lib/logstorage: allow special chars in unquoted _stream tag names and values

This simplifies writing _stream filters. For example,

{foo-bar=abc:de}

can be written instead of

{"foo-bar"="abc:de"}

lib/logstorage/parser.go

@@ -1233,6 +1233,10 @@ func getCompoundSuffix(lex *lexer, allowColon bool) string {
 
 func getCompoundToken(lex *lexer) (string, error) {
 	stopTokens := []string{",", "(", ")", "[", "]", "|", ""}
+	return getCompoundTokenExt(lex, stopTokens)
+}
+
+func getCompoundTokenExt(lex *lexer, stopTokens []string) (string, error) {
 	if lex.isKeyword(stopTokens...) {
 		return "", fmt.Errorf("compound token cannot start with '%s'", lex.token)
 	}

lib/logstorage/stream_filter.go

@@ -86,7 +86,8 @@ func (af *andStreamFilter) String() string {
 type streamTagFilter struct {
 	// tagName is the name for the tag to filter
 	tagName string
-	// op is operation such as `=`, `!=`, `=~` or `!~`
+
+	// op is operation such as `=`, `!=`, `=~`, `!~` or `:`
 	op string
 
 	// value is the value
@@ -165,20 +166,23 @@ func parseAndStreamFilter(lex *lexer) (*andStreamFilter, error) {
 }
 
 func parseStreamTagFilter(lex *lexer) (*streamTagFilter, error) {
-	tagName := lex.token
-	if !lex.mustNextToken() {
-		return nil, fmt.Errorf("missing operation in _stream filter for %q field", tagName)
+	// parse tagName
+	tagName, err := parseStreamTagName(lex)
+	if err != nil {
+		return nil, fmt.Errorf("cannot parse stream tag name: %w", err)
 	}
 	if !lex.isKeyword("=", "!=", "=~", "!~") {
 		return nil, fmt.Errorf("unsupported operation %q in _steam filter for %q field; supported operations: =, !=, =~, !~", lex.token, tagName)
 	}
+
+	// parse op
 	op := lex.token
-	if !lex.mustNextToken() {
-		return nil, fmt.Errorf("missing _stream filter value for %q field", tagName)
-	}
-	value := lex.token
-	if !lex.mustNextToken() {
-		return nil, fmt.Errorf("missing token after %q%s%q filter", tagName, op, value)
+	lex.nextToken()
+
+	// parse tag value
+	value, err := parseStreamTagValue(lex)
+	if err != nil {
+		return nil, fmt.Errorf("cannot parse value for tag %q: %w", tagName, err)
 	}
 	stf := &streamTagFilter{
 		tagName: tagName,
@@ -195,6 +199,16 @@ func parseStreamTagFilter(lex *lexer) (*streamTagFilter, error) {
 	return stf, nil
 }
 
+func parseStreamTagName(lex *lexer) (string, error) {
+	stopTokens := []string{"=", "!=", "=~", "!~", ",", "{", "}", "'", `"`, "`", ""}
+	return getCompoundTokenExt(lex, stopTokens)
+}
+
+func parseStreamTagValue(lex *lexer) (string, error) {
+	stopTokens := []string{",", "{", "}", "'", `"`, "`", ""}
+	return getCompoundTokenExt(lex, stopTokens)
+}
+
 func getStreamName() *streamName {
 	v := streamNamePool.Get()
 	if v == nil {

lib/logstorage/stream_filter_test.go

@@ -163,7 +163,7 @@ func TestNewTestStreamFilterSuccess(t *testing.T) {
 	f(`{foo="bar"}`, `{foo="bar"}`)
 	f(`{ "foo" =~ "bar.+" , baz!="a" or x="y"}`, `{foo=~"bar.+",baz!="a" or x="y"}`)
 	f(`{"a b"='c}"d' OR de="aaa"}`, `{"a b"="c}\"d" or de="aaa"}`)
-	f(`{a="b", c="d" or x="y"}`, `{a="b",c="d" or x="y"}`)
+	f(`{a-q:w.z="b", c="d" or 'x a'=y-z=q}`, `{"a-q:w.z"="b",c="d" or "x a"="y-z=q"}`)
 }
 
 func TestNewTestStreamFilterFailure(t *testing.T) {