Move to vendor

Signed-off-by: Olivier Gambier <olivier@docker.com>

vendor/github.com/gorilla/mux/regexp.go

@@ -0,0 +1,276 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mux
+
+import (
+	"bytes"
+	"fmt"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strings"
+)
+
+// newRouteRegexp parses a route template and returns a routeRegexp,
+// used to match a host, a path or a query string.
+//
+// It will extract named variables, assemble a regexp to be matched, create
+// a "reverse" template to build URLs and compile regexps to validate variable
+// values used in URL building.
+//
+// Previously we accepted only Python-like identifiers for variable
+// names ([a-zA-Z_][a-zA-Z0-9_]*), but currently the only restriction is that
+// name and pattern can't be empty, and names can't contain a colon.
+func newRouteRegexp(tpl string, matchHost, matchPrefix, matchQuery, strictSlash bool) (*routeRegexp, error) {
+	// Check if it is well-formed.
+	idxs, errBraces := braceIndices(tpl)
+	if errBraces != nil {
+		return nil, errBraces
+	}
+	// Backup the original.
+	template := tpl
+	// Now let's parse it.
+	defaultPattern := "[^/]+"
+	if matchQuery {
+		defaultPattern = "[^?&]+"
+		matchPrefix = true
+	} else if matchHost {
+		defaultPattern = "[^.]+"
+		matchPrefix = false
+	}
+	// Only match strict slash if not matching
+	if matchPrefix || matchHost || matchQuery {
+		strictSlash = false
+	}
+	// Set a flag for strictSlash.
+	endSlash := false
+	if strictSlash && strings.HasSuffix(tpl, "/") {
+		tpl = tpl[:len(tpl)-1]
+		endSlash = true
+	}
+	varsN := make([]string, len(idxs)/2)
+	varsR := make([]*regexp.Regexp, len(idxs)/2)
+	pattern := bytes.NewBufferString("")
+	if !matchQuery {
+		pattern.WriteByte('^')
+	}
+	reverse := bytes.NewBufferString("")
+	var end int
+	var err error
+	for i := 0; i < len(idxs); i += 2 {
+		// Set all values we are interested in.
+		raw := tpl[end:idxs[i]]
+		end = idxs[i+1]
+		parts := strings.SplitN(tpl[idxs[i]+1:end-1], ":", 2)
+		name := parts[0]
+		patt := defaultPattern
+		if len(parts) == 2 {
+			patt = parts[1]
+		}
+		// Name or pattern can't be empty.
+		if name == "" || patt == "" {
+			return nil, fmt.Errorf("mux: missing name or pattern in %q",
+				tpl[idxs[i]:end])
+		}
+		// Build the regexp pattern.
+		fmt.Fprintf(pattern, "%s(%s)", regexp.QuoteMeta(raw), patt)
+		// Build the reverse template.
+		fmt.Fprintf(reverse, "%s%%s", raw)
+		// Append variable name and compiled pattern.
+		varsN[i/2] = name
+		varsR[i/2], err = regexp.Compile(fmt.Sprintf("^%s$", patt))
+		if err != nil {
+			return nil, err
+		}
+	}
+	// Add the remaining.
+	raw := tpl[end:]
+	pattern.WriteString(regexp.QuoteMeta(raw))
+	if strictSlash {
+		pattern.WriteString("[/]?")
+	}
+	if !matchPrefix {
+		pattern.WriteByte('$')
+	}
+	reverse.WriteString(raw)
+	if endSlash {
+		reverse.WriteByte('/')
+	}
+	// Compile full regexp.
+	reg, errCompile := regexp.Compile(pattern.String())
+	if errCompile != nil {
+		return nil, errCompile
+	}
+	// Done!
+	return &routeRegexp{
+		template:    template,
+		matchHost:   matchHost,
+		matchQuery:  matchQuery,
+		strictSlash: strictSlash,
+		regexp:      reg,
+		reverse:     reverse.String(),
+		varsN:       varsN,
+		varsR:       varsR,
+	}, nil
+}
+
+// routeRegexp stores a regexp to match a host or path and information to
+// collect and validate route variables.
+type routeRegexp struct {
+	// The unmodified template.
+	template string
+	// True for host match, false for path or query string match.
+	matchHost bool
+	// True for query string match, false for path and host match.
+	matchQuery bool
+	// The strictSlash value defined on the route, but disabled if PathPrefix was used.
+	strictSlash bool
+	// Expanded regexp.
+	regexp *regexp.Regexp
+	// Reverse template.
+	reverse string
+	// Variable names.
+	varsN []string
