(U 'old->new
'new->old))
+(define-type Result
+ (∀ (α β) (U (cons 'ok α)
+ (cons 'error β))))
+
(struct Msg
([ts-epoch : Integer]
[ts-orig : String]
[uri : Url])
#:transparent)
+(struct Resp
+ ([status-line : String]
+ [headers : (Listof Bytes)]
+ [body-input : Input-Port])
+ #:transparent)
+
(: tt-home-dir Path-String)
(define tt-home-dir (build-path (expand-user-path "~") ".tt"))
[(list val) val]
[_ #f]))
-(: uri-download (-> Url Void))
-(define (uri-download u)
+(: uri-download-from-port
+ (-> Url (Listof (U Bytes String)) Input-Port
+ (U 'skipped-cached 'downloaded-new))) ; TODO 'ok|'error ?
+(define (uri-download-from-port u headers body-input)
+ (define u-str (url->string u))
+ (log-debug "uri-download-from-port ~v into ~v" u-str cached-object-path)
(define cached-object-path (url->cache-object-path u))
(define cached-etag-path (url->cache-etag-path u))
(define cached-lmod-path (url->cache-lmod-path u))
- (log-debug "uri-download ~v into ~v" u cached-object-path)
- (define-values (status-line headers body-input)
- ; TODO Timeout. Currently hangs on slow connections.
- (http-sendrecv/url u #:headers (list (format "User-Agent: ~a" user-agent))))
- (log-debug "headers: ~v" headers)
- (log-debug "status-line: ~v" status-line)
- (define status
- (string->number (second (string-split (bytes->string/utf-8 status-line)))))
- (log-debug "status: ~v" status)
- ; TODO Handle redirects
- (match status
- [200
- (let* ([etag (header-get headers #"ETag")]
- [lmod (header-get headers #"Last-Modified")]
- [lmod-curr (if lmod (rfc2822->epoch lmod) #f)]
- [lmod-prev (if (file-exists? cached-lmod-path)
- (rfc2822->epoch (file->bytes cached-lmod-path))
- #f)])
- (log-debug "lmod-curr:~v lmod-prev:~v" lmod-curr lmod-prev)
- (unless (or (and etag
- (file-exists? cached-etag-path)
- (bytes=? etag (file->bytes cached-etag-path))
- (begin
- (log-info "ETags match, skipping the rest of ~v" (url->string u))
- #t))
- (and lmod-curr
- lmod-prev
- (<= lmod-curr lmod-prev)
- (begin
- (log-info "Last-Modified <= current skipping the rest of ~v" (url->string u))
- #t)))
- (begin
- (log-info
- "Downloading the rest of ~v. ETag: ~a, Last-Modified: ~v"
- (url->string u) etag lmod)
- (make-parent-directory* cached-object-path)
- (make-parent-directory* cached-etag-path)
- (make-parent-directory* cached-lmod-path)
- (call-with-output-file cached-object-path
- (curry copy-port body-input)
- #:exists 'replace)
- (when etag
- (display-to-file etag cached-etag-path #:exists 'replace))
- (when lmod
- (display-to-file lmod cached-lmod-path #:exists 'replace))))
- (close-input-port body-input))]
- [_
- (raise status)]))
+ (define etag (header-get headers #"ETag"))
+ (define lmod (header-get headers #"Last-Modified"))
+ (define lmod-curr (if lmod (rfc2822->epoch lmod) #f))
+ (define lmod-prev (if (file-exists? cached-lmod-path)
+ (rfc2822->epoch (file->bytes cached-lmod-path))
+ #f))
+ (log-debug "lmod-curr:~v lmod-prev:~v" lmod-curr lmod-prev)
+ (define cached?
+ (or (and etag
+ (file-exists? cached-etag-path)
+ (bytes=? etag (file->bytes cached-etag-path))
+ (begin
+ (log-debug "ETags match, skipping the rest of ~v" u-str)
+ #t))
+ (and lmod-curr
+ lmod-prev
+ (<= lmod-curr lmod-prev)
+ (begin
+ (log-debug "Last-Modified <= current skipping the rest of ~v" u-str)
+ #t))))
+ (if (not cached?)
+ (begin
+ (log-debug
+ "Downloading the rest of ~v. ETag: ~a, Last-Modified: ~v"
+ u-str etag lmod)
+ (make-parent-directory* cached-object-path)
+ (make-parent-directory* cached-etag-path)
+ (make-parent-directory* cached-lmod-path)
+ (call-with-output-file cached-object-path
+ (curry copy-port body-input)
+ #:exists 'replace)
+ (when etag
+ (display-to-file etag cached-etag-path #:exists 'replace))
+ (when lmod
+ (display-to-file lmod cached-lmod-path #:exists 'replace))
+ 'downloaded-new)
+ 'skipped-cached))
+
+(: uri-download
+ (-> Positive-Float Url
+ (Result (U 'skipped-cached 'downloaded-new)
+ Any))) ; TODO Maybe more-precise error type?
+(define (uri-download timeout u)
+ (define u-str (url->string u))
+ (define timeout-chan (make-channel))
+ (define result-chan (make-channel))
+ (define timeout-thread
+ (thread (λ ()
+ ; Doing this instead of sync/timeout to distinguish error values,
+ ; rather than just have #f to work with.
+ (sleep timeout)
+ (channel-put timeout-chan '(error . timeout)))))
+ (define result-thread
+ (thread (λ ()
+ ; XXX We timeout getting a response, but body download could
+ ; also take a long time and we might want to time that out as
+ ; well, but then we may end-up with partially downloaded
+ ; objects. But that could happen anyway if the server drops the
+ ; connection for whatever reason.
