use regex implementing wildcard

database/keys.go

@@ -280,7 +280,10 @@ func execPersist(db *DB, args [][]byte) redis.Reply {
 
 // execKeys returns all keys matching the given pattern
 func execKeys(db *DB, args [][]byte) redis.Reply {
-	pattern := wildcard.CompilePattern(string(args[0]))
+	pattern, err := wildcard.CompilePattern(string(args[0]))
+	if err != nil {
+		return protocol.MakeErrReply("ERR illegal wildcard")
+	}
 	result := make([][]byte, 0)
 	db.data.ForEach(func(key string, val interface{}) bool {
 		if pattern.IsMatch(key) {

lib/wildcard/wildcard.go

@@ -1,131 +1,75 @@
 package wildcard
 
-const (
-	normal     = iota
-	all        // *
-	any        // ?
-	setSymbol  // []
-	rangSymbol // [a-b]
-	negSymbol  // [^a]
+import (
+	"errors"
+	"regexp"
+	"strings"
 )
 
-type item struct {
-	character byte
-	set       map[byte]bool
-	typeCode  int
-}
-
-func (i *item) contains(c byte) bool {
-	if i.typeCode == setSymbol {
-		_, ok := i.set[c]
-		return ok
-	} else if i.typeCode == rangSymbol {
-		if _, ok := i.set[c]; ok {
-			return true
-		}
-		var (
-			min uint8 = 255
-			max uint8 = 0
-		)
-		for k := range i.set {
-			if min > k {
-				min = k
-			}
-			if max < k {
-				max = k
-			}
-		}
-		return c >= min && c <= max
-	} else {
-		_, ok := i.set[c]
-		return !ok
-	}
-}
-
 // Pattern represents a wildcard pattern
 type Pattern struct {
-	items []*item
+	exp *regexp.Regexp
+}
+
+var replaceMap = map[byte]string{
+	// characters in the wildcard that must be escaped in the regexp
+	'+': `\+`,
+	')': `\)`,
+	'$': `\$`,
+	'.': `\.`,
+	'{': `\{`,
+	'}': `\}`,
+	'|': `\|`,
+	'*': ".*",
+	'?': ".",
 }
 
 // CompilePattern convert wildcard string to Pattern
-func CompilePattern(src string) *Pattern {
-	items := make([]*item, 0)
-	escape := false
-	inSet := false
-	var set map[byte]bool
-	for _, v := range src {
-		c := byte(v)
-		if escape {
-			items = append(items, &item{typeCode: normal, character: c})
-			escape = false
-		} else if c == '*' {
-			items = append(items, &item{typeCode: all})
-		} else if c == '?' {
-			items = append(items, &item{typeCode: any})
-		} else if c == '\\' {
-			escape = true
-		} else if c == '[' {
-			if !inSet {
-				inSet = true
-				set = make(map[byte]bool)
-			} else {
-				set[c] = true
+func CompilePattern(src string) (*Pattern, error) {
+	regexSrc := strings.Builder{}
+	regexSrc.WriteByte('^')
+	for i := 0; i < len(src); i++ {
+		ch := src[i]
+		if ch == '\\' {
+			if i == len(src)-1 {
+				return nil, errors.New("end with escape \\")
 			}
-		} else if c == ']' {
-			if inSet {
-				inSet = false
-				typeCode := setSymbol
-				if _, ok := set['-']; ok {
-					typeCode = rangSymbol
-					delete(set, '-')
+			regexSrc.WriteByte(ch)
+			regexSrc.WriteByte(src[i+1])
+			i++ // skip escaped character
+		} else if ch == '^' {
+			if i == 0 {
+				regexSrc.WriteString(`\^`)
+			} else if i == 1 {
+				if src[i-1] == '[' {
+					regexSrc.WriteString(`^`) // src is: [^
+				} else {
+					regexSrc.WriteString(`\^`)
 				}
-				if _, ok := set['^']; ok {
-					typeCode = negSymbol
-					delete(set, '^')
-				}
-				items = append(items, &item{typeCode: typeCode, set: set})
 			} else {
-				items = append(items, &item{typeCode: normal, character: c})
+				if src[i-1] == '[' && src[i-2] != '\\' {
+					regexSrc.WriteString(`^`) // src is: [^, except \[^
+				} else {
+					regexSrc.WriteString(`\^`)
+				}
 			}
+		} else if escaped, toEscape := replaceMap[ch]; toEscape {
+			regexSrc.WriteString(escaped)
 		} else {
-			if inSet {
-				set[c] = true
-			} else {
-				items = append(items, &item{typeCode: normal, character: c})
-			}
+			regexSrc.WriteByte(ch)
 		}
 	}
-	return &Pattern{
-		items: items,
+	regexSrc.WriteByte('$')
+	re, err := regexp.Compile(regexSrc.String())
+	if err != nil {
+		return nil, err
 	}
+	return &Pattern{
+		exp: re,
+	}, nil
 }
 
