From e0a1ccb64a637673195804513902cba6b1d4e97c Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Mon, 31 Oct 2016 16:36:17 +0000 Subject: Update dependencies --- .../googleapis/gax-go/path_template_parser.go | 227 +++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 vendor/github.com/googleapis/gax-go/path_template_parser.go (limited to 'vendor/github.com/googleapis/gax-go/path_template_parser.go') 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-- +} -- cgit v1.2.3