parser.cpp revision 7d0a5c3656ee56eb81e442b58063d500b4f506e0 
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    int section_start_line = -1;
54    std::vector<std::string> args;
55
56    auto end_section = [&] {
57        if (section_parser == nullptr) return;
58
59        if (auto result = section_parser->EndSection(); !result) {
60            LOG(ERROR) << filename << ": " << section_start_line << ": " << result.error();
61        }
62
63        section_parser = nullptr;
64        section_start_line = -1;
65    };
66
67    for (;;) {
68        switch (next_token(&state)) {
69            case T_EOF:
70                end_section();
71                return;
72            case T_NEWLINE:
73                state.line++;
74                if (args.empty()) break;
75                // If we have a line matching a prefix we recognize, call its callback and unset any
76                // current section parsers.  This is meant for /sys/ and /dev/ line entries for
77                // uevent.
78                for (const auto& [prefix, callback] : line_callbacks_) {
79                    if (android::base::StartsWith(args[0], prefix.c_str())) {
80                        end_section();
81
82                        if (auto result = callback(std::move(args)); !result) {
83                            LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
84                        }
85                        break;
86                    }
87                }
88                if (section_parsers_.count(args[0])) {
89                    end_section();
90                    section_parser = section_parsers_[args[0]].get();
91                    section_start_line = state.line;
92                    if (auto result =
93                            section_parser->ParseSection(std::move(args), filename, state.line);
94                        !result) {
95                        LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
96                        section_parser = nullptr;
97                    }
98                } else if (section_parser) {
99                    if (auto result = section_parser->ParseLineSection(std::move(args), state.line);
100                        !result) {
101                        LOG(ERROR) << filename << ": " << state.line << ": " << result.error();
102                    }
103                }
104                args.clear();
105                break;
106            case T_TEXT:
107                args.emplace_back(state.text);
108                break;
109        }
110    }
111}
112
113bool Parser::ParseConfigFile(const std::string& path) {
114    LOG(INFO) << "Parsing file " << path << "...";
115    android::base::Timer t;
116    auto config_contents = ReadFile(path);
117    if (!config_contents) {
118        LOG(ERROR) << "Unable to read config file '" << path << "': " << config_contents.error();
119        return false;
120    }
121
122    config_contents->push_back('\n');  // TODO: fix parse_config.
123    ParseData(path, *config_contents);
124    for (const auto& [section_name, section_parser] : section_parsers_) {
125        section_parser->EndFile();
126    }
127
128    LOG(VERBOSE) << "(Parsing " << path << " took " << t << ".)";
129    return true;
130}
131
132bool Parser::ParseConfigDir(const std::string& path) {
133    LOG(INFO) << "Parsing directory " << path << "...";
134    std::unique_ptr<DIR, decltype(&closedir)> config_dir(opendir(path.c_str()), closedir);
135    if (!config_dir) {
136        PLOG(ERROR) << "Could not import directory '" << path << "'";
137        return false;
138    }
139    dirent* current_file;
140    std::vector<std::string> files;
141    while ((current_file = readdir(config_dir.get()))) {
142        // Ignore directories and only process regular files.
143        if (current_file->d_type == DT_REG) {
144            std::string current_path =
145                android::base::StringPrintf("%s/%s", path.c_str(), current_file->d_name);
146            files.emplace_back(current_path);
147        }
148    }
149    // Sort first so we load files in a consistent order (bug 31996208)
150    std::sort(files.begin(), files.end());
151    for (const auto& file : files) {
152        if (!ParseConfigFile(file)) {
153            LOG(ERROR) << "could not import file '" << file << "'";
154        }
155    }
156    return true;
157}
158
159bool Parser::ParseConfig(const std::string& path) {
160    if (is_dir(path.c_str())) {
161        return ParseConfigDir(path);
162    }
163    return ParseConfigFile(path);
164}
165
166}  // namespace init
167}  // namespace android
168