JClient.hh

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#ifndef __JRUNCONTROL__JCLIENT__
#define __JRUNCONTROL__JCLIENT__

#include <string>
#include <iostream>
#include <sstream>

#include "JLang/JException.hh"
#include "JLang/JString.hh"
#include "JLang/JWhiteSpacesFacet.hh"
#include "JDAQ/JDAQTags.hh"
#include "JRuncontrol/JRuncontrolToolkit.hh"
#include "JNet/JPrefix.hh"
#include "JSystem/JShell.hh"


/**
 * \author mdejong
 */

namespace KM3NETDAQ {


  /**
   * Client data structure.
   */
  class JClient {
  public:


    static std::string  SERVER;    //!< host name of message server
    static std::string  LOGGER;    //!< host name of message logger


    /**
     * Client modi.
     */
    enum JMode { UNKNOWN = -1, SLEEP = 0, ACTIVE, IGNORE = -2, ILLEGAL = -3 };


    /**
     * Default constructor.
     */
    JClient() :
      name         (),
      hostname     (),
      start_command(),
      mode(UNKNOWN),
      born(0),
      died(0),
      is_alive(false),
      state_name("?"),
      event_name("?"),
      event_number(-1)
    {}


    /**
     * Constructor.
     *
     * \param  __name             name of client
     * \param  __hostname         host name
     * \param  __start_command    start command
     */
    JClient(const std::string& __name,
            const std::string& __hostname,
            const std::string& __start_command = "") :
      name         (__name),
      hostname     (__hostname),
      start_command(__start_command),
      mode(UNKNOWN),
      born(0),
      died(0),
      is_alive(false),
      state_name("?"),
      event_name("?"),
      event_number(-1)
    {
      configure();
    }


    /**
     * Start process.
     * The start command is issued on the (remote) host.
     */
    void start()
    {
      using JSYSTEM::JShell;

      if (start_command != "") {

        JShell& shell = JShell::getInstance();

        shell << start_command << std::endl;
        shell.flush();
      }
    }


    /**
     * Stop process.
     * A kill command is issued on the (remote) host.
     * To determine the PID for the kill command, the start command is compared to 
     * the output of a ps command on the (remote) host.
     *
     * \param  signal             signal
     */
    void stop(const int signal = -9)
    {
      using namespace std;
      using JSYSTEM::JShell;

      if (start_command != "") {

        const string header  = "__header___";
        const string trailer = "__trailer__";

        ostringstream os;

        os << "ssh " << hostname << ' '
           << "\""
           << "echo" << ' ' << header << ";"
           << "ps hax -o '%p %a'"     << ";"
           << "echo" << ' ' << trailer
           << "\"";

        JShell& shell = JShell::getInstance();

        shell << os.str() << endl;

        os.str("");

        string buffer;

        while (getline(shell, buffer) && buffer.find(header)  == string::npos) {}

        istringstream is;

        while (getline(shell, buffer) && buffer.find(trailer) == string::npos) {

          is.clear();
          is.str(buffer);

          int pid;

          if (is >> pid && getline(is >> ws, buffer)) {
            if (start_command.find(buffer) != string::npos) {
              os << "ssh " << hostname << ' '
                 << "\""
                 << "kill " << signal << " " << pid << " </dev/null >&/dev/null"
                 << "\"";
            }
          }
        }

        shell.flush();

        if (os.str() != "") {
          shell << os.str() << endl;
          shell.flush();
        }
      }
    }


    /**
     * Get name of run control client.
     *
     * \return                    name
     */
    const std::string& getName() const
    {
      return name;
    }


    /**
     * Get host name of run control client.
     *
     * \return                    host name
     */
    const std::string& getHostname() const
    {
      return hostname;
    }


    /**
     * Get full name of run control client.
     *
     * \return                    full name
     */
    const std::string& getFullName() const
    {
      return full_name;
    }


    /**
     * Get start command of run control client.
     *
     * \return                    name
     */
    const std::string& getStartCommand() const
    {
      return start_command;
    }


    /**
     * Check sleep mode.
     *
     * \return                    true if sleep; else false
     */
    bool isSleep() const
    {
      return mode == SLEEP;
    }


    /**
     * Check active mode.
     *
     * \return                    true if active; else false
     */
    bool isActive() const
    {
      return mode == ACTIVE;
    }


    /**
     * Check ignore mode.
     *
     * \return                    true if ignore; else false
     */
    bool isIgnore() const
    {
      return mode == IGNORE;
    }


