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- // Copyright 2015 Google Inc. All rights reserved.
- //
- // 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 martianurl
-
- import (
- "encoding/json"
- "regexp"
-
- "github.com/google/martian/filter"
- "github.com/google/martian/parse"
- )
-
- func init() {
- parse.Register("url.RegexFilter", regexFilterFromJSON)
- }
-
- // URLRegexFilter runs Modifier if the request URL matches the regex, and runs ElseModifier if not.
- // This is not to be confused with url.Filter that does string matching on URL segments.
- type URLRegexFilter struct {
- *filter.Filter
- }
-
- type regexFilterJSON struct {
- Regex string `json:"regex"`
- Modifier json.RawMessage `json:"modifier"`
- ElseModifier json.RawMessage `json:"else"`
- Scope []parse.ModifierType `json:"scope"`
- }
-
- // NewRegexFilter constructs a filter that matches on regular expressions.
- func NewRegexFilter(r *regexp.Regexp) *URLRegexFilter {
- filter := filter.New()
- matcher := NewRegexMatcher(r)
- filter.SetRequestCondition(matcher)
- filter.SetResponseCondition(matcher)
- return &URLRegexFilter{filter}
- }
-
- // regexFilterFromJSON takes a JSON message as a byte slice and returns a
- // parse.Result that contains a URLRegexFilter and a scope. The regex syntax is RE2
- // as described at https://golang.org/s/re2syntax.
- //
- // Example JSON configuration message:
- // {
- // "scope": ["request", "response"],
- // "regex": ".*www.example.com.*"
- // }
- func regexFilterFromJSON(b []byte) (*parse.Result, error) {
- msg := ®exFilterJSON{}
- if err := json.Unmarshal(b, msg); err != nil {
- return nil, err
- }
-
- matcher, err := regexp.Compile(msg.Regex)
- if err != nil {
- return nil, err
- }
-
- filter := NewRegexFilter(matcher)
-
- m, err := parse.FromJSON(msg.Modifier)
- if err != nil {
- return nil, err
- }
-
- filter.RequestWhenTrue(m.RequestModifier())
- filter.ResponseWhenTrue(m.ResponseModifier())
-
- if len(msg.ElseModifier) > 0 {
- em, err := parse.FromJSON(msg.ElseModifier)
- if err != nil {
- return nil, err
- }
- if em != nil {
- filter.RequestWhenFalse(em.RequestModifier())
- filter.ResponseWhenFalse(em.ResponseModifier())
- }
- }
-
- return parse.NewResult(filter, msg.Scope)
- }
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