1. 框架

1.1 SrsConfig 类

/**
* the config service provider.
* for the config supports reload, so never keep the reference cross st-thread,
* that is, never save the SrsConfDirective* get by any api of config,
* for it maybe free in the reload st-thread cycle.
* you can keep it before st-thread switch, or simply never keep it.
*/
class SrsConfig
{
// user command
private:
    /**
     * whether srs is run in dolphin mode.
     * @see https://github.com/ossrs/srs-dolphin
     */
    bool dolphin;
    std::string dolphin_rtmp_port;
    std::string dolphin_http_port;
    /**
    * whether show help and exit.
    */
    bool show_help;
    /**
    * whether test config file and exit.
    */
    bool test_conf;
    /**
    * whether show SRS version and exit.
    */
    bool show_version;
// global env variables.
private:
    /**
    * the user parameters, the argc and argv.
    * the argv is " ".join(argv), where argv is from main(argc, argv).
    */
    std::string _argv;
    /**
    * current working directory.
    */
    std::string _cwd;
// config section
private:
    /**
    * the last parsed config file.
    * if reload, reload the config file.
    */
    std::string config_file;
    /**
    * the directive root.
    */
    SrsConfDirective* root;
// reload section
private:
    /**
    * the reload subscribers, when reload, callback all handlers.
    */
    std::vector<ISrsReloadHandler*> subscribes;
public:
    SrsConfig();
    virtual ~SrsConfig();
// dolphin
public:
    /**
     * whether srs is in dolphin mode.
     */
    virtual bool is_dolphin();
private:
    virtual void set_config_directive(SrsConfDirective* parent, std::string dir, std::string value);
// reload
public:
    /**
    * for reload handler to register itself,
    * when config service do the reload, callback the handler.
    */
    virtual void subscribe(ISrsReloadHandler* handler);
    /**
    * for reload handler to unregister itself.
    */
    virtual void unsubscribe(ISrsReloadHandler* handler);
    /**
    * reload the config file.
    * @remark, user can test the config before reload it.
    */
    virtual int reload();
private:
    /**
    * reload the vhost section of config.
    */
    virtual int reload_vhost(SrsConfDirective* old_root);
protected:
    /**
    * reload from the config.
    * @remark, use protected for the utest to override with mock.
    */
    virtual int reload_conf(SrsConfig* conf);
private:
    /**
    * reload the http_api section of config.
    */
    virtual int reload_http_api(SrsConfDirective* old_root);
    /**
    * reload the http_stream section of config.
    */
    virtual int reload_http_stream(SrsConfDirective* old_root);
    /**
    * reload the transcode section of vhost of config.
    */
    virtual int reload_transcode(SrsConfDirective* new_vhost, SrsConfDirective* old_vhost);
    /**
    * reload the ingest section of vhost of config.
    */
    virtual int reload_ingest(SrsConfDirective* new_vhost, SrsConfDirective* old_vhost);
// parse options and file
public:
    /**
    * parse the cli, the main(argc,argv) function.
    */
    virtual int parse_options(int argc, char** argv);
    /**
     * initialize the cwd for server,
     * because we may change the workdir.
     */
    virtual int initialize_cwd();
    /**
    * get the config file path.
    */
    virtual std::string config();
private:
    /**
    * parse each argv.
    */
    virtual int parse_argv(int& i, char** argv);
    /**
    * print help and exit.
    */
    virtual void print_help(char** argv);
public:
    /**
    * parse the config file, which is specified by cli.
    */
    virtual int parse_file(const char* filename);
    /**
    * check the parsed config.
    */
    virtual int check_config();
protected:
    /**
    * parse config from the buffer.
    * @param buffer, the config buffer, user must delete it.
    * @remark, use protected for the utest to override with mock.
    */
    virtual int parse_buffer(_srs_internal::SrsConfigBuffer* buffer);
// global env
public:
    /**
    * get the current work directory.
    */
    virtual std::string         cwd();
    /**
    * get the cli, the main(argc,argv), program start command.
    */
    virtual std::string         argv();
// global section
public:
    /**
    * get the directive root, corresponding to the config file.
    * the root directive, no name and args, contains directives.
    * all directive parsed can retrieve from root.
    */
    virtual SrsConfDirective*   get_root();
    /**
    * get the deamon config.
    * if true, SRS will run in deamon mode, fork and fork to reap the
    * grand-child process to init process.
    */
    virtual bool                get_deamon();
    /**
    * get the max connections limit of system.
    * if exceed the max connection, SRS will disconnect the connection.
    * @remark, linux will limit the connections of each process,
    *       for example, when you need SRS to service 10000+ connections,
    *       user must use "ulimit -HSn 10000" and config the max connections
    *       of SRS.
    */
    virtual int                 get_max_connections();
    /**
    * get the listen port of SRS.
    * user can specifies multiple listen ports,
    * each args of directive is a listen port.
    */
    virtual std::vector<std::string>        get_listens();
    /**
    * get the pid file path.
