1 files changed, 368 insertions, 0 deletions
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/v2/internal/httprule/parse.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/v2/internal/httprule/parse.go
new file mode 100644
index 000000000..5edd784e6
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/v2/internal/httprule/parse.go
@@ -0,0 +1,368 @@
+package httprule
+
+import (
+	"fmt"
+	"strings"
+)
+
+// InvalidTemplateError indicates that the path template is not valid.
+type InvalidTemplateError struct {
+	tmpl string
+	msg  string
+}
+
+func (e InvalidTemplateError) Error() string {
+	return fmt.Sprintf("%s: %s", e.msg, e.tmpl)
+}
+
+// Parse parses the string representation of path template
+func Parse(tmpl string) (Compiler, error) {
+	if !strings.HasPrefix(tmpl, "/") {
+		return template{}, InvalidTemplateError{tmpl: tmpl, msg: "no leading /"}
+	}
+	tokens, verb := tokenize(tmpl[1:])
+
+	p := parser{tokens: tokens}
+	segs, err := p.topLevelSegments()
+	if err != nil {
+		return template{}, InvalidTemplateError{tmpl: tmpl, msg: err.Error()}
+	}
+
+	return template{
+		segments: segs,
+		verb:     verb,
+		template: tmpl,
+	}, nil
+}
+
+func tokenize(path string) (tokens []string, verb string) {
+	if path == "" {
+		return []string{eof}, ""
+	}
+
+	const (
+		init = iota
+		field
+		nested
+	)
+	st := init
+	for path != "" {
+		var idx int
+		switch st {
+		case init:
+			idx = strings.IndexAny(path, "/{")
+		case field:
+			idx = strings.IndexAny(path, ".=}")
+		case nested:
+			idx = strings.IndexAny(path, "/}")
+		}
+		if idx < 0 {
+			tokens = append(tokens, path)
+			break
+		}
+		switch r := path[idx]; r {
+		case '/', '.':
+		case '{':
+			st = field
+		case '=':
+			st = nested
+		case '}':
+			st = init
+		}
+		if idx == 0 {
+			tokens = append(tokens, path[idx:idx+1])
+		} else {
+			tokens = append(tokens, path[:idx], path[idx:idx+1])
+		}
+		path = path[idx+1:]
+	}
+
+	l := len(tokens)
+	// See
+	// https://github.com/grpc-ecosystem/grpc-gateway/pull/1947#issuecomment-774523693 ;
+	// although normal and backwards-compat logic here is to use the last index
+	// of a colon, if the final segment is a variable followed by a colon, the
+	// part following the colon must be a verb. Hence if the previous token is
+	// an end var marker, we switch the index we're looking for to Index instead
+	// of LastIndex, so that we correctly grab the remaining part of the path as
+	// the verb.
+	var penultimateTokenIsEndVar bool
+	switch l {
+	case 0, 1:
+		// Not enough to be variable so skip this logic and don't result in an
+		// invalid index
+	default:
+		penultimateTokenIsEndVar = tokens[l-2] == "}"
+	}
+	t := tokens[l-1]
+	var idx int
+	if penultimateTokenIsEndVar {
+		idx = strings.Index(t, ":")
+	} else {
+		idx = strings.LastIndex(t, ":")
+	}
+	if idx == 0 {
+		tokens, verb = tokens[:l-1], t[1:]
+	} else if idx > 0 {
+		tokens[l-1], verb = t[:idx], t[idx+1:]
+	}
+	tokens = append(tokens, eof)
+	return tokens, verb
+}
+
+// parser is a parser of the template syntax defined in github.com/googleapis/googleapis/google/api/http.proto.
+type parser struct {
+	tokens   []string
+	accepted []string
+}
+
+// topLevelSegments is the target of this parser.
+func (p *parser) topLevelSegments() ([]segment, error) {
+	if _, err := p.accept(typeEOF); err == nil {
+		p.tokens = p.tokens[:0]
+		return []segment{literal(eof)}, nil
+	}
+	segs, err := p.segments()
+	if err != nil {
+		return nil, err
+	}
+	if _, err := p.accept(typeEOF); err != nil {
+		return nil, fmt.Errorf("unexpected token %q after segments %q", p.tokens[0], strings.Join(p.accepted, ""))
+	}
+	return segs, nil
+}
+
+func (p *parser) segments() ([]segment, error) {
+	s, err := p.segment()
+	if err != nil {
+		return nil, err
+	}
+
+	segs := []segment{s}
+	for {
+		if _, err := p.accept("/"); err != nil {
+			return segs, nil
+		}
+		s, err := p.segment()
+		if err != nil {
+			return segs, err
+		}
+		segs = append(segs, s)
+	}
+}
+
+func (p *parser) segment() (segment, error) {
+	if _, err := p.accept("*"); err == nil {
+		return wildcard{}, nil
+	}
+	if _, err := p.accept("**"); err == nil {
+		return deepWildcard{}, nil
+	}
+	if l, err := p.literal(); err == nil {
+		return l, nil
+	}
+
+	v, err := p.variable()
+	if err != nil {
+		return nil, fmt.Errorf("segment neither wildcards, literal or variable: %v", err)
+	}
+	return v, err
+}
+
+func (p *parser) literal() (segment, error) {
+	lit, err := p.accept(typeLiteral)
+	if err != nil {
+		return nil, err
+	}
+	return literal(lit), nil
+}
+
+func (p *parser) variable() (segment, error) {
+	if _, err := p.accept("{"); err != nil {
+		return nil, err
+	}
+
+	path, err := p.fieldPath()
+	if err != nil {
+		return nil, err
+	}
+
+	var segs []segment
+	if _, err := p.accept("="); err == nil {
+		segs, err = p.segments()
+		if err != nil {
+			return nil, fmt.Errorf("invalid segment in variable %q: %v", path, err)
+		}
+	} else {
+		segs = []segment{wildcard{}}
+	}
+
+	if _, err := p.accept("}"); err != nil {
+		return nil, fmt.Errorf("unterminated variable segment: %s", path)
+	}
+	return variable{
+		path:     path,
+		segments: segs,
+	}, nil
+}
+
+func (p *parser) fieldPath() (string, error) {
+	c, err := p.accept(typeIdent)
+	if err != nil {
+		return "", err
+	}
+	components := []string{c}
+	for {
+		if _, err = p.accept("."); err != nil {
+			return strings.Join(components, "."), nil
+		}
+		c, err := p.accept(typeIdent)
+		if err != nil {
+			return "", fmt.Errorf("invalid field path component: %v", err)
+		}
+		components = append(components, c)
+	}
+}
+
+// A termType is a type of terminal symbols.
