guix-devel/guix/build/download.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2012, 2013, 2014 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 build download)
#:use-module (web uri)
#:use-module (web client)
#:use-module (web response)
#:use-module (guix ftp-client)
#:use-module (guix build utils)
#:use-module (rnrs io ports)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-26)
#:use-module (ice-9 match)
#:use-module (ice-9 format)
#:export (url-fetch
progress-proc
uri-abbreviation))
;;; Commentary:
;;;
;;; Fetch data such as tarballs over HTTP or FTP (builder-side code).
;;;
;;; Code:
(define* (progress-proc file size #:optional (log-port (current-output-port)))
"Return a procedure to show the progress of FILE's download, which is
SIZE byte long. The returned procedure is suitable for use as an
argument to `dump-port'. The progress report is written to LOG-PORT."
(if (number? size)
(lambda (transferred cont)
(let ((% (* 100.0 (/ transferred size))))
(display #\cr log-port)
(format log-port "~a\t~5,1f% of ~,1f KiB"
file % (/ size 1024.0))
(flush-output-port log-port)
(cont)))
(lambda (transferred cont)
(display #\cr log-port)
(format log-port "~a\t~6,1f KiB transferred"
file (/ transferred 1024.0))
(flush-output-port log-port)
(cont))))
(define* (uri-abbreviation uri #:optional (max-length 42))
"If URI's string representation is larger than MAX-LENGTH, return an
abbreviation of URI showing the scheme, host, and basename of the file."
(define uri-as-string
(uri->string uri))
(define (elide-path)
(let ((path (uri-path uri)))
(string-append (symbol->string (uri-scheme uri)) "://"
;; `file' URIs have no host part.
(or (uri-host uri) "")
(string-append "/.../" (basename path)))))
(if (> (string-length uri-as-string) max-length)
(let ((short (elide-path)))
(if (< (string-length short) (string-length uri-as-string))
short
uri-as-string))
uri-as-string))
(define (ftp-fetch uri file)
"Fetch data from URI and write it to FILE. Return FILE on success."
(let* ((conn (ftp-open (uri-host uri)))
(size (false-if-exception (ftp-size conn (uri-path uri))))
(in (ftp-retr conn (basename (uri-path uri))
(dirname (uri-path uri)))))
(call-with-output-file file
(lambda (out)
(dump-port in out
#:buffer-size 65536 ; don't flood the log
#:progress (progress-proc (uri-abbreviation uri) size))))
(ftp-close conn))
(newline)
file)
;; Autoload GnuTLS so that this module can be used even when GnuTLS is
;; not available. At compile time, this yields "possibly unbound
;; variable" warnings, but these are OK: we know that the variables will
;; be bound if we need them, because (guix download) adds GnuTLS as an
;; input in that case.
;; XXX: Use this hack instead of #:autoload to avoid compilation errors.
;; See <http://bugs.gnu.org/12202>.
(module-autoload! (current-module)
'(gnutls) '(make-session connection-end/client))
(define add-weak-reference
(let ((table (make-weak-key-hash-table)))
(lambda (from to)
"Hold a weak reference from FROM to TO."
(hashq-set! table from to))))
(define (tls-wrap port)
"Return PORT wrapped in a TLS connection."
(define (log level str)
(format (current-error-port)
"gnutls: [~a|~a] ~a" (getpid) level str))
(let ((session (make-session connection-end/client)))
(set-session-transport-fd! session (fileno port))
(set-session-default-priority! session)
(set-session-credentials! session (make-certificate-credentials))
;; Uncomment the following lines in case of debugging emergency.
;;(set-log-level! 10)
;;(set-log-procedure! log)
(handshake session)
(let ((record (session-record-port session)))
;; Since we use `fileno' above, the file descriptor behind PORT would be
;; closed when PORT is GC'd. If we used `port->fdes', it would instead
;; never be closed. So we use `fileno', but keep a weak reference to
;; PORT, so the file descriptor gets closed when RECORD is GC'd.
(add-weak-reference record port)
record)))
(define (open-connection-for-uri uri)
"Return an open input/output port for a connection to URI.
This is the same as Guile's `open-socket-for-uri', except that we always
use a numeric port argument, to avoid the need to go through libc's NSS,
which is not available during bootstrap."
(define addresses
(let ((port (or (uri-port uri)
(case (uri-scheme uri)
((http) 80) ; /etc/services, not for me!
((https) 443)
(else
(error "unsupported URI scheme" uri))))))
(delete-duplicates (getaddrinfo (uri-host uri)
(number->string port)
AI_NUMERICSERV)
(lambda (ai1 ai2)
(equal? (addrinfo:addr ai1)
(addrinfo:addr ai2))))))
(let loop ((addresses addresses))
(let* ((ai (car addresses))
(s (with-fluids ((%default-port-encoding #f))
;; Restrict ourselves to TCP.
