parser.cpp revision b592dd8afff487e5ba73bbd782cfa7501a65e88e 
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                        if (auto result = callback(std::move(args)); !result) {
71                            LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
72                        }
73                        section_parser = nullptr;
74                        break;
75                    }
76                }
77                if (section_parsers_.count(args[0])) {
78                    if (section_parser) section_parser->EndSection();
79                    section_parser = section_parsers_[args[0]].get();
80                    if (auto result =
81                            section_parser->ParseSection(std::move(args), filename, state.line);
82                        !result) {
83                        LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
84                        section_parser = nullptr;
85                    }
86                } else if (section_parser) {
87                    if (auto result = section_parser->ParseLineSection(std::move(args), state.line);
88                        !result) {
89                        LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
90                    }
91                }
92                args.clear();
93                break;
94            case T_TEXT:
95                args.emplace_back(state.text);
96                break;
97        }
98    }
99}
100
101bool Parser::ParseConfigFile(const std::string& path) {
102    LOG(INFO) << "Parsing file " << path << "...";
103    android::base::Timer t;
104    auto config_contents = ReadFile(path);
105    if (!config_contents) {
106        LOG(ERROR) << "Unable to read config file '" << path << "': " << config_contents.error();
107        return false;
108    }
109
110    config_contents->push_back('\n');  // TODO: fix parse_config.
111    ParseData(path, *config_contents);
112    for (const auto& [section_name, section_parser] : section_parsers_) {
113        section_parser->EndFile();
114    }
115
116    LOG(VERBOSE) << "(Parsing " << path << " took " << t << ".)";
117    return true;
118}
119
120bool Parser::ParseConfigDir(const std::string& path) {
121    LOG(INFO) << "Parsing directory " << path << "...";
122    std::unique_ptr<DIR, decltype(&closedir)> config_dir(opendir(path.c_str()), closedir);
123    if (!config_dir) {
124        PLOG(ERROR) << "Could not import directory '" << path << "'";
125        return false;
126    }
127    dirent* current_file;
128    std::vector<std::string> files;
129    while ((current_file = readdir(config_dir.get()))) {
130        // Ignore directories and only process regular files.
131        if (current_file->d_type == DT_REG) {
132            std::string current_path =
133                android::base::StringPrintf("%s/%s", path.c_str(), current_file->d_name);
134            files.emplace_back(current_path);
135        }
136    }
137    // Sort first so we load files in a consistent order (bug 31996208)
138    std::sort(files.begin(), files.end());
139    for (const auto& file : files) {
140        if (!ParseConfigFile(file)) {
141            LOG(ERROR) << "could not import file '" << file << "'";
142        }
143    }
144    return true;
145}
146
147bool Parser::ParseConfig(const std::string& path) {
148    if (is_dir(path.c_str())) {
149        return ParseConfigDir(path);
150    }
151    return ParseConfigFile(path);
152}
153
154}  // namespace init
155}  // namespace android
156