;; Copyright 2006-2012, Matthew Welland.
;;
;; This program is made available under the GNU GPL version 2.0 or
;; greater. See the accompanying file COPYING for details.
;;
;; This program is distributed WITHOUT ANY WARRANTY; without even the
;; implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
;; PURPOSE.
(require-extension (srfi 18) extras tcp s11n)
(use sqlite3 srfi-1 posix regex regex-case srfi-69 hostinfo md5 message-digest)
(import (prefix sqlite3 sqlite3:))
(use nanomsg)
(declare (unit nmsg-transport))
(declare (uses common))
(declare (uses db))
(declare (uses tests))
(declare (uses tasks)) ;; tasks are where stuff is maintained about what is running.
(declare (uses server))
(include "common_records.scm")
(include "db_records.scm")
;; Transition to pub --> sub with pull <-- push
;;
;; 1. client sends request to server via push to the pull port
;; 2. server puts request in queue or processes immediately as appropriate
;; 3. server puts responses from completed requests into pub port
;;
;; TODO
;;
;; Done Tested
;; [x] [ ] 1. Add columns pullport pubport to servers table
;; [x] [ ] 2. Add rm of monitor.db if older than 11/12/2012
;; [x] [ ] 3. Add create of pullport and pubport with finding of available ports
;; [x] [ ] 4. Add client compose of request
;; [x] [ ] - name of client: testname/itempath-test_id-hostname
;; [x] [ ] - name of request: callname, params
;; [x] [ ] - request key: f(clientname, callname, params)
;; [x] [ ] 5. Add processing of subscription hits
;; [x] [ ] - done when get key
;; [x] [ ] - return results
;; [x] [ ] 6. Add timeout processing
;; [x] [ ] - after 60 seconds
;; [ ] [ ] i. check server alive, connect to new if necessary
;; [ ] [ ] ii. resend request
;; [ ] [ ] 7. Turn self ping back on
(define (nmsg-transport:make-server-url hostport #!key (bindall #f))
(if (not hostport)
#f
(conc "tcp://" (if bindall "*" (car hostport)) ":" (cadr hostport))))
(define *server-loop-heart-beat* (current-seconds))
(define *heartbeat-mutex* (make-mutex))
;;======================================================================
;; S E R V E R
;;======================================================================
(define (nmsg-transport:run dbstruct hostn run-id server-id)
(debug:print 2 "Attempting to start the server ...")
(let* ((start-port (portlogger:open-run-close portlogger:find-port))
(server-thread (make-thread (lambda ()
(nmsg-transport:try-start-server dbstruct run-id start-port server-id))
"server thread"))
(tdbdat (tasks:open-db)))
(thread-start! server-thread)
(if (nmsg-transport:ping hostn start-port timeout: 2 expected-key: (current-process-id))
(let ((interface (if (equal? hostn "-")(get-host-name) hostn)))
(tasks:server-set-interface-port (db:delay-if-busy tdbdat) server-id interface start-port)
(tasks:server-set-state! (db:delay-if-busy tdbdat) server-id "dbprep")
(set! *server-info* (list hostn start-port)) ;; probably not needed anymore? currently used by keep-running
(thread-sleep! 3) ;; give some margin for queries to complete before switching from file based access to server based access
(set! *inmemdb* dbstruct)
(tasks:server-set-state! (db:delay-if-busy tdbdat) server-id "running")
(thread-start! (make-thread
(lambda ()(nmsg-transport:keep-running server-id))
"keep running"))
(thread-join! server-thread))
(begin
(tasks:server-delete-record (db:delay-if-busy tdbdat) server-id "failed to start, never received server alive signature")
(portlogger:open-run-close portlogger:set-failed start-port)
(nmsg-transport:run dbstruct hostn run-id server-id)))))
(define (nmsg-transport:try-start-server dbstruct run-id portnum server-id)
(let ((repsoc (nn-socket 'rep)))
(nn-bind repsoc (conc "tcp://*:" portnum))
(let loop ((msg-in (nn-recv repsoc)))
(cond
((equal? msg-in "quit")
(nn-send repsoc "Ok, quitting"))
((and (>= (string-length msg-in) 4)
(equal? (substring msg-in 0 4) "ping"))
(nn-send repsoc (conc (current-process-id)))
(loop (nn-recv repsoc)))
(else
(let* ((dat (db:string->obj msg-in transport: 'nmsg))
(cmd (vector-ref dat 0))
(params (vector-ref dat 1))
(result (api:execute-requests dbstruct cmd params))
(newdat (db:obj->string result transport: 'nmsg)))
(nn-send repsoc newdat)
(loop (nn-recv repsoc))))))))
;; all routes though here end in exit ...
