604 lines
24 KiB
Scheme
604 lines
24 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
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;;; Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
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;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
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;;; Copyright © 2015 Steve Sprang <scs@stevesprang.com>
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;;;
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;;; This file is part of GNU Guix.
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;;;
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;;; GNU Guix is free software; you can redistribute it and/or modify it
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;;; under the terms of the GNU General Public License as published by
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;;; the Free Software Foundation; either version 3 of the License, or (at
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;;; your option) any later version.
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;;;
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;;; GNU Guix is distributed in the hope that it will be useful, but
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;;; WITHOUT ANY WARRANTY; without even the implied warranty of
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;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;;; GNU General Public License for more details.
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;;;
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;;; You should have received a copy of the GNU General Public License
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;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
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(define-module (guix build download)
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#:use-module (web uri)
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#:use-module (web http)
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#:use-module ((web client) #:hide (open-socket-for-uri))
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#:use-module (web response)
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#:use-module (guix ftp-client)
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#:use-module (guix build utils)
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#:use-module (rnrs io ports)
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#:use-module (srfi srfi-1)
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#:use-module (srfi srfi-11)
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#:use-module (srfi srfi-19)
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#:use-module (srfi srfi-26)
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#:use-module (ice-9 match)
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#:use-module (ice-9 format)
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#:export (open-socket-for-uri
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open-connection-for-uri
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resolve-uri-reference
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maybe-expand-mirrors
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url-fetch
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byte-count->string
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progress-proc
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uri-abbreviation
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store-path-abbreviation))
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;;; Commentary:
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;;;
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;;; Fetch data such as tarballs over HTTP or FTP (builder-side code).
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;;;
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;;; Code:
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(define %http-receive-buffer-size
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;; Size of the HTTP receive buffer.
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65536)
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(define (nearest-exact-integer x)
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"Given a real number X, return the nearest exact integer, with ties going to
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the nearest exact even integer."
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(inexact->exact (round x)))
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(define (duration->seconds duration)
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"Return the number of seconds represented by DURATION, a 'time-duration'
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object, as an inexact number."
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(+ (time-second duration)
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(/ (time-nanosecond duration) 1e9)))
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(define (seconds->string duration)
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"Given DURATION in seconds, return a string representing it in 'mm:ss' or
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'hh:mm:ss' format, as needed."
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(if (not (number? duration))
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"00:00"
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(let* ((total-seconds (nearest-exact-integer duration))
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(extra-seconds (modulo total-seconds 3600))
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(num-hours (quotient total-seconds 3600))
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(hours (and (positive? num-hours) num-hours))
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(mins (quotient extra-seconds 60))
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(secs (modulo extra-seconds 60)))
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(format #f "~@[~2,'0d:~]~2,'0d:~2,'0d" hours mins secs))))
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(define (byte-count->string size)
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"Given SIZE in bytes, return a string representing it in a human-readable
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way."
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(let ((KiB 1024.)
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(MiB (expt 1024. 2))
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(GiB (expt 1024. 3))
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(TiB (expt 1024. 4)))
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(cond
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((< size KiB) (format #f "~dB" (nearest-exact-integer size)))
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((< size MiB) (format #f "~dKiB" (nearest-exact-integer (/ size KiB))))
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((< size GiB) (format #f "~,1fMiB" (/ size MiB)))
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((< size TiB) (format #f "~,2fGiB" (/ size GiB)))
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(else (format #f "~,3fTiB" (/ size TiB))))))
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(define* (progress-bar % #:optional (bar-width 20))
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"Return % as a string representing an ASCII-art progress bar. The total
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width of the bar is BAR-WIDTH."
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(let* ((fraction (/ % 100))
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(filled (inexact->exact (floor (* fraction bar-width))))
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(empty (- bar-width filled)))
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(format #f "[~a~a]"
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(make-string filled #\#)
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(make-string empty #\space))))
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(define (string-pad-middle left right len)
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"Combine LEFT and RIGHT with enough padding in the middle so that the
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resulting string has length at least LEN (it may overflow). If the string
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does not overflow, the last char in RIGHT will be flush with the LEN
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column."
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(let* ((total-used (+ (string-length left)
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(string-length right)))
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(num-spaces (max 1 (- len total-used)))
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(padding (make-string num-spaces #\space)))
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(string-append left padding right)))
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(define* (ellipsis #:optional (port (current-output-port)))
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"Make a rough guess at whether Unicode's HORIZONTAL ELLIPSIS can be written
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in PORT's encoding, and return either that or ASCII dots."
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(if (equal? (port-encoding port) "UTF-8")
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"…"
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"..."))
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(define* (store-path-abbreviation store-path #:optional (prefix-length 6))
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"If STORE-PATH is the file name of a store entry, return an abbreviation of
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STORE-PATH for display, showing PREFIX-LENGTH characters of the hash.
