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racketmq-2017
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Add upstream polling

This commit is contained in:
Tony Garnock-Jones 2016-10-31 19:34:58 -04:00
parent 9a98bcac0d
commit 38e6510b52
2 changed files with 122 additions and 37 deletions
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1
rmq/poke.rkt
View File

@ -91,6 +91,7 @@
#:body (string->bytes/utf-8 #:body (string->bytes/utf-8
(alist->form-urlencoded (alist->form-urlencoded
`((hub.callback . "http://localhost:7000/sink") `((hub.callback . "http://localhost:7000/sink")
(hub.poll_interval_seconds . "10")
(hub.mode . "subscribe") (hub.mode . "subscribe")
(hub.topic . ,topic)))))) (hub.topic . ,topic))))))

158
rmq/server.rkt
View File

@ -8,6 +8,7 @@
(require racket/set) (require racket/set)
(require net/url) (require net/url)
(require net/uri-codec) (require net/uri-codec)
(require file/sha1)
(require/activate syndicate/drivers/timer) (require/activate syndicate/drivers/timer)
(require/activate syndicate/drivers/timestate) (require/activate syndicate/drivers/timestate)
@ -27,17 +28,22 @@
;; and numbers indicate a moment in time as a Unix epoch timestamp as ;; and numbers indicate a moment in time as a Unix epoch timestamp as
;; might be returned from `current-seconds`. ;; might be returned from `current-seconds`.
;; (notification Topic Bytes String (Option URIString)) ;; (notification Topic Bytes (Option String))
(struct notification (topic-name content content-type) #:prefab) (struct notification (topic-name content content-type) #:prefab)
;; (subscription Topic Deadline URLString URLString (Option Bytes)) (struct subscription (topic-name ;; Topic
(struct subscription (topic-name expiry-deadline canonical-hub callback secret) #:prefab) expiry-deadline ;; Deadline
canonical-hub ;; URLString
callback ;; URLString
secret ;; Option Bytes
poll-interval-seconds) ;; Option Number
#:prefab)
;; (local-topic-config Topic (Option Number) (Option Number)) ;; (local-topic-config Topic (Option Number) (Option Number))
(struct local-topic-config (name max-age max-count) #:prefab) (struct local-topic-config (name max-age max-count) #:prefab)
;; (topic-demand Topic) ;; (topic-demand Topic (Option Number))
(struct topic-demand (topic-name) #:prefab) (struct topic-demand (topic-name poll-interval-seconds) #:prefab)
;; (local-topic-demand String) ;; (local-topic-demand String)
(struct local-topic-demand (name) #:prefab) (struct local-topic-demand (name) #:prefab)
@ -115,7 +121,7 @@
(actor #:name 'topic-demand-analyzer (actor #:name 'topic-demand-analyzer
(define/query-set local-hosts (local-host $host-name) host-name) (define/query-set local-hosts (local-host $host-name) host-name)
(during/actor (topic-demand $full-topic) (during/actor (topic-demand $full-topic _)
#:name (list 'general-topic full-topic) #:name (list 'general-topic full-topic)
#:let [(local-hosts-snapshot (local-hosts))] #:let [(local-hosts-snapshot (local-hosts))]
(with-handlers [(exn? (lambda (e) (with-handlers [(exn? (lambda (e)
@ -124,11 +130,10 @@
(url->resource (string->url full-topic))) (url->resource (string->url full-topic)))
(define maybe-local-topic (define maybe-local-topic
(match topic-path [`("topic" (,topic ())) topic] [_ #f])) (match topic-path [`("topic" (,topic ())) topic] [_ #f]))
(on-start (general-topic-main full-topic
(general-topic-main full-topic topic-host
topic-host maybe-local-topic
maybe-local-topic (set-member? local-hosts-snapshot topic-host)))))
(set-member? local-hosts-snapshot topic-host))))))
(define (general-topic-main full-topic topic-host maybe-local-topic start-as-local?) (define (general-topic-main full-topic topic-host maybe-local-topic start-as-local?)
(define (local-state) (define (local-state)
@ -139,17 +144,25 @@
(react (stop-when #:when maybe-local-topic (asserted (local-host topic-host)) (local-state)) (react (stop-when #:when maybe-local-topic (asserted (local-host topic-host)) (local-state))
(remote-topic-main full-topic))) (remote-topic-main full-topic)))
(if (and maybe-local-topic start-as-local?) (on-start
(local-state) (if (and maybe-local-topic start-as-local?)