+ ;
+ ; Maybe that is OK once we start treating the
+ ; downloaded object as an addition to the stored set of
+ ; messages, rather than the final set of messages.
+
+ ; TODO message db
+ ; - 1st try can just be an in-memory set that gets written-to
+ ; and read-from disk as a whole.
+ (define result
+ (with-handlers
+ ; TODO Maybe name each known errno? (exn:fail:network:errno-errno e)
+ ([exn:fail:network?
+ (λ (e) `(error . (net-error . ,e)))]
+ [exn?
+ (λ (e) `(error . (other . ,e)))])
+ (define-values (status-line headers body-input)
+ (http-sendrecv/url
+ u
+ #:headers (list (format "User-Agent: ~a" user-agent))))
+ `(ok . ,(Resp status-line headers body-input))))
+ (channel-put result-chan result))))
+ (define result
+ (sync timeout-chan
+ result-chan))
+ (kill-thread result-thread)
+ (kill-thread timeout-thread)
+ (match result
+ [(cons 'error _)
+ result]
+ [(cons 'ok (Resp status-line headers body-input))
+ (log-debug "headers: ~v" headers)
+ (log-debug "status-line: ~v" status-line)
+ (define status
+ (string->number (second (string-split (bytes->string/utf-8 status-line)))))
+ (log-debug "status: ~v" status)
+ ; TODO Handle redirects. Should be within same timeout as req and body.
+ (let ([result
+ (match status
+ [200
+ `(ok . ,(uri-download-from-port u headers body-input))]
+ [_
+ `(error . (http . ,status))])])
+ (close-input-port body-input)
+ result)]))
(: timeline-print (-> Out-Format (Listof Msg) Void))
(define (timeline-print out-format timeline)
(log-info "Reading peer nick:~v uri:~v" nick (url->string uri))
(str->msgs nick uri (uri-read-cached uri)))
-(: peer-download (-> Peer Void))
-(define (peer-download f)
- (match-define (Peer nick uri) f)
+(: peer-download
+ (-> Positive-Float Peer
+ (Result (U 'skipped-cached 'downloaded-new)
+ Any)))
+(define (peer-download timeout peer)
+ (match-define (Peer nick uri) peer)
(define u (url->string uri))
- (log-info "Downloading peer uri:~a" u)
- (with-handlers
- ([exn:fail?
- (λ (e)
- (log-error "Network error nick:~v uri:~v exn:~v" nick u e)
- #f)]
- [integer?
- (λ (status)
- (log-error "HTTP error nick:~v uri:~a status:~a" nick u status)
- #f)])
- (define-values (_result _tm-cpu-ms tm-real-ms _tm-gc-ms)
- (time-apply uri-download (list uri)))
- (log-info "Peer downloaded in ~a seconds, uri: ~a" (/ tm-real-ms 1000.0) u)))
-
-(: timeline-download (-> Integer (Listof Peer) Void))
-(define (timeline-download num-workers peers)
- ; TODO No need for map - can just iter
- (void (concurrent-filter-map num-workers peer-download peers)))
+ (log-info "Download BEGIN URL:~a" u)
+ (define-values (results _tm-cpu-ms tm-real-ms _tm-gc-ms)
+ (time-apply uri-download (list timeout uri)))
+ (define result (car results))
+ (log-info "Download END in ~a seconds, URL:~a, result:~s"
+ (/ tm-real-ms 1000.0)
+ u
+ result)
+ result)
+
+(: timeline-download (-> Integer Positive-Float (Listof Peer) Void))
+(define (timeline-download num-workers timeout peers)
+ (define results
+ (concurrent-filter-map num-workers
+ (λ (p) (cons p (peer-download timeout p)))
+ peers))
+ (define ok? (match-lambda
+ [(cons _ (cons 'ok _)) #t]
+ [(cons _ (cons 'error _)) #f]))
+ (define (err? r) (not (ok? r)))
+ (define peers-ok (map car (filter ok? results)))
+ (define peers-err (map car (filter err? results)))
+ (peers->file peers-ok (build-path tt-home-dir "peers-last-downloaded-ok"))
+ ; TODO Append error as a comment: <nick> <uri> # <error>
+ ; TODO Support inline/trailing comments in peer files
+ (peers->file peers-err (build-path tt-home-dir "peers-last-downloaded-err")))
(: uniq (∀ (α) (-> (Listof α) (Listof α))))
(define (uniq xs)
[(or "d" "download")
; Initially, 15 was fastest out of the tried: 1, 5, 10, 20. Then I
; started noticing significant slowdowns. Reducing to 5 seems to help.
- (let ([num-workers 5])
+ (let ([num-workers 5]
+ [timeout 10.0])
(command-line
#:program
"tt download"
[("-j" "--jobs")
njobs "Number of concurrent jobs."
(set! num-workers (string->number njobs))]
+ [("-t" "--timeout")
+ seconds "Timeout seconds per request."
+ (set! timeout (string->number seconds))]
#:args file-paths
(let ([peers (paths->peers file-paths)])
(define-values (_res _cpu real-ms _gc)
- (time-apply timeline-download (list num-workers peers)))
+ (time-apply timeline-download (list num-workers timeout peers)))
(log-info "Downloaded timelines from ~a peers in ~a seconds."
(length peers)
(/ real-ms 1000.0)))))]
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