code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2013 Nikita Karetnikov <nikita@karetnikov.org>
;;; Copyright © 2014 Eric Bavier <bavier@member.fsf.org>
;;; Copyright © 2015 Alex Kost <alezost@gmail.com>
;;; Copyright © 2016 Ben Woodcroft <donttrustben@gmail.com>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2018 Efraim Flashner <efraim@flashner.co.il>
;;; Copyright © 2019 Ricardo Wurmus <rekado@elephly.net>
;;; Copyright © 2020 Simon Tournier <zimon.toutoune@gmail.com>
;;;
;;; 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 scripts refresh)
  #:use-module (guix ui)
  #:use-module (gcrypt hash)
  #:use-module (guix scripts)
  #:use-module ((guix scripts build) #:select (%standard-build-options))
  #:use-module (guix store)
  #:use-module (guix utils)
  #:use-module (guix packages)
  #:use-module (guix profiles)
  #:use-module (guix upstream)
  #:use-module (guix graph)
  #:use-module (guix scripts graph)
  #:use-module (guix monads)
  #:use-module (guix gnupg)
  #:use-module (gnu packages)
  #:use-module ((gnu packages commencement) #:select (%final-inputs))
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:use-module (ice-9 vlist)
  #:use-module (ice-9 format)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-37)
  #:use-module (ice-9 binary-ports)
  #:export (guix-refresh))

;;;
;;; Command-line options.
;;;

(define %default-options
  ;; Alist of default option values.
  '())

(define %options
  ;; Specification of the command-line options.
  (list (option '(#\u "update") #f #f
                (lambda (opt name arg result)
                  (alist-cons 'update? #t result)))
        (option '(#\s "select") #t #f
                (lambda (opt name arg result)
                  (match arg
                    ((or "core" "non-core")
                     (alist-cons 'select (string->symbol arg)
                                 result))
                    (x
                     (leave (G_ "~a: invalid selection; expected `core' or `non-core'~%")
                            arg)))))
        (option '(#\t "type") #t #f
                (lambda (opt name arg result)
                  (let* ((not-comma (char-set-complement (char-set #\,)))
                         (names (map string->symbol
                                     (string-tokenize arg not-comma))))
                    (alist-cons 'updaters names result))))
        (option '(#\L "list-updaters") #f #f
                (lambda args
                  (list-updaters-and-exit)))
        (option '(#\m "manifest") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'manifest arg result)))
        (option '(#\e "expression") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'expression arg result)))
        (option '(#\l "list-dependent") #f #f
                (lambda (opt name arg result)
                  (alist-cons 'list-dependent? #t result)))
        (option '(#\r "recursive") #f #f
                (lambda (opt name arg result)
                  (alist-cons 'recursive? #t result)))
        (option '("list-transitive") #f #f
                (lambda (opt name arg result)
                  (alist-cons 'list-transitive? #t result)))

        (option '("keyring") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'keyring arg result)))
        (option '("key-server") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'key-server arg result)))
        (option '("gpg") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'gpg-command arg result)))
        (option '("key-download") #t #f
                (lambda (opt name arg result)
                  (match arg
                    ((or "interactive" "always" "never")
                     (alist-cons 'key-download (string->symbol arg)
                                 result))
                    (x
                     (leave (G_ "unsupported policy: ~a~%")
                            arg)))))

        ;; The short option -L is already used by --list-updaters, therefore
        ;; it needs to be removed from %standard-build-options.
        (let ((load-path-option (find (lambda (option)
                                         (member "load-path"
                                                 (option-names option)))
                                       %standard-build-options)))
          (option
           (filter (lambda (name) (not (equal? #\L name)))
                   (option-names load-path-option))
           (option-required-arg? load-path-option)
           (option-optional-arg? load-path-option)
           (option-processor     load-path-option)))

        (option '(#\h "help") #f #f
                (lambda args
                  (show-help)
                  (exit 0)))
        (option '(#\V "version") #f #f
                (lambda args
                  (show-version-and-exit "guix refresh")))))

(define (show-help)
  (display (G_ "Usage: guix refresh [OPTION]... [PACKAGE]...
Update package definitions to match the latest upstream version.