(remote-state))) (local-state)
(remote-state))))
(define (req-content-type req) (define (req-content-type req)
(dict-ref (web-request-header-headers req) 'content-type "application/octet-stream")) (dict-ref (web-request-header-headers req) 'content-type #f))
(define (canonical-url canonical-host-name path)
(url->string (resource->url (web-resource (vh canonical-host-name) path))))
(define (local-topic-main topic) (define (local-topic-main topic)
(field [max-age #f] (field [max-age #f]
[max-count #f]) [max-count #f])
(field [current-content #f]
[current-content-type #f]
[last-modified-seconds #f])
(on (asserted (local-topic-config topic $age $count)) (on (asserted (local-topic-config topic $age $count))
(max-age age) (max-age age)
(max-count count)) (max-count count))
@ -163,25 +176,80 @@
(on-stop (log-info "Terminating local topic ~v" topic)) (on-stop (log-info "Terminating local topic ~v" topic))
(during (local-host $host-name) (during (local-host $host-name)
(during (canonical-local-host $canonical-host-name)
(define hub-url (canonical-url canonical-host-name `("hub" ())))
(define self-url (canonical-url canonical-host-name `("topic" (,topic ()))))
(define discovery-headers (list (cons 'link (format "<~a>; rel=hub" hub-url))
(cons 'link (format "<~a>; rel=self" self-url))))
(on (web-request-get (id req) (vh host-name) ("topic" (,topic ())))
(if (current-content)
(web-respond/bytes! id
#:header (web-response-header
#:last-modified-seconds (last-modified-seconds)
#:mime-type (and (current-content-type)
(string->bytes/utf-8
(current-content-type)))
#:headers discovery-headers)
(current-content))
(web-respond/bytes! id
#:header (web-response-header
#:code 204
#:message #"No Content"
#:mime-type #f
#:headers discovery-headers)
#"")))) ;; MUST NOT include a response body for 204
(on (web-request-incoming (id req) (vh host-name) 'post ("topic" (,topic ())) $body) (on (web-request-incoming (id req) (vh host-name) 'post ("topic" (,topic ())) $body)
(define content-type (req-content-type req))
(log-info "Local topic ~a got ~v message ~v" topic content-type body)
(current-content body)
(current-content-type content-type)
(last-modified-seconds (current-seconds))
(actor* (actor*
(define content-type (req-content-type req))
(log-info "Local topic ~a got ~v message ~v" topic content-type body)
(define full-topic (url->string (resource->url (web-request-header-resource req)))) (define full-topic (url->string (resource->url (web-request-header-resource req))))
(send! (notification full-topic body content-type)) (send! (notification full-topic body content-type))
(web-respond/status! id 201 #"Created"))))) (web-respond/status! id 201 #"Created")))))
(define (maintain-remote-subscription full-topic canonical-host-name sub-id) (define (maintain-remote-subscription full-topic canonical-host-name sub-id)
(define callback (url->string (define callback (canonical-url canonical-host-name `("sub" (,sub-id ()))))
(resource->url
(web-resource (vh canonical-host-name) `("sub" (,sub-id ()))))))
(react (react
(field [next-upstream-check (current-inexact-milliseconds)]) (field [last-upstream-check 0]
(on (asserted (later-than (next-upstream-check))) [poll-interval-seconds #f])
(log-info "Rechecking upstream for ~a" full-topic)
(field [current-content-hash #f]
[current-content-type #f])
(define/query-set poll-intervals (topic-demand full-topic $i) i)
(begin/dataflow
(poll-interval-seconds (for/fold [(i #f)] [(candidate (in-set (poll-intervals)))]
(cond [(not i) candidate]
[(< candidate i) candidate]
[else i]))))
(begin/dataflow
(log-info "Poll interval for ~a is now ~a"
full-topic
(match (poll-interval-seconds)
[#f "disabled"]
[n (format "~a seconds" n)])))
(on (asserted (later-than (+ (last-upstream-check) (* 1000 (or (poll-interval-seconds) 0)))))
(log-info "Checking upstream ~a" full-topic)
(define-values (resp response-body) (define-values (resp response-body)
(web-request! 'get full-topic #:redirect-budget 5)) (web-request! 'get full-topic #:redirect-budget 5))
(log-info "Resource: ~v" resp)))) (last-upstream-check (current-inexact-milliseconds))
(match (web-response-header-code-type resp)
['successful
(define new-content-hash (sha1 (open-input-bytes response-body)))
(define new-content-type (dict-ref (web-response-header-headers resp) 'content-type #f))
(when (not (and (equal? (current-content-hash) new-content-hash)
(equal? (current-content-type) new-content-type)))
(current-content-hash new-content-hash)
(current-content-type new-content-type)
(send! (notification full-topic response-body new-content-type)))]
[other
(log-warning "Upstream ~a yielded ~a code ~a"
full-topic
other
(web-response-header-code resp))]))))
(define (remote-topic-main full-topic) (define (remote-topic-main full-topic)
(define sub-id (random-hex-string 16)) (define sub-id (random-hex-string 16))
@ -218,6 +286,10 @@
(match (hash-ref params 'hub.lease_seconds "unbounded") (match (hash-ref params 'hub.lease_seconds "unbounded")
["unbounded" #f] ["unbounded" #f]
[n (string->number n)])) [n (string->number n)]))
(define poll-interval-seconds
(match (hash-ref params 'hub.poll_interval_seconds "none")
["none" #f]
[n (string->number n)]))
(define secret-string (hash-ref params 'hub.secret #f)) (define secret-string (hash-ref params 'hub.secret #f))
(define secret-bytes (and secret-string (string->bytes/utf-8 secret-string))) (define secret-bytes (and secret-string (string->bytes/utf-8 secret-string)))
(define expiry-deadline (and lease-seconds (+ (current-seconds) lease-seconds))) (define expiry-deadline (and lease-seconds (+ (current-seconds) lease-seconds)))
@ -230,9 +302,13 @@
topic topic
callback) callback)
(begin (begin
(retract! (subscription topic ? ? callback ?)) (retract! (subscription topic ? ? callback ? ?))
