelHypTokenAdapter
   extends SealevelTokenAdapter
   implements IHypTokenAdapter
@@ -271,15 +280,24 @@ export abstract class SealevelHypTokenAdapter
       ]),
     });
 
+    const setComputeLimitInstruction = ComputeBudgetProgram.setComputeUnitLimit(
+      {
+        units: TRANSFER_REMOTE_COMPUTE_LIMIT,
+      },
+    );
+
     const recentBlockhash = (
       await this.getProvider().getLatestBlockhash('finalized')
     ).blockhash;
+
     // @ts-ignore Workaround for bug in the web3 lib, sometimes uses recentBlockhash and sometimes uses blockhash
     const tx = new Transaction({
       feePayer: fromWalletPubKey,
       blockhash: recentBlockhash,
       recentBlockhash,
-    }).add(transferRemoteInstruction);
+    })
+      .add(setComputeLimitInstruction)
+      .add(transferRemoteInstruction);
     tx.partialSign(randomWallet);
     return tx;
   }