perf: use strings.Builder

instead of concatenating strings in a loop
Avoids quadratic complexity

accounts/abi/selector_parser.go

@@ -19,6 +19,7 @@ package abi
 import (
 	"errors"
 	"fmt"
+	"strings"
 )
 
 type SelectorMarshaling struct {
@@ -68,19 +69,23 @@ func parseElementaryType(unescapedSelector string) (string, string, error) {
 		return "", "", fmt.Errorf("failed to parse elementary type: %v", err)
 	}
 	// handle arrays
+	var parsedTypeSb71 strings.Builder
 	for len(rest) > 0 && rest[0] == '[' {
-		parsedType = parsedType + string(rest[0])
+		parsedTypeSb71.WriteString(string(rest[0]))
 		rest = rest[1:]
+		var parsedTypeSb74 strings.Builder
 		for len(rest) > 0 && isDigit(rest[0]) {
-			parsedType = parsedType + string(rest[0])
+			parsedTypeSb74.WriteString(string(rest[0]))
 			rest = rest[1:]
 		}
+		parsedType += parsedTypeSb74.String()
 		if len(rest) == 0 || rest[0] != ']' {
 			return "", "", fmt.Errorf("failed to parse array: expected ']', got %c", unescapedSelector[0])
 		}
-		parsedType = parsedType + string(rest[0])
+		parsedTypeSb71.WriteString(string(rest[0]))
 		rest = rest[1:]
 	}
+	parsedType += parsedTypeSb71.String()
 	return parsedType, rest, nil
 }
 

accounts/abi/type.go

@@ -171,6 +171,7 @@ func NewType(t string, internalType string, components []ArgumentMarshaling) (ty
 			used       = make(map[string]bool)
 		)
 		expression += "("
+		var expressionSb174 strings.Builder
 		for idx, c := range components {
 			cType, err := NewType(c.Type, c.InternalType, c.Components)
 			if err != nil {
@@ -192,11 +193,12 @@ func NewType(t string, internalType string, components []ArgumentMarshaling) (ty
 			})
 			elems = append(elems, &cType)
 			names = append(names, c.Name)
-			expression += cType.stringKind
+			expressionSb174.WriteString(cType.stringKind)
 			if idx != len(components)-1 {
-				expression += ","
+				expressionSb174.WriteString(",")
 			}
 		}
+		expression += expressionSb174.String()
 		expression += ")"
 
 		typ.TupleType = reflect.StructOf(fields)

accounts/hd.go

@@ -121,6 +121,7 @@ func ParseDerivationPath(path string) (DerivationPath, error) {
 // to its canonical representation.
 func (path DerivationPath) String() string {
 	result := "m"
+	var resultSb124 strings.Builder
 	for _, component := range path {
 		var hardened bool
 		if component >= 0x80000000 {
@@ -129,9 +130,10 @@ func (path DerivationPath) String() string {
 		}
 		result = fmt.Sprintf("%s/%d", result, component)
 		if hardened {
-			result += "'"
+			resultSb124.WriteString("'")
 		}
 	}
+	result += resultSb124.String()
 	return result
 }
 

accounts/keystore/account_cache.go

@@ -52,12 +52,14 @@ type AmbiguousAddrError struct {
 
 func (err *AmbiguousAddrError) Error() string {
 	files := ""
+	var filesSb55 strings.Builder
 	for i, a := range err.Matches {
-		files += a.URL.Path
+		filesSb55.WriteString(a.URL.Path)
 		if i < len(err.Matches)-1 {
-			files += ", "
+			filesSb55.WriteString(", ")
 		}
 	}
+	files += filesSb55.String()
 	return fmt.Sprintf("multiple keys match address (%s)", files)
 }
 

cmd/devp2p/enrcmd.go

@@ -109,22 +109,24 @@ func dumpRecordKV(kv []interface{}, indent int) string {
 		}
 	}
 	// Print the keys, invoking formatters for known keys.
+	var outSb112 strings.Builder
 	for i := 0; i < len(kv); i += 2 {
 		key := kv[i].(string)
 		val := kv[i+1].(rlp.RawValue)
 		pad := longestKey - len(key)
-		out += strings.Repeat(" ", indent) + strconv.Quote(key) + strings.Repeat(" ", pad+1)
+		outSb112.WriteString(strings.Repeat(" ", indent) + strconv.Quote(key) + strings.Repeat(" ", pad+1))
 		formatter := attrFormatters[key]
 		if formatter == nil {
 			formatter = formatAttrRaw
 		}
 		fmtval, ok := formatter(val)
 		if ok {
-			out += fmtval + "\n"
+			outSb112.WriteString(fmtval + "\n")
 		} else {
-			out += hex.EncodeToString(val) + " (!)\n"
+			outSb112.WriteString(hex.EncodeToString(val) + " (!)\n")
 		}
 	}
+	out += outSb112.String()
 	return out
 }
 

