pasterack/pasterack.rkt

270 lines
11 KiB
Racket

#lang racket
(require web-server/servlet
web-server/dispatch)
(require xml xml/path)
(require racket/system racket/runtime-path)
(require redis
data/ring-buffer)
(require "pasterack-utils.rkt")
(provide/contract (start (request? . -> . response?)))
(define-runtime-path htdocs-dir "htdocs")
(define-runtime-path here ".")
(define-runtime-path tmp-dir "tmp")
(define pastebin-url "http://www.pasterack.org/")
(define paste-url-base (++ pastebin-url "pastes/"))
(define racket-docs-url "http://docs.racket-lang.org/")
(define racket-lang-url "http://racket-lang.org")
(define racket-logo-url "http://racket-lang.org/logo.png")
(define (mk-paste-url paste-num) (++ paste-url-base paste-num))
;; the top.location breaks out of the current frame
(define (mk-link url txt)
`(a ((href ,url) (onclick ,(++ "top.location.href=\"" url "\""))) ,txt))
(define (fresh-str)
(let loop () (define str (mk-rand-str)) (if (EXISTS str) (loop) str)))
(define NUM-RECENT-PASTES 10)
(define recent-pastes (empty-ring-buffer NUM-RECENT-PASTES))
;; initialize buffer with some pastes
(ring-buffer-push! recent-pastes "9965")
(ring-buffer-push! recent-pastes "3542")
(ring-buffer-push! recent-pastes "3414")
(ring-buffer-push! recent-pastes "5237")
(ring-buffer-push! recent-pastes "9647")
(ring-buffer-push! recent-pastes "5434")
;; returns output file name (as path), or #f on fail
(define (write-codeblock-scrbl-file code)
(define tmp-name (mk-rand-str))
(define tmp-scrbl-file (build-path tmp-dir (++ tmp-name ".scrbl")))
(with-output-to-file tmp-scrbl-file
(lambda () (printf (++ "#lang scribble/manual\n"
"@(require (for-label racket))\n"
"@codeblock{\n~a}")
code))
#:mode 'text
#:exists 'replace)
tmp-name)
(define (write-eval-scrbl-file code)
;; parse out #lang if it's there
(define lang-match (regexp-match #px"^\\#lang ([\\w/]+)\\s*(.*)" code))
(define-values (code-no-lang lang)
(match lang-match [(list _ lang rst) (values rst lang)]
[_ (values code "racket")]))
(define tmp-name (mk-rand-str))
(define tmp-scrbl-file (build-path tmp-dir (++ tmp-name ".scrbl")))
(with-output-to-file tmp-scrbl-file
(lambda ()
(printf (++ "#lang scribble/manual\n"
"@(require scribble/eval)\n"
"@(define the-eval (make-base-eval"
(if (string=? "racket" lang) "" (++ " #:lang '" lang))
"))\n"
"@interaction[#:eval the-eval\n~a]")
code-no-lang))
#:mode 'text
#:exists 'replace)
tmp-name)
(define (compile-scrbl-file/get-html name)
(and
(system (++ "/home/stchang/pltpkg/racket/bin/scribble --html +m "
"--redirect-main " racket-docs-url " "
"--dest " (path->string tmp-dir) " "
(path->string (build-path tmp-dir (++ name ".scrbl")))))
(with-input-from-file (build-path tmp-dir (++ name ".html")) port->bytes)))
(define (compile-eval-scrbl-file/get-html name)
(and
(system (++ "/home/stchang/pltpkg/racket/bin/scribble --html "
"--dest " (path->string tmp-dir) " "
(path->string (build-path tmp-dir (++ name ".scrbl")))))
(with-input-from-file (build-path tmp-dir (++ name ".html")) port->bytes)))
(define (generate-paste-html code)
(compile-scrbl-file/get-html (write-codeblock-scrbl-file code)))
(define (generate-eval-html code)
(compile-eval-scrbl-file/get-html (write-eval-scrbl-file code)))
(define google-analytics-script
(++ "var _gaq = _gaq || [];\n"
"_gaq.push(['_setAccount', 'UA-44480001-1']);\n"
"_gaq.push(['_trackPageview']);\n"
"(function() {\n"
"var ga = document.createElement('script'); "
"ga.type = 'text/javascript'; ga.async = true;\n"
"ga.src = ('https:' == document.location.protocol "
"? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';\n"
"var s = document.getElementsByTagName('script')[0];"
"s.parentNode.insertBefore(ga, s);\n"
"})();"))
(define (serve-home request)
(define (response-generator embed/url)
(response/xexpr
`(html
(head
(title "PasteRack: The Racket pastebin.")
(script ((type "text/javascript")) ,google-analytics-script))
(body
(center
(img ((src ,racket-logo-url)))
(h1 ,(mk-link pastebin-url "PasteRack") ": The "
,(mk-link racket-lang-url "Racket") " pastebin.")
