use go 1.12

Signed-off-by: hongming <talonwan@yunify.com>

vendor/github.com/mholt/caddy/caddyhttp/httpserver/condition.go

@@ -0,0 +1,202 @@
+// Copyright 2015 Light Code Labs, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package httpserver
+
+import (
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+
+	"github.com/mholt/caddy"
+)
+
+// SetupIfMatcher parses `if` or `if_op` in the current dispenser block.
+// It returns a RequestMatcher and an error if any.
+func SetupIfMatcher(controller *caddy.Controller) (RequestMatcher, error) {
+	var c = controller.Dispenser // copy the dispenser
+	var matcher IfMatcher
+	for c.NextBlock() {
+		switch c.Val() {
+		case "if":
+			args1 := c.RemainingArgs()
+			if len(args1) != 3 {
+				return matcher, c.ArgErr()
+			}
+			ifc, err := newIfCond(args1[0], args1[1], args1[2])
+			if err != nil {
+				return matcher, err
+			}
+			matcher.ifs = append(matcher.ifs, ifc)
+			matcher.Enabled = true
+		case "if_op":
+			if !c.NextArg() {
+				return matcher, c.ArgErr()
+			}
+			switch c.Val() {
+			case "and":
+				matcher.isOr = false
+			case "or":
+				matcher.isOr = true
+			default:
+				return matcher, c.ArgErr()
+			}
+		}
+	}
+	return matcher, nil
+}
+
+// operators
+const (
+	isOp         = "is"
+	notOp        = "not"
+	hasOp        = "has"
+	startsWithOp = "starts_with"
+	endsWithOp   = "ends_with"
+	matchOp      = "match"
+)
+
+// ifCondition is a 'if' condition.
+type ifFunc func(a, b string) bool
+
+// ifCond is statement for a IfMatcher condition.
+type ifCond struct {
+	a   string
+	op  string
+	b   string
+	neg bool
+	rex *regexp.Regexp
+	f   ifFunc
+}
+
+// newIfCond creates a new If condition.
+func newIfCond(a, op, b string) (ifCond, error) {
+	i := ifCond{a: a, op: op, b: b}
+	if strings.HasPrefix(op, "not_") {
+		i.neg = true
+		i.op = op[4:]
+	}
+
+	switch i.op {
+	case isOp:
+		// It checks for equality.
+		i.f = i.isFunc
+	case notOp:
+		// It checks for inequality.
+		i.f = i.notFunc
+	case hasOp:
+		// It checks if b is a substring of a.
+		i.f = strings.Contains
+	case startsWithOp:
+		// It checks if b is a prefix of a.
+		i.f = strings.HasPrefix
+	case endsWithOp:
+		// It checks if b is a suffix of a.
+		i.f = strings.HasSuffix
+	case matchOp:
+		// It does regexp matching of a against pattern in b and returns if they match.
+		var err error
+		if i.rex, err = regexp.Compile(i.b); err != nil {
+			return ifCond{}, fmt.Errorf("Invalid regular expression: '%s', %v", i.b, err)
+		}
+		i.f = i.matchFunc
+	default:
+		return ifCond{}, fmt.Errorf("Invalid operator %v", i.op)
+	}
+
+	return i, nil
+}
+
+// isFunc is condition for Is operator.
+func (i ifCond) isFunc(a, b string) bool {
+	return a == b
+}
+
+// notFunc is condition for Not operator.
+func (i ifCond) notFunc(a, b string) bool {
+	return a != b
+}
+
+// matchFunc is condition for Match operator.
+func (i ifCond) matchFunc(a, b string) bool {
+	return i.rex.MatchString(a)
+}
+
+// True returns true if the condition is true and false otherwise.
+// If r is not nil, it replaces placeholders before comparison.
+func (i ifCond) True(r *http.Request) bool {
+	if i.f != nil {
+		a, b := i.a, i.b
+		if r != nil {
+			replacer := NewReplacer(r, nil, "")
+			a = replacer.Replace(i.a)
+			if i.op != matchOp {
+				b = replacer.Replace(i.b)
+			}
+		}
+		if i.neg {
+			return !i.f(a, b)
+		}
+		return i.f(a, b)
+	}
+	return i.neg // false if not negated, true otherwise
+}
+
+// IfMatcher is a RequestMatcher for 'if' conditions.
+type IfMatcher struct {
+	Enabled bool     // if true, matcher has been configured; otherwise it's no-op
+	ifs     []ifCond // list of If
+	isOr    bool     // if true, conditions are 'or' instead of 'and'
+}
+
+// Match satisfies RequestMatcher interface.
+// It returns true if the conditions in m are true.
+func (m IfMatcher) Match(r *http.Request) bool {
+	if m.isOr {
+		return m.Or(r)
+	}
+	return m.And(r)
+}
+
+// And returns true if all conditions in m are true.
+func (m IfMatcher) And(r *http.Request) bool {
+	for _, i := range m.ifs {
+		if !i.True(r) {
+			return false
+		}
+	}
+	return true
+}
+
+// Or returns true if any of the conditions in m is true.
+func (m IfMatcher) Or(r *http.Request) bool {
+	for _, i := range m.ifs {
+		if i.True(r) {
+			return true
+		}
+	}
+	return false
+}
+
+// IfMatcherKeyword checks if the next value in the dispenser is a keyword for 'if' config block.
+// If true, remaining arguments in the dispenser are cleared to keep the dispenser valid for use.
+func IfMatcherKeyword(c *caddy.Controller) bool {
+	if c.Val() == "if" || c.Val() == "if_op" {
+		// clear remaining args
+		c.RemainingArgs()
+		return true
+	}
+	return false
+}