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- ;;; GNU Guix --- Functional package management for GNU
- ;;; Copyright © 2012, 2013, 2014 Ludovic Courtès <ludo@gnu.org>
- ;;; Copyright © 2012 Free Software Foundation, Inc.
- ;;;
- ;;; 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 (guix utils)
- #:use-module (web uri)
- #:use-module (web client)
- #:use-module (web response)
- #:use-module (srfi srfi-11)
- #:use-module (srfi srfi-34)
- #:use-module (srfi srfi-35)
- #:use-module (rnrs io ports)
- #:use-module (rnrs bytevectors)
- #:use-module (guix ui)
- #:use-module (guix utils)
- #:export (&http-get-error
- http-get-error?
- http-get-error-uri
- http-get-error-code
- http-get-error-reason
-
- open-socket-for-uri
- http-fetch))
-
- ;;; 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-syntax when-guile<=2.0.5
- (lambda (s)
- (syntax-case s ()
- ((_ body ...)
- ;; Always emit BODY, regardless of VERSION, because sometimes this code
- ;; might be compiled with a recent Guile and run with 2.0.5---e.g.,
- ;; when using "guix pull".
- #'(begin body ...)))))
-
- (when-guile<=2.0.5
- ;; Backport of Guile commit 312e79f8 ("Add HTTP Chunked Encoding support to
- ;; web modules.").
-
- (use-modules (ice-9 rdelim))
-
- ;; Chunked Responses
- (define (read-chunk-header port)
- (let* ((str (read-line port))
- (extension-start (string-index str (lambda (c) (or (char=? c #\;)
- (char=? c #\return)))))
- (size (string->number (if extension-start ; unnecessary?
- (substring str 0 extension-start)
- str)
- 16)))
- size))
-
- (define (read-chunk port)
- (let ((size (read-chunk-header port)))
- (read-chunk-body port size)))
-
- (define (read-chunk-body port size)
- (let ((bv (get-bytevector-n port size)))
- (get-u8 port) ; CR
- (get-u8 port) ; LF
- bv))
-
- (define* (make-chunked-input-port port #:key (keep-alive? #f))
- "Returns a new port which translates HTTP chunked transfer encoded
- data from PORT into a non-encoded format. Returns eof when it has
- read the final chunk from PORT. This does not necessarily mean
- that there is no more data on PORT. When the returned port is
- closed it will also close PORT, unless the KEEP-ALIVE? is true."
- (define (next-chunk)
- (read-chunk port))
- (define finished? #f)
- (define (close)
- (unless keep-alive?
- (close-port port)))
- (define buffer #vu8())
- (define buffer-size 0)
- (define buffer-pointer 0)
- (define (read! bv idx to-read)
- (define (loop to-read num-read)
- (cond ((or finished? (zero? to-read))
- num-read)
- ((<= to-read (- buffer-size buffer-pointer))
- (bytevector-copy! buffer buffer-pointer
- bv (+ idx num-read)
- to-read)
- (set! buffer-pointer (+ buffer-pointer to-read))
- (loop 0 (+ num-read to-read)))
- (else
- (let ((n (- buffer-size buffer-pointer)))
- (bytevector-copy! buffer buffer-pointer
- bv (+ idx num-read)
- n)
- (set! buffer (next-chunk))
- (set! buffer-pointer 0)
- (set! buffer-size (bytevector-length buffer))
- (set! finished? (= buffer-size 0))
- (loop (- to-read n)
- (+ num-read n))))))
- (loop to-read 0))
- (make-custom-binary-input-port "chunked input port" read! #f #f close))
-
- (define (read-response-body* r)
- "Reads the response body from @var{r}, as a bytevector. Returns
- @code{#f} if there was no response body."
- (define bad-response
- (@@ (web response) bad-response))
-
- (if (member '(chunked) (response-transfer-encoding r))
- (let ((chunk-port (make-chunked-input-port (response-port r)
- #:keep-alive? #t)))
- (get-bytevector-all chunk-port))
- (let ((nbytes (response-content-length r)))
- ;; Backport of Guile commit 84dfde82ae8f6ec247c1c147c1e2ae50b207bad9
- ;; ("fix response-body-port for responses without content-length").
- (if nbytes
- (let ((bv (get-bytevector-n (response-port r) nbytes)))
- (if (= (bytevector-length bv) nbytes)
- bv
- (bad-response "EOF while reading response body: ~a bytes of ~a"
- (bytevector-length bv) nbytes)))
- (get-bytevector-all (response-port r))))))
-
- ;; Install this patch only on Guile 2.0.5.
- (unless (guile-version>? "2.0.5")
- (module-set! (resolve-module '(web response))
- 'read-response-body read-response-body*)))
-
- ;; 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* (open-socket-for-uri uri #:key (buffered? #t))
- "Return an open port for URI. When BUFFERED? is false, the returned port is
- unbuffered."
- (define rmem-max
- ;; The maximum size for a receive buffer on Linux, see socket(7).
- "/proc/sys/net/core/rmem_max")
-
- (define buffer-size
- (if (file-exists? rmem-max)
- (call-with-input-file rmem-max read)
- 126976)) ; the default for Linux, per 'rmem_default'
-
- (let ((s ((@ (web client) open-socket-for-uri) uri)))
- ;; Work around <http://bugs.gnu.org/15368> by restoring a decent
- ;; buffer size.
- (setsockopt s SOL_SOCKET SO_RCVBUF buffer-size)
- (unless buffered?
- (setvbuf s _IONBF))
- s))
-
- (define* (http-fetch uri #:key port (text? #f) (buffered? #t))
- "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'.
-
- Raise an '&http-get-error' condition if downloading fails."
- (let loop ((uri uri))
- (let ((port (or port
- (open-socket-for-uri uri
- #:buffered? buffered?))))
- (let*-values (((resp data)
- ;; Try hard to use the API du jour to get an input port.
- ;; On Guile 2.0.5 and before, we can only get a string or
- ;; bytevector, and not an input port. Work around that.
- (if (guile-version>? "2.0.7")
- (http-get uri #:streaming? #t #:port port) ; 2.0.9+
- (if (defined? 'http-get*)
- (http-get* uri #:decode-body? text?
- #:port port) ; 2.0.7
- (http-get uri #:decode-body? text?
- #:port port)))) ; 2.0.5-
- ((code)
- (response-code resp)))
- (case code
- ((200)
- (let ((len (response-content-length resp)))
- (cond ((not data)
- (begin
- ;; Guile 2.0.5 and earlier did not support chunked
- ;; transfer encoding, which is required for instance when
- ;; fetching %PACKAGE-LIST-URL (see
- ;; <http://lists.gnu.org/archive/html/guile-devel/2011-09/msg00089.html>).
- ;; Normally the `when-guile<=2.0.5' block above fixes
- ;; that, but who knows what could happen.
- (warning (_ "using Guile ~a, which does not support ~s encoding~%")
- (version)
- (response-transfer-encoding resp))
- (leave (_ "download failed; use a newer Guile~%")
- uri resp)))
- ((string? data) ; `http-get' from 2.0.5-
- (values (open-input-string data) len))
- ((bytevector? data) ; likewise
- (values (open-bytevector-input-port data) len))
- (else ; input port
- (values data len)))))
- ((301 ; moved permanently
- 302) ; found (redirection)
- (let ((uri (response-location resp)))
- (close-port port)
- (format #t (_ "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 "download failed"))))))))))
-
- ;;; http-client.scm ends here
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