;; 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 #!key (retrynum 1000))
(debug:print 2 #f "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)
(thread-sleep! 0.1)
(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 run-id))
"keep running"))
(thread-join! server-thread))
(if (> retrynum 0)
(begin
(debug:print 0 #f "WARNING: Failed to connect to server (self) on host " hostn ":" start-port ", trying again.")
(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))
(begin
(debug:print 0 #f "ERROR: could not find an open port to start server on. Giving up")
(exit 1))))))
(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)))
(let* ((dat (db:string->obj msg-in transport: 'nmsg)))
(debug:print 0 #f "server, received: " dat)
(let ((result (api:execute-requests dbstruct dat)))
(debug:print 0 #f "server, sending: " result)
(nn-send repsoc (db:obj->string result transport: 'nmsg)))
(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)
(set! *inmemdb* dbstruct)
;; 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 #f "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 #f "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 #f "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* ((host (if (or (not hostn)
(equal? hostn "-")) ;; use localhost
(get-host-name)
hostn))
(req (or socket
(let ((soc (nn-socket 'req)))
(nn-connect soc (conc "tcp://" host ":" port))
soc)))
(success #t)
(dat (vector "ping" our-key))
(result (condition-case
(nmsg-transport:client-api-send-receive-raw req dat timeout: timeout)
((timeout)(set! success #f) #f)))
(key (if success
(vector-ref result 1)
#f)))
(debug:print 0 #f "success=" success ", key=" key ", expected-key=" expected-key ", equal? " (equal? key expected-key))
(if (and success
(or (not expected-key) ;; just getting a reply is good enough then
(equal? key expected-key)))
(if return-socket
req
(begin
(if (not socket)(nn-close req)) ;; don't want a side effect of closing socket if handed it
#t))
(begin
(if (not socket)(nn-close req)) ;; failed to ping, close socket as side effect
#f))))
;; send data to server, wait max of timeout seconds for a response.
;; return #( success/fail result )
;;
;; for effiency it is easier to do the obj->string and string->obj here.
;;
(define (nmsg-transport:client-api-send-receive-raw socreq indat #!key (enable-send #t)(timeout 25))
(let* ((success #f)
(result #f)
(keepwaiting #t)
(dat (db:obj->string indat transport: 'nmsg))
(send-recv (make-thread
(lambda ()
(nn-send socreq dat)
(let* ((res (nn-recv socreq)))
(set! success #t)
(set! result (db:string->obj res transport: 'nmsg))))
"send-recv"))
(timeout (make-thread
(lambda ()
(let loop ((count 0))
(thread-sleep! 1)
(debug:print-info 1 #f "send-receive-raw, 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! send-recv))))
"timeout")))
;; replace with condition-case?
(handle-exceptions
exn
(set! result "timeout")
(thread-start! timeout)
(thread-start! send-recv)
(thread-join! send-recv)
(if success (thread-terminate! timeout)))
;; raise timeout error if timed out
(if success
(if (and (vector? result)
(vector-ref result 0)) ;; did it fail at the server?
result ;; nope, all good
(begin
(debug:print 0 #f "ERROR: error occured at server, info=" (vector-ref result 2))
(debug:print 0 #f " client call chain:")
(print-call-chain (current-error-port))
(debug:print 0 #f " server call chain:")
(pp (vector-ref result 1) (current-error-port))
(signal (vector-ref result 0))))
(signal (make-composite-condition
(make-property-condition 'timeout 'message "nmsg-transport:client-api-send-receive-raw timed out talking to server"))))))
;; 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 run-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 #f "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))
(server-timeout (let ((tmo (configf:lookup *configdat* "server" "timeout")))
(if (and (string? tmo)
(string->number tmo))
(* 60 60 (string->number tmo))
;; (* 3 24 60 60) ;; default to three days
(* 60 1) ;; default to one minute
;; (* 60 60 25) ;; default to 25 hours
))))
(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)))
(mutex-lock! *heartbeat-mutex*)
(set! last-access *last-db-access*)
(mutex-unlock! *heartbeat-mutex*)
(db:sync-touched *inmemdb* run-id force-sync: #t)
(if (and *server-run*
(> (+ last-access server-timeout)
(current-seconds)))
(begin
(debug:print-info 0 #f "Server continuing, seconds since last db access: " (- (current-seconds) last-access))
(loop 0))
(begin
(debug:print-info 0 #f "Starting to shutdown the server.")
(set! *time-to-exit* #t)
(db:sync-touched *inmemdb* run-id force-sync: #t)
(tasks:server-delete-record (db:delay-if-busy tdbdat) server-id " http-transport:keep-running")
(debug:print-info 0 #f "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)))
;; returns result, there is no sucess/fail flag - handled via excpections
;;
(define (nmsg-transport:client-api-send-receive run-id connection-info cmd param #!key (remtries 5))
;; NB// In the html version of this routine there is a call to
;; tasks:kill-server-run-id when there is an exception
(mutex-lock! *http-mutex*)
(let* ((packet (vector cmd param))
(reqsoc (http-transport:server-dat-get-socket connection-info))
(res (nmsg-transport:client-api-send-receive-raw reqsoc packet)))
;; (status (vector-ref rawres 0))
;; (result (vector-ref rawres 1)))
(mutex-unlock! *http-mutex*)
res)) ;; (vector status (if status (db:string->obj result transport: 'nmsg) result))))
;;======================================================================
;; J U N K
;;======================================================================
;; DO NOT USE
;;
(define (nmsg-transport:client-signal-handler signum)
(handle-exceptions
exn
(debug:print 0 #f " ... 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 #f "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 #f " Done.")
(exit 4))
"exit on ^C timer")))
(thread-start! th2)
(thread-start! th1)
(thread-join! th2))))