main函数分析:
位于main\srs_main_server.cpp
// never use srs log(srs_trace, srs_error, etc) before config parse the option,
// which will load the log config and apply it.
if ((ret = _srs_config->parse_options(argc, argv)) != ERROR_SUCCESS) {
return ret;
}
先调用 SrsConfig类的 parse_options函数解析命令行参数
位于app\srs_app_config.cpp
// see: ngx_get_options
int SrsConfig::parse_options(int argc, char** argv)
{
int ret = ERROR_SUCCESS;
// argv
for (int i = 0; i < argc; i++) {
_argv.append(argv[i]);
if (i < argc - 1) {
_argv.append(" ");
}
}
// config
show_help = true;
for (int i = 1; i < argc; i++) {
if ((ret = parse_argv(i, argv)) != ERROR_SUCCESS) {
return ret;
}
}
if (show_help) {
print_help(argv);
exit(0);
}
if (show_version) {
fprintf(stderr, "%s\n", RTMP_SIG_SRS_VERSION);
exit(0);
}
// first hello message.
srs_trace(_srs_version);
if (config_file.empty()) {
ret = ERROR_SYSTEM_CONFIG_INVALID;
srs_error("config file not specified, see help: %s -h, ret=%d", argv[0], ret);
return ret;
}
ret = parse_file(config_file.c_str());
if (test_conf) {
// the parse_file never check the config,
// we check it when user requires check config file.
if (ret == ERROR_SUCCESS) {
ret = check_config();
}
if (ret == ERROR_SUCCESS) {
srs_trace("config file is ok");
exit(0);
} else {
srs_error("config file is invalid");
exit(ret);
}
}
////////////////////////////////////////////////////////////////////////
// check log name and level
////////////////////////////////////////////////////////////////////////
if (true) {
std::string log_filename = this->get_log_file();
if (get_log_tank_file() && log_filename.empty()) {
ret = ERROR_SYSTEM_CONFIG_INVALID;
srs_error("must specifies the file to write log to. ret=%d", ret);
return ret;
}
if (get_log_tank_file()) {
srs_trace("write log to file %s", log_filename.c_str());
srs_trace("you can: tailf %s", log_filename.c_str());
srs_trace("@see: %s", SRS_WIKI_URL_LOG);
} else {
srs_trace("write log to console");
}
}
return ret;
}
parse_options 函数的作用如下
1. 将命令行参数保存在成员变量_argv(std::string),参数之间用空格分隔.
2. 调用 parse_argv函数对命令行参数进行分析,并设置相应的标志变量,
show_help(显示帮助信息后退出)
test_conf(测试配置文件后退出)
show_version(显示版本信息后退出)
config_file(保存从命令行传入的配置文件路径)
3. show_help和show_version都等于false,调用 parse_file函数
ret = parse_file(config_file.c_str());
if (test_conf) {
// the parse_file never check the config,
// we check it when user requires check config file.
if (ret == ERROR_SUCCESS) {
ret = check_config();
}
if (ret == ERROR_SUCCESS) {
srs_trace("config file is ok");
exit(0);
} else {
srs_error("config file is invalid");
exit(ret);
}
}
如果测试配置,调用check_config函数检查配置信息
4.检查写日志到控制台还是文件,如果是文件,检查文件名是否不为空
////////////////////////////////////////////////////////////////////////
// check log name and level
////////////////////////////////////////////////////////////////////////
if (true) {
std::string log_filename = this->get_log_file();
if (get_log_tank_file() && log_filename.empty()) {
ret = ERROR_SYSTEM_CONFIG_INVALID;
srs_error("must specifies the file to write log to. ret=%d", ret);
return ret;
}
if (get_log_tank_file()) {
srs_trace("write log to file %s", log_filename.c_str());
srs_trace("you can: tailf %s", log_filename.c_str());
srs_trace("@see: %s", SRS_WIKI_URL_LOG);
} else {
srs_trace("write log to console");
}
}
parse_file函数
int SrsConfig::parse_file(const char* filename)
{
int ret = ERROR_SUCCESS;
config_file = filename;
if (config_file.empty()) {
return ERROR_SYSTEM_CONFIG_INVALID;
}
SrsConfigBuffer buffer;
if ((ret = buffer.fullfill(config_file.c_str())) != ERROR_SUCCESS) {
return ret;
}
return parse_buffer(&buffer);
}
1. 调用 SrsConfigBuffer函数 fullfill填充缓冲区
2. 调用 parse_buffer解析配置
int SrsConfigBuffer::fullfill(const char* filename)
{
int ret = ERROR_SUCCESS;
SrsFileReader reader;
// open file reader.
