ae533e3084
* guix/http-client.scm (http-fetch/cached): Use 'string->uri' if URI is a string, as with 'http-fetch'. Signed-off-by: Ludovic Courtès <ludo@gnu.org>
370 lines
15 KiB
Scheme
370 lines
15 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
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;;; Copyright © 2012-2018, 2020-2022 Ludovic Courtès <ludo@gnu.org>
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;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
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;;; Copyright © 2012, 2015 Free Software Foundation, Inc.
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;;; Copyright © 2017 Tobias Geerinckx-Rice <me@tobias.gr>
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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 http-client)
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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 request)
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#:use-module (web response)
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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 (srfi srfi-34)
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#:use-module (srfi srfi-35)
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#:use-module (ice-9 match)
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#:use-module (ice-9 binary-ports)
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#:use-module (rnrs bytevectors)
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#:use-module (guix ui)
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#:use-module (guix utils)
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#:use-module (guix base64)
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#:autoload (gcrypt hash) (sha256)
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#:autoload (gnutls) (error/invalid-session error/again error/interrupted)
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#:use-module ((guix build utils)
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#:select (mkdir-p dump-port))
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#:use-module ((guix build download)
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#:select (open-socket-for-uri
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(open-connection-for-uri
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. guix:open-connection-for-uri)
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resolve-uri-reference))
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#:re-export (open-socket-for-uri)
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#:export (&http-get-error
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http-get-error?
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http-get-error-uri
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http-get-error-code
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http-get-error-reason
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http-get-error-headers
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http-fetch
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http-multiple-get
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%http-cache-ttl
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http-fetch/cached))
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;;; Commentary:
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;;;
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;;; HTTP client portable among Guile versions, and with proper error condition
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;;; reporting.
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;;;
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;;; Code:
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;; HTTP GET error.
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(define-condition-type &http-get-error &error
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http-get-error?
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(uri http-get-error-uri) ;URI
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(code http-get-error-code) ;integer
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(reason http-get-error-reason) ;string
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(headers http-get-error-headers)) ;alist
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(define* (http-fetch uri #:key port (text? #f) (buffered? #t)
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(open-connection guix:open-connection-for-uri)
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(keep-alive? #f)
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(verify-certificate? #t)
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(headers '((user-agent . "GNU Guile")))
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(log-port (current-error-port))
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timeout)
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"Return an input port containing the data at URI, and the expected number of
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bytes available or #f. If TEXT? is true, the data at URI is considered to be
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textual. Follow any HTTP redirection. When BUFFERED? is #f, return an
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unbuffered port, suitable for use in `filtered-port'. HEADERS is an alist of
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extra HTTP headers.
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When KEEP-ALIVE? is true, the connection is marked as 'keep-alive' and PORT is
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not closed upon completion.
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When VERIFY-CERTIFICATE? is true, verify HTTPS server certificates.
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TIMEOUT specifies the timeout in seconds for connection establishment; when
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TIMEOUT is #f, connection establishment never times out.
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Write information about redirects to LOG-PORT.
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Raise an '&http-get-error' condition if downloading fails."
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(define uri*
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(if (string? uri) (string->uri uri) uri))
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(let loop ((uri uri*)
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(port (or port (open-connection uri*
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#:verify-certificate?
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verify-certificate?
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#:timeout timeout))))
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(let ((headers (match (uri-userinfo uri)
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((? string? str)
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(cons (cons 'Authorization
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(string-append "Basic "
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(base64-encode
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(string->utf8 str))))
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headers))
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(_ headers))))
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(unless (or buffered? (not (file-port? port)))
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(setvbuf port 'none))
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(let*-values (((resp data)
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(http-get uri #:streaming? #t #:port port
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#:keep-alive? keep-alive?