    * the pid file is used to save the pid of SRS,
    * use file lock to prevent multiple SRS starting.
    * @remark, if user need to run multiple SRS instance,
    *       for example, to start multiple SRS for multiple CPUs,
    *       user can use different pid file for each process.
    */
    virtual std::string         get_pid_file();
    /**
    * get pithy print pulse ms,
    * for example, all rtmp connections only print one message
    * every this interval in ms.
    */
    virtual int                 get_pithy_print_ms();
    /**
     * whether use utc-time to format the time.
     */
    virtual bool                get_utc_time();
    /**
     * get the configed work dir.
     * ignore if empty string.
     */
    virtual std::string         get_work_dir();
    // whether use asprocess mode.
    virtual bool                get_asprocess();
// stream_caster section
public:
    /**
    * get all stream_caster in config file.
    */
    virtual std::vector<SrsConfDirective*>  get_stream_casters();
    /**
    * get whether the specified stream_caster is enabled.
    */
    virtual bool                get_stream_caster_enabled(SrsConfDirective* sc);
    /**
    * get the engine of stream_caster, the caster config.
    */
    virtual std::string         get_stream_caster_engine(SrsConfDirective* sc);
    /**
    * get the output rtmp url of stream_caster, the output config.
    */
    virtual std::string         get_stream_caster_output(SrsConfDirective* sc);
    /**
    * get the listen port of stream caster.
    */
    virtual int                 get_stream_caster_listen(SrsConfDirective* sc);
    /**
    * get the min udp port for rtp of stream caster rtsp.
    */
    virtual int                 get_stream_caster_rtp_port_min(SrsConfDirective* sc);
    /**
    * get the max udp port for rtp of stream caster rtsp.
    */
    virtual int                 get_stream_caster_rtp_port_max(SrsConfDirective* sc);
// vhost specified section
public:
    /**
    * get the vhost directive by vhost name.
    * @param vhost, the name of vhost to get.
    */
    virtual SrsConfDirective*   get_vhost(std::string vhost);
    /**
    * get all vhosts in config file.
    */
    virtual void get_vhosts(std::vector<SrsConfDirective*>& vhosts);
    /**
    * whether vhost is enabled
    * @param vhost, the vhost name.
    * @return true when vhost is ok; otherwise, false.
    */
    virtual bool                get_vhost_enabled(std::string vhost);
    /**
    * whether vhost is enabled
    * @param vhost, the vhost directive.
    * @return true when vhost is ok; otherwise, false.
    */
    virtual bool                get_vhost_enabled(SrsConfDirective* vhost);
    /**
    * whether gop_cache is enabled of vhost.
    * gop_cache used to cache last gop, for client to fast startup.
    * @return true when gop_cache is ok; otherwise, false.
    * @remark, default true.
    */
    virtual bool                get_gop_cache(std::string vhost);
    /**
    * whether debug_srs_upnode is enabled of vhost.
    * debug_srs_upnode is very important feature for tracable log,
    * but some server, for instance, flussonic donot support it.
    * @see https://github.com/ossrs/srs/issues/160
    * @return true when debug_srs_upnode is ok; otherwise, false.
    * @remark, default true.
    */
    virtual bool                get_debug_srs_upnode(std::string vhost);
    /**
    * whether atc is enabled of vhost.
    * atc always use encoder timestamp, SRS never adjust the time.
    * @return true when atc is ok; otherwise, false.
    * @remark, default false.
    */
    virtual bool                get_atc(std::string vhost);
    /**
    * whether atc_auto is enabled of vhost.
    * atc_auto used to auto enable atc, when metadata specified the bravo_atc.
    * @return true when atc_auto is ok; otherwise, false.
    * @remark, default true.
    */
    virtual bool                get_atc_auto(std::string vhost);
    /**
    * get the time_jitter algorithm.
    * @return the time_jitter algorithm, defined in SrsRtmpJitterAlgorithm.
    * @remark, default full.
    */
    virtual int                 get_time_jitter(std::string vhost);
    /**
     * whether use mix correct algorithm to ensure the timestamp
     * monotonically increase.
     */
    virtual bool                get_mix_correct(std::string vhost);
    /**
    * get the cache queue length, in seconds.
    * when exceed the queue length, drop packet util I frame.
    * @remark, default 10.
    */
    virtual double              get_queue_length(std::string vhost);
    /**
    * get the refer antisuck directive.
    * each args of directive is a refer config.
    * when the client refer(pageUrl) not match the refer config,
    * SRS will reject the connection.
    * @remark, default NULL.
    */
    virtual SrsConfDirective*   get_refer(std::string vhost);
    /**
    * get the play refer, refer for play clients.
    * @remark, default NULL.
    */
    virtual SrsConfDirective*   get_refer_play(std::string vhost);
    /**
    * get the publish refer, refer for publish clients.
    * @remark, default NULL.
    */
    virtual SrsConfDirective*   get_refer_publish(std::string vhost);
    /**
    * get the chunk size of vhost.
    * @param vhost, the vhost to get the chunk size. use global if not specified.
    *       empty string to get the global.
    * @remark, default 60000.
