;;======================================================================
;; Copyright 2019, Matthew Welland.
;;
;; This file is part of Megatest.
;;
;; Megatest is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; Megatest is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with Megatest. If not, see <http://www.gnu.org/licenses/>.
;;======================================================================
(declare (unit rmtmod))
(declare (uses commonmod))
(module rmtmod
*
(import scheme chicken data-structures extras)
(import (prefix sqlite3 sqlite3:) posix typed-records srfi-18)
(import commonmod)
(use (prefix ulex ulex:))
(define (member:print msg x lst)
(print "member-" msg ": x=" x " lst=" lst)
(member x lst))
;; Hack to make these functions visible to the refactored code, goal is to eliminate these over time.
(define (rmt:send-receive . params) #f)
(define (http-transport:close-connections . params) #f)
;; from remote defstruct in common.scm
(define (remote-conndat-set! . params) #f)
(define (remote-server-url-set! . params) #f)
(define (remote-ro-mode . params) #f)
(define (remote-ro-mode-set! . params) #f)
(define (remote-ro-mode-checked-set! . params) #f)
(define (remote-ro-mode-checked . params) #f)
(define (debug:print . params) #f)
(define (debug:print-info . params) #f)
(define (debug:print-error . params) #f)
(define (db:dbfile-path . params) #f)
(define (db:setup . params) #f)
(define (api:execute-requests . params) #f)
(define (set-functions send-receive rsus
close-connections rcs
dbgp dbgpinfo
dbgperr
ro-mode ro-mode-set
ro-mode-checked-set ro-mode-checked
dbfile-path dbsetup
exec-req read-only-queries
)
(set! rmt:send-receive send-receive)
(set! remote-server-url-set! rsus)
(set! http-transport:close-connections close-connections)
(set! remote-conndat-set! rcs)
;; print stuff
(set! debug:print dbgp)
(set! debug:print-info dbgpinfo)
(set! debug:print-error dbgperr)
;;
(set! remote-ro-mode ro-mode)
(set! remote-ro-mode-set! ro-mode-set)
(set! remote-ro-mode-checked-set! ro-mode-checked-set)
(set! remote-ro-mode-checked ro-mode-checked)
;; db stuff for local db access
(set! db:dbfile-path dbfile-path)
(set! db:setup dbsetup)
(set! apt:execute-requests exec-req)
)
(define (rmt:open-qry-close-locally log-port multi-sync-mutex cmd run-id params #!key (ro-queries '())(remretries 5))
(let* ((qry-is-write (not (member:print "#1" cmd ro-queries)))
(db-file-path (db:dbfile-path)) ;; 0))
(dbstruct-local (db:setup #t)) ;; make-dbr:dbstruct path: dbdir local: #t)))
(read-only (not (file-write-access? db-file-path)))
(start (current-milliseconds))
(resdat (if (not (and read-only qry-is-write))
(let ((v (api:execute-requests dbstruct-local (vector (symbol->string cmd) params))))
(handle-exceptions ;; there has been a long history of receiving strange errors from values returned by the client when things go wrong..
exn ;; This is an attempt to detect that situation and recover gracefully
(begin
(debug:print 0 log-port "ERROR: bad data from server " v " message: " ((condition-property-accessor 'exn 'message) exn))
(vector #t '())) ;; should always get a vector but if something goes wrong return a dummy
(if (and (vector? v)
(> (vector-length v) 1))
(let ((newvec (vector (vector-ref v 0)(vector-ref v 1))))
newvec) ;; by copying the vector while inside the error handler we should force the detection of a corrupted record
(vector #t '())))) ;; we could also check that the returned types are valid
(vector #t '())))
(success (vector-ref resdat 0))
(res (vector-ref resdat 1))
(duration (- (current-milliseconds) start)))
(if (and read-only qry-is-write)
(debug:print 0 log-port "ERROR: attempt to write to read-only database ignored. cmd=" cmd))
(if (not success)
(if (> remretries 0)
(begin
(debug:print-error 0 log-port "local query failed. Trying again.")
(thread-sleep! (/ (random 5000) 1000)) ;; some random delay
(rmt:open-qry-close-locally log-port multi-sync-mutex cmd run-id params ro-queries: ro-queries remretries: (- remretries 1)))
(begin
(debug:print-error 0 log-port "too many retries in rmt:open-qry-close-locally, giving up")
#f))
(begin
;; (rmt:update-db-stats run-id cmd params duration)
;; mark this run as dirty if this was a write, the watchdog is responsible for syncing it
#;(if qry-is-write
(let ((start-time (current-seconds)))
(mutex-lock! multi-sync-mutex)
(set! *db-last-access* start-time) ;; THIS IS PROBABLY USELESS? (we are on a client)
(mutex-unlock! multi-sync-mutex)))))
res))
(define (rmtmod:calc-ro-mode runremote toppath)
(if (and runremote
(remote-ro-mode-checked runremote))
(remote-ro-mode runremote)
(let* ((dbfile (conc toppath "/megatest.db"))
(ro-mode (not (file-write-access? dbfile)))) ;; TODO: use dbstruct or runremote to figure this out in future
(if runremote
(begin
(remote-ro-mode-set! runremote ro-mode)
(remote-ro-mode-checked-set! runremote #t)
ro-mode)
ro-mode))))
(define (extras-readonly-mode rmt-mutex log-port cmd params)
;;(mutex-unlock! rmt-mutex)
(debug:print-info 12 log-port "rmt:send-receive, case 3")
(debug:print 0 log-port "WARNING: write transaction requested on a readonly area. cmd="cmd" params="params)
#f)
(define (extras-transport-failed *default-log-port* *rmt-mutex* attemptnum runremote cmd rid params)
(debug:print 0 *default-log-port* "WARNING: communication failed. Trying again, try num: " attemptnum)
;;(mutex-lock! *rmt-mutex*)
(remote-conndat-set! runremote #f)
(http-transport:close-connections area-dat: runremote)
(remote-server-url-set! runremote #f)
;;(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 9.1")
(rmt:send-receive cmd rid params attemptnum: (+ attemptnum 1)))
(define (extras-transport-succeded *default-log-port* *rmt-mutex* attemptnum runremote res params rid cmd)
(if (and (vector? res)
(eq? (vector-length res) 2)
(eq? (vector-ref res 1) 'overloaded)) ;; since we are
;; looking at the
;; data to carry the
;; error we'll use a
;; fairly obtuse
;; combo to minimise
;; the chances of
;; some sort of
;; collision. this
;; is the case where
;; the returned data
;; is bad or the
;; server is
;; overloaded and we
;; want to ease off
;; the queries
(let ((wait-delay (+ attemptnum (* attemptnum 10))))
(debug:print 0 *default-log-port* "WARNING: server is overloaded. Delaying " wait-delay " seconds and trying call again.")
;;(mutex-lock! *rmt-mutex*)
(http-transport:close-connections area-dat: runremote)
(set! *runremote* #f) ;; force starting over
;;(mutex-unlock! *rmt-mutex*)
(thread-sleep! wait-delay)
(rmt:send-receive cmd rid params attemptnum: (+ attemptnum 1)))
res)) ;; All good, return res
;;======================================================================
;; ulex and steps stuff
;;======================================================================
(define (rmtmod:setup-ulex toppath)
(ulex:make-area
dbdir: (conc toppath "/ulexdb")
pktsdir: (conc toppath "/pkts")
))
(define (rmtmod:send-receive-ulex ulex:conn cmd rid params attemptnum area-dat)
#f)
(use trace)(trace-call-sites #t)
(trace member rmtmod:calc-ro-mode rmt:open-qry-close-locally member:print)
)