74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
-
+
-
+
-
+
-
+
-
+
-
-
+
+
-
+
-
+
-
-
+
+
-
-
+
+
-
-
-
+
+
+
-
-
+
+
-
-
+
+
-
-
+
+
-
-
+
+
-
-
-
-
-
-
+
+
+
+
+
+
-
-
+
+
-
+
|
(if (member cmd '(blah))
(begin
(mutex-lock! *send-receive-mutex*)
(if (not *runremote*)(set! *runremote* (make-remote)))
(let ((ulex:conn (remote-ulex:conn *runremote*)))
(if (not ulex:conn)(remote-ulex:conn-set! *runremote* (rmtmod:setup-ulex *toppath*)))
(rmtmod:send-receive-ulex ulex:conn cmd rid params attemptnum area-dat)))
(rmt:send-receive-orig runremote *rmt-mutex* areapath cmd rid params attemptnum: attemptnum area-dat: area-dat))))
(rmt:send-receive-orig *default-log-port* runremote *rmt-mutex* areapath cmd rid params attemptnum: attemptnum area-dat: area-dat))))
;; RA => e.g. usage (rmt:send-receive 'get-var #f (list varname))
;;
(define (rmt:send-receive-orig runremote rmt-mutex toppath cmd rid params #!key (attemptnum 1)(area-dat #f)) ;; start attemptnum at 1 so the modulo below works as expected
(define (rmt:send-receive-orig log-port runremote rmt-mutex toppath cmd rid params #!key (attemptnum 1)(area-dat #f)) ;; start attemptnum at 1 so the modulo below works as expected
#;(common:telemetry-log (conc "rmt:"(->string cmd))
payload: `((rid . ,rid)
(params . ,params)))
;; do all the prep locked under the rmt-mutex
(mutex-lock! *rmt-mutex*)
(mutex-lock! rmt-mutex)
;; 1. check if server is started IFF cmd is a write OR if we are not on the homehost, store in runremote
;; 2. check the age of the connections. refresh the connection if it is older than timeout-20 seconds.
;; 3. do the query, if on homehost use local access
;;
(let* ((start-time (current-seconds)) ;; snapshot time so all use cases get same value
(readonly-mode (rmtmod:calc-ro-mode runremote *toppath*)))
(readonly-mode (rmtmod:calc-ro-mode runremote toppath)))
;; ensure we have a homehost record
(if (not (pair? (remote-hh-dat runremote))) ;; not on homehost
(thread-sleep! 0.1) ;; since we shouldn't get here, delay a little
(remote-hh-dat-set! runremote (common:get-homehost)))
;;(print "BB> readonly-mode is "readonly-mode" dbfile is "dbfile)
(cond
;; give up if more than 15 attempts
((> attemptnum 15)
(debug:print 0 *default-log-port* "ERROR: 15 tries to start/connect to server. Giving up.")
(debug:print 0 log-port "ERROR: 15 tries to start/connect to server. Giving up.")
(exit 1))
;; readonly mode, read request- handle it - case 2
((and readonly-mode
(member cmd api:read-only-queries))
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 2")
(mutex-unlock! rmt-mutex)
(debug:print-info 12 log-port "rmt:send-receive, case 2")
(rmt:open-qry-close-locally cmd 0 params)
)
;; readonly mode, write request. Do nothing, return #f
(readonly-mode (extras-readonly-mode *rmt-mutex* *default-log-port* cmd params))
(readonly-mode (extras-readonly-mode rmt-mutex log-port cmd params))
;; This block was for pre-emptively resetting the connection if there had been no communication for some time.
;; I don't think it adds any value. If the server is not there, just fail and start a new connection.
;; also, the expire-time calculation might not be correct. We want, time-since-last-server-access > (server:get-timeout)
;;
;; reset the connection if it has been unused too long
((and runremote
(remote-conndat runremote)
(> (current-seconds) ;; if it has been more than server-timeout seconds since last contact, close this connection and start a new on
(+ (http-transport:server-dat-get-last-access (remote-conndat runremote))
(remote-server-timeout runremote))))
(debug:print-info 0 *default-log-port* "Connection to " (remote-server-url runremote) " expired due to no accesses, forcing new connection.")
(debug:print-info 0 log-port "Connection to " (remote-server-url runremote) " expired due to no accesses, forcing new connection.")
(http-transport:close-connections area-dat: runremote)
(remote-conndat-set! runremote #f) ;; invalidate the connection, thus forcing a new connection.
(mutex-unlock! *rmt-mutex*)
(rmt:send-receive-orig runremote rmt-mutex toppath cmd rid params attemptnum: attemptnum))
(mutex-unlock! rmt-mutex)
(rmt:send-receive-orig log-port runremote rmt-mutex toppath cmd rid params attemptnum: attemptnum))
;; on homehost and this is a read
((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
(cdr (remote-hh-dat runremote)) ;; on homehost
(member cmd api:read-only-queries)) ;; this is a read
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 5")
(mutex-unlock! rmt-mutex)
(debug:print-info 12 log-port "rmt:send-receive, case 5")
(rmt:open-qry-close-locally cmd 0 params))
;; on homehost and this is a write, we already have a server, but server has died
((and (cdr (remote-hh-dat runremote)) ;; on homehost
(not (member cmd api:read-only-queries)) ;; this is a write
(remote-server-url runremote) ;; have a server
(not (server:ping (remote-server-url runremote)))) ;; server has died. NOTE: this is not a cheap call! Need better approach.
