1 files changed, 227 insertions, 0 deletions
diff --git a/vendor/github.com/googleapis/gax-go/path_template_parser.go b/vendor/github.com/googleapis/gax-go/path_template_parser.go
new file mode 100644
index 0000000..79c8e75
--- /dev/null
+++ b/vendor/github.com/googleapis/gax-go/path_template_parser.go
@@ -0,0 +1,227 @@
+// Copyright 2016, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package gax
+
+import (
+	"fmt"
+	"io"
+	"strings"
+)
+
+// This parser follows the syntax of path templates, from
+// https://github.com/googleapis/googleapis/blob/master/google/api/http.proto.
+// The differences are that there is no custom verb, we allow the initial slash
+// to be absent, and that we are not strict as
+// https://tools.ietf.org/html/rfc6570 about the characters in identifiers and
+// literals.
+
+type pathTemplateParser struct {
+	r                *strings.Reader
+	runeCount        int             // the number of the current rune in the original string
+	nextVar          int             // the number to use for the next unnamed variable
+	seenName         map[string]bool // names we've seen already
+	seenPathWildcard bool            // have we seen "**" already?
+}
+
+func parsePathTemplate(template string) (pt *PathTemplate, err error) {
+	p := &pathTemplateParser{
+		r:        strings.NewReader(template),
+		seenName: map[string]bool{},
+	}
+
+	// Handle panics with strings like errors.
+	// See pathTemplateParser.error, below.
+	defer func() {
+		if x := recover(); x != nil {
+			errmsg, ok := x.(errString)
+			if !ok {
+				panic(x)
+			}
+			pt = nil
+			err = ParseError{p.runeCount, template, string(errmsg)}
+		}
+	}()
+
+	segs := p.template()
+	// If there is a path wildcard, set its length. We can't do this
+	// until we know how many segments we've got all together.
+	for i, seg := range segs {
+		if _, ok := seg.matcher.(pathWildcardMatcher); ok {
+			segs[i].matcher = pathWildcardMatcher(len(segs) - i - 1)
+			break
+		}
+	}
+	return &PathTemplate{segments: segs}, nil
+
+}
+
+// Used to indicate errors "thrown" by this parser. We don't use string because
+// many parts of the standard library panic with strings.
+type errString string
+
+// Terminates parsing immediately with an error.
+func (p *pathTemplateParser) error(msg string) {
+	panic(errString(msg))
+}
+
+// Template = [ "/" ] Segments
+func (p *pathTemplateParser) template() []segment {
+	var segs []segment
+	if p.consume('/') {
+		// Initial '/' needs an initial empty matcher.
+		segs = append(segs, segment{matcher: labelMatcher("")})
+	}
+	return append(segs, p.segments("")...)
+}
+
+// Segments = Segment { "/" Segment }
+func (p *pathTemplateParser) segments(name string) []segment {
+	var segs []segment
+	for {
+		subsegs := p.segment(name)
+		segs = append(segs, subsegs...)
+		if !p.consume('/') {
+			break
+		}
+	}
+	return segs
+}
+
+// Segment  = "*" | "**" | LITERAL | Variable
+func (p *pathTemplateParser) segment(name string) []segment {
+	if p.consume('*') {
+		if name == "" {
+			name = fmt.Sprintf("$%d", p.nextVar)
+			p.nextVar++
+		}
+		if p.consume('*') {
+			if p.seenPathWildcard {
+				p.error("multiple '**' disallowed")
+			}
+			p.seenPathWildcard = true
+			// We'll change 0 to the right number at the end.
+			return []segment{{name: name, matcher: pathWildcardMatcher(0)}}
+		}
+		return []segment{{name: name, matcher: wildcardMatcher(0)}}
+	}
+	if p.consume('{') {
+		if name != "" {
+			p.error("recursive named bindings are not allowed")
+		}
+		return p.variable()
+	}
+	return []segment{{name: name, matcher: labelMatcher(p.literal())}}
+}
+
+// Variable = "{" FieldPath [ "=" Segments ] "}"
+// "{" is already consumed.
+func (p *pathTemplateParser) variable() []segment {
+	// Simplification: treat FieldPath as LITERAL, instead of IDENT { '.' IDENT }
+	name := p.literal()
+	if p.seenName[name] {
+		p.error(name + " appears multiple times")
+	}
+	p.seenName[name] = true
+	var segs []segment
+	if p.consume('=') {
+		segs = p.segments(name)
+	} else {
+		// "{var}" is equivalent to "{var=*}"
+		segs = []segment{{name: name, matcher: wildcardMatcher(0)}}
+	}
+	if !p.consume('}') {
+		p.error("expected '}'")
+	}
+	return segs
+}
+
+// A literal is any sequence of characters other than a few special ones.
+// The list of stop characters is not quite the same as in the template RFC.
+func (p *pathTemplateParser) literal() string {
+	lit := p.consumeUntil("/*}{=")
+	if lit == "" {
+		p.error("empty literal")
+	}
+	return lit
+}
+
+// Read runes until EOF or one of the runes in stopRunes is encountered.
+// If the latter, unread the stop rune. Return the accumulated runes as a string.
+func (p *pathTemplateParser) consumeUntil(stopRunes string) string {
+	var runes []rune
+	for {
+		r, ok := p.readRune()
+		if !ok {
+			break
+		}
+		if strings.IndexRune(stopRunes, r) >= 0 {
+			p.unreadRune()
+			break
+		}
+		runes = append(runes, r)
+	}
+	return string(runes)
+}
+
+// If the next rune is r, consume it and return true.
+// Otherwise, leave the input unchanged and return false.
+func (p *pathTemplateParser) consume(r rune) bool {
+	rr, ok := p.readRune()
+	if !ok {
+		return false
+	}
+	if r == rr {
+		return true
+	}
+	p.unreadRune()
+	return false
+}
+
+// Read the next rune from the input. Return it.
+// The second return value is false at EOF.
+func (p *pathTemplateParser) readRune() (rune, bool) {
+	r, _, err := p.r.ReadRune()
+	if err == io.EOF {
+		return r, false
+	}
+	if err != nil {
+		p.error(err.Error())
+	}
+	p.runeCount++
+	return r, true
+}
+
+// Put the last rune that was read back on the input.
+func (p *pathTemplateParser) unreadRune() {
+	if err := p.r.UnreadRune(); err != nil {
+		p.error(err.Error())
+	}
+	p.runeCount--
+}