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Otherwise return STORE-PATH."
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(if (string-prefix? (%store-directory) store-path)
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(let ((base (basename store-path)))
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(string-append (string-take base prefix-length)
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(ellipsis)
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(string-drop base 32)))
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store-path))
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(define* (progress-proc file size
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#:optional (log-port (current-output-port))
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#:key (abbreviation basename))
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"Return a procedure to show the progress of FILE's download, which is SIZE
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bytes long. The returned procedure is suitable for use as an argument to
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`dump-port'. The progress report is written to LOG-PORT, with ABBREVIATION
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used to shorten FILE for display."
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;; XXX: Because of <http://bugs.gnu.org/19939> this procedure is often not
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;; called as frequently as we'd like too; this is especially bad with Nginx
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;; on hydra.gnu.org, which returns whole nars as a single chunk.
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(let ((start-time #f))
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(let-syntax ((with-elapsed-time
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(syntax-rules ()
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((_ elapsed body ...)
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(let* ((now (current-time time-monotonic))
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(elapsed (and start-time
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(duration->seconds
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(time-difference now
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start-time)))))
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(unless start-time
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(set! start-time now))
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body ...)))))
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(if (number? size)
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(lambda (transferred cont)
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(with-elapsed-time elapsed
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(let* ((% (* 100.0 (/ transferred size)))
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(throughput (if elapsed
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(/ transferred elapsed)
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0))
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(left (format #f " ~a ~a"
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(abbreviation file)
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(byte-count->string size)))
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(right (format #f "~a/s ~a ~a~6,1f%"
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(byte-count->string throughput)
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(seconds->string elapsed)
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(progress-bar %) %)))
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;; TODO: Make this adapt to the actual terminal width.
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(display (string-pad-middle left right 80) log-port)
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(display #\cr log-port)
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(flush-output-port log-port)
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(cont))))
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(lambda (transferred cont)
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(with-elapsed-time elapsed
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(let* ((throughput (if elapsed
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(/ transferred elapsed)
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0))
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(left (format #f " ~a"
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(abbreviation file)))
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(right (format #f "~a/s ~a | ~a transferred"
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(byte-count->string throughput)
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(seconds->string elapsed)
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(byte-count->string transferred))))
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;; TODO: Make this adapt to the actual terminal width.
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(display (string-pad-middle left right 80) log-port)
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(display #\cr log-port)
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(flush-output-port log-port)
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(cont))))))))
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(define* (uri-abbreviation uri #:optional (max-length 42))
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"If URI's string representation is larger than MAX-LENGTH, return an
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abbreviation of URI showing the scheme, host, and basename of the file."
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(define uri-as-string
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(uri->string uri))
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(define (elide-path)
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(let ((path (uri-path uri)))
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(string-append (symbol->string (uri-scheme uri)) "://"
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;; `file' URIs have no host part.
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(or (uri-host uri) "")
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(string-append "/.../" (basename path)))))
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(if (> (string-length uri-as-string) max-length)
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(let ((short (elide-path)))
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(if (< (string-length short) (string-length uri-as-string))
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short
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uri-as-string))
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uri-as-string))
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(define (ftp-fetch uri file)
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"Fetch data from URI and write it to FILE. Return FILE on success."
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(let* ((conn (ftp-open (uri-host uri)))
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(size (false-if-exception (ftp-size conn (uri-path uri))))
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(in (ftp-retr conn (basename (uri-path uri))
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(dirname (uri-path uri)))))
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(call-with-output-file file
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(lambda (out)
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(dump-port in out
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#:buffer-size %http-receive-buffer-size
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#:progress (progress-proc (uri-abbreviation uri) size))))
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(ftp-close conn))
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(newline)
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file)
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;; Autoload GnuTLS so that this module can be used even when GnuTLS is
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;; not available. At compile time, this yields "possibly unbound
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;; variable" warnings, but these are OK: we know that the variables will
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;; be bound if we need them, because (guix download) adds GnuTLS as an
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;; input in that case.
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;; XXX: Use this hack instead of #:autoload to avoid compilation errors.
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;; See <http://bugs.gnu.org/12202>.
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(module-autoload! (current-module)
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'(gnutls) '(make-session connection-end/client))
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(define add-weak-reference
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(let ((table (make-weak-key-hash-table)))
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(lambda (from to)
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"Hold a weak reference from FROM to TO."
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(hashq-set! table from to))))
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(define (tls-wrap port server)
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"Return PORT wrapped in a TLS connection to SERVER. SERVER must be a DNS
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host name without trailing dot."
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(define (log level str)
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(format (current-error-port)
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"gnutls: [~a|~a] ~a" (getpid) level str))
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(let ((session (make-session connection-end/client)))
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;; Some servers such as 'cloud.github.com' require the client to support
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;; the 'SERVER NAME' extension. However, 'set-session-server-name!' is
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;; not available in older GnuTLS releases. See
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;; <http://bugs.gnu.org/18526> for details.