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#:headers headers))
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((code)
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(response-code resp)))
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(case code
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((200)
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(values data (response-content-length resp)))
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((301 ; moved permanently
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302 ; found (redirection)
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303 ; see other
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307 ; temporary redirection
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308) ; permanent redirection
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(let ((host (uri-host uri))
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(uri (resolve-uri-reference (response-location resp) uri)))
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(if keep-alive?
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(dump-port data (%make-void-port "w0")
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(response-content-length resp))
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(close-port port))
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(format log-port (G_ "following redirection to `~a'...~%")
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(uri->string uri))
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(loop uri
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(or (and keep-alive?
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(or (not (uri-host uri))
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(string=? host (uri-host uri)))
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port)
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(open-connection uri
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#:verify-certificate?
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verify-certificate?
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#:timeout timeout)))))
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(else
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(raise (condition (&http-get-error
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(uri uri)
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(code code)
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(reason (response-reason-phrase resp))
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(headers (response-headers resp)))
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(&message
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(message
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(format
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#f
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(G_ "~a: HTTP download failed: ~a (~s)")
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(uri->string uri) code
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(response-reason-phrase resp))))))))))))
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(define-syntax-rule (false-if-networking-error exp)
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"Return #f if EXP triggers a network related exception as can occur when
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reusing stale cached connections."
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;; FIXME: Duplicated from 'with-cached-connection'.
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(catch #t
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(lambda ()
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exp)
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(lambda (key . args)
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;; If PORT was cached and the server closed the connection in the
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;; meantime, we get EPIPE. In that case, open a fresh connection and
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;; retry. We might also get 'bad-response or a similar exception from
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;; (web response) later on, once we've sent the request, or a
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;; ERROR/INVALID-SESSION from GnuTLS.
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(if (or (and (eq? key 'system-error)
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(= EPIPE (system-error-errno `(,key ,@args))))
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(and (eq? key 'gnutls-error)
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(memq (first args)
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(list error/invalid-session
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;; XXX: These two are not properly handled in
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;; GnuTLS < 3.7.2, in
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;; 'write_to_session_record_port'; see
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;; <https://bugs.gnu.org/47867>.
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error/again error/interrupted)))
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(memq key
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'(bad-response bad-header bad-header-component)))
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#f
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(apply throw key args)))))
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(define* (http-multiple-get base-uri proc seed requests
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#:key port (verify-certificate? #t)
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(open-connection guix:open-connection-for-uri)
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(keep-alive? #t)
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(batch-size 1000))
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"Send all of REQUESTS to the server at BASE-URI. Call PROC for each
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response, passing it the request object, the response, a port from which to
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read the response body, and the previous result, starting with SEED, à la
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'fold'. Return the final result.
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When PORT is specified, use it as the initial connection on which HTTP
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requests are sent; otherwise call OPEN-CONNECTION to open a new connection for
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a URI. When KEEP-ALIVE? is false, close the connection port before
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returning."
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(let connect ((port port)
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(requests requests)
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(result seed))
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(define batch
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(if (>= batch-size (length requests))
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requests
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(take requests batch-size)))
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;; (format (current-error-port) "connecting (~a requests left)..."
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;; (length requests))
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(let ((p (or port (open-connection base-uri
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#:verify-certificate?
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verify-certificate?))))
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;; For HTTPS, P is not a file port and does not support 'setvbuf'.
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(when (file-port? p)
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(setvbuf p 'block (expt 2 16)))
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;; Send BATCH in a row.
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;; XXX: Do our own caching to work around inefficiencies when
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;; communicating over TLS: <http://bugs.gnu.org/22966>.
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(let-values (((buffer get) (open-bytevector-output-port)))
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;; Inherit the HTTP proxying property from P.
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(set-http-proxy-port?! buffer (http-proxy-port? p))
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;; Swallow networking errors that could occur due to connection reuse
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;; and the like; they will be handled down the road when trying to
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;; read responses.
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(false-if-networking-error
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(begin
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(for-each (cut write-request <> buffer) batch)
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(put-bytevector p (get))
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(force-output p))))
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;; Now start processing responses.