;;
(define (nmsg-transport:launch run-id)
(let* ((tdbdat (tasks:open-db))
(dbstruct (db:setup run-id))
(hostn (or (args:get-arg "-server") "-")))
(set! *run-id* run-id)
;; with nbfake daemonize isn't really needed
;;
;; (if (args:get-arg "-daemonize")
;; (begin
;; (daemon:ize)
;; (if *alt-log-file* ;; we should re-connect to this port, I think daemon:ize disrupts it
;; (begin
;; (current-error-port *alt-log-file*)
;; (current-output-port *alt-log-file*)))))
(if (server:check-if-running run-id)
(begin
(debug:print-info 0 "Server for run-id " run-id " already running")
(exit 0)))
(let loop ((server-id (tasks:server-lock-slot (db:delay-if-busy tdbdat) run-id))
(remtries 4))
(if (not server-id)
(if (> remtries 0)
(begin
(thread-sleep! 2)
(if (not (server:check-if-running run-id))
(loop (tasks:server-lock-slot (db:delay-if-busy tdbdat) run-id)
(- remtries 1))
(begin
(debug:print-info 0 "Another server took the slot, exiting")
(exit 0))))
(begin
;; since we didn't get the server lock we are going to clean up and bail out
(debug:print-info 2 "INFO: server pid=" (current-process-id) ", hostname=" (get-host-name) " not starting due to other candidates ahead in start queue")
(tasks:server-delete-records-for-this-pid (db:delay-if-busy tdbdat) " http-transport:launch")
))
;; locked in a server id, try to start up
(nmsg-transport:run dbstruct hostn run-id server-id))
(set! *didsomething* #t)
(exit))))
;;======================================================================
;; S E R V E R U T I L I T I E S
;;======================================================================
(define (nmsg-transport:mk-signature)
(message-digest-string (md5-primitive)
(with-output-to-string
(lambda ()
(write (list (current-directory)
(argv)))))))
;;======================================================================
;; C L I E N T S
;;======================================================================
;; ping the server at host:port
;; return the open socket if successful (return-socket == #t)
;; expect the key expected-key returned in payload
;; send our-key or #f as payload
;;
(define (nmsg-transport:ping hostn port #!key (timeout 3)(return-socket #t)(expected-key #f)(our-key #f)(socket #f))
;; send a random number along with pid and check that we get it back
(let* ((req (or socket (nn-socket 'req)))
(host (if (or (not hostn)
(equal? hostn "-")) ;; use localhost
(get-host-name)
hostn))
(success #f)
(keepwaiting #t)
(dat (db:obj->string (vector "ping" our-key) transport: 'nmsg))
(ping (make-thread
(lambda ()
(nn-send req dat)
(let* ((result (nn-recv req))
(key (vector-ref (db:string->obj result transport: 'nmsg) 1)))
(if (or (not expected-key) ;; just getting a reply is good enough then
(equal? key expected-key))
(begin
;; (print "ping, success: received \"" result "\"")
(set! success #t))
(begin
;; (print "ping, failed: received key \"" result "\"")
(set! keepwaiting #f)
(set! success #f)))))
"ping"))
(timeout (make-thread (lambda ()
(let loop ((count 0))
(thread-sleep! 1)
(print "still waiting after count seconds...")
