pkg/wildcard: Simplify the wildcard logic further. (#2555)

cmd/bucket-policy-handlers.go

@@ -70,12 +70,12 @@ func bucketPolicyActionMatch(action string, statement policyStatement) bool {
 
 // Match function matches wild cards in 'pattern' for resource.
 func resourceMatch(pattern, resource string) bool {
-	return wildcard.MatchExtended(pattern, resource)
+	return wildcard.Match(pattern, resource)
 }
 
 // Match function matches wild cards in 'pattern' for action.
 func actionMatch(pattern, action string) bool {
-	return wildcard.Match(pattern, action)
+	return wildcard.MatchSimple(pattern, action)
 }
 
 // Verify if given resource matches with policy statement.

cmd/notifiers.go

@@ -114,7 +114,7 @@ func isElasticQueue(sqsArn arnSQS) bool {
 // Match function matches wild cards in 'pattern' for events.
 func eventMatch(eventType string, events []string) (ok bool) {
 	for _, event := range events {
-		ok = wildcard.Match(event, eventType)
+		ok = wildcard.MatchSimple(event, eventType)
 		if ok {
 			break
 		}

pkg/wildcard/match.go

@@ -16,123 +16,68 @@
 
 package wildcard
 
-import (
-	"strings"
-	"unicode/utf8"
-)
-
-// Match - finds whether the text matches/satisfies the pattern string.
+// MatchSimple - finds whether the text matches/satisfies the pattern string.
 // supports only '*' wildcard in the pattern.
 // considers a file system path as a flat name space.
-func Match(pattern, text string) bool {
+func MatchSimple(pattern, name string) bool {
 	if pattern == "" {
-		return text == pattern
+		return name == pattern
 	}
 	if pattern == "*" {
 		return true
 	}
-	parts := strings.Split(pattern, "*")
-	if len(parts) == 1 {
-		return text == pattern
-	}
-	tGlob := strings.HasSuffix(pattern, "*")
-	end := len(parts) - 1
-	if !strings.HasPrefix(text, parts[0]) {
-		return false
+	rname := make([]rune, 0, len(name))
+	rpattern := make([]rune, 0, len(pattern))
+	for _, r := range name {
+		rname = append(rname, r)
 	}
-	for i := 1; i < end; i++ {
-		if !strings.Contains(text, parts[i]) {
-			return false
-		}
-		idx := strings.Index(text, parts[i]) + len(parts[i])
-		text = text[idx:]
+	for _, r := range pattern {
+		rpattern = append(rpattern, r)
 	}
-	return tGlob || strings.HasSuffix(text, parts[end])
+	simple := true // Does only wildcard '*' match.
+	return deepMatchRune(rname, rpattern, simple)
 }
 
-// MatchExtended -  finds whether the text matches/satisfies the pattern string.
+// Match -  finds whether the text matches/satisfies the pattern string.
 // supports  '*' and '?' wildcards in the pattern string.
 // unlike path.Match(), considers a path as a flat name space while matching the pattern.
 // The difference is illustrated in the example here https://play.golang.org/p/Ega9qgD4Qz .
-func MatchExtended(pattern, name string) (matched bool) {
-Pattern:
-	for len(pattern) > 0 {
-		var star bool
-		var chunk string
-		star, chunk, pattern = scanChunk(pattern)
-		if star && chunk == "" {
-			// Trailing * matches rest of string.
-			return true
-		}
-		// Look for match at current position.
-		t, ok := matchChunk(chunk, name)
-		// if we're the last chunk, make sure we've exhausted the name
-		// otherwise we'll give a false result even if we could still match
-		// using the star
-		if ok && (len(t) == 0 || len(pattern) > 0) {
-			name = t
-			continue
-		}
-		if star {
-			// Look for match skipping i+1 bytes.
-			for i := 0; i < len(name); i++ {
-				t, ok := matchChunk(chunk, name[i+1:])
-				if ok {
-					// if we're the last chunk, make sure we exhausted the name
-					if len(pattern) == 0 && len(t) > 0 {
-						continue
-					}
-					name = t
-					continue Pattern
-				}
-			}
-		}
-		return false
+func Match(pattern, name string) (matched bool) {
+	if pattern == "" {
+		return name == pattern
 	}
-	return len(name) == 0
-}
-
-// scanChunk gets the next segment of pattern, which is a non-star string
-// possibly preceded by a star.
-func scanChunk(pattern string) (star bool, chunk, rest string) {
-	for len(pattern) > 0 && pattern[0] == '*' {
-		pattern = pattern[1:]
-		star = true
+	if pattern == "*" {
+		return true
 	}
-	inrange := false
-	var i int
-Scan:
-	for i = 0; i < len(pattern); i++ {
-		switch pattern[i] {
-		case '*':
-			if !inrange {
-				break Scan
-			}
-		}
+	rname := make([]rune, 0, len(name))
+	rpattern := make([]rune, 0, len(pattern))
+	for _, r := range name {
+		rname = append(rname, r)
+	}
+	for _, r := range pattern {
+		rpattern = append(rpattern, r)
 	}
-	return star, pattern[0:i], pattern[i:]
+	simple := false // Does extended wildcard '*' and '?' match.
+	return deepMatchRune(rname, rpattern, simple)
 }
 
