From af2deee7c96df93999ebd433293c76a85957cb92 Mon Sep 17 00:00:00 2001
From: Mateusz Sekara <mateusz.sekara@gmail.com>
Date: Mon, 6 Nov 2023 18:17:57 +0100
Subject: [PATCH] CCIP-1261 Don't cache DB values on the USDC Reader level
 (#251)

---
 core/chains/evm/logpoller/observability.go    |  2 +-
 .../ocr2/plugins/ccip/tokendata/usdc/usdc.go  | 21 +++----------------
 .../plugins/ccip/tokendata/usdc/usdc_test.go  |  6 ------
 3 files changed, 4 insertions(+), 25 deletions(-)

diff --git a/core/chains/evm/logpoller/observability.go b/core/chains/evm/logpoller/observability.go
index 4e0ebe7418..c102bc42db 100644
--- a/core/chains/evm/logpoller/observability.go
+++ b/core/chains/evm/logpoller/observability.go
@@ -186,7 +186,7 @@ func (o *ObservedORM) SelectLogs(start, end int64, address common.Address, event
 	})
 }
 
-func (o *ObservedORM) IndexedLogsByTxHash(eventSig common.Hash, txHash common.Hash, qopts ...pg.QOpt) ([]Log, error) {
+func (o *ObservedORM) SelectIndexedLogsByTxHash(eventSig common.Hash, txHash common.Hash, qopts ...pg.QOpt) ([]Log, error) {
 	return withObservedQueryAndResults(o, "IndexedLogsByTxHash", func() ([]Log, error) {
 		return o.ORM.SelectIndexedLogsByTxHash(eventSig, txHash, qopts...)
 	})
diff --git a/core/services/ocr2/plugins/ccip/tokendata/usdc/usdc.go b/core/services/ocr2/plugins/ccip/tokendata/usdc/usdc.go
index 684df2bf4d..8f36886c4c 100644
--- a/core/services/ocr2/plugins/ccip/tokendata/usdc/usdc.go
+++ b/core/services/ocr2/plugins/ccip/tokendata/usdc/usdc.go
@@ -9,7 +9,6 @@ import (
 	"net/http"
 	"net/url"
 	"strings"
-	"sync"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
@@ -67,9 +66,6 @@ type TokenDataReader struct {
 	lggr           logger.Logger
 	usdcReader     ccipdata.USDCReader
 	attestationApi *url.URL
-	// Cache of sequence number -> usdc message body
-	usdcMessageHashCache      map[uint64][]byte
-	usdcMessageHashCacheMutex sync.Mutex
 }
 
 type attestationResponse struct {
@@ -81,10 +77,9 @@ var _ tokendata.Reader = &TokenDataReader{}
 
 func NewUSDCTokenDataReader(lggr logger.Logger, usdcReader ccipdata.USDCReader, usdcAttestationApi *url.URL) *TokenDataReader {
 	return &TokenDataReader{
-		lggr:                 lggr,
-		usdcReader:           usdcReader,
-		attestationApi:       usdcAttestationApi,
-		usdcMessageHashCache: make(map[uint64][]byte),
+		lggr:           lggr,
+		usdcReader:     usdcReader,
+		attestationApi: usdcAttestationApi,
 	}
 }
 
@@ -130,21 +125,11 @@ func encodeMessageAndAttestation(messageBody []byte, attestation string) ([]byte
 }
 
 func (s *TokenDataReader) getUSDCMessageBody(ctx context.Context, msg internal.EVM2EVMOnRampCCIPSendRequestedWithMeta) ([]byte, error) {
-	s.usdcMessageHashCacheMutex.Lock()
-	defer s.usdcMessageHashCacheMutex.Unlock()
-
-	if body, ok := s.usdcMessageHashCache[msg.SequenceNumber]; ok {
-		return body, nil
-	}
-
 	parsedMsgBody, err := s.usdcReader.GetLastUSDCMessagePriorToLogIndexInTx(ctx, int64(msg.LogIndex), msg.TxHash)
 	if err != nil {
 		return []byte{}, err
 	}
 	s.lggr.Infow("Got USDC message body", "messageBody", hexutil.Encode(parsedMsgBody), "messageID", hexutil.Encode(msg.MessageId[:]))
-
-	// Save the attempt in the cache in case the external call fails
-	s.usdcMessageHashCache[msg.SequenceNumber] = parsedMsgBody
 	return parsedMsgBody, nil
 }
 
diff --git a/core/services/ocr2/plugins/ccip/tokendata/usdc/usdc_test.go b/core/services/ocr2/plugins/ccip/tokendata/usdc/usdc_test.go
index 4f7b8fa05f..91c647871c 100644
--- a/core/services/ocr2/plugins/ccip/tokendata/usdc/usdc_test.go
+++ b/core/services/ocr2/plugins/ccip/tokendata/usdc/usdc_test.go
@@ -106,10 +106,4 @@ func TestGetUSDCMessageBody(t *testing.T) {
 	require.Equal(t, body, expectedBody)
 
 	usdcReader.AssertNumberOfCalls(t, "GetLastUSDCMessagePriorToLogIndexInTx", 1)
-
-	// Make another call and assert that the cache is used
-	body, err = usdcService.getUSDCMessageBody(context.Background(), internal.EVM2EVMOnRampCCIPSendRequestedWithMeta{})
-	require.NoError(t, err)
-	require.Equal(t, body, expectedBody)
-	usdcReader.AssertNumberOfCalls(t, "GetLastUSDCMessagePriorToLogIndexInTx", 1)
 }