    /**
     * Check illegal mode.
     *
     * \return                    true if illegal; else false
     */
    bool isIllegal() const
    {
      return mode == ILLEGAL;
    }
    
    
    /**
     * Update client.
     * The client parameters are updated according to the ControlHost tag and message.
     *
     * \param  tag                tag
     * \param  buffer             message
     * \return                    true if OK; else false
     */
    bool update(const JNET::JTag& tag, const std::string& buffer)
    {
      using namespace std;
      using JLANG::JWhiteSpacesFacet;
        
      if        (tag == JNET::DISPTAG_Born) {

        this->is_alive  = true;
        this->born     += 1;
        
        return true;

      } else if (tag == JNET::DISPTAG_Died) {
        
        this->is_alive  = false;
        this->died     += 1;
        
        return true;

      } else if (tag == RC_REPLY) {
        
        string   key;
        string   ip;
        string   name;
        JEvent_t event;
        string   state;
        
        istringstream is(buffer);
        
        const locale loc(is.getloc(), new JWhiteSpacesFacet(is.getloc(), TOKEN_DELIMETER));
          
        is.imbue(loc);
        
        if (is >> key >> ip >> name >> event >> state && key == RUN_CONTROL_CLIENT) {

          this->event_name   = event.getName();
          this->event_number = event.getNumber();
          this->state_name   = state;

          return true;
        }
      }

      return false;
    }


    /**
     * Get name of current state.
     *
     * \return                    state name
     */
    const std::string& getStatename() const
    {
      return state_name;
    }


    /**
     * Get name of last event.
     *
     * \return                    event name
     */
    const std::string& getEventname() const
    {
      return event_name;
    }


    /**
     * Get number of last event.
     *
     * \return                    event number
     */
    int getEventnumber() const
    {
      return event_number;
    }


    /**
     * Get alive status.
     *
     * \return                    true if alive; else false
     */
    bool getAlive() const
    {
      return is_alive;
    }


    /**
     * Set alive status.
     *
     * \param  alive              alive
     */
    void setAlive(const bool alive)
    {
      is_alive = alive;
    }


    /**
     * Get mode.
     *
     * \return                    mode
     */
    JMode getMode() const
    {
      return mode;
    }


    /**
     * Set mode.
     *
     * \param  mode               mode
     */
    void setMode(const JMode mode) 
    {
      this->mode = mode;
    }


    /**
     * Get born count.
     *
     * \return                    number of times born
     */
    int getBorn() const
    {
      return born;
    }


    /**
     * Get died count.
     *
     * \return                    number of times died
     */
    int getDied() const
    {
      return died;
    }


    /**
     * Read client from input.
     *
     * \param  in                 istream
     * \param  client             client
     * \return                    istream
     */
    friend inline std::istream& operator>>(std::istream& in, JClient& client)
    {
      in >> client.name;
      in >> client.hostname;

      if (in) {

        getline(in >> std::ws, client.start_command);

        in.clear();    // clear error state of input stream if no start command is available.

        client.configure();
      }

      return in;
    }


    /**
     * Write client to output.
     *
     * \param  out                ostream
     * \param  client             client
     * \return                    ostream
     */
    friend inline std::ostream& operator<<(std::ostream& out, const JClient& client)
    {
      out << client.name;
      out << ' ';
      out << client.hostname;
      out << ' ';
      out << client.start_command;

      return out;
    }


  protected:
    /**
     * Configure client parameters.
     * In this, the following tokens in the start command are substituted:
     *    $HOST$    by  <host name>;
     *    $NAME$    by  <process name>;
     *    $SERVER$  by  JClient::SERVER;
     *    $LOGGER$  by  JClient::LOGGER;
     *    $ARGS$    by  part following last '/' in <process name>;
     */
    void configure()
    {
      using std::string;

      full_name = KM3NETDAQ::getFullName(hostname, name);

      start_command = start_command.trim();
      start_command = start_command.replace("  ", " ");

      start_command.replace("$HOST$",   hostname);
      start_command.replace("$NAME$",   name);
      start_command.replace("$SERVER$", SERVER);
      start_command.replace("$LOGGER$", LOGGER);

      string::size_type pos = name.find_last_of(CLIENTNAME_DELIMETER);
                    
      if (pos != string::npos) {
        start_command.replace("$ARGS$", name.substr(pos + 1));
      }
    }


    std::string    name;
    std::string    hostname;
    JLANG::JString start_command;
    std::string    full_name;
    JMode          mode;
    int            born;
    int            died;
    bool           is_alive;
    std::string    state_name;
    std::string    event_name;
    int            event_number;
  };
}

#endif