1 //
2 // Copyright (C) 2022 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15
16 #include <memory>
17 #include <string>
18 #include <string_view>
19
20 #include "common/libs/fs/shared_buf.h"
21 #include "common/libs/fs/shared_fd.h"
22 #include "common/libs/utils/json.h"
23
24 namespace cuttlefish {
25
ParseJson(std::string_view input)26 Result<Json::Value> ParseJson(std::string_view input) {
27 Json::Value root;
28 JSONCPP_STRING err;
29 Json::CharReaderBuilder builder;
30 const std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
31 auto begin = input.data();
32 auto end = begin + input.length();
33 CF_EXPECT(reader->parse(begin, end, &root, &err), err);
34 return root;
35 }
36
LoadFromFile(SharedFD json_fd)37 Result<Json::Value> LoadFromFile(SharedFD json_fd) {
38 CF_EXPECT(json_fd->IsOpen(), "json_fd is not open.");
39 std::string json_contents;
40 // on success, this must return a positive integer
41 CF_EXPECT_GE(ReadAll(json_fd, &json_contents), 0,
42 "ReadAll() failed and returned 0 or -1");
43 Json::Value json_value = CF_EXPECTF(
44 ParseJson(json_contents), "Failed to parse json: \n{}", json_contents);
45 return json_value;
46 }
47
LoadFromFile(const std::string & path_to_file)48 Result<Json::Value> LoadFromFile(const std::string& path_to_file) {
49 SharedFD json_fd = SharedFD::Open(path_to_file, O_RDONLY);
50 auto json_value =
51 CF_EXPECTF(LoadFromFile(json_fd), "Failed to open {}", path_to_file);
52 return json_value;
53 }
54
55 } // namespace cuttlefish
56