(set! *runremote* (make-remote))
(remote-force-server-set! runremote (common:force-server?))
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 6")
(rmt:send-receive-orig runremote rmt-mutex toppath cmd rid params attemptnum: attemptnum))
(mutex-unlock! rmt-mutex)
(debug:print-info 12 log-port "rmt:send-receive, case 6")
(rmt:send-receive-orig log-port runremote rmt-mutex toppath cmd rid params attemptnum: attemptnum))
;; on homehost and this is a write, we already have a server
((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
(cdr (remote-hh-dat runremote)) ;; on homehost
(not (member cmd api:read-only-queries)) ;; this is a write
(remote-server-url runremote)) ;; have a server
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 4.1")
(mutex-unlock! rmt-mutex)
(debug:print-info 12 log-port "rmt:send-receive, case 4.1")
(rmt:open-qry-close-locally cmd 0 params))
;; on homehost, no server contact made and this is a write, passively start a server
((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
(cdr (remote-hh-dat runremote)) ;; have homehost
(not (remote-server-url runremote)) ;; no connection yet
(not (member cmd api:read-only-queries))) ;; not a read-only query
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 8")
(let ((server-url (server:check-if-running *toppath*))) ;; (server:read-dotserver->url *toppath*))) ;; (server:check-if-running *toppath*))) ;; Do NOT want to run server:check-if-running - very expensive to do for every write call
(debug:print-info 12 log-port "rmt:send-receive, case 8")
(let ((server-url (server:check-if-running toppath))) ;; (server:read-dotserver->url toppath))) ;; (server:check-if-running toppath))) ;; Do NOT want to run server:check-if-running - very expensive to do for every write call
(if server-url
(remote-server-url-set! runremote server-url) ;; the string can be consumed by the client setup if needed
(if (common:force-server?)
(server:start-and-wait *toppath*)
(server:kind-run *toppath*))))
(server:start-and-wait toppath)
(server:kind-run toppath))))
(remote-force-server-set! runremote (common:force-server?))
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 8.1")
(mutex-unlock! rmt-mutex)
(debug:print-info 12 log-port "rmt:send-receive, case 8.1")
(rmt:open-qry-close-locally cmd 0 params))
((or (and (remote-force-server runremote) ;; we are forcing a server and don't yet have a connection to one
(not (remote-conndat runremote)))
(and (not (cdr (remote-hh-dat runremote))) ;; not on a homehost
(not (remote-conndat runremote)))) ;; and no connection
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 9, hh-dat: " (remote-hh-dat runremote) " conndat: " (remote-conndat runremote))
(mutex-unlock! *rmt-mutex*)
(if (not (server:check-if-running *toppath*)) ;; who knows, maybe one has started up?
(server:start-and-wait *toppath*))
(remote-conndat-set! runremote (rmt:get-connection-info *toppath*)) ;; calls client:setup which calls client:setup-http
(rmt:send-receive-orig runremote rmt-mutex toppath cmd rid params attemptnum: attemptnum)) ;; TODO: add back-off timeout as
(debug:print-info 12 log-port "rmt:send-receive, case 9, hh-dat: " (remote-hh-dat runremote) " conndat: " (remote-conndat runremote))
(mutex-unlock! rmt-mutex)
(if (not (server:check-if-running toppath)) ;; who knows, maybe one has started up?
(server:start-and-wait toppath))
(remote-conndat-set! runremote (rmt:get-connection-info toppath)) ;; calls client:setup which calls client:setup-http
(rmt:send-receive-orig log-port runremote rmt-mutex toppath cmd rid params attemptnum: attemptnum)) ;; TODO: add back-off timeout as
;; all set up if get this far, dispatch the query
((and (not (remote-force-server runremote))
(cdr (remote-hh-dat runremote))) ;; we are on homehost
(mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 10")
(mutex-unlock! rmt-mutex)
(debug:print-info 12 log-port "rmt:send-receive, case 10")
(rmt:open-qry-close-locally cmd (if rid rid 0) params))
;; not on homehost, do server query
(else (extras-case-11 *default-log-port* runremote cmd params attemptnum rid)))))
(else (extras-case-11 log-port runremote cmd params attemptnum rid)))))
;; bunch of small functions factored out of send-receive to make debug easier
;;
(define (extras-case-11 *default-log-port* runremote cmd params attemptnum rid)
;; (mutex-unlock! *rmt-mutex*)
(debug:print-info 12 *default-log-port* "rmt:send-receive, case 9")
|