if ((ret = reader.open(filename)) != ERROR_SUCCESS) {
srs_error("open conf file error. ret=%d", ret);
return ret;
}
// read all.
int filesize = (int)reader.filesize();
// create buffer
srs_freepa(start);
pos = last = start = new char[filesize];
end = start + filesize;
// read total content from file.
ssize_t nread = 0;
if ((ret = reader.read(start, filesize, &nread)) != ERROR_SUCCESS) {
srs_error("read file read error. expect %d, actual %d bytes, ret=%d",
filesize, nread, ret);
return ret;
}
return ret;
}
调用SrsFileReader类读配置文件内容到SrsConfigBuffer类的内部缓冲区,设置start,end,pos.last指针
SrsFileReader类位于kernel\srs_kernel_file.cpp
int SrsConfig::parse_buffer(SrsConfigBuffer* buffer)
{
int ret = ERROR_SUCCESS;
if ((ret = root->parse(buffer)) != ERROR_SUCCESS) {
return ret;
}
// mock by dolphin mode.
// for the dolphin will start srs with specified params.
if (dolphin) {
// for RTMP.
set_config_directive(root, "listen", dolphin_rtmp_port);
// for HTTP
set_config_directive(root, "http_server", "");
SrsConfDirective* http_server = root->get("http_server");
set_config_directive(http_server, "enabled", "on");
set_config_directive(http_server, "listen", dolphin_http_port);
// others.
set_config_directive(root, "daemon", "off");
set_config_directive(root, "srs_log_tank", "console");
}
return ret;
}
root变量的类型SrsConfDirective
int SrsConfDirective::parse(SrsConfigBuffer* buffer)
{
return parse_conf(buffer, parse_file);
}
parse_file枚举变量
/**
* the directive parsing type.
*/
enum SrsDirectiveType {
/**
* the root directives, parsing file.
*/
parse_file,
/**
* for each direcitve, parsing text block.
*/
parse_block
// see: ngx_conf_parseint SrsConfDirective::parse_conf(SrsConfigBuffer* buffer, SrsDirectiveType type){int ret = ERROR_SUCCESS;
while (true) {
std::vector<string> args;
int line_start = 0;
ret = read_token(buffer, args, line_start);
// 从buffer中读一行数据,args返回单词数组,line_start返回当前行数 /**
* ret maybe:
* ERROR_SYSTEM_CONFIG_INVALID error.
* ERROR_SYSTEM_CONFIG_DIRECTIVE directive terminated by ‘;‘ found
* ERROR_SYSTEM_CONFIG_BLOCK_START token terminated by ‘{‘ found
* ERROR_SYSTEM_CONFIG_BLOCK_END the ‘}‘ found
* ERROR_SYSTEM_CONFIG_EOF the config file is done
*/
if (ret == ERROR_SYSTEM_CONFIG_INVALID) {
return ret;
}
if (ret == ERROR_SYSTEM_CONFIG_BLOCK_END) {
if (type != parse_block) { // 此时没有遇到 { type 是 parse_file// 相当于 } 没有匹配的 { srs_error("line %d: unexpected \"}\", ret=%d", buffer->line, ret);
return ret;
}
return ERROR_SUCCESS;
}
if (ret == ERROR_SYSTEM_CONFIG_EOF) {
if (type == parse_block) {// { 没有匹配的 } srs_error("line %d: unexpected end of file, expecting \"}\", ret=%d", conf_line, ret);
return ret;
}
return ERROR_SUCCESS;
}
if (args.empty()) {// ret = ERROR_SYSTEM_CONFIG_INVALID;
srs_error("line %d: empty directive. ret=%d", conf_line, ret);
return ret;
}
// build directive tree.