    */
    virtual int                 get_chunk_size(std::string vhost);
    /**
     * whether parse the sps when publish stream to SRS.
     */
    virtual bool                get_parse_sps(std::string vhost);
    /**
    * whether mr is enabled for vhost.
    * @param vhost, the vhost to get the mr.
    */
    virtual bool                get_mr_enabled(std::string vhost);
    /**
    * get the mr sleep time in ms for vhost.
    * @param vhost, the vhost to get the mr sleep time.
    */
    // TODO: FIXME: add utest for mr config.
    virtual int                 get_mr_sleep_ms(std::string vhost);
    /**
    * get the mw sleep time in ms for vhost.
    * @param vhost, the vhost to get the mw sleep time.
    */
    // TODO: FIXME: add utest for mw config.
    virtual int                 get_mw_sleep_ms(std::string vhost);
    /**
    * whether min latency mode enabled.
    * @param vhost, the vhost to get the min_latency.
    */
    // TODO: FIXME: add utest for min_latency.
    virtual bool                get_realtime_enabled(std::string vhost);
    /**
     * whether enable tcp nodelay for all clients of vhost.
     */
    virtual bool                get_tcp_nodelay(std::string vhost);
    /**
     * the minimal send interval in ms.
     */
    virtual double              get_send_min_interval(std::string vhost);
    /**
     * whether reduce the sequence header.
     */
    virtual bool                get_reduce_sequence_header(std::string vhost);
    /**
     * the 1st packet timeout in ms for encoder.
     */
    virtual int                 get_publish_1stpkt_timeout(std::string vhost);
    /**
     * the normal packet timeout in ms for encoder.
     */
    virtual int                 get_publish_normal_timeout(std::string vhost);
private:
    /**
    * get the global chunk size.
    */
    virtual int                 get_global_chunk_size();
// forward section
public:
    /**
    * get the forward directive of vhost.
    */
    virtual SrsConfDirective*   get_forward(std::string vhost);
// http_hooks section
private:
    /**
    * get the http_hooks directive of vhost.
    */
    virtual SrsConfDirective*   get_vhost_http_hooks(std::string vhost);
public:
    /**
    * whether vhost http-hooks enabled.
    * @remark, if not enabled, donot callback all http hooks.
    */
    virtual bool                get_vhost_http_hooks_enabled(std::string vhost);
    /**
    * get the on_connect callbacks of vhost.
    * @return the on_connect callback directive, the args is the url to callback.
    */
    virtual SrsConfDirective*   get_vhost_on_connect(std::string vhost);
    /**
    * get the on_close callbacks of vhost.
    * @return the on_close callback directive, the args is the url to callback.
    */
    virtual SrsConfDirective*   get_vhost_on_close(std::string vhost);
    /**
    * get the on_publish callbacks of vhost.
    * @return the on_publish callback directive, the args is the url to callback.
    */
    virtual SrsConfDirective*   get_vhost_on_publish(std::string vhost);
    /**
    * get the on_unpublish callbacks of vhost.
    * @return the on_unpublish callback directive, the args is the url to callback.
    */
    virtual SrsConfDirective*   get_vhost_on_unpublish(std::string vhost);
    /**
    * get the on_play callbacks of vhost.
    * @return the on_play callback directive, the args is the url to callback.
    */
    virtual SrsConfDirective*   get_vhost_on_play(std::string vhost);
    /**
    * get the on_stop callbacks of vhost.
    * @return the on_stop callback directive, the args is the url to callback.
    */
    virtual SrsConfDirective*   get_vhost_on_stop(std::string vhost);
    /**
     * get the on_dvr callbacks of vhost.
     * @return the on_dvr callback directive, the args is the url to callback.
     */
    virtual SrsConfDirective*   get_vhost_on_dvr(std::string vhost);
    /**
     * get the on_hls callbacks of vhost.
     * @return the on_hls callback directive, the args is the url to callback.
     */
    virtual SrsConfDirective*   get_vhost_on_hls(std::string vhost);
    /**
     * get the on_hls_notify callbacks of vhost.
     * @return the on_hls_notify callback directive, the args is the url to callback.
     */
    virtual SrsConfDirective*   get_vhost_on_hls_notify(std::string vhost);
// bwct(bandwidth check tool) section
public:
    /**
    * whether bw check enabled for vhost.
    * if enabled, serve all clients with bandwidth check services.
    * oterwise, serve all cleints with stream.
    */
    virtual bool                get_bw_check_enabled(std::string vhost);
    /**
    * the key of server, if client key mot match, reject.
    */
    virtual std::string         get_bw_check_key(std::string vhost);
    /**
    * the check interval, in ms.
    * if the client request check in very short time(in the interval),
    * SRS will reject client.
    * @remark this is used to prevent the bandwidth check attack.
    */
    virtual int                 get_bw_check_interval_ms(std::string vhost);
    /**
    * the max kbps that user can test,
    * if exceed the kbps, server will slowdown the send-recv.
    * @remark this is used to protect the service bandwidth.
    */
    virtual int                 get_bw_check_limit_kbps(std::string vhost);
// vhost edge section
public:
    /**
    * whether vhost is edge mode.