(assert! (assert! (subscription topic
(subscription topic expiry-deadline canonical-hub callback secret-bytes)) expiry-deadline
canonical-hub
callback
secret-bytes
poll-interval-seconds))
#t) #t)
#f)] #f)]
['unsubscribe ['unsubscribe
@ -241,16 +317,16 @@
topic topic
callback) callback)
(begin (begin
(retract! (subscription topic ? ? callback ?)) (retract! (subscription topic ? ? callback ? ?))
#t) #t)
#f)]))) #f)])))
(if ok? (if ok?
(web-respond/status! id 202 #"Accepted") (web-respond/status! id 202 #"Accepted")
(web-respond/status! id 403 #"Forbidden" #"Validation failed")))) (web-respond/status! id 403 #"Forbidden" #"Validation failed"))))
(during/actor (subscription $partial-topic _ _ $callback _) (during/actor (subscription $partial-topic _ _ $callback _ _)
#:name (list 'subscription partial-topic callback) #:name (list 'subscription partial-topic callback)
#:on-crash (retract! (subscription partial-topic ? ? callback ?)) #:on-crash (retract! (subscription partial-topic ? ? callback ? ?))
(subscription-main partial-topic callback))) (subscription-main partial-topic callback)))
(define (subscription-change-validate mode lease topic callback) (define (subscription-change-validate mode lease topic callback)
@ -289,14 +365,16 @@
(define-values (n newq) (dequeue (message-queue))) (define-values (n newq) (dequeue (message-queue)))
(message-queue newq) (message-queue newq)
(match-define (notification topic body content-type) n) (match-define (notification topic body content-type) n)
(define link-headers (list (cons 'link (format "<~a>; rel=hub" canonical-hub))
(cons 'link (format "<~a>; rel=self" topic))))
(let deliver-one ((retries-remaining 1) (let deliver-one ((retries-remaining 1)
(retry-delay 5.0)) (retry-delay 5.0))
(define-values (resp _body) (define-values (resp _body)
(web-request! 'post (web-request! 'post
callback callback
#:headers (list (cons 'content-type content-type) #:headers (if content-type
(cons 'link (format "<~a>; rel=hub" canonical-hub)) (cons (cons 'content-type content-type) link-headers)
(cons 'link (format "<~a>; rel=self" topic))) link-headers)
#:body body)) #:body body))
(cond (cond
[(eq? (web-response-header-code-type resp) 'successful) [(eq? (web-response-header-code-type resp) 'successful)
@ -317,17 +395,23 @@
(min (* retry-delay 1.618) 30))])))) (min (* retry-delay 1.618) 30))]))))
(delivery-active? #f)) (delivery-active? #f))
(during (subscription partial-topic $expiry-deadline $canonical-hub callback $secret-bytes) (during (subscription partial-topic
$expiry-deadline
$canonical-hub
callback
$secret-bytes
$poll-interval-seconds)
(define topic (url->string (combine-url/relative (canonical-topic-base-url canonical-hub) (define topic (url->string (combine-url/relative (canonical-topic-base-url canonical-hub)
partial-topic))) partial-topic)))
(assert (topic-demand topic)) (assert (topic-demand topic poll-interval-seconds))
(on-start (log-info "Subscription configured: ~v ~v ~v ~v" (on-start (log-info "Subscription configured: ~v ~v ~v ~v ~v"
topic topic
expiry-deadline expiry-deadline
canonical-hub canonical-hub
secret-bytes) secret-bytes
poll-interval-seconds)
(cond (cond
[expiry-deadline [expiry-deadline
(expiry-timer-id (gensym 'subscription-expiry)) (expiry-timer-id (gensym 'subscription-expiry))