When PACKAGE... is given, update only the specified packages.  Otherwise
update all the packages of the distribution, or the subset thereof
specified with `--select'.\n"))
  (display (G_ "
  -e, --expression=EXPR  consider the package EXPR evaluates to"))
  (display (G_ "
  -u, --update           update source files in place"))
  (display (G_ "
  -s, --select=SUBSET    select all the packages in SUBSET, one of
                         `core' or `non-core'"))
  (display (G_ "
  -m, --manifest=FILE    select all the packages from the manifest in FILE"))
  (display (G_ "
  -t, --type=UPDATER,... restrict to updates from the specified updaters
                         (e.g., 'gnu')"))
  (display (G_ "
  -L, --list-updaters    list available updaters and exit"))
  (display (G_ "
  -l, --list-dependent   list top-level dependent packages that would need to
                         be rebuilt as a result of upgrading PACKAGE..."))
  (display (G_ "
  -r, --recursive        check the PACKAGE and its inputs for upgrades"))
  (display (G_ "
      --list-transitive  list all the packages that PACKAGE depends on"))
  (newline)
  (display (G_ "
      --keyring=FILE     use FILE as the keyring of upstream OpenPGP keys"))
  (display (G_ "
      --key-server=HOST  use HOST as the OpenPGP key server"))
  (display (G_ "
      --gpg=COMMAND      use COMMAND as the GnuPG 2.x command"))
  (display (G_ "
      --key-download=POLICY
                         handle missing OpenPGP keys according to POLICY:
                         'always', 'never', and 'interactive', which is also
                         used when 'key-download' is not specified"))
  (newline)
  (display (G_ "
      --load-path=DIR    prepend DIR to the package module search path"))
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (show-bug-report-information))

(define (options->packages opts)
  "Return the list of packages requested by OPTS, honoring options like
'--recursive'."
  (define core-package?
    (let* ((input->package (match-lambda
                             ((name (? package? package) _ ...) package)
                             (_ #f)))
           (final-inputs   (map input->package %final-inputs))
           (core           (append final-inputs
                                   (append-map (compose (cut filter-map input->package <>)
                                                        package-transitive-inputs)
                                               final-inputs)))
           (names          (delete-duplicates (map package-name core))))
      (lambda (package)
        "Return true if PACKAGE is likely a \"core package\"---i.e., one whose
update would trigger a complete rebuild."
        ;; Compare by name because packages in base.scm basically inherit
        ;; other packages.  So, even if those packages are not core packages
        ;; themselves, updating them would also update those who inherit from
        ;; them.
        ;; XXX: Fails to catch MPFR/MPC, whose *source* is used as input.
        (member (package-name package) names))))

  (define (keep-newest package lst)
    ;; If a newer version of PACKAGE is already in LST, return LST; otherwise
    ;; return LST minus the other version of PACKAGE in it, plus PACKAGE.
    (let ((name (package-name package)))
      (match (find (lambda (p)
                     (string=? (package-name p) name))
                   lst)
        ((? package? other)
         (if (version>? (package-version other) (package-version package))
             lst
             (cons package (delq other lst))))
        (_
         (cons package lst)))))

  (define args-packages
    ;; Packages explicitly passed as command-line arguments.
    (match (filter-map (match-lambda
                         (('argument . spec)
                          ;; Take either the specified version or the
                          ;; latest one.
                          (specification->package spec))
                         (('expression . exp)
                          (read/eval-package-expression exp))
                         (_ #f))
                       opts)
      (()                                         ;default to all packages
       (let ((select? (match (assoc-ref opts 'select)
                        ('core core-package?)
                        ('non-core (negate core-package?))
                        (_ (const #t)))))
         (fold-packages (lambda (package result)
                          (if (select? package)
                              (keep-newest package result)
                              result))
                        '())))
      (some                                       ;user-specified packages
       some)))

  (define packages
    (match (assoc-ref opts 'manifest)
      (#f args-packages)
      ((? string? file) (packages-from-manifest file))))

  (if (assoc-ref opts 'recursive?)
      (mlet %store-monad ((edges (node-edges %bag-node-type
                                             (all-packages))))
        (return (node-transitive-edges packages edges)))
      (with-monad %store-monad
        (return packages))))

;;;
;;; Updates.
;;;