cmd/geth/dbcmd.go

@@ -265,9 +265,11 @@ func confirmAndRemoveDB(paths []string, kind string, ctx *cli.Context, removeFla
 		err     error
 	)
 	msg := fmt.Sprintf("Location(s) of '%s': \n", kind)
+	var msgSb268 strings.Builder
 	for _, path := range paths {
-		msg += fmt.Sprintf("\t- %s\n", path)
+		msgSb268.WriteString(fmt.Sprintf("\t- %s\n", path))
 	}
+	msg += msgSb268.String()
 	fmt.Println(msg)
 	if ctx.IsSet(removeFlagName) {
 		confirm = ctx.Bool(removeFlagName)

core/blockchain.go

@@ -711,7 +711,7 @@ func (bc *BlockChain) initializeHistoryPruning(latest uint64) error {
 			// here, but it'd be a bit dangerous since they may not have intended this
 			// action to happen. So just tell them how to do it.
 			log.Error(fmt.Sprintf("Chain history mode is configured as %q, but database is not pruned.", bc.cfg.ChainHistoryMode.String()))
-			log.Error(fmt.Sprintf("Run 'geth prune-history' to prune pre-merge history."))
+			log.Error("Run 'geth prune-history' to prune pre-merge history.")
 			return errors.New("history pruning requested via configuration")
 		}
 		predefinedPoint := history.PrunePoints[bc.genesisBlock.Hash()]
@@ -2704,11 +2704,13 @@ func (bc *BlockChain) logForkReadiness(block *types.Block) {
 // relevant information.
 func summarizeBadBlock(block *types.Block, receipts []*types.Receipt, config *params.ChainConfig, err error) string {
 	var receiptString string
+	var receiptStringSb2707 strings.Builder
 	for i, receipt := range receipts {
-		receiptString += fmt.Sprintf("\n  %d: cumulative: %v gas: %v contract: %v status: %v tx: %v logs: %v bloom: %x state: %x",
+		receiptStringSb2707.WriteString(fmt.Sprintf("\n  %d: cumulative: %v gas: %v contract: %v status: %v tx: %v logs: %v bloom: %x state: %x",
 			i, receipt.CumulativeGasUsed, receipt.GasUsed, receipt.ContractAddress.Hex(),
-			receipt.Status, receipt.TxHash.Hex(), receipt.Logs, receipt.Bloom, receipt.PostState)
+			receipt.Status, receipt.TxHash.Hex(), receipt.Logs, receipt.Bloom, receipt.PostState))
 	}
+	receiptString += receiptStringSb2707.String()
 	version, vcs := version.Info()
 	platform := fmt.Sprintf("%s %s %s %s", version, runtime.Version(), runtime.GOARCH, runtime.GOOS)
 	if vcs != "" {

ethdb/leveldb/leveldb.go

@@ -24,6 +24,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -280,6 +281,7 @@ func (db *Database) Stat() (string, error) {
 	if len(stats.LevelSizes) > 0 {
 		message += " Level |   Tables   |    Size(MB)   |    Time(sec)  |    Read(MB)   |   Write(MB)\n" +
 			"-------+------------+---------------+---------------+---------------+---------------\n"
+		var messageSb283 strings.Builder
 		for level, size := range stats.LevelSizes {
 			read := stats.LevelRead[level]
 			write := stats.LevelWrite[level]
@@ -294,10 +296,11 @@ func (db *Database) Stat() (string, error) {
 			totalRead += read
 			totalWrite += write
 			totalDuration += duration
-			message += fmt.Sprintf(" %3d   | %10d | %13.5f | %13.5f | %13.5f | %13.5f\n",
+			messageSb283.WriteString(fmt.Sprintf(" %3d   | %10d | %13.5f | %13.5f | %13.5f | %13.5f\n",
 				level, tables, float64(size)/1048576.0, duration.Seconds(),
-				float64(read)/1048576.0, float64(write)/1048576.0)
+				float64(read)/1048576.0, float64(write)/1048576.0))
 		}
+		message += messageSb283.String()
 		message += "-------+------------+---------------+---------------+---------------+---------------\n"
 		message += fmt.Sprintf(" Total | %10d | %13.5f | %13.5f | %13.5f | %13.5f\n",
 			totalTables, float64(totalSize)/1048576.0, totalDuration.Seconds(),