    * for edge, publish client will be proxyed to upnode,
    * for edge, play client will share a connection to get stream from upnode.
    */
    virtual bool                get_vhost_is_edge(std::string vhost);
    /**
    * whether vhost is edge mode.
    * for edge, publish client will be proxyed to upnode,
    * for edge, play client will share a connection to get stream from upnode.
    */
    virtual bool                get_vhost_is_edge(SrsConfDirective* vhost);
    /**
    * get the origin config of edge,
    * specifies the origin ip address, port.
    */
    virtual SrsConfDirective*   get_vhost_edge_origin(std::string vhost);
    /**
    * whether edge token tranverse is enabled,
    * if true, edge will send connect origin to verfy the token of client.
    * for example, we verify all clients on the origin FMS by server-side as,
    * all clients connected to edge must be tranverse to origin to verify.
    */
    virtual bool                get_vhost_edge_token_traverse(std::string vhost);
    /**
     * get the transformed vhost for edge,
     * @see https://github.com/ossrs/srs/issues/372
     */
    virtual std::string         get_vhost_edge_transform_vhost(std::string vhost);
// vhost security section
public:
    /**
    * whether the secrity of vhost enabled.
    */
    virtual bool                get_security_enabled(std::string vhost);
    /**
    * get the security rules.
    */
    virtual SrsConfDirective*   get_security_rules(std::string vhost);
// vhost transcode section
public:
    /**
    * get the transcode directive of vhost in specified scope.
    * @param vhost, the vhost name to get the transcode directive.
    * @param scope, the scope, empty to get all. for example, user can transcode
    *       the app scope stream, by config with app:
    *                   transcode live {...}
    *       when the scope is "live", this directive is matched.
    *       the scope can be: empty for all, app, app/stream.
    * @remark, please see the samples of full.conf, the app.transcode.srs.com
    *       and stream.transcode.srs.com.
    */
    virtual SrsConfDirective*   get_transcode(std::string vhost, std::string scope);
    /**
    * whether the transcode directive is enabled.
    */
    virtual bool                get_transcode_enabled(SrsConfDirective* transcode);
    /**
    * get the ffmpeg tool path of transcode.
    */
    virtual std::string         get_transcode_ffmpeg(SrsConfDirective* transcode);
    /**
    * get the engines of transcode.
    */
    virtual std::vector<SrsConfDirective*>      get_transcode_engines(SrsConfDirective* transcode);
    /**
    * whether the engine is enabled.
    */
    virtual bool                get_engine_enabled(SrsConfDirective* engine);
    /**
    * get the iformat of engine
    */
    virtual std::string         get_engine_iformat(SrsConfDirective* engine);
    /**
    * get the vfilter of engine,
    * the video filter set before the vcodec of FFMPEG.
    */
    virtual std::vector<std::string> get_engine_vfilter(SrsConfDirective* engine);
    /**
    * get the vcodec of engine,
    * the codec of video, can be vn, copy or libx264
    */
    virtual std::string         get_engine_vcodec(SrsConfDirective* engine);
    /**
    * get the vbitrate of engine,
    * the bitrate in kbps of video, for example, 800kbps
    */
    virtual int                 get_engine_vbitrate(SrsConfDirective* engine);
    /**
    * get the vfps of engine.
    * the video fps, for example, 25fps
    */
    virtual double              get_engine_vfps(SrsConfDirective* engine);
    /**
    * get the vwidth of engine,
    * the video width, for example, 1024
    */
    virtual int                 get_engine_vwidth(SrsConfDirective* engine);
    /**
    * get the vheight of engine,
    * the video height, for example, 576
    */
    virtual int                 get_engine_vheight(SrsConfDirective* engine);
    /**
    * get the vthreads of engine,
    * the video transcode libx264 threads, for instance, 8
    */
    virtual int                 get_engine_vthreads(SrsConfDirective* engine);
    /**
    * get the vprofile of engine,
    * the libx264 profile, can be high,main,baseline
    */
    virtual std::string         get_engine_vprofile(SrsConfDirective* engine);
    /**
    * get the vpreset of engine,
    * the libx264 preset, can be ultrafast,superfast,veryfast,faster,fast,medium,slow,slower,veryslow,placebo
    */
    virtual std::string         get_engine_vpreset(SrsConfDirective* engine);
    /**
    * get the additional video params.
    */
    virtual std::vector<std::string> get_engine_vparams(SrsConfDirective* engine);
    /**
    * get the acodec of engine,
    * the audio codec can be an, copy or libfdk_aac
    */
    virtual std::string         get_engine_acodec(SrsConfDirective* engine);
    /**
    * get the abitrate of engine,
    * the audio bitrate in kbps, for instance, 64kbps.
    */
    virtual int                 get_engine_abitrate(SrsConfDirective* engine);
    /**
    * get the asample_rate of engine,
    * the audio sample_rate, for instance, 44100HZ
    */
    virtual int                 get_engine_asample_rate(SrsConfDirective* engine);
    /**
    * get the achannels of engine,
    * the audio channel, for instance, 1 for mono, 2 for stereo.
    */
    virtual int                 get_engine_achannels(SrsConfDirective* engine);