(define (lookup-updater-by-name name)
  "Return the updater called NAME."
  (or (find (lambda (updater)
              (eq? name (upstream-updater-name updater)))
            (force %updaters))
      (leave (G_ "~a: no such updater~%") name)))

(define (list-updaters-and-exit)
  "Display available updaters and exit."
  (format #t (G_ "Available updaters:~%"))
  (newline)

  (let* ((packages (fold-packages cons '()))
         (total    (length packages)))
    (define uncovered
      (fold (lambda (updater uncovered)
              (let ((matches (filter (upstream-updater-predicate updater)
                                     packages)))
                ;; TRANSLATORS: The parenthetical expression here is rendered
                ;; like "(42% coverage)" and denotes the fraction of packages
                ;; covered by the given updater.
                (format #t (G_ "  - ~a: ~a (~2,1f% coverage)~%")
                        (upstream-updater-name updater)
                        (G_ (upstream-updater-description updater))
                        (* 100. (/ (length matches) total)))
                (lset-difference eq? uncovered matches)))
            packages
            (force %updaters)))

    (newline)
    (format #t (G_ "~2,1f% of the packages are covered by these updaters.~%")
            (* 100. (/ (- total (length uncovered)) total))))
  (exit 0))

(define (warn-no-updater package)
  (warning (package-location package)
           (G_ "no updater for ~a~%")
           (package-name package)))

(define* (update-package store package updaters
                         #:key (key-download 'interactive) warn?)
  "Update the source file that defines PACKAGE with the new version.
KEY-DOWNLOAD specifies a download policy for missing OpenPGP keys; allowed
values: 'interactive' (default), 'always', and 'never'.  When WARN? is true,
warn about packages that have no matching updater."
  (if (lookup-updater package updaters)
      (let-values (((version tarball source)
                    (package-update store package updaters
                                    #:key-download key-download))
                   ((loc)
                    (or (package-field-location package 'version)
                        (package-location package))))
        (when version
          (if (and=> tarball file-exists?)
              (begin
                (info loc
                      (G_ "~a: updating from version ~a to version ~a...~%")
                      (package-name package)
                      (package-version package) version)
                (for-each
                 (lambda (change)
                   (format (current-error-port)
                           (match (list (upstream-input-change-action change)
                                        (upstream-input-change-type change))
                             (('add 'regular)
                              (G_ "~a: consider adding this input: ~a~%"))
                             (('add 'native)
                              (G_ "~a: consider adding this native input: ~a~%"))
                             (('add 'propagated)
                              (G_ "~a: consider adding this propagated input: ~a~%"))
                             (('remove 'regular)
                              (G_ "~a: consider removing this input: ~a~%"))
                             (('remove 'native)
                              (G_ "~a: consider removing this native input: ~a~%"))
                             (('remove 'propagated)
                              (G_ "~a: consider removing this propagated input: ~a~%")))
                           (package-name package)
                           (upstream-input-change-name change)))
                 (upstream-source-input-changes source))
                (let ((hash (call-with-input-file tarball
                              port-sha256)))
                  (update-package-source package source hash)))
              (warning (G_ "~a: version ~a could not be \
downloaded and authenticated; not updating~%")
                       (package-name package) version))))
      (when warn?
        (warn-no-updater package))))

(define* (check-for-package-update package updaters #:key warn?)
  "Check whether an update is available for PACKAGE and print a message.  When
WARN? is true and no updater exists for PACKAGE, print a warning."
  (match (package-latest-release package updaters)
    ((? upstream-source? source)
     (let ((loc (or (package-field-location package 'version)
                    (package-location package))))
       (case (version-compare (upstream-source-version source)
                              (package-version package))
         ((>)
          (info loc
                (G_ "~a would be upgraded from ~a to ~a~%")
                (package-name package) (package-version package)
                (upstream-source-version source)))
         ((=)
          (when warn?
            (info loc
                  (G_ "~a is already the latest version of ~a~%")
                  (package-version package)
                  (package-name package))))
         (else
          (when warn?
            (warning loc
                     (G_ "~a is greater than \
the latest known version of ~a (~a)~%")
                     (package-version package)
                     (package-name package)
                     (upstream-source-version source)))))))
    (#f
     (when warn?
       ;; Distinguish between "no updater" and "failing updater."
       (match (lookup-updater package updaters)
         ((? upstream-updater? updater)
          (warning (package-location package)
                   (G_ "'~a' updater failed to determine available \
releases for ~a~%")
                   (upstream-updater-name updater)
                   (package-name package)))
         (#f
          (warn-no-updater package)))))))