log/handler_glog.go

@@ -113,13 +113,15 @@ func (h *GlogHandler) Vmodule(ruleset string) error {
 		}
 		// Compile the rule pattern into a regular expression
 		matcher := ".*"
+		var matcherSb116 strings.Builder
 		for _, comp := range strings.Split(parts[0], "/") {
 			if comp == "*" {
-				matcher += "(/.*)?"
+				matcherSb116.WriteString("(/.*)?")
 			} else if comp != "" {
 				matcher += "/" + regexp.QuoteMeta(comp)
 			}
 		}
+		matcher += matcherSb116.String()
 		if !strings.HasSuffix(parts[0], ".go") {
 			matcher += "/[^/]+\\.go"
 		}

params/config.go

@@ -693,7 +693,7 @@ func (c *ChainConfig) Description() string {
 	if c.VerkleTime != nil {
 		banner += fmt.Sprintf(" - Verkle:                      @%-10v blob: (%s)\n", *c.VerkleTime, c.BlobScheduleConfig.Verkle)
 	}
-	banner += fmt.Sprintf("\nAll fork specifications can be found at https://ethereum.github.io/execution-specs/src/ethereum/forks/\n")
+	banner += "\nAll fork specifications can be found at https://ethereum.github.io/execution-specs/src/ethereum/forks/\n"
 	return banner
 }
 

rlp/rlpgen/gen.go

@@ -22,6 +22,7 @@ import (
 	"go/format"
 	"go/types"
 	"sort"
+	"strings"
 
 	"github.com/ethereum/go-ethereum/rlp/internal/rlpstruct"
 	"golang.org/x/tools/go/packages"
@@ -624,12 +625,14 @@ func (op structOp) writeOptionalFields(b *bytes.Buffer, ctx *genContext, v strin
 	for i, field := range op.optionalFields {
 		selector := v + "." + field.name
 		cond := ""
+		var condSb627 strings.Builder
 		for j := i; j < len(op.optionalFields); j++ {
 			if j > i {
-				cond += " || "
+				condSb627.WriteString(" || ")
 			}
-			cond += zeroV[j]
+			condSb627.WriteString(zeroV[j])
 		}
+		cond += condSb627.String()
 		fmt.Fprintf(b, "if %s {\n", cond)
 		fmt.Fprint(b, field.elem.genWrite(ctx, selector))
 		fmt.Fprintf(b, "}\n")

trie/node.go

@@ -101,13 +101,15 @@ func (n valueNode) String() string  { return n.fstring("") }
 
 func (n *fullNode) fstring(ind string) string {
 	resp := fmt.Sprintf("[\n%s  ", ind)
+	var respSb104 strings.Builder
 	for i, node := range &n.Children {
 		if node == nil {
-			resp += fmt.Sprintf("%s: <nil> ", indices[i])
+			respSb104.WriteString(fmt.Sprintf("%s: <nil> ", indices[i]))
 		} else {
-			resp += fmt.Sprintf("%s: %v", indices[i], node.fstring(ind+"  "))
+			respSb104.WriteString(fmt.Sprintf("%s: %v", indices[i], node.fstring(ind+"  ")))
 		}
 	}
+	resp += respSb104.String()
 	return resp + fmt.Sprintf("\n%s] ", ind)
 }
 

triedb/pathdb/database.go

@@ -606,9 +606,9 @@ func (db *Database) journalPath() string {
 	}
 	var fname string
 	if db.isVerkle {
-		fname = fmt.Sprintf("verkle.journal")
+		fname = "verkle.journal"
 	} else {
-		fname = fmt.Sprintf("merkle.journal")
+		fname = "merkle.journal"
 	}
 	return filepath.Join(db.config.JournalDirectory, fname)
 }