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(let loop ((sent batch)
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(processed 0)
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(result result))
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(match sent
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(()
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(match (drop requests processed)
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(()
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(unless keep-alive?
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(close-port p))
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(reverse result))
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(remainder
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(connect p remainder result))))
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((head tail ...)
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(match (false-if-networking-error (read-response p))
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((? response? resp)
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(let* ((body (response-body-port resp))
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(result (proc head resp body result)))
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;; The server can choose to stop responding at any time,
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;; in which case we have to try again. Check whether
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;; that is the case. Note that even upon "Connection:
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;; close", we can read from BODY.
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(match (assq 'connection (response-headers resp))
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(('connection 'close)
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(close-port p)
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(connect #f ;try again
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(drop requests (+ 1 processed))
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result))
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(_
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(loop tail (+ 1 processed) result)))))
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(#f
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(close-port p)
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(connect #f ; try again
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(drop requests processed)
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result)))))))))
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;;;
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;;; Caching.
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;;;
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(define %http-cache-ttl
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;; Time-to-live in seconds of the HTTP cache of in ~/.cache/guix.
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(make-parameter
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(* 3600 (or (and=> (getenv "GUIX_HTTP_CACHE_TTL")
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string->number*)
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36))))
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(define (cache-file-for-uri uri)
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"Return the name of the file in the cache corresponding to URI."
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(let ((digest (sha256 (string->utf8 (uri->string uri)))))
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;; Use the "URL" alphabet because it does not contain "/".
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(string-append (cache-directory) "/http/"
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(base64-encode digest 0 (bytevector-length digest)
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#f #f base64url-alphabet))))
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(define* (http-fetch/cached uri #:key (ttl (%http-cache-ttl)) text?
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(headers '((user-agent . "GNU Guile")))
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(write-cache dump-port)
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(cache-miss (const #t))
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(log-port (current-error-port))
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(timeout 10))
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"Like 'http-fetch', return an input port, but cache its contents in
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~/.cache/guix. The cache remains valid for TTL seconds.
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Call WRITE-CACHE with the HTTP input port and the cache output port to write
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the data to cache. Call CACHE-MISS with URI just before fetching data from
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URI.
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HEADERS is an alist of extra HTTP headers, to which cache-related headers are
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added automatically as appropriate.
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TIMEOUT specifies the timeout in seconds for connection establishment.
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Write information about redirects to LOG-PORT."
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(let* ((uri (if (string? uri)
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(string->uri uri)
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uri))
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(file (cache-file-for-uri uri)))
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(define (update-cache cache-port)
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(define cache-time
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(and cache-port
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(stat:mtime (stat cache-port))))
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(define extended-headers
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(if cache-time
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`((if-modified-since
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. ,(time-utc->date (make-time time-utc 0 cache-time)))
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,@headers)
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headers))
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;; Update the cache and return an input port.
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(guard (c ((http-get-error? c)
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(if (= 304 (http-get-error-code c)) ;"Not Modified"
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(begin
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(utime file) ;update FILE's mtime
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cache-port)
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(raise c))))
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(let ((port (http-fetch uri #:text? text?
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#:log-port log-port
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#:headers extended-headers
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#:timeout timeout)))
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(cache-miss uri)
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(mkdir-p (dirname file))
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(when cache-port
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(close-port cache-port))
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(with-atomic-file-output file
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(cut write-cache port <>))
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(close-port port)
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(open-input-file file))))
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(define (old? port)
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;; Return true if PORT has passed TTL.
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(let* ((s (stat port))
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(now (current-time time-utc)))
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(< (+ (stat:mtime s) ttl) (time-second now))))
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(catch 'system-error
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(lambda ()
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(let ((port (open-input-file file)))
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(if (old? port)
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(update-cache port)
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port)))
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(lambda args
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(if (= ENOENT (system-error-errno args))
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(update-cache #f)
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(apply throw args))))))
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;;; http-client.scm ends here
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