SrsConfDirective* directive = new SrsConfDirective();
directive->conf_line = line_start;
directive->name = args[0];
args.erase(args.begin());
directive->args.swap(args);
directives.push_back(directive);
// 解析 {} 里面的内容
if (ret == ERROR_SYSTEM_CONFIG_BLOCK_START) {
if ((ret = directive->parse_conf(buffer, parse_block)) != ERROR_SUCCESS) {
return ret;
}
}
}
return ret;
}
// see: ngx_conf_read_token
int SrsConfDirective::read_token(SrsConfigBuffer* buffer, vector<string>& args, int& line_start)
{
int ret = ERROR_SUCCESS;
char* pstart = buffer->pos;
bool sharp_comment = false;
bool d_quoted = false;
bool s_quoted = false;
bool need_space = false;
bool last_space = true;
while (true) {
if (buffer->empty()) {
ret = ERROR_SYSTEM_CONFIG_EOF;
if (!args.empty() || !last_space) {
srs_error("line %d: unexpected end of file, expecting ; or \"}\"", buffer->line);
return ERROR_SYSTEM_CONFIG_INVALID;
}
srs_trace("config parse complete");
return ret;
}
char ch = *buffer->pos++;
if (ch == SRS_LF) {
buffer->line++;
sharp_comment = false;
}
if (sharp_comment) {
continue;
}
if (need_space) {
if (is_common_space(ch)) {
last_space = true;
need_space = false;
continue;
}
if (ch == ‘;‘) {
return ERROR_SYSTEM_CONFIG_DIRECTIVE;
}
if (ch == ‘{‘) {
return ERROR_SYSTEM_CONFIG_BLOCK_START;
}
srs_error("line %d: unexpected ‘%c‘", buffer->line, ch);
return ERROR_SYSTEM_CONFIG_INVALID;
}
// last charecter is space.
if (last_space) {
if (is_common_space(ch)) {
continue;
}
pstart = buffer->pos - 1;
switch (ch) {
case ‘;‘:
if (args.size() == 0) {//只有一个 ;的一行 srs_error("line %d: unexpected ‘;‘", buffer->line);
return ERROR_SYSTEM_CONFIG_INVALID;
}
return ERROR_SYSTEM_CONFIG_DIRECTIVE;
case ‘{‘://只有一个 { 的一行
if (args.size() == 0) {
srs_error("line %d: unexpected ‘{‘", buffer->line);
return ERROR_SYSTEM_CONFIG_INVALID;
}
return ERROR_SYSTEM_CONFIG_BLOCK_START;
case ‘}‘:
if (args.size() != 0) {
srs_error("line %d: unexpected ‘}‘", buffer->line);
return ERROR_SYSTEM_CONFIG_INVALID;
}
return ERROR_SYSTEM_CONFIG_BLOCK_END;
case ‘#‘:
sharp_comment = 1;
continue;
case ‘"‘:
pstart++;
d_quoted = true;
last_space = 0;
continue;
case ‘\‘‘:
pstart++;
s_quoted = true;
last_space = 0;
continue;
default:
last_space = 0;
continue;
}
} else {
// last charecter is not space
if (line_start == 0) {
line_start = buffer->line;
}
bool found = false;
if (d_quoted) {
if (ch == ‘"‘) {
d_quoted = false;
need_space = true;
found = true;
}
} else if (s_quoted) {
if (ch == ‘\‘‘) {
s_quoted = false;
need_space = true;
found = true;
}
} else if (is_common_space(ch) || ch == ‘;‘ || ch == ‘{‘) {
last_space = true;
found = 1;
}
if (found) {
int len = (int)(buffer->pos - pstart);
char* aword = new char[len];
memcpy(aword, pstart, len);
aword[len - 1] = 0;
string word_str = aword;
if (!word_str.empty()) {
args.push_back(word_str);
}
srs_freepa(aword);
if (ch == ‘;‘) {
return ERROR_SYSTEM_CONFIG_DIRECTIVE;
}
if (ch == ‘{‘) {
return ERROR_SYSTEM_CONFIG_BLOCK_START;
}
}
}
}
return ret;
}
至此 parse_file函数分析完毕,下一篇分析check_config函数
未完待续...
时间： 2024-11-07 15:04:12