Push nesting-depth checks down in to the parser [ci-skip]

1 files changed, 14 insertions, 1 deletions

diff --git a/parse.go b/parse.go
index 23df5bc..fb72280 100644
--- a/parse.go
+++ b/parse.go
@@ -204,6 +204,11 @@ func (t RuneType) IsNumber() bool {
 }
 
 type Parser struct {
+	// Setting MaxError to a value greater than 0 causes
+	// HandleRune to return ErrParserExceededMaxDepth if
+	// objects/arrays become nested more deeply than this.
+	MaxDepth int
+
 	initialized bool
 
 	err    error
@@ -286,7 +291,9 @@ func (par *Parser) stackString() string {
 
 // Reset all Parser state.
 func (par *Parser) Reset() {
-	*par = Parser{}
+	*par = Parser{
+		MaxDepth: par.MaxDepth,
+	}
 }
 
 // HandleEOF feeds EOF to the Parser.  The returned RuneType is either
@@ -370,8 +377,14 @@ func (par *Parser) HandleRune(c rune) (RuneType, error) {
 		case 0x0020, 0x000A, 0x000D, 0x0009:
 			return RuneTypeSpace, nil
 		case '{':
+			if par.MaxDepth > 0 && len(par.stack) > par.MaxDepth {
+				return RuneTypeError, ErrParserExceededMaxDepth
+			}
 			return par.replaceState(RuneTypeObjectBeg), nil
 		case '[':
+			if par.MaxDepth > 0 && len(par.stack) > par.MaxDepth {
+				return RuneTypeError, ErrParserExceededMaxDepth
+			}
 			return par.replaceState(RuneTypeArrayBeg), nil
 		case '"':
 			return par.replaceState(RuneTypeStringBeg), nil