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(if (module-defined? (resolve-interface '(gnutls))
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'set-session-server-name!)
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(set-session-server-name! session server-name-type/dns server)
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(format (current-error-port)
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"warning: TLS 'SERVER NAME' extension not supported~%"))
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(set-session-transport-fd! session (fileno port))
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(set-session-default-priority! session)
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(set-session-credentials! session (make-certificate-credentials))
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;; Uncomment the following lines in case of debugging emergency.
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;;(set-log-level! 10)
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;;(set-log-procedure! log)
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(handshake session)
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(let ((record (session-record-port session)))
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;; Since we use `fileno' above, the file descriptor behind PORT would be
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;; closed when PORT is GC'd. If we used `port->fdes', it would instead
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;; never be closed. So we use `fileno', but keep a weak reference to
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;; PORT, so the file descriptor gets closed when RECORD is GC'd.
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(add-weak-reference record port)
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record)))
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(define (ensure-uri uri-or-string) ;XXX: copied from (web http)
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(cond
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((string? uri-or-string) (string->uri uri-or-string))
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((uri? uri-or-string) uri-or-string)
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(else (error "Invalid URI" uri-or-string))))
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(define current-http-proxy
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;; XXX: Add a dummy definition for Guile < 2.0.10; this is used in
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;; 'open-socket-for-uri'.
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(or (and=> (module-variable (resolve-interface '(web client))
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'current-http-proxy)
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variable-ref)
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(const #f)))
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(define* (open-socket-for-uri uri-or-string #:key timeout)
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"Return an open input/output port for a connection to URI. When TIMEOUT is
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not #f, it must be a (possibly inexact) number denoting the maximum duration
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in seconds to wait for the connection to complete; passed TIMEOUT, an
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ETIMEDOUT error is raised."
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;; Includes a fix for <http://bugs.gnu.org/15368> which affects Guile's
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;; 'open-socket-for-uri' up to 2.0.11 included, uses 'connect*' instead
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;; of 'connect', and uses AI_ADDRCONFIG.
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(define http-proxy (current-http-proxy))
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(define uri (ensure-uri (or http-proxy uri-or-string)))
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(define addresses
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(let ((port (uri-port uri)))
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(delete-duplicates
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(getaddrinfo (uri-host uri)
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(cond (port => number->string)
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(else (symbol->string (uri-scheme uri))))
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(if (number? port)
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(logior AI_ADDRCONFIG AI_NUMERICSERV)
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AI_ADDRCONFIG))
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(lambda (ai1 ai2)
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(equal? (addrinfo:addr ai1) (addrinfo:addr ai2))))))
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(let loop ((addresses addresses))
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(let* ((ai (car addresses))
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(s (with-fluids ((%default-port-encoding #f))
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;; Restrict ourselves to TCP.
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(socket (addrinfo:fam ai) SOCK_STREAM IPPROTO_IP))))
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(catch 'system-error
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(lambda ()
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(connect* s (addrinfo:addr ai) timeout)
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;; Buffer input and output on this port.
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(setvbuf s _IOFBF)
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;; If we're using a proxy, make a note of that.
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(when http-proxy (set-http-proxy-port?! s #t))
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s)
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(lambda args
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;; Connection failed, so try one of the other addresses.
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(close s)
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(if (null? (cdr addresses))
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(apply throw args)
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(loop (cdr addresses))))))))
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(define* (open-connection-for-uri uri #:key timeout)
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"Like 'open-socket-for-uri', but also handle HTTPS connections."
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(define https?
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(eq? 'https (uri-scheme uri)))
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(let-syntax ((with-https-proxy
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(syntax-rules ()
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((_ exp)
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;; For HTTPS URIs, honor 'https_proxy', not 'http_proxy'.
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;; FIXME: Proxying is not supported for https.
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(let ((thunk (lambda () exp)))
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(if (and https?
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(module-variable
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(resolve-interface '(web client))
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'current-http-proxy))
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(parameterize ((current-http-proxy #f))
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(when (and=> (getenv "https_proxy")
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(negate string-null?))
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(format (current-error-port)
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"warning: 'https_proxy' is ignored~%"))
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(thunk))
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(thunk)))))))
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(with-https-proxy
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(let ((s (open-socket-for-uri uri #:timeout timeout)))
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;; Buffer input and output on this port.
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(setvbuf s _IOFBF %http-receive-buffer-size)
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(if https?
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(tls-wrap s (uri-host uri))
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s)))))
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;; XXX: This is an awful hack to make sure the (set-port-encoding! p
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;; "ISO-8859-1") call in `read-response' passes, even during bootstrap
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;; where iconv is not available.