-// matchChunk checks whether chunk matches the beginning of s.
-// If so, it returns the remainder of s (after the match).
-// Chunk is all single-character operators: literals, char classes, and ?.
-func matchChunk(chunk, s string) (rest string, ok bool) {
-	for len(chunk) > 0 {
-		if len(s) == 0 {
-			return
-		}
-		switch chunk[0] {
-		case '?':
-			_, n := utf8.DecodeRuneInString(s)
-			s = s[n:]
-			chunk = chunk[1:]
+func deepMatchRune(str, pattern []rune, simple bool) bool {
+	for len(pattern) > 0 {
+		switch pattern[0] {
 		default:
-			if chunk[0] != s[0] {
-				return
+			if len(str) == 0 || str[0] != pattern[0] {
+				return false
+			}
+		case '?':
+			if len(str) == 0 && !simple {
+				return false
 			}
-			s = s[1:]
-			chunk = chunk[1:]
+		case '*':
+			return deepMatchRune(str, pattern[1:], simple) ||
+				(len(str) > 0 && deepMatchRune(str[1:], pattern, simple))
 		}
+		str = str[1:]
+		pattern = pattern[1:]
 	}
-	return s, true
+	return len(str) == 0 && len(pattern) == 0
 }

pkg/wildcard/match_test.go

@@ -14,16 +14,18 @@
  * limitations under the License.
  */
 
-package wildcard
+package wildcard_test
 
 import (
 	"testing"
+
+	"github.com/minio/minio/pkg/wildcard"
 )
 
-// TestMatchExtended - Tests validate the logic of wild card matching.
-// `MatchExtended` supports '*' and '?' wildcards.
+// TestMatch - Tests validate the logic of wild card matching.
+// `Match` supports '*' and '?' wildcards.
 // Sample usage: In resource matching for bucket policy validation.
-func TestMatchExtended(t *testing.T) {
+func TestMatch(t *testing.T) {
 	testCases := []struct {
 		pattern string
 		text    string
@@ -131,7 +133,8 @@ func TestMatchExtended(t *testing.T) {
 		},
 		// Test case - 15.
 		// Test case where the keyname part of the pattern is expanded in the text.
-		{pattern: "my-bucket/In*/Ka*/Ban",
+		{
+			pattern: "my-bucket/In*/Ka*/Ban",
 			text:    "my-bucket/India/Karnataka/Bangalore",
 			matched: false,
 		},
@@ -144,7 +147,8 @@ func TestMatchExtended(t *testing.T) {
 		},
 		// Test case - 17.
 		// Test case with keyname part being a wildcard in the pattern.
-		{pattern: "my-bucket/*",
+		{
+			pattern: "my-bucket/*",
 			text:    "my-bucket/India",
 			matched: true,
 		},
@@ -367,16 +371,16 @@ func TestMatchExtended(t *testing.T) {
 	}
 	// Iterating over the test cases, call the function under test and asert the output.
 	for i, testCase := range testCases {
-		actualResult := MatchExtended(testCase.pattern, testCase.text)
+		actualResult := wildcard.Match(testCase.pattern, testCase.text)
 		if testCase.matched != actualResult {
 			t.Errorf("Test %d: Expected the result to be `%v`, but instead found it to be `%v`", i+1, testCase.matched, actualResult)
 		}
 	}
 }
 
-// TestMatch - Tests validate the logic of wild card matching.
-// `Match` supports matching for only '*' in the pattern string.
-func TestMatch(t *testing.T) {
+// TestMatchSimple - Tests validate the logic of wild card matching.
+// `MatchSimple` supports matching for only '*' in the pattern string.
+func TestMatchSimple(t *testing.T) {
 	testCases := []struct {
 		pattern string
 		text    string
@@ -484,7 +488,8 @@ func TestMatch(t *testing.T) {
 		},
 		// Test case - 15.
 		// Test case where the keyname part of the pattern is expanded in the text.
-		{pattern: "my-bucket/In*/Ka*/Ban",
+		{
+			pattern: "my-bucket/In*/Ka*/Ban",
 			text:    "my-bucket/India/Karnataka/Bangalore",
 			matched: false,
 		},
@@ -497,7 +502,8 @@ func TestMatch(t *testing.T) {
 		},
 		// Test case - 17.
 		// Test case with keyname part being a wildcard in the pattern.
-		{pattern: "my-bucket/*",
+		{
+			pattern: "my-bucket/*",
 			text:    "my-bucket/India",
 			matched: true,
 		},
@@ -507,10 +513,28 @@ func TestMatch(t *testing.T) {
 			text:    "my-bucket/odo",
 			matched: false,
 		},
+		// Test case - 11.
+		{
+			pattern: "my-bucket/oo?*",
+			text:    "my-bucket/oo???",
+			matched: true,
+		},
+		// Test case - 12:
+		{
+			pattern: "my-bucket/oo??*",
+			text:    "my-bucket/odo",
+			matched: false,
+		},
+		// Test case - 13:
+		{
+			pattern: "?h?*",
+			text:    "?h?hello",
+			matched: true,
+		},
 	}
 	// Iterating over the test cases, call the function under test and asert the output.
 	for i, testCase := range testCases {
-		actualResult := Match(testCase.pattern, testCase.text)
+		actualResult := wildcard.MatchSimple(testCase.pattern, testCase.text)
 		if testCase.matched != actualResult {
 			t.Errorf("Test %d: Expected the result to be `%v`, but instead found it to be `%v`", i+1, testCase.matched, actualResult)
 		}