guix-kreyren/guix/http-client.scm
Ludovic Courtès d11f7f62b6
http-client: 'http-fetch' and 'http-fetch/cached' accept #:timeout.
* guix/http-client.scm (http-fetch): Add #:timeout and pass it to
'guix:open-connection-for-uri'.
(http-fetch/cached): Add #:timeout parameter and pass it to
'http-fetch'.
2020-10-12 11:28:56 +02:00

222 lines
8.7 KiB
Scheme
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
;;; Copyright © 2012, 2015 Free Software Foundation, Inc.
;;; Copyright © 2017 Tobias Geerinckx-Rice <me@tobias.gr>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix 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.
;;;
;;; GNU Guix 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 GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix http-client)
#:use-module (web uri)
#:use-module ((web client) #:hide (open-socket-for-uri))
#:use-module (web response)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-19)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-35)
#:use-module (ice-9 match)
#:use-module (ice-9 binary-ports)
#:use-module (rnrs bytevectors)
#:use-module (guix ui)
#:use-module (guix utils)
#:use-module (guix base64)
#:autoload (gcrypt hash) (sha256)
#:use-module ((guix build utils)
#:select (mkdir-p dump-port))
#:use-module ((guix build download)
#:select (open-socket-for-uri
(open-connection-for-uri
. guix:open-connection-for-uri)
resolve-uri-reference))
#:re-export (open-socket-for-uri)
#:export (&http-get-error
http-get-error?
http-get-error-uri
http-get-error-code
http-get-error-reason
http-fetch
%http-cache-ttl
http-fetch/cached))
;;; Commentary:
;;;
;;; HTTP client portable among Guile versions, and with proper error condition
;;; reporting.
;;;
;;; Code:
;; HTTP GET error.
(define-condition-type &http-get-error &error
http-get-error?
(uri http-get-error-uri) ; URI
(code http-get-error-code) ; integer
(reason http-get-error-reason)) ; string
(define* (http-fetch uri #:key port (text? #f) (buffered? #t)
(verify-certificate? #t)
(headers '((user-agent . "GNU Guile")))
timeout)
"Return an input port containing the data at URI, and the expected number of
bytes available or #f. If TEXT? is true, the data at URI is considered to be
textual. Follow any HTTP redirection. When BUFFERED? is #f, return an
unbuffered port, suitable for use in `filtered-port'. HEADERS is an alist of
extra HTTP headers.
When VERIFY-CERTIFICATE? is true, verify HTTPS server certificates.
TIMEOUT specifies the timeout in seconds for connection establishment; when
TIMEOUT is #f, connection establishment never times out.
Raise an '&http-get-error' condition if downloading fails."
(let loop ((uri (if (string? uri)
(string->uri uri)
uri)))
(let ((port (or port (guix:open-connection-for-uri uri
#:verify-certificate?
verify-certificate?
#:timeout timeout)))
(headers (match (uri-userinfo uri)
((? string? str)
(cons (cons 'Authorization
(string-append "Basic "
(base64-encode
(string->utf8 str))))
headers))
(_ headers))))
(unless (or buffered? (not (file-port? port)))
(setvbuf port 'none))
(let*-values (((resp data)
(http-get uri #:streaming? #t #:port port
;; XXX: When #:keep-alive? is true, if DATA is
;; a chunked-encoding port, closing DATA won't
;; close PORT, leading to a file descriptor
;; leak.
#:keep-alive? #f
#:headers headers))
((code)
(response-code resp)))
(case code
((200)
(values data (response-content-length resp)))
((301 ; moved permanently
302 ; found (redirection)
303 ; see other
307 ; temporary redirection
308) ; permanent redirection
(let ((uri (resolve-uri-reference (response-location resp) uri)))
(close-port port)
(format (current-error-port) (G_ "following redirection to `~a'...~%")
(uri->string uri))
(loop uri)))
(else
(raise (condition (&http-get-error
(uri uri)
(code code)
(reason (response-reason-phrase resp)))
(&message
(message
(format
#f
(G_ "~a: HTTP download failed: ~a (~s)")
(uri->string uri) code
(response-reason-phrase resp))))))))))))
;;;
;;; Caching.
;;;
(define %http-cache-ttl
;; Time-to-live in seconds of the HTTP cache of in ~/.cache/guix.
(make-parameter
(* 3600 (or (and=> (getenv "GUIX_HTTP_CACHE_TTL")
string->number*)
36))))
(define (cache-file-for-uri uri)
"Return the name of the file in the cache corresponding to URI."
(let ((digest (sha256 (string->utf8 (uri->string uri)))))
;; Use the "URL" alphabet because it does not contain "/".
(string-append (cache-directory) "/http/"
(base64-encode digest 0 (bytevector-length digest)
#f #f base64url-alphabet))))
(define* (http-fetch/cached uri #:key (ttl (%http-cache-ttl)) text?
(write-cache dump-port)
(cache-miss (const #t))
(timeout 10))
"Like 'http-fetch', return an input port, but cache its contents in
~/.cache/guix. The cache remains valid for TTL seconds.
Call WRITE-CACHE with the HTTP input port and the cache output port to write
the data to cache. Call CACHE-MISS with URI just before fetching data from
URI.
TIMEOUT specifies the timeout in seconds for connection establishment."
(let ((file (cache-file-for-uri uri)))
(define (update-cache cache-port)
(define cache-time
(and cache-port
(stat:mtime (stat cache-port))))
(define headers
`((user-agent . "GNU Guile")
,@(if cache-time
`((if-modified-since
. ,(time-utc->date (make-time time-utc 0 cache-time))))
'())))
;; Update the cache and return an input port.
(guard (c ((http-get-error? c)
(if (= 304 (http-get-error-code c)) ;"Not Modified"
(begin
(utime file) ;update FILE's mtime
cache-port)
(raise c))))
(let ((port (http-fetch uri #:text? text?
#:headers headers #:timeout timeout)))
(cache-miss uri)
(mkdir-p (dirname file))
(when cache-port
(close-port cache-port))
(with-atomic-file-output file
(cut write-cache port <>))
(close-port port)
(open-input-file file))))
(define (old? port)
;; Return true if PORT has passed TTL.
(let* ((s (stat port))
(now (current-time time-utc)))
(< (+ (stat:mtime s) ttl) (time-second now))))
(catch 'system-error
(lambda ()
(let ((port (open-input-file file)))
(if (old? port)
(update-cache port)
port)))
(lambda args
(if (= ENOENT (system-error-errno args))
(update-cache #f)
(apply throw args))))))
;;; http-client.scm ends here