    /**
    * get the aparams of engine,
    * the audio additional params.
    */
    virtual std::vector<std::string> get_engine_aparams(SrsConfDirective* engine);
    /**
    * get the oformat of engine
    */
    virtual std::string         get_engine_oformat(SrsConfDirective* engine);
    /**
    * get the output of engine, for example, rtmp://localhost/live/livestream,
    * @remark, we will use some variable, for instance, [vhost] to substitude with vhost.
    */
    virtual std::string         get_engine_output(SrsConfDirective* engine);
// vhost ingest section
public:
    /**
    * get the ingest directives of vhost.
    */
    virtual std::vector<SrsConfDirective*> get_ingesters(std::string vhost);
    /**
    * get specified ingest.
    */
    virtual SrsConfDirective*   get_ingest_by_id(std::string vhost, std::string ingest_id);
    /**
    * whether ingest is enalbed.
    */
    virtual bool                get_ingest_enabled(SrsConfDirective* ingest);
    /**
    * get the ingest ffmpeg tool
    */
    virtual std::string         get_ingest_ffmpeg(SrsConfDirective* ingest);
    /**
    * get the ingest input type, file or stream.
    */
    virtual std::string         get_ingest_input_type(SrsConfDirective* ingest);
    /**
    * get the ingest input url.
    */
    virtual std::string         get_ingest_input_url(SrsConfDirective* ingest);
// log section
public:
    /**
    * whether log to file.
    */
    virtual bool                get_log_tank_file();
    /**
    * get the log level.
    */
    virtual std::string         get_log_level();
    /**
    * get the log file path.
    */
    virtual std::string         get_log_file();
    /**
    * whether ffmpeg log enabled
    */
    virtual bool                get_ffmpeg_log_enabled();
    /**
    * the ffmpeg log dir.
    * @remark, /dev/null to disable it.
    */
    virtual std::string         get_ffmpeg_log_dir();
// hls section
private:
    /**
    * get the hls directive of vhost.
    */
    virtual SrsConfDirective*   get_hls(std::string vhost);
public:
    /**
    * whether HLS is enabled.
    */
    virtual bool                get_hls_enabled(std::string vhost);
    /**
    * get the HLS m3u8 list ts segment entry prefix info.
    */
    virtual std::string         get_hls_entry_prefix(std::string vhost);
    /**
     * get the HLS ts/m3u8 file store path.
     */
    virtual std::string         get_hls_path(std::string vhost);
    /**
     * get the HLS m3u8 file path template.
     */
    virtual std::string         get_hls_m3u8_file(std::string vhost);
    /**
     * get the HLS ts file path template.
     */
    virtual std::string         get_hls_ts_file(std::string vhost);
    /**
     * whether enable the floor(timestamp/hls_fragment) for variable timestamp.
     */
    virtual bool                get_hls_ts_floor(std::string vhost);
    /**
    * get the hls fragment time, in seconds.
    */
    virtual double              get_hls_fragment(std::string vhost);
    /**
    * get the hls td(target duration) ratio.
    */
    virtual double              get_hls_td_ratio(std::string vhost);
    /**
     * get the hls aof(audio overflow) ratio.
     */
    virtual double              get_hls_aof_ratio(std::string vhost);
    /**
    * get the hls window time, in seconds.
    * a window is a set of ts, the ts collection in m3u8.
    * @remark SRS will delete the ts exceed the window.
    */
    virtual double              get_hls_window(std::string vhost);
    /**
    * get the hls hls_on_error config.
    * the ignore will ignore error and disable hls.
    * the disconnect will disconnect publish connection.
    * @see https://github.com/ossrs/srs/issues/264
    */
    virtual std::string         get_hls_on_error(std::string vhost);
    /**
    * get the HLS default audio codec.
    */
    virtual std::string         get_hls_acodec(std::string vhost);
    /**
    * get the HLS default video codec.
    */
    virtual std::string         get_hls_vcodec(std::string vhost);
    /**
     * whether cleanup the old ts files.
     */
    virtual bool                get_hls_cleanup(std::string vhost);
    /**
     * the timeout to dispose the hls.
     */
    virtual int                 get_hls_dispose(std::string vhost);
    /**
     * whether reap the ts when got keyframe.
     */
    virtual bool                get_hls_wait_keyframe(std::string vhost);
    /**
     * get the size of bytes to read from cdn network, for the on_hls_notify callback,
     * that is, to read max bytes of the bytes from the callback, or timeout or error.
     */
    virtual int                 get_vhost_hls_nb_notify(std::string vhost);
// hds section
private:
    /**
    * get the hds directive of vhost.
    */
    virtual SrsConfDirective*   get_hds(const std::string &vhost);
public:
    /**
    * whether HDS is enabled.
    */
    virtual bool                get_hds_enabled(const std::string &vhost);
    /**
    * get the HDS file store path.
    */
    virtual std::string         get_hds_path(const std::string &vhost);
    /**
    * get the hds fragment time, in seconds.
    */
    virtual double              get_hds_fragment(const std::string &vhost);
    /**
    * get the hds window time, in seconds.
    * a window is a set of hds fragments.
    */
    virtual double              get_hds_window(const std::string &vhost);

