parser.cpp revision 62ca663475ff5284503cb82cae3e92e93d56bbea 
1/*
2 * Copyright (C) 2010 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
17#include "parser.h"
18
19#include <dirent.h>
20
21#include <android-base/chrono_utils.h>
22#include <android-base/logging.h>
23#include <android-base/stringprintf.h>
24#include <android-base/strings.h>
25
26#include "tokenizer.h"
27#include "util.h"
28
29namespace android {
30namespace init {
31
32Parser::Parser() {}
33
34void Parser::AddSectionParser(const std::string& name, std::unique_ptr<SectionParser> parser) {
35    section_parsers_[name] = std::move(parser);
36}
37
38void Parser::AddSingleLineParser(const std::string& prefix, LineCallback callback) {
39    line_callbacks_.emplace_back(prefix, callback);
40}
41
42void Parser::ParseData(const std::string& filename, const std::string& data) {
43    // TODO: Use a parser with const input and remove this copy
44    std::vector<char> data_copy(data.begin(), data.end());
45    data_copy.push_back('\0');
46
47    parse_state state;
48    state.line = 0;
49    state.ptr = &data_copy[0];
50    state.nexttoken = 0;
51
52    SectionParser* section_parser = nullptr;
53    std::vector<std::string> args;
54
55    for (;;) {
56        switch (next_token(&state)) {
57            case T_EOF:
58                if (section_parser) section_parser->EndSection();
59                return;
60            case T_NEWLINE:
61                state.line++;
62                if (args.empty()) break;
63                // If we have a line matching a prefix we recognize, call its callback and unset any
64                // current section parsers.  This is meant for /sys/ and /dev/ line entries for
65                // uevent.
66                for (const auto& [prefix, callback] : line_callbacks_) {
67                    if (android::base::StartsWith(args[0], prefix.c_str())) {
68                        if (section_parser) section_parser->EndSection();
69
70                        std::string ret_err;
71                        if (!callback(std::move(args), &ret_err)) {
72                            LOG(ERROR) << filename << ": " << state.line << ": " << ret_err;
73                        }
74                        section_parser = nullptr;
75                        break;
76                    }
77                }
78                if (section_parsers_.count(args[0])) {
79                    if (section_parser) section_parser->EndSection();
80                    section_parser = section_parsers_[args[0]].get();
81                    std::string ret_err;
82                    if (!section_parser->ParseSection(std::move(args), filename, state.line,
83                                                      &ret_err)) {
84                        LOG(ERROR) << filename << ": " << state.line << ": " << ret_err;
85                        section_parser = nullptr;
86                    }
87                } else if (section_parser) {
88                    std::string ret_err;
89                    if (!section_parser->ParseLineSection(std::move(args), state.line, &ret_err)) {
90                        LOG(ERROR) << filename << ": " << state.line << ": " << ret_err;
91                    }
92                }
93                args.clear();
94                break;
95            case T_TEXT:
96                args.emplace_back(state.text);
97                break;
98        }
99    }
100}
101
102bool Parser::ParseConfigFile(const std::string& path) {
103    LOG(INFO) << "Parsing file " << path << "...";
104    android::base::Timer t;
105    auto config_contents = ReadFile(path);
106    if (!config_contents) {
107        LOG(ERROR) << "Unable to read config file '" << path << "': " << config_contents.error();
108        return false;
109    }
110
111    config_contents->push_back('\n');  // TODO: fix parse_config.
112    ParseData(path, *config_contents);
113    for (const auto& [section_name, section_parser] : section_parsers_) {
114        section_parser->EndFile();
115    }
116
117    LOG(VERBOSE) << "(Parsing " << path << " took " << t << ".)";
118    return true;
119}
120
121bool Parser::ParseConfigDir(const std::string& path) {
122    LOG(INFO) << "Parsing directory " << path << "...";
123    std::unique_ptr<DIR, decltype(&closedir)> config_dir(opendir(path.c_str()), closedir);
124    if (!config_dir) {
125        PLOG(ERROR) << "Could not import directory '" << path << "'";
126        return false;
127    }
128    dirent* current_file;
129    std::vector<std::string> files;
130    while ((current_file = readdir(config_dir.get()))) {
131        // Ignore directories and only process regular files.
132        if (current_file->d_type == DT_REG) {
133            std::string current_path =
134                android::base::StringPrintf("%s/%s", path.c_str(), current_file->d_name);
135            files.emplace_back(current_path);
136        }
137    }
138    // Sort first so we load files in a consistent order (bug 31996208)
139    std::sort(files.begin(), files.end());
140    for (const auto& file : files) {
141        if (!ParseConfigFile(file)) {
142            LOG(ERROR) << "could not import file '" << file << "'";
143        }
144    }
145    return true;
146}
147
148bool Parser::ParseConfig(const std::string& path) {
149    if (is_dir(path.c_str())) {
150        return ParseConfigDir(path);
151    }
152    return ParseConfigFile(path);
153}
154
155}  // namespace init
156}  // namespace android
157