libldms_msg.ipp

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/* Copyright 2025 NTESS. See the top-level LICENSE.txt file for details.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
#include <adc/builder/builder.hpp>
#include <adc/publisher/publisher.hpp>
#include <cstdlib>
#include <iostream>
#include <fstream>
#include <filesystem>
#include <unistd.h>
#include <ldms.h>
 
namespace adc {
 
using std::cout;
 
typedef std::string string;
typedef std::string_view string_view;
 
 
/*! \brief libldms_msg_publish publisher_api implementation.
  This plugin calls the ldms libraries for sending messages.
 
  Multiple independent instances of this plugin may be used simultaneously.
  The asynchronous tranmission spawns (or recycles) a separate thread to
  handle tranmission.
 */
class libldms_msg_publish_plugin : public publisher_api {
    enum state {
        ok,
        err
    };
    enum mode {
        /* the next mode needed for correct operation */
        pi_config,
        pi_init,
        pi_pub_or_final
    };
public:
    /// \brief name of the channel ADC messages go into
    /// LDMS aggregators must be subscribed to this name.
    /// Overridden with env("ADC_LIBLDMS_MSG_PUBLISH_PLUGIN_CHANNEL").
    inline static const char* adc_libldms_msg_publish_plugin_channel_default = "adc_publish_api";
 
    /// \brief authentication method for channel connections; ldmsd listeners must match.
    /// Overridden with env("ADC_LIBLDMS_MSG_PUBLISH_PLUGIN_AUTH").
    inline static const char* adc_libldms_msg_publish_plugin_auth_default = "munge";
 
    /// \brief port for channel connections; ldmsd listeners must match.
    /// Overridden with env("ADC_LIBLDMS_MSG_PUBLISH_PLUGIN_PORT").
    inline static const char* adc_libldms_msg_publish_plugin_port_default = "412";
 
    /// \brief host for channel connections; ldmsd must be listening on the host.
    /// Overridden with env("ADC_LIBLDMS_MSG_PUBLISH_PLUGIN_HOST").
    inline static const char* adc_libldms_msg_publish_plugin_host_default = "localhost";
 
private:
    const std::map< const string, const string > plugin_libldms_msg_publish_config_defaults =
    {
        {"CHANNEL", adc_libldms_msg_publish_plugin_channel_default},
        {"AUTH", adc_libldms_msg_publish_plugin_auth_default},
        {"HOST", adc_libldms_msg_publish_plugin_host_default},
        {"PORT", adc_libldms_msg_publish_plugin_port_default}
    };
 
    inline static const char *plugin_prefix = "ADC_LIBLDMS_MSG_PUBLISH_PLUGIN_";
 
    const string vers;
    const std::vector<string> tags;
    string auth;
    string channel;
    string port;
    string host;
    enum state state;
    bool paused;
    enum mode mode;
    bool configured;
 
    int config(const string& dir, string_view shost, string_view sport, string_view sauth, string_view schannel) {
        if (mode != pi_config)
            return 2;
        uid_t ui = geteuid();
        port = sport;
        host = shost;
        auth = sauth;
        channel = schannel;
        mode = pi_init;
        configured = true;
        return 0;
    }
 
    // find field in m, then with prefix in env, then the default.
    const string get(const std::map< string, string >& m,
            string field, const string& env_prefix) {
        // fields not defined in config_defaults raise an exception.
        auto it = m.find(field);
        if (it != m.end()) {
            return it->second;
        }
        string en = env_prefix + field;
        char *ec = getenv(en.c_str());
        if (!ec) {
            return plugin_libldms_msg_publish_config_defaults.at(field);
        } else {
            return string(ec);
        }
    }
    
    // invoke ldms_stream_publish with json in f, then delete f.
    // wrap this in a thread to make it non-blocking eventually.
    int libldms_msg_publish_send(string& f)
    {
// fixme libldms_msg_publish_plugin::libldms_msg_publish_send
#if 0
        string qcmd = "(" + prog + 
            " -t json "
            " -x sock "
            " -h " + host +
            " -p " + port +
            " -a " + auth +
            " -s " + stream +
            " -f " + f +
            "> /dev/null 2>&1 ; /bin/rm " + f + ") &";
        int err2 = std::system(qcmd.c_str());
        std::cout << f << std::endl;
        std::cout << err2 << std::endl;
#endif
        return 0;
    }
 
public:
    libldms_msg_publish_plugin() : vers("0.0.0") , tags({"unimplemented"}), state(ok), paused(false), mode(pi_config), configured(false) {
        std::cout << "Constructing libldms_msg_publish_plugin" << std::endl;
    }
 
        int publish(std::shared_ptr<builder_api> b) {
        if (paused)
            return 0;
        if (state != ok)
            return 1;
        if (mode != pi_pub_or_final)
            return 2;
// fixme // send to ldms_msg api; libldms_msg_publish_plugin::publish
        return 1;
    }
 
        int config(const std::map< std::string, std::string >& m) {
        return config(m, plugin_prefix);
    }
 
        int config(const std::map< std::string, std::string >& m, const std::string& env_prefix) {
        string host = get(m, "HOST", env_prefix);
        string port = get(m, "PORT", env_prefix);
        string auth = get(m, "AUTH", env_prefix);
        string channel = get(m, "CHANNEL", env_prefix);
        return config(d, host, port, auth, channel);
    }
        
    const std::map< const std::string, const std::string> & get_option_defaults() {
        return plugin_libldms_msg_publish_config_defaults;
    }
 
    int initialize() {
        std::map <string, string >m;
        if (!configured)
            config(m);
        if (mode != pi_init) {
            return 2;
        }
        if ( state == err ) {
            std::cout << "libldms_msg_publish plugin initialize found pre-existing error" << std::endl;
            return 3;
        }
        // fixme: try connect to ldmsd; libldms_msg_publish_plugin::initialize
        std::error_code ec;
        // attach msg channel
        mode = pi_pub_or_final;
        return 0;
    }
 
        void finalize() {
        if (mode == pi_pub_or_final) {
            state = ok;
            paused = false;
            mode = pi_config;
        } else {
            std::cout << "libldms_msg_publish plugin finalize on non-running plugin" << std::endl;
        }
    }
 
    void pause() {
        paused = true;
    }
 
        void resume() {
        paused = false;
    }
 
    string_view name() const {
        return "libldms_msg_publish";
    }
 
    string_view version() const {
        return vers;
    }
 
    ~libldms_msg_publish_plugin() {
        std::cout << "Destructing libldms_msg_publish_plugin" << std::endl;
    }
};
 
} // adc