executor: Optimize slow log parsing's splitByColon function (#54630)

close #54538

pkg/executor/slow_query.go

@@ -22,7 +22,6 @@ import (
  "io"
  "os"
  "path/filepath"
- "regexp"
  "runtime"
  "slices"
  "strconv"
@@ -523,32 +522,99 @@ func getLineIndex(offset offset, index int) int {
  return fileLine
 }
 
-// kvSplitRegex: it was just for split "field: value field: value..."
-var kvSplitRegex = regexp.MustCompile(`\w+: `)
+// findMatchedRightBracket returns the rightBracket index which matchs line[leftBracketIdx]
+// leftBracketIdx should be valid string index for line
+// Returns -1 if invalid inputs are given
+func findMatchedRightBracket(line string, leftBracketIdx int) int {
+ leftBracket := line[leftBracketIdx]
+ rightBracket := byte('}')
+ if leftBracket == '[' {
+ rightBracket = ']'
+ } else if leftBracket != '{' {
+ return -1
+ }
+ lineLength := len(line)
+ current := leftBracketIdx
+ leftBracketCnt := 0
+ for current < lineLength {
+ b := line[current]
+ if b == leftBracket {
+ leftBracketCnt++
+ current++
+ } else if b == rightBracket {
+ leftBracketCnt--
+ if leftBracketCnt > 0 {
+ current++
+ } else if leftBracketCnt == 0 {
+ if current+1 < lineLength && line[current+1] != ' ' {
+ return -1
+ }
+ return current
+ } else {
+ return -1
+ }
+ } else {
+ current++
+ }
+ }
+ return -1
+}
+
+func isLetterOrNumeric(b byte) bool {
+ return ('A' <= b && b <= 'Z') || ('a' <= b && b <= 'z') || ('0' <= b && b <= '9')
+}
 
 // splitByColon split a line like "field: value field: value..."
+// Note:
+// 1. field string's first character can only be ASCII letters or digits, and can't contain ':'
+// 2. value string may be surrounded by brackets, allowed brackets includes "[]" and "{}", like {key: value,{key: value}}
+// "[]" can only be nested inside "[]"; "{}" can only be nested inside "{}"
+// 3. value string can't contain ' ' character unless it is inside brackets
 func splitByColon(line string) (fields []string, values []string) {
- matches := kvSplitRegex.FindAllStringIndex(line, -1)
- fields = make([]string, 0, len(matches))
- values = make([]string, 0, len(matches))
-
- beg := 0
- end := 0
- for _, match := range matches {
- // trim ": "
- fields = append(fields, line[match[0]:match[1]-2])
-
- end = match[0]
- if beg != 0 {
- // trim " "
- values = append(values, line[beg:end-1])
- }
- beg = match[1]
+ fields = make([]string, 0, 1)
+ values = make([]string, 0, 1)
+
+ lineLength := len(line)
+ parseKey := true
+ start := 0
+ errMsg := ""
+ for current := 0; current < lineLength; {
+ if parseKey {
+ // Find key start
+ for current < lineLength && !isLetterOrNumeric(line[current]) {
+ current++
+ }
+ start = current
+ if current >= lineLength {
+ break
+ }
+ for current < lineLength && line[current] != ':' {
+ current++
+ }
+ fields = append(fields, line[start:current])
+ parseKey = false
+ current += 2 // bypass ": "
+ } else {
+ start = current
+ if current < lineLength && (line[current] == '{' || line[current] == '[') {
+ rBraceIdx := findMatchedRightBracket(line, current)
+ if rBraceIdx == -1 {
+ errMsg = "Braces matched error"
+ break
+ }
+ current = rBraceIdx + 1
+ } else {
+ for current < lineLength && line[current] != ' ' {
+ current++
+ }
+ }
+ values = append(values, line[start:min(current, len(line))])
+ parseKey = true
+ }
  }
-
- if end != len(line) {
- // " " does not exist in the end
- values = append(values, line[beg:])
+ if len(errMsg) > 0 {
+ logutil.BgLogger().Warn("slow query parse slow log error", zap.String("Error", errMsg), zap.String("Log", line))
+ return nil, nil
  }
  return fields, values
 }

pkg/executor/slow_query_test.go

@@ -532,8 +532,8 @@ func TestSplitbyColon(t *testing.T) {
  },
  {
  "123a",
- []string{},
  []string{"123a"},
+ []string{},
  },
  {
  "1a: 2b",
@@ -550,6 +550,36 @@ func TestSplitbyColon(t *testing.T) {
  []string{"1a", "4d"},
  []string{"[2b,3c]", "5e"},
  },
+ {
+ "1a: [2b,[3c: 3cc]] 4d: 5e",
+ []string{"1a", "4d"},
+ []string{"[2b,[3c: 3cc]]", "5e"},
+ },
+ {
+ "1a: {2b 3c} 4d: 5e",
+ []string{"1a", "4d"},
+ []string{"{2b 3c}", "5e"},
+ },
+ {
+ "1a: {2b,3c} 4d: 5e",
+ []string{"1a", "4d"},
+ []string{"{2b,3c}", "5e"},
+ },
+ {
+ "1a: {2b,{3c: 3cc}} 4d: 5e",
+ []string{"1a", "4d"},
+ []string{"{2b,{3c: 3cc}}", "5e"},
+ },
+ {
+ "1a: {{{2b,{3c: 3cc}} 4d: 5e",
+ nil,
+ nil,
+ },
+ {
+ "1a: [2b,[3c: 3cc]]]] 4d: 5e",
+ nil,
+ nil,
+ },
  {
 
  "Time: 2021-09-08T14:39:54.506967433+08:00",