(if (and keepwaiting (< count timeout)) ;; yes, this is very aproximate
(loop (+ count 1))))
(if keepwaiting
(begin
(print "timeout waiting for ping")
(thread-terminate! ping))))
"timeout")))
(if (not socket)(nn-connect req (conc "tcp://" host ":" port)))
(handle-exceptions
exn
(begin
;; (print-call-chain)
;; (print 0 " message: " ((condition-property-accessor 'exn 'message) exn))
;; (print "exn=" (condition->list exn))
(debug:print-info 1 "ping failed to connect to " host ":" port))
(thread-start! timeout)
(thread-start! ping)
(thread-join! ping)
(if success (thread-terminate! timeout)))
(if return-socket
(if success req #f)
(begin
(nn-close req) ;; should it be closed if we were handed a socket?
success))))
;; run nmsg-transport:keep-running in a parallel thread to monitor that the db is being
;; used and to shutdown after sometime if it is not.
;;
(define (nmsg-transport:keep-running server-id)
;; if none running or if > 20 seconds since
;; server last used then start shutdown
;; This thread waits for the server to come alive
(let* ((server-info (let loop ()
(let ((sdat #f))
(mutex-lock! *heartbeat-mutex*)
(set! sdat *server-info*)
(mutex-unlock! *heartbeat-mutex*)
(if sdat
(begin
(debug:print-info 0 "keep-running got sdat=" sdat)
sdat)
(begin
(thread-sleep! 0.5)
(loop))))))
(iface (car server-info))
(port (cadr server-info))
(last-access 0)
(tdbdat (tasks:open-db)))
(print "Keep-running got server pid " server-id ", using iface " iface " and port " port)
(let loop ((count 0))
(thread-sleep! 4) ;; no need to do this very often
;; NB// sync currently does NOT return queue-length
(let () ;; (queue-len (cdb:client-call server-info 'sync #t 1)))
;; (print "Server running, count is " count)
(if (< count 1) ;; 3x3 = 9 secs aprox
(loop (+ count 1)))
;; (if ;; (or (> numrunning 0) ;; stay alive for two days after last access
(mutex-lock! *heartbeat-mutex*)
(set! last-access *last-db-access*)
(mutex-unlock! *heartbeat-mutex*)
(if (> (+ last-access
;; (* 50 60 60) ;; 48 hrs
;; 60 ;; one minute
;; (* 60 60) ;; one hour
(* 45 60) ;; 45 minutes, until the db deletion bug is fixed.
)
(current-seconds))
(begin
(debug:print-info 0 "Server continuing, seconds since last db access: " (- (current-seconds) last-access))
(loop 0))
(begin
(debug:print-info 0 "Starting to shutdown the server.")
(set! *time-to-exit* #t)
(tasks:server-delete-record (db:delay-if-busy tdbdat) server-id " http-transport:keep-running")
(debug:print-info 0 "Server shutdown complete. Exiting")
;; (exit)
))))))
;;======================================================================
;; C L I E N T S
;;======================================================================
(define (nmsg-transport:client-connect iface portnum)
(let* ((reqsoc (nmsg-transport:ping iface portnum return-socket: #t)))
(vector iface portnum #f #f #f (current-seconds) reqsoc)))
(define (nmsg-transport:client-api-send-receive run-id connection-info cmd param)
(let ((packet (vector cmd param))
(reqsoc (http-transport:server-dat-get-socket connection-info)))
(nn-send reqsoc (db:obj->string packet transport: 'nmsg))
(db:string->obj (nn-recv reqsoc) transport: 'nmsg)))
;;======================================================================
;; J U N K
;;======================================================================
;; DO NOT USE
;;
(define (nmsg-transport:client-signal-handler signum)
(handle-exceptions
exn
(debug:print " ... exiting ...")
(let ((th1 (make-thread (lambda ()
(if (not *received-response*)
(receive-message* *runremote*))) ;; flush out last call if applicable
"eat response"))
(th2 (make-thread (lambda ()
(debug:print 0 "ERROR: Received ^C, attempting clean exit. Please be patient and wait a few seconds before hitting ^C again.")
(thread-sleep! 3) ;; give the flush three seconds to do it's stuff
(debug:print 0 " Done.")
(exit 4))
"exit on ^C timer")))
(thread-start! th2)
(thread-start! th1)
(thread-join! th2))))