1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
;;; Copyright © 2012, 2015 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 (web uri)
#:use-module ((web client) #:hide (open-socket-for-uri))
#: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)
#:use-module ((guix build download)
#:select (open-socket-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))
;;; 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-or-otherwise-broken
(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-or-otherwise-broken
;; Backport of Guile commits 312e79f8 ("Add HTTP Chunked Encoding support to
;; web modules.") and 00d3ecf2 ("http: Do not buffer HTTP chunks.")
(use-modules (ice-9 rdelim))
(define %web-http
(resolve-module '(web http)))
;; 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* (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 (close)
(unless keep-alive?
(close-port port)))
(define chunk-size 0) ;size of the current chunk
(define remaining 0) ;number of bytes left from the current chunk
(define finished? #f) ;did we get all the chunks?
(define (read! bv idx to-read)
(define (loop to-read num-read)
(cond ((or finished? (zero? to-read))
num-read)
((zero? remaining) ;get a new chunk
(let ((size (read-chunk-header port)))
(set! chunk-size size)
(set! remaining size)
(if (zero? size)
(begin
(set! finished? #t)
num-read)
(loop to-read num-read))))
(else ;read from the current chunk
(let* ((ask-for (min to-read remaining))
(read (get-bytevector-n! port bv (+ idx num-read)
ask-for)))
(if (eof-object? read)
(begin ;premature termination
(set! finished? #t)
num-read)
(let ((left (- remaining read)))
(set! remaining left)
(when (zero? left)
;; We're done with this chunk; read CR and LF.
(get-u8 port) (get-u8 port))
(loop (- to-read read)
(+ num-read read))))))))
(loop to-read 0))
(make-custom-binary-input-port "chunked input port" read! #f #f close))
;; Chunked encoding support in Guile <= 2.0.11 would load whole chunks in
;; memory---see <http://bugs.gnu.org/19939>.
(when (module-variable %web-http 'read-chunk-body)
(module-set! %web-http 'make-chunked-input-port make-chunked-input-port))
(define (make-delimited-input-port port len keep-alive?)
"Return an input port that reads from PORT, and makes sure that
exactly LEN bytes are available from PORT. Closing the returned port
closes PORT, unless KEEP-ALIVE? is true."
(define bytes-read 0)
(define (fail)
((@@ (web response) bad-response)
"EOF while reading response body: ~a bytes of ~a"
bytes-read len))
(define (read! bv start count)
;; Read at most LEN bytes in total. HTTP/1.1 doesn't say what to do
;; when a server provides more than the Content-Length, but it seems
;; wise to just stop reading at LEN.
(let ((count (min count (- len bytes-read))))
(let loop ((ret (get-bytevector-n! port bv start count)))
(cond ((eof-object? ret)
(if (= bytes-read len)
0 ; EOF
(fail)))
((and (zero? ret) (> count 0))
;; Do not return zero since zero means EOF, so try again.
(loop (get-bytevector-n! port bv start count)))
(else
(set! bytes-read (+ bytes-read ret))
ret)))))
(define close
(and (not keep-alive?)
(lambda ()
(close-port port))))
(make-custom-binary-input-port "delimited input port" read! #f #f close))
(unless (guile-version>? "2.0.11")
;; Guile <= 2.0.9 had a bug whereby 'response-body-port' would read more
;; than what 'content-length' says. See Guile commit 802a25b.
;; Guile <= 2.0.12 had a bug whereby the 'close' method of the response
;; body port would fail with wrong-arg-num. See Guile commit 5a10e41.
(module-set! (resolve-module '(web response))
'make-delimited-input-port make-delimited-input-port)))
;; 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 #: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))))
(unless buffered?
(setvbuf port _IONBF))
(let*-values (((resp data)
;; Try hard to use the API du jour to get an input port.
(if (guile-version>? "2.0.7")
(http-get uri #:streaming? #t #:port port) ; 2.0.9+
(http-get* uri #:decode-body? text? ; 2.0.7
#:port port)))
((code)
(response-code resp)))
(case code
((200)
(values data (response-content-length resp)))
((301 ; moved permanently
302) ; found (redirection)
(let ((uri (resolve-uri-reference (response-location resp) uri)))
(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
|