;;;
;;; Dependents.
;;;

(define (all-packages)
  "Return the list of all the distro's packages."
  (fold-packages (lambda (package result)
                   ;; Ignore deprecated packages.
                   (if (package-superseded package)
                       result
                       (cons package result)))
                 '()
                 #:select? (const #t)))           ;include hidden packages

(define (list-dependents packages)
  "List all the things that would need to be rebuilt if PACKAGES are changed."
  ;; Using %BAG-NODE-TYPE is more accurate than using %PACKAGE-NODE-TYPE
  ;; because it includes implicit dependencies.
  (define (full-name package)
    (string-append (package-name package) "@"
                   (package-version package)))

  (mlet %store-monad ((edges (node-back-edges %bag-node-type
                                              (package-closure (all-packages)))))
    (let* ((dependents (node-transitive-edges packages edges))
           (covering   (filter (lambda (node)
                                 (null? (edges node)))
                               dependents)))
      (match dependents
        (()
         (format (current-output-port)
                 (N_ "No dependents other than itself: ~{~a~}~%"
                     "No dependents other than themselves: ~{~a~^ ~}~%"
                     (length packages))
                 (map full-name packages)))

        ((x)
         (format (current-output-port)
                 (G_ "A single dependent package: ~a~%")
                 (full-name x)))
        (lst
         (format (current-output-port)
                 (N_ "Building the following ~*package would ensure ~d \
dependent packages are rebuilt: ~{~a~^ ~}~%"
                     "Building the following ~d packages would ensure ~d \
dependent packages are rebuilt: ~{~a~^ ~}~%"
                     (length covering))
                 (length covering) (length dependents)
                 (map full-name covering))))
      (return #t))))

(define (list-transitive packages)
  "List all the packages that would cause PACKAGES to be rebuilt if they are changed."
  ;; Using %BAG-NODE-TYPE is more accurate than using %PACKAGE-NODE-TYPE
  ;; because it includes implicit dependencies.
  (define (full-name package)
    (string-append (package-name package) "@"
                   (package-version package)))

  (mlet %store-monad ((edges (node-edges %bag-node-type
                                         ;; Here we don't want the -boot0 packages.
                                         (fold-packages cons '()))))
    (let ((dependent (node-transitive-edges packages edges)))
      (match packages
        ((x)
         (format (current-output-port)
                 (G_ "~a depends on the following ~d packages: ~{~a~^ ~}~%.")
                 (full-name x) (length dependent) (map full-name dependent)))
        (lst
         (format (current-output-port)
                 (G_ "The following ~d packages \
all are dependent packages: ~{~a~^ ~}~%")
                 (length dependent) (map full-name dependent))))
      (return #t))))

;;;
;;; Manifest.
;;;

(define (manifest->packages manifest)
  "Return the list of packages in MANIFEST."
  (filter-map (lambda (entry)
                (let ((item (manifest-entry-item entry)))
                  (if (package? item) item #f)))
              (manifest-entries manifest)))

(define (packages-from-manifest manifest)
  "Return the list of packages in loaded MANIFEST."
  (let* ((user-module (make-user-module '((guix profiles) (gnu))))
         (manifest    (load* manifest user-module)))
    (manifest->packages manifest)))

;;;
;;; Entry point.
;;;

(define-command (guix-refresh . args)
  (category packaging)
  (synopsis "update existing package definitions")

  (define (parse-options)
    ;; Return the alist of option values.
    (parse-command-line args %options (list %default-options)
                        #:build-options? #f))

  (define (options->updaters opts)
    ;; Return the list of updaters to use.
    (match (filter-map (match-lambda
                         (('updaters . names)
                          (map lookup-updater-by-name names))
                         (_ #f))
                       opts)
      (()
       ;; Use the default updaters.
       (force %updaters))
      (lists
       (concatenate lists))))

  (let* ((opts            (parse-options))
         (update?         (assoc-ref opts 'update?))
         (updaters        (options->updaters opts))
         (recursive?      (assoc-ref opts 'recursive?))
         (list-dependent? (assoc-ref opts 'list-dependent?))
         (list-transitive? (assoc-ref opts 'list-transitive?))
         (key-download    (assoc-ref opts 'key-download))