(socket (addrinfo:fam ai) SOCK_STREAM IPPROTO_IP))))
(catch 'system-error
(lambda ()
(connect s (addrinfo:addr ai))
;; Buffer input and output on this port.
(setvbuf s _IOFBF)
;; Enlarge the receive buffer.
(setsockopt s SOL_SOCKET SO_RCVBUF (* 12 1024))
(if (eq? 'https (uri-scheme uri))
(tls-wrap s)
s))
(lambda args
;; Connection failed, so try one of the other addresses.
(close s)
(if (null? (cdr addresses))
(apply throw args)
(loop (cdr addresses))))))))
;; XXX: This is an awful hack to make sure the (set-port-encoding! p
;; "ISO-8859-1") call in `read-response' passes, even during bootstrap
;; where iconv is not available.
(module-define! (resolve-module '(web response))
'set-port-encoding!
(lambda (p e) #f))
;; XXX: Work around <http://bugs.gnu.org/13095>, present in Guile
;; up to 2.0.7.
(module-define! (resolve-module '(web client))
'shutdown (const #f))
(define (http-fetch uri file)
"Fetch data from URI and write it to FILE. Return FILE on success."
(define post-2.0.7?
(or (string>? (major-version) "2")
(string>? (minor-version) "0")
(string>? (micro-version) "7")
(string>? (version) "2.0.7")))
(define headers
;; Some web sites, such as http://dist.schmorp.de, would block you if
;; there's no 'User-Agent' header, presumably on the assumption that
;; you're a spammer. So work around that.
'((User-Agent . "GNU Guile")))
(let*-values (((connection)
(open-connection-for-uri uri))
((resp bv-or-port)
;; XXX: `http-get*' was introduced in 2.0.7, and replaced by
;; #:streaming? in 2.0.8. We know we're using it within the
;; chroot, but `guix-download' might be using a different
;; version. So keep this compatibility hack for now.
(if post-2.0.7?
(http-get uri #:port connection #:decode-body? #f
#:streaming? #t
#:headers headers)
(if (module-defined? (resolve-interface '(web client))
'http-get*)
(http-get* uri #:port connection #:decode-body? #f
#:headers headers)
(http-get uri #:port connection #:decode-body? #f
#:extra-headers headers))))
((code)
(response-code resp))
((size)
(response-content-length resp)))
(case code
((200) ; OK
(begin
(call-with-output-file file
(lambda (p)
(if (port? bv-or-port)
(begin
(dump-port bv-or-port p
#:buffer-size 65536 ; don't flood the log
#:progress (progress-proc (uri-abbreviation uri)
size))
(newline))
(put-bytevector p bv-or-port))))
file))
((301 ; moved permanently
302) ; found (redirection)
(let ((uri (response-location resp)))
(format #t "following redirection to `~a'...~%"
(uri->string uri))
(close connection)
(http-fetch uri file)))
(else
(error "download failed" (uri->string uri)
code (response-reason-phrase resp))))))
(define-syntax-rule (false-if-exception* body ...)
"Like `false-if-exception', but print the exception on the error port."
(catch #t
(lambda ()
body ...)
(lambda (key . args)
#f)
(lambda (key . args)
(print-exception (current-error-port) #f key args))))
(define* (url-fetch url file #:key (mirrors '()))
"Fetch FILE from URL; URL may be either a single string, or a list of
string denoting alternate URLs for FILE. Return #f on failure, and FILE
on success."
(define (uri-vicinity dir file)
;; Concatenate DIR, slash, and FILE, keeping only one slash in between.
;; This is required by some HTTP servers.
(string-append (string-trim-right dir #\/) "/"
(string-trim file #\/)))
(define (maybe-expand-mirrors uri)
(case (uri-scheme uri)
((mirror)
(let ((kind (string->symbol (uri-host uri)))
(path (uri-path uri)))
(match (assoc-ref mirrors kind)
((mirrors ..1)
(map (compose string->uri (cut uri-vicinity <> path))
mirrors))
(_
(error "unsupported URL mirror kind" kind uri)))))
(else
(list uri))))
(define uri
(append-map maybe-expand-mirrors
(match url
((_ ...) (map string->uri url))
(_ (list (string->uri url))))))
(define (fetch uri file)
(format #t "starting download of `~a' from `~a'...~%"
file (uri->string uri))
(case (uri-scheme uri)
((http https)
(false-if-exception* (http-fetch uri file)))
((ftp)
(false-if-exception* (ftp-fetch uri file)))
(else
(format #t "skipping URI with unsupported scheme: ~s~%"
uri)
#f)))
(setvbuf (current-output-port) _IOLBF)
(setvbuf (current-error-port) _IOLBF)
(let try ((uri uri))
(match uri
((uri tail ...)
(or (fetch uri file)
(try tail)))
(()
(format (current-error-port) "failed to download ~s from ~s~%"
file url)
#f))))
;;; download.scm ends here