1 // Copyright 2017 The Bazel Authors. All rights reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //    http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 package com.google.devtools.common.options;
15 
16 import com.google.common.base.CharMatcher;
17 import com.google.common.base.Strings;
18 import com.google.common.io.BaseEncoding;
19 import com.google.devtools.build.lib.runtime.proto.InvocationPolicyOuterClass.InvocationPolicy;
20 import com.google.protobuf.InvalidProtocolBufferException;
21 import com.google.protobuf.TextFormat;
22 
23 /**
24  * Parses the given InvocationPolicy string, which may be a base64-encoded binary-serialized
25  * InvocationPolicy message, or a text formatted InvocationPolicy message. Note that the text
26  * format is not backwards compatible as the binary format is.
27  */
28 public class InvocationPolicyParser {
29   /**
30    * Parses InvocationPolicy in either of the accepted formats. Returns an empty policy if no policy
31    * is provided.
32    *
33    * @throws com.google.devtools.common.options.OptionsParsingException if the value of
34    *     --invocation_policy is invalid.
35    */
36   public static InvocationPolicy parsePolicy(String policy) throws OptionsParsingException {
37     if (Strings.isNullOrEmpty(policy)) {
38       return InvocationPolicy.getDefaultInstance();
39     }
40 
41     try {
42       try {
43         // First try decoding the policy as a base64 encoded binary proto.
44         return InvocationPolicy.parseFrom(
45             BaseEncoding.base64().decode(CharMatcher.whitespace().removeFrom(policy)));
46       } catch (IllegalArgumentException e) {
47         // If the flag value can't be decoded from base64, try decoding the policy as a text
48         // formatted proto.
49         InvocationPolicy.Builder builder = InvocationPolicy.newBuilder();
50         TextFormat.merge(policy, builder);
51         return builder.build();
52       }
53     } catch (InvalidProtocolBufferException | TextFormat.ParseException e) {
54       throw new OptionsParsingException("Malformed value of --invocation_policy: " + policy, e);
55     }
56   }
57 }
58