// dvr section
private:
    /**
    * get the dvr directive.
    */
    virtual SrsConfDirective*   get_dvr(std::string vhost);
public:
    /**
    * whether dvr is enabled.
    */
    virtual bool                get_dvr_enabled(std::string vhost);
    /**
    * get the dvr path, the flv file to save in.
    */
    virtual std::string         get_dvr_path(std::string vhost);
    /**
    * get the plan of dvr, how to reap the flv file.
    */
    virtual std::string         get_dvr_plan(std::string vhost);
    /**
    * get the duration of dvr flv.
    */
    virtual int                 get_dvr_duration(std::string vhost);
    /**
    * whether wait keyframe to reap segment.
    */
    virtual bool                get_dvr_wait_keyframe(std::string vhost);
    /**
    * get the time_jitter algorithm for dvr.
    */
    virtual int                 get_dvr_time_jitter(std::string vhost);
// http api section
private:
    /**
    * get the http api directive.
    */
    virtual SrsConfDirective*   get_http_api();
    /**
    * whether http api enabled
    */
    virtual bool                get_http_api_enabled(SrsConfDirective* conf);
public:
    /**
    * whether http api enabled.
    */
    virtual bool                get_http_api_enabled();
    /**
    * get the http api listen port.
    */
    virtual std::string         get_http_api_listen();
    /**
    * whether enable crossdomain for http api.
    */
    virtual bool                get_http_api_crossdomain();
// http stream section
private:
    /**
    * get the http stream directive.
    */
    virtual SrsConfDirective*   get_http_stream();
    /**
    * whether http stream enabled.
    */
    virtual bool                get_http_stream_enabled(SrsConfDirective* conf);
public:
    /**
    * whether http stream enabled.
    */
    virtual bool                get_http_stream_enabled();
    /**
    * get the http stream listen port.
    */
    virtual std::string         get_http_stream_listen();
    /**
    * get the http stream root dir.
    */
    virtual std::string         get_http_stream_dir();
public:
    /**
    * get whether vhost enabled http stream
    */
    virtual bool                get_vhost_http_enabled(std::string vhost);
    /**
    * get the http mount point for vhost.
    * for example, http://vhost/live/livestream
    */
    virtual std::string         get_vhost_http_mount(std::string vhost);
    /**
    * get the http dir for vhost.
    * the path on disk for mount root of http vhost.
    */
    virtual std::string         get_vhost_http_dir(std::string vhost);
// flv live streaming section
public:
    /**
    * get whether vhost enabled http flv live stream
    */
    virtual bool                get_vhost_http_remux_enabled(std::string vhost);
    /**
    * get the fast cache duration for http audio live stream.
    */
    virtual double              get_vhost_http_remux_fast_cache(std::string vhost);
    /**
    * get the http flv live stream mount point for vhost.
    * used to generate the flv stream mount path.
    */
    virtual std::string         get_vhost_http_remux_mount(std::string vhost);
    /**
    * get whether the hstrs(http stream trigger rtmp source) enabled.
    */
    virtual bool                get_vhost_http_remux_hstrs(std::string vhost);
// http heartbeart section
private:
    /**
    * get the heartbeat directive.
    */
    virtual SrsConfDirective*   get_heartbeart();
public:
    /**
    * whether heartbeat enabled.
    */
    virtual bool                get_heartbeat_enabled();
    /**
    * get the heartbeat interval, in ms.
    */
    virtual int64_t             get_heartbeat_interval();
    /**
    * get the heartbeat report url.
    */
    virtual std::string         get_heartbeat_url();
    /**
    * get the device id of heartbeat, to report to server.
    */
    virtual std::string         get_heartbeat_device_id();
    /**
    * whether report with summaries of http api: /api/v1/summaries.
    */
    virtual bool                get_heartbeat_summaries();
// stats section
private:
    /**
    * get the stats directive.
    */
    virtual SrsConfDirective*   get_stats();
public:
    /**
    * get the network device index, used to retrieve the ip of device,
    * for heartbeat to report to server, or to get the local ip.
    * for example, 0 means the eth0 maybe.
    */
    virtual int                 get_stats_network();
    /**
    * get the disk stat device name list.
    * the device name configed in args of directive.
    * @return the disk device name to stat. NULL if not configed.
    */
    virtual SrsConfDirective*   get_stats_disk_device();
};

