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Diffstat (limited to 'guix/http-client.scm')
| -rw-r--r-- | guix/http-client.scm | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/guix/http-client.scm b/guix/http-client.scm new file mode 100644 index 0000000000..898b1669e5 --- /dev/null +++ b/guix/http-client.scm @@ -0,0 +1,208 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2012, 2013 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 (rnrs io ports) + #:use-module (rnrs bytevectors) + #:use-module (guix ui) + #:use-module (guix utils) + #:export (open-socket-for-uri + http-fetch)) + +;;; Commentary: +;;; +;;; HTTP client portable among Guile versions. +;;; +;;; Code: + +(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. + (when (version>? "2.0.6" (version)) + (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." + (let ((s ((@ (web client) open-socket-for-uri) uri))) + (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'." + (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 (version>? (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 + (error "download failed" uri code + (response-reason-phrase resp)))))))) + +;;; http-client.scm ends here |