(form ((action ,(embed/url process-paste)) (method "post"))
(textarea ((rows "20") (cols "79") (name "paste")))
(br)
(input ((type "submit") (value "Submit Paste"))))
(br)
(h3 "Total pastes: " ,(number->string (DBSIZE)))
(h3 "Recent pastes:")
,@(apply append
(reverse
(for/list ([pnum recent-pastes] #:when pnum)
(list (mk-link (mk-paste-url pnum) pnum) '(br))))))))))
(send/suspend/dispatch response-generator))
(define (process-paste request)
(define bs (request-bindings request))
(cond
[(exists-binding? 'paste bs)
(define paste-num (fresh-str))
(define pasted-code (extract-binding/single 'paste bs))
(define html-res (generate-paste-html pasted-code))
(define paste-html-str (or html-res pasted-code))
(define eval-html-str (and html-res (generate-eval-html pasted-code)))
(define paste-url (mk-paste-url paste-num))
(ring-buffer-push! recent-pastes paste-num)
(SET/hash paste-num (hash 'code paste-html-str
'eval (or eval-html-str "")
'time (get-time/iso8601)))
(response/xexpr
`(html ()
(head ()
(script () ,(++ "top.location.href=\"" paste-url "\"")))
(body ())))]
[else
(response/xexpr
`(html ()
(head ())
(body () "ERROR: bad paste" ,(mk-link pastebin-url "Go Back"))))]))
(define (get-main-div html-bytes)
(with-handlers ([exn:fail? (lambda (x) (bytes->string/utf-8 html-bytes))])
(car (filter
(lambda (d) (equal? "main" (se-path* '(div #:class) d)))
(se-path*/list '(div)
(xml->xexpr (document-element
(with-input-from-bytes html-bytes read-xml))))))))
(define (serve-paste request pastenum)
(define retrieved-paste-hash (GET/hash pastenum #:map-key bytes->symbol))
(cond
[(equal? (hash) retrieved-paste-hash)
(response/xexpr
`(html() (head ())
(body ()
,(format "Paste # ~a doesn't exist." pastenum) (br)
,(mk-link pastebin-url "Go Back"))))]
[else
(match-define (hash-table ('code code-html)
('eval eval-html)
('time time-str)) retrieved-paste-hash)
(define code-main-div (get-main-div code-html))
(define eval-main-div (get-main-div eval-html))
(define paste-url (string-append paste-url-base pastenum))
(response/xexpr
`(html ()
(head ()
(meta ((content "text-html; charset=utf-8")
(http-equiv "content-type")))
(title ())
(link ((href "/scribble.css") (rel "stylesheet")
(title "default") (type "text/css")))
(link ((href "/racket.css") (rel "stylesheet")
(title "default") (type "text/css")))
(link ((href "/scribble-style.css") (rel "stylesheet")
(title "default") (type "text/css")))
(script ((src "/scribble-common.js") (type "text/javascript"))))
(body ()
(div () ,(mk-link pastebin-url "Paste")
" # " (a ((href ,paste-url)) ,pastenum) (br)
(small ,(bytes->string/utf-8 time-str)) (br))
(div ((class "maincolumn"))
,(match code-main-div
[`(div ((class "main")) ,ver ,body)
`(div ((class "main"))
,body
(p "=>")
,(match eval-main-div
[`(div ((class "main")) ,ver
(blockquote ,attr1 (table ,attr2 . ,results)))
`(blockquote ,attr1 (table ,attr2 .
,(filter
identity
(map
(lambda (x)
;; (printf "~v\n" x)
;; (flush-output)
(match x
;; single-line evaled expr (with ">" prompt), skip
[`(tr () (td () (span ((class "stt")) ">" " ") . ,rst))
#f]
;; multi-line evaled expr
[`(tr () (td ()
(table ((cellspacing "0")
(class "RktBlk"))
(tr () (td () (span ((class "stt")) ">" " ")
. ,rst1)) . ,rst))) #f]
;; void result, skip
[`(tr () (td () (table ,attr (tr () (td ()))))) #f]
;; fix filename in image link
[`(tr () (td () (p () (img
((alt "image") ,height
(src ,filename) ,width)))))
;; rename file to avoid future clashes
(define rxmatch
(regexp-match #px"^(pict|\\d+)\\_*(\\d+)*\\.png"
filename))
(unless rxmatch
(error "scribble made non-pict.png ~a" filename))
(match-define (list _ base offset) rxmatch)
(define new-file
(++ pastenum (if offset (++ "_" offset) "") ".png"))
(define curr-file-path (build-path tmp-dir filename))
(define new-file-path (build-path tmp-dir new-file))
(unless (file-exists? new-file-path)
(copy-file curr-file-path new-file-path)
(delete-file curr-file-path))
`(tr () (td () (p () (img
((alt "image") ,height
(src ,(++ "/" new-file)) ,width)))))]
[x x]))
results))))]
[_ `(div ,eval-main-div)]))]
[_ `(div ,code-main-div)])))))]))
(define-values (do-dispatch mk-url)
(dispatch-rules
[("") serve-home]
[("pastes" (string-arg)) serve-paste]
#;[else serve-home]))
(current-redis-connection (connect))
(define (start request) (do-dispatch request))
(require web-server/servlet-env)
(serve/servlet start
#:launch-browser? #f
#:quit? #f
#:listen-ip #f
#:port 8000
#:extra-files-paths (list tmp-dir htdocs-dir)
#:servlet-path "/"
#:servlet-regexp #rx".*")