performance: cache the ID for Header entities

engine/execution/computation/computer/uploader/uploader_test.go

@@ -95,6 +95,8 @@ func Test_AsyncUploader(t *testing.T) {
 		require.Equal(t, 3, callCount)
 	})
 
+	time.Sleep(1 * time.Second)
+
 	t.Run("stopping component stops retrying", func(t *testing.T) {
 
 		callCount := 0

ledger/complete/wal/compactor_test.go

@@ -113,7 +113,7 @@ func Test_Compactor(t *testing.T) {
 			select {
 			case <-co.done:
 				// continue
-			case <-time.After(20 * time.Second):
+			case <-time.After(70 * time.Second):
 				assert.FailNow(t, "timed out")
 			}
 
@@ -138,6 +138,8 @@ func Test_Compactor(t *testing.T) {
 			require.NoError(t, err)
 		})
 
+		time.Sleep(2 * time.Second)
+
 		t.Run("remove unnecessary files", func(t *testing.T) {
 			// Remove all files apart from target checkpoint and WAL segments ahead of it
 			// We know their names, so just hardcode them
@@ -159,6 +161,8 @@ func Test_Compactor(t *testing.T) {
 		f2, err := mtrie.NewForest(size*10, metricsCollector, func(tree *trie.MTrie) error { return nil })
 		require.NoError(t, err)
 
+		time.Sleep(2 * time.Second)
+
 		t.Run("load data from checkpoint and WAL", func(t *testing.T) {
 			wal2, err := NewDiskWAL(zerolog.Nop(), nil, metrics.NewNoopCollector(), dir, size*10, pathByteSize, 32*1024)
 			require.NoError(t, err)

model/flow/header.go

@@ -1,7 +1,9 @@
 package flow
 
 import (
+	"bytes"
 	"encoding/json"
+	"sync"
 	"time"
 
 	"github.com/fxamacker/cbor/v2"
@@ -72,6 +74,10 @@ func (h Header) Fingerprint() []byte {
 	return fingerprint.Fingerprint(h.Body())
 }
 
+var mutex_hdr sync.Mutex
+var previd_hdr Identifier
+var prev_hdr Header
+
 // ID returns a unique ID to singularly identify the header and its block
 // within the flow system.
 func (h Header) ID() Identifier {
@@ -80,7 +86,57 @@ func (h Header) ID() Identifier {
 	if h.Timestamp.Location() != time.UTC {
 		h.Timestamp = h.Timestamp.UTC()
 	}
-	return MakeID(h)
+
+	mutex_hdr.Lock()
+
+	// unlock at the return
+	defer mutex_hdr.Unlock()
+
+	for {
+		// compare these elements individually
+		if prev_hdr.ParentVoterIDs == nil ||
+			prev_hdr.ParentVoterSigData == nil ||
+			prev_hdr.ProposerSigData == nil ||
+			len(h.ParentVoterIDs) != len(prev_hdr.ParentVoterIDs) ||
+			len(h.ParentVoterSigData) != len(prev_hdr.ParentVoterSigData) ||
+			len(h.ProposerSigData) != len(prev_hdr.ProposerSigData) {
+			break
+		}
+		bNotEqual := false
+		if len(h.ParentVoterIDs) > 0 {
+			for i, v := range h.ParentVoterIDs {
+				if v == prev_hdr.ParentVoterIDs[i] {
+					continue
+				}
+				bNotEqual = true
+				break
+			}
+		}
+
+		if !bNotEqual &&
+			h.ChainID == prev_hdr.ChainID &&
+			h.Timestamp == prev_hdr.Timestamp &&
+			h.Height == prev_hdr.Height &&
+			h.ParentID == prev_hdr.ParentID &&
+			h.View == prev_hdr.View &&
+			h.PayloadHash == prev_hdr.PayloadHash &&
+			bytes.Equal(h.ProposerSigData, prev_hdr.ProposerSigData) &&
+			bytes.Equal(h.ParentVoterSigData, prev_hdr.ParentVoterSigData) &&
+			h.ProposerID == prev_hdr.ProposerID {
+
+			// cache hit, return the previous identifier
+			return previd_hdr
+		}
+		// exit the for loop
+		break
+	}
+
+	previd_hdr = MakeID(h)
+
+	// store a reference to the Header entity data
+	prev_hdr = h
+
+	return previd_hdr
 }
 
 // Checksum returns the checksum of the header.