+type termType string
+
+// These constants define some of valid values of termType.
+// They improve readability of parse functions.
+//
+// You can also use "/", "*", "**", "." or "=" as valid values.
+const (
+	typeIdent   = termType("ident")
+	typeLiteral = termType("literal")
+	typeEOF     = termType("$")
+)
+
+const (
+	// eof is the terminal symbol which always appears at the end of token sequence.
+	eof = "\u0000"
+)
+
+// accept tries to accept a token in "p".
+// This function consumes a token and returns it if it matches to the specified "term".
+// If it doesn't match, the function does not consume any tokens and return an error.
+func (p *parser) accept(term termType) (string, error) {
+	t := p.tokens[0]
+	switch term {
+	case "/", "*", "**", ".", "=", "{", "}":
+		if t != string(term) && t != "/" {
+			return "", fmt.Errorf("expected %q but got %q", term, t)
+		}
+	case typeEOF:
+		if t != eof {
+			return "", fmt.Errorf("expected EOF but got %q", t)
+		}
+	case typeIdent:
+		if err := expectIdent(t); err != nil {
+			return "", err
+		}
+	case typeLiteral:
+		if err := expectPChars(t); err != nil {
+			return "", err
+		}
+	default:
+		return "", fmt.Errorf("unknown termType %q", term)
+	}
+	p.tokens = p.tokens[1:]
+	p.accepted = append(p.accepted, t)
+	return t, nil
+}
+
+// expectPChars determines if "t" consists of only pchars defined in RFC3986.
+//
+// https://www.ietf.org/rfc/rfc3986.txt, P.49
+//   pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"
+//   unreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~"
+//   sub-delims    = "!" / "$" / "&" / "'" / "(" / ")"
+//                 / "*" / "+" / "," / ";" / "="
+//   pct-encoded   = "%" HEXDIG HEXDIG
+func expectPChars(t string) error {
+	const (
+		init = iota
+		pct1
+		pct2
+	)
+	st := init
+	for _, r := range t {
+		if st != init {
+			if !isHexDigit(r) {
+				return fmt.Errorf("invalid hexdigit: %c(%U)", r, r)
+			}
+			switch st {
+			case pct1:
+				st = pct2
+			case pct2:
+				st = init
+			}
+			continue
+		}
+
+		// unreserved
+		switch {
+		case 'A' <= r && r <= 'Z':
+			continue
+		case 'a' <= r && r <= 'z':
+			continue
+		case '0' <= r && r <= '9':
+			continue
+		}
+		switch r {
+		case '-', '.', '_', '~':
+			// unreserved
+		case '!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '=':
+			// sub-delims
+		case ':', '@':
+			// rest of pchar
+		case '%':
+			// pct-encoded
+			st = pct1
+		default:
+			return fmt.Errorf("invalid character in path segment: %q(%U)", r, r)
+		}
+	}
+	if st != init {
+		return fmt.Errorf("invalid percent-encoding in %q", t)
+	}
+	return nil
+}
+
+// expectIdent determines if "ident" is a valid identifier in .proto schema ([[:alpha:]_][[:alphanum:]_]*).
+func expectIdent(ident string) error {
+	if ident == "" {
+		return fmt.Errorf("empty identifier")
+	}
+	for pos, r := range ident {
+		switch {
+		case '0' <= r && r <= '9':
+			if pos == 0 {
+				return fmt.Errorf("identifier starting with digit: %s", ident)
+			}
+			continue
+		case 'A' <= r && r <= 'Z':
+			continue
+		case 'a' <= r && r <= 'z':
+			continue
+		case r == '_':
+			continue
+		default:
+			return fmt.Errorf("invalid character %q(%U) in identifier: %s", r, r, ident)
+		}
+	}
+	return nil
+}
+
+func isHexDigit(r rune) bool {
+	switch {
+	case '0' <= r && r <= '9':
+		return true
+	case 'A' <= r && r <= 'F':
+		return true
+	case 'a' <= r && r <= 'f':
+		return true
+	}
+	return false
+}