+	// Variable regexps (validators).
+	varsR []*regexp.Regexp
+}
+
+// Match matches the regexp against the URL host or path.
+func (r *routeRegexp) Match(req *http.Request, match *RouteMatch) bool {
+	if !r.matchHost {
+		if r.matchQuery {
+			return r.regexp.MatchString(req.URL.RawQuery)
+		} else {
+			return r.regexp.MatchString(req.URL.Path)
+		}
+	}
+	return r.regexp.MatchString(getHost(req))
+}
+
+// url builds a URL part using the given values.
+func (r *routeRegexp) url(pairs ...string) (string, error) {
+	values, err := mapFromPairs(pairs...)
+	if err != nil {
+		return "", err
+	}
+	urlValues := make([]interface{}, len(r.varsN))
+	for k, v := range r.varsN {
+		value, ok := values[v]
+		if !ok {
+			return "", fmt.Errorf("mux: missing route variable %q", v)
+		}
+		urlValues[k] = value
+	}
+	rv := fmt.Sprintf(r.reverse, urlValues...)
+	if !r.regexp.MatchString(rv) {
+		// The URL is checked against the full regexp, instead of checking
+		// individual variables. This is faster but to provide a good error
+		// message, we check individual regexps if the URL doesn't match.
+		for k, v := range r.varsN {
+			if !r.varsR[k].MatchString(values[v]) {
+				return "", fmt.Errorf(
+					"mux: variable %q doesn't match, expected %q", values[v],
+					r.varsR[k].String())
+			}
+		}
+	}
+	return rv, nil
+}
+
+// braceIndices returns the first level curly brace indices from a string.
+// It returns an error in case of unbalanced braces.
+func braceIndices(s string) ([]int, error) {
+	var level, idx int
+	idxs := make([]int, 0)
+	for i := 0; i < len(s); i++ {
+		switch s[i] {
+		case '{':
+			if level++; level == 1 {
+				idx = i
+			}
+		case '}':
+			if level--; level == 0 {
+				idxs = append(idxs, idx, i+1)
+			} else if level < 0 {
+				return nil, fmt.Errorf("mux: unbalanced braces in %q", s)
+			}
+		}
+	}
+	if level != 0 {
+		return nil, fmt.Errorf("mux: unbalanced braces in %q", s)
+	}
+	return idxs, nil
+}
+
+// ----------------------------------------------------------------------------
+// routeRegexpGroup
+// ----------------------------------------------------------------------------
+
+// routeRegexpGroup groups the route matchers that carry variables.
+type routeRegexpGroup struct {
+	host    *routeRegexp
+	path    *routeRegexp
+	queries []*routeRegexp
+}
+
+// setMatch extracts the variables from the URL once a route matches.
+func (v *routeRegexpGroup) setMatch(req *http.Request, m *RouteMatch, r *Route) {
+	// Store host variables.
+	if v.host != nil {
+		hostVars := v.host.regexp.FindStringSubmatch(getHost(req))
+		if hostVars != nil {
+			for k, v := range v.host.varsN {
+				m.Vars[v] = hostVars[k+1]
+			}
+		}
+	}
+	// Store path variables.
+	if v.path != nil {
+		pathVars := v.path.regexp.FindStringSubmatch(req.URL.Path)
+		if pathVars != nil {
+			for k, v := range v.path.varsN {
+				m.Vars[v] = pathVars[k+1]
+			}
+			// Check if we should redirect.
+			if v.path.strictSlash {
+				p1 := strings.HasSuffix(req.URL.Path, "/")
+				p2 := strings.HasSuffix(v.path.template, "/")
+				if p1 != p2 {
+					u, _ := url.Parse(req.URL.String())
+					if p1 {
+						u.Path = u.Path[:len(u.Path)-1]
+					} else {
+						u.Path += "/"
+					}
+					m.Handler = http.RedirectHandler(u.String(), 301)
+				}
+			}
+		}
+	}
+	// Store query string variables.
+	rawQuery := req.URL.RawQuery
+	for _, q := range v.queries {
+		queryVars := q.regexp.FindStringSubmatch(rawQuery)
+		if queryVars != nil {
+			for k, v := range q.varsN {
+				m.Vars[v] = queryVars[k+1]
+			}
+		}
+	}
+}
+
+// getHost tries its best to return the request host.
+func getHost(r *http.Request) string {
+	if r.URL.IsAbs() {
+		return r.URL.Host
+	}
+	host := r.Host
+	// Slice off any port information.
+	if i := strings.Index(host, ":"); i != -1 {
+		host = host[:i]
+	}
+	return host
+
+}