 // IsMatch returns whether the given string matches pattern
 func (p *Pattern) IsMatch(s string) bool {
-	if len(p.items) == 0 {
-		return len(s) == 0
-	}
-	m := len(s)
-	n := len(p.items)
-	table := make([][]bool, m+1)
-	for i := 0; i < m+1; i++ {
-		table[i] = make([]bool, n+1)
-	}
-	table[0][0] = true
-	for j := 1; j < n+1; j++ {
-		table[0][j] = table[0][j-1] && p.items[j-1].typeCode == all
-	}
-	for i := 1; i < m+1; i++ {
-		for j := 1; j < n+1; j++ {
-			if p.items[j-1].typeCode == all {
-				table[i][j] = table[i-1][j] || table[i][j-1]
-			} else {
-				table[i][j] = table[i-1][j-1] &&
-					(p.items[j-1].typeCode == any ||
-						(p.items[j-1].typeCode == normal && uint8(s[i-1]) == p.items[j-1].character) ||
-						(p.items[j-1].typeCode >= setSymbol && p.items[j-1].contains(s[i-1])))
-			}
-		}
-	}
-	return table[m][n]
+	return p.exp.Match([]byte(s))
 }

lib/wildcard/wildcard_test.go

@@ -3,11 +3,19 @@ package wildcard
 import "testing"
 
 func TestWildCard(t *testing.T) {
-	p := CompilePattern("")
+	p, err := CompilePattern("")
+	if err != nil {
+		t.Error(err)
+		return
+	}
 	if !p.IsMatch("") {
 		t.Error("expect true actually false")
 	}
-	p = CompilePattern("a")
+	p, err = CompilePattern("a")
+	if err != nil {
+		t.Error(err)
+		return
+	}
 	if !p.IsMatch("a") {
 		t.Error("expect true actually false")
 	}
@@ -16,7 +24,11 @@ func TestWildCard(t *testing.T) {
 	}
 
 	// test '?'
-	p = CompilePattern("a?")
+	p, err = CompilePattern("a?")
+	if err != nil {
+		t.Error(err)
+		return
+	}
 	if !p.IsMatch("ab") {
 		t.Error("expect true actually false")
 	}
@@ -31,7 +43,11 @@ func TestWildCard(t *testing.T) {
 	}
 
 	// test *
-	p = CompilePattern("a*")
+	p, err = CompilePattern("a*")
+	if err != nil {
+		t.Error(err)
+		return
+	}
 	if !p.IsMatch("ab") {
 		t.Error("expect true actually false")
 	}
@@ -46,7 +62,11 @@ func TestWildCard(t *testing.T) {
 	}
 
 	// test []
-	p = CompilePattern("a[ab[]")
+	p, err = CompilePattern("a[ab[]")
+	if err != nil {
+		t.Error(err)
+		return
+	}
 	if !p.IsMatch("ab") {
 		t.Error("expect true actually false")
 	}
@@ -64,7 +84,11 @@ func TestWildCard(t *testing.T) {
 	}
 
 	// test [a-c]
-	p = CompilePattern("h[a-c]llo")
+	p, err = CompilePattern("h[a-c]llo")
+	if err != nil {
+		t.Error(err)
+		return
+	}
 	if !p.IsMatch("hallo") {
 		t.Error("expect true actually false")
 	}
@@ -81,8 +105,12 @@ func TestWildCard(t *testing.T) {
 		t.Error("expect false actually true")
 	}
 
-	// test [^]
-	p = CompilePattern("h[^ab]llo")
+	//test [^]
+	p, err = CompilePattern("h[^ab]llo")
+	if err != nil {
+		t.Error(err)
+		return
+	}
 	if p.IsMatch("hallo") {
 		t.Error("expect false actually true")
 	}
@@ -94,12 +122,20 @@ func TestWildCard(t *testing.T) {
 	}
 
 	// test escape
-	p = CompilePattern("\\\\") // pattern: \\
-	if !p.IsMatch("\\") {
+	p, err = CompilePattern(`\\\\`)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	if !p.IsMatch(`\\`) {
 		t.Error("expect true actually false")
 	}
 
-	p = CompilePattern("\\*")
+	p, err = CompilePattern("\\*")
+	if err != nil {
+		t.Error(err)
+		return
+	}
 	if !p.IsMatch("*") {
 		t.Error("expect true actually false")
 	}