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(module-define! (resolve-module '(web response))
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'set-port-encoding!
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(lambda (p e) #f))
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;; XXX: Work around <http://bugs.gnu.org/13095>, present in Guile
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;; up to 2.0.7.
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(module-define! (resolve-module '(web client))
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'shutdown (const #f))
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;; XXX: Work around <http://bugs.gnu.org/19840>, present in Guile
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;; up to 2.0.11.
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(unless (or (> (string->number (major-version)) 2)
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(> (string->number (minor-version)) 0)
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(> (string->number (micro-version)) 11))
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(let ((var (module-variable (resolve-module '(web http))
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'declare-relative-uri-header!)))
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;; If 'declare-relative-uri-header!' doesn't exist, forget it.
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(when (and var (variable-bound? var))
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(let ((declare-relative-uri-header! (variable-ref var)))
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(declare-relative-uri-header! "Location")))))
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(define (resolve-uri-reference ref base)
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"Resolve the URI reference REF, interpreted relative to the BASE URI, into a
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target URI, according to the algorithm specified in RFC 3986 section 5.2.2.
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Return the resulting target URI."
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(define (merge-paths base-path rel-path)
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(let* ((base-components (string-split base-path #\/))
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(base-directory-components (match base-components
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((components ... last) components)
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(() '())))
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(base-directory (string-join base-directory-components "/")))
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(string-append base-directory "/" rel-path)))
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(define (remove-dot-segments path)
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(let loop ((in
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;; Drop leading "." and ".." components from a relative path.
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;; (absolute paths will start with a "" component)
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(drop-while (match-lambda
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((or "." "..") #t)
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(_ #f))
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(string-split path #\/)))
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(out '()))
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(match in
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(("." . rest)
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(loop rest out))
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((".." . rest)
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(match out
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((or () (""))
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(error "remove-dot-segments: too many '..' components" path))
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(_
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(loop rest (cdr out)))))
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((component . rest)
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(loop rest (cons component out)))
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(()
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(string-join (reverse out) "/")))))
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(cond ((or (uri-scheme ref)
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(uri-host ref))
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(build-uri (or (uri-scheme ref)
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(uri-scheme base))
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#:userinfo (uri-userinfo ref)
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#:host (uri-host ref)
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#:port (uri-port ref)
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#:path (remove-dot-segments (uri-path ref))
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#:query (uri-query ref)
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#:fragment (uri-fragment ref)))
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((string-null? (uri-path ref))
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(build-uri (uri-scheme base)
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#:userinfo (uri-userinfo base)
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#:host (uri-host base)
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#:port (uri-port base)
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#:path (remove-dot-segments (uri-path base))
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#:query (or (uri-query ref)
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(uri-query base))
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#:fragment (uri-fragment ref)))
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(else
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(build-uri (uri-scheme base)
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#:userinfo (uri-userinfo base)
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#:host (uri-host base)
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#:port (uri-port base)
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#:path (remove-dot-segments
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(if (string-prefix? "/" (uri-path ref))
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(uri-path ref)
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(merge-paths (uri-path base)
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(uri-path ref))))
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#:query (uri-query ref)
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#:fragment (uri-fragment ref)))))
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(define (http-fetch uri file)
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"Fetch data from URI and write it to FILE. Return FILE on success."
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|
||
(define post-2.0.7?
|
||
(or (> (string->number (major-version)) 2)
|
||
(> (string->number (minor-version)) 0)
|
||
(> (string->number (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")
|
||
|
||
;; Some servers, such as https://alioth.debian.org, return "406 Not
|
||
;; Acceptable" when not explicitly told that everything is accepted.
|
||
(Accept . "*/*")))
|
||
|
||
(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 %http-receive-buffer-size
|
||
#:progress (progress-proc (uri-abbreviation uri)
|
||
size))
|
||
(newline))
|
||
(put-bytevector p bv-or-port))))
|
||
file))
|
||
((301 ; moved permanently
|
||
302) ; found (redirection)
|
||
(let ((uri (resolve-uri-reference (response-location resp) uri)))
|
||
(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 (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 mirrors)
|
||
"If URI uses the 'mirror' scheme, expand it according to the MIRRORS alist.
|
||
Return a list of URIs."
|
||
(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* (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
|
||
(append-map (cut maybe-expand-mirrors <> 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)))
|
||
|
||
;; Make this unbuffered so 'progress-proc' works as expected. _IOLBF means
|
||
;; '\n', not '\r', so it's not appropriate here.
|
||
(setvbuf (current-output-port) _IONBF)
|
||
|
||
(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))))
|
||
|
||
;;; Local Variables:
|
||
;;; eval: (put 'with-elapsed-time 'scheme-indent-function 1)
|
||
;;; End:
|
||
|
||
;;; download.scm ends here
|