1.2 SrsConfDirective 类

/**
* the config directive.
* the config file is a group of directives,
* all directive has name, args and child-directives.
* for example, the following config text:
        vhost vhost.ossrs.net {
            enabled         on;
            ingest livestream {
                enabled      on;
                ffmpeg       /bin/ffmpeg;
            }
        }
* will be parsed to:
*       SrsConfDirective: name="vhost", arg0="vhost.ossrs.net", child-directives=[
*           SrsConfDirective: name="enabled", arg0="on", child-directives=[]
*           SrsConfDirective: name="ingest", arg0="livestream", child-directives=[
*               SrsConfDirective: name="enabled", arg0="on", child-directives=[]
*               SrsConfDirective: name="ffmpeg", arg0="/bin/ffmpeg", child-directives=[]
*           ]
*       ]
* @remark, allow empty directive, for example: "dir0 {}"
* @remark, don‘t allow empty name, for example: ";" or "{dir0 arg0;}
*/
class SrsConfDirective
{
public:
    /**
    * the line of config file in which the directive from
    */
    int conf_line;
    /**
    * the name of directive, for example, the following config text:
    *       enabled     on;
    * will be parsed to a directive, its name is "enalbed"
    */
    std::string name;
    /**
    * the args of directive, for example, the following config text:
    *       listen      1935 1936;
    * will be parsed to a directive, its args is ["1935", "1936"].
    */
    std::vector<std::string> args;
    /**
    * the child directives, for example, the following config text:
    *       vhost vhost.ossrs.net {
    *           enabled         on;
    *       }
    * will be parsed to a directive, its directives is a vector contains
    * a directive, which is:
    *       name:"enalbed", args:["on"], directives:[]
    *
    * @remark, the directives can contains directives.
    */
    std::vector<SrsConfDirective*> directives;
public:
    SrsConfDirective();
    virtual ~SrsConfDirective();
// args
public:
    /**
    * get the args0,1,2, if user want to get more args,
    * directly use the args.at(index).
    */
    virtual std::string arg0();
    virtual std::string arg1();
    virtual std::string arg2();
// directives
public:
    /**
    * get the directive by index.
    * @remark, assert the index<directives.size().
    */
    virtual SrsConfDirective* at(int index);
    /**
    * get the directive by name, return the first match.
    */
    virtual SrsConfDirective* get(std::string _name);
    /**
    * get the directive by name and its arg0, return the first match.
    */
    virtual SrsConfDirective* get(std::string _name, std::string _arg0);
// help utilities
public:
    /**
    * whether current directive is vhost.
    */
    virtual bool is_vhost();
    /**
    * whether current directive is stream_caster.
    */
    virtual bool is_stream_caster();
// parse utilities
public:
    /**
    * parse config directive from file buffer.
    */
    virtual int parse(_srs_internal::SrsConfigBuffer* buffer);
// private parse.
private:
    /**
    * the directive parsing type.
    */
    enum SrsDirectiveType {
        /**
        * the root directives, parsing file.
        */
        parse_file,
        /**
        * for each direcitve, parsing text block.
        */
        parse_block
    };
    /**
    * parse the conf from buffer. the work flow:
    * 1. read a token(directive args and a ret flag),
    * 2. initialize the directive by args, args[0] is name, args[1-N] is args of directive,
    * 3. if ret flag indicates there are child-directives, read_conf(directive, block) recursively.
    */
    virtual int parse_conf(_srs_internal::SrsConfigBuffer* buffer, SrsDirectiveType type);
    /**
    * read a token from buffer.
    * a token, is the directive args and a flag indicates whether has child-directives.
    * @param args, the output directive args, the first is the directive name, left is the args.
    * @param line_start, the actual start line of directive.
    * @return, an error code indicates error or has child-directives.
    */
    virtual int read_token(_srs_internal::SrsConfigBuffer* buffer, std::vector<std::string>& args, int& line_start);
};

1.3 SrsConfigBuffer

namespace _srs_internal
{
    class SrsConfigBuffer;
}

namespace _srs_internal
{
    /**
    * the buffer of config content.
    */
    class SrsConfigBuffer
    {
    protected:
        // last available position.
        char* last;
        // end of buffer.
        char* end;
        // start of buffer.
        char* start;
    public:
        // current consumed position.
        char* pos;
        // current parsed line.
        int line;
    public:
        SrsConfigBuffer();
        virtual ~SrsConfigBuffer();
    public:
        /**
        * fullfill the buffer with content of file specified by filename.
        */
        virtual int fullfill(const char* filename);
        /**
        * whether buffer is empty.
        */
        virtual bool empty();
    };
};

2. 函数实现

2.1 SrsConfig::parse_options

// see: ngx_get_options
int SrsConfig::parse_options(int argc, char** argv)
{
    int ret = ERROR_SUCCESS;

    // argv: 将 argv 中的数据拷贝到 _argv 中，多个字符串之间以 " " 间隔
    for (int i = 0; i < argc; i++) {
        _argv.append(argv[i]);

        if (i < argc - 1) {
            _argv.append(" ");
        }
    }

    // config: 解析通过命令行传入的参数
    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;
    }

    // 解析配置文件
    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_ocnfig();
        }

        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) {
        /* 从 root 指令中获取"srs_log_file"指令指定的log文件路径，若没有找到，
         * 则使用默认log文件: "./objs/srs.log" */
        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;
        }
        // 将日志保存到文件中
        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 { // 否则，将日志打印到 console 中
            srs_trace("write log to console");
        }
    }
}

2.2 SrsConfig::parse_argv

int SrsConfig::parse_argv(int& i, char** argv)
{
    int ret = ERROR_SUCCESS;

    char* p = argv[i];

    if (*p++ != ‘-‘) {
        show_help = true;
        return ret;
    }

    while (*p) {
        switch (*p++) {
            case ‘?‘:
            case ‘h‘:
                show_help = true;
                break;
            case ‘t‘:
                show_help = false;
                test_conf = true;
                break;
            case ‘p‘:
                dolphin = true;
                if (*p) {
                    dolphin_rtmp_port = p;
                    continue;
                }
                if (argv[++i]) {
                    dolphin_rtmp_port = argv[i];
                    continue;
                }
                ret = ERROR_SYSTEM_CONFIG_INVALID;
                srs_error("option \"-p\" requires params, ret=%d", ret);
                return ret;
            case ‘x‘:
                dolphin = true;
                if (*p) {
                    dolphin_http_port = p;
                    continue;
                }
                if (argv[++i]) {
                    dolphin_http_port = argv[i];
                    continue;
                }
                ret = ERROR_SYSTEM_CONFIG_INVALID;
                srs_error("option \"-x\" requires params, ret=%d", ret);
                return ret;
            case ‘v‘:
            case ‘V‘:
                show_help = false;
                show_version = true;
                break;
            case ‘c‘:
                show_help = false;
                if (*p) {
                    config_file = p;
                    continue;
                }
                if (argv[++i]) {
                    config_file = argv[i];
                    continue;
                }
                ret = ERROR_SYSTEM_CONFIG_INVALID;
                srs_error("option \"-c\" requires parameter, ret=%d", ret);
                return ret;
            default:
                ret = ERROR_SYSTEM_CONFIG_INVALID;
                srs_error("invalid option: \"%c\", see help: %s -h, ret=%d", *(p - 1), argv[0], ret);
                return ret;
        }
    }

    return ret;
}

2.3 SrsConfig::parse_file

int SrsConfig::parse_file(const char *filename)
{
    int ret = ERROR_SUCCESS;

    config_file = filename;

    if (config_file.empty()) {
        return ERROR_SYSTEM_CONFIG_INVALID;
    }

    // 构造一个 SrsConfigBuffer 类的变量，用于存放配置文件的内容
    SrsConfigBuffer buffer;

    // 将配置文件的内容填充到 buffer 缓存中
    if ((ret = buffer.fullfill(config_file.c_str())) != ERROR_SUCCESS) {
        return ret;
    }

    // 解析 buffer 中的配置项
    return parse_buffer(&buffer);
}

2.4 namespace _srs_internal

namespace _srs_internal
{
    SrsConfigBuffer::SrsConfigBuffer()
    {
        line = 1;

        pos = last = start = NULL;
        end = start;
    }

    SrsConfigBuffer::~SrsConfigBuffer()
    {
        srs_freepa(start);
    }

    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;
    }

    bool SrsConfigBuffer::empty()
    {
        return pos >= end;
    }
}

2.5 SrsConfig::parse_buffer

int SrsConfig::parse_buffer(SrsConfigBuffer* buffer)
{
    int ret = ERROR_SUCCESS;

    /* 解析 buffer 中的配置，解析出来的配置值保存在 root 指令中,
     * root 构建了一个指令树，保存着配置文件中所有指令 */
    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;
}

2.5.1 SrsConfig::set_config_directive

void SrsConfig::set_config_directive(SrsConfDirective* parent, string dir, string value)
{
    // 尝试从 parent 中获取该 dir 指令
    SrsConfDirective* d = parent->get(dir);

    // 若 parent 指令中没有该 dir 子指令，则创建一个新指令
    if (!d) {
        d = new SrsConfDirective();
        if (!dir.empty()) {
            d->name = dir;
        }
        parent->directive.push_back(d);
    }

    // 清空该指令的参数
    d->args.clear();

    if (!value.empty) {
        d->args.push_back(value);
    }
}

2.6 SrsConfDirective::parse

int SrsConfDirective::parse(SrsConfigBuffer* buffer)
{
    // parse_file 表示当前开始解析配置文件
    return parse_conf(buffer, parse_file);
}

2.7 SrsConfDirective::parse_conf

// see: ngx_conf_parse
int SrsConfDirective::parse_conf(SrsConfigBuffer* buffer, SrsDirectiveType type)
{
    int ret = ERROR_SUCCESS;

    while (true) {
        std::vector<string> args;
        int line_start = 0;
        // 读取一行内容
        ret = read_token(buffer, args, line_start);

        /**
         * 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) {
                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) {
                srs_error("line %d: unexpected end of file, expecting \"}\", ret=%d", conf_line, ret);
                return ret;
            }
            return ERROR_SUCCESS;
        }

        // 若没有读取到任何数据，则表示出错了
        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];
        // 将 args[0] 从 args vector 容器中删除
        args.erase(args.begin());
        /* 将 args 中的全部数据和 directive->args 中的数据进行交换，
         * 即相等于将 args 中的数据拷贝给 directive->args */
        directive->args.swap(args);

        // 将该新解析的指令放入到 vector 类的 directives 容器中
        directives.push_back(directive);

        // 若为一个配置块的开始，则递归调用 parse_conf
        if (ret == ERROR_SYSTEM_CONFIG_BLOCK_START) {
            if ((ret = directive->parse_conf(buffer, parse_block) != ERROR_SUCCESS) {
                return ret;
            }
        }
    }

    return ret;
}

2.8 SrsConfDirective::read_token

// 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;

    // 若为 true，表示当前行是注释
    bool sharp_comment = false;

    // 若为 true，表示当前字符是 双引号 "
    bool d_quoted = false;
    // 若为 true，表示当前字符是 单引号 ‘
    bool s_quoted = false;

    // 若为 true，表示下一个的字符必须是空格
    bool need_space = false;
    // 若为 true，表示当前字符是最后一个空格，即下一个字符不是空格了
    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++;

        // 若当前字符为 换行符，则表示当前行结束
        if (ch == SRS_LF) {
            buffer->line++;
            sharp_comment = false;
        }

        // 表示遇到注释了
        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) {
            // 若当前字符是空格，则继续取下一个字符
            if (is_common_space(ch)) {
                continue;
            }
            pstart = buffer->pos - 1;
            switch (ch) {
                case ‘;‘:
                    if (args.size() == 0) {
                        srs_error("line %d: unexpected ‘;‘", buffer->line);
                        return ERROR_SYSTEM_CONFIG_INVALID;
                    }
                    return ERROR_SYSTEM_CONFIG_DIRECTIVE;
                case ‘{‘:
                    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;
                }
            // 若当前字符是空格 或 ; 或 {，则置位 found
            } 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;

                // 将其放入到 vector 类型的 args 容器中
                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;
}

原文地址：https://www.cnblogs.com/jimodetiantang/p/9013794.html