         ;; Warn about missing updaters when a package is explicitly given on
         ;; the command line.
         (warn?           (and (or (assoc-ref opts 'argument)
                                   (assoc-ref opts 'expression)
                                   (assoc-ref opts 'manifest))
                               (not recursive?))))
    (with-error-handling
      (with-store store
        (run-with-store store
          (mlet %store-monad ((packages (options->packages opts)))
            (cond
             (list-dependent?
              (list-dependents packages))
             (list-transitive?
              (list-transitive packages))
             (update?
              (parameterize ((%openpgp-key-server
                              (or (assoc-ref opts 'key-server)
                                  (%openpgp-key-server)))
                             (%gpg-command
                              (or (assoc-ref opts 'gpg-command)
                                  (%gpg-command)))
                             (current-keyring
                              (or (assoc-ref opts 'keyring)
                                  (string-append (config-directory)
                                                 "/upstream/trustedkeys.kbx"))))
                (for-each
                 (cut update-package store <> updaters
                      #:key-download key-download
                      #:warn? warn?)
                 packages)
                (return #t)))
             (else
              (for-each (cut check-for-package-update <> updaters
                             #:warn? warn?)
                        packages)
              (return #t)))))))))


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 scripts remove)
  #:use-module (guix ui)
  #:use-module (guix scripts package)
  #:use-module (guix scripts build)
  #:use-module (guix scripts)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-37)
  #:export (guix-remove))

(define (show-help)
  (display (G_ "Usage: guix remove [OPTION] PACKAGES...
Remove the given PACKAGES.
This is an alias for 'guix package -r'.\n"))
  (display (G_ "
  -p, --profile=PROFILE  use PROFILE instead of the user's default profile"))
  ;; '--bootstrap' not shown here.
  (display (G_ "
  -v, --verbosity=LEVEL  use the given verbosity LEVEL"))
  (newline)
  (show-build-options-help)
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (show-bug-report-information))

(define %options
  ;; Specification of the command-line options.
  (cons* (option '(#\h "help") #f #f
                 (lambda args
                   (show-help)
                   (exit 0)))
         (option '(#\V "version") #f #f
                 (lambda args
                   (show-version-and-exit "guix remove")))

         ;; Preserve some of the 'guix package' options.
         (append (filter (lambda (option)
                           (any (cut member <> (option-names option))
                                '("profile" "dry-run" "verbosity" "bootstrap")))
                         %package-options)

                 %standard-build-options)))

(define-command (guix-remove . args)
  (synopsis "remove installed packages")

  (define (handle-argument arg result arg-handler)
    ;; Treat all non-option arguments as package specs.
    (values (alist-cons 'remove arg result)
            arg-handler))

  (define opts
    (parse-command-line args %options
                        (list %package-default-options #f)
                        #:argument-handler handle-argument))

  (guix-package* opts))

license: mit


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2020 Simon Tournier <zimon.toutoune@gmail.com>
;;; Copyright © 2020 Konrad Hinsen <konrad.hinsen@fastmail.net>
;;;
;;; 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 scripts repl)
  #:use-module (guix ui)
  #:use-module (guix scripts)
  #:use-module (guix repl)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-37)
  #:use-module (ice-9 match)
  #:use-module (rnrs bytevectors)
  #:autoload   (system repl repl) (start-repl)
  #:autoload   (system repl server)
                  (make-tcp-server-socket make-unix-domain-server-socket)
  #:export (guix-repl))

;;; Commentary:
;;;
;;; This command provides a Guile script runner and REPL in an environment
;;; that contains all the modules comprising Guix.

(define %default-options
  `((type . guile)))

(define %options
  (list (option '(#\h "help") #f #f
                (lambda args
                  (show-help)
                  (exit 0)))
        (option '(#\V "version") #f #f
                (lambda args
                  (show-version-and-exit "guix repl")))
        (option '(#\t "type") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'type (string->symbol arg) result)))
        (option '("listen") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'listen arg result)))
        (option '(#\q) #f #f
                (lambda (opt name arg result)
                  (alist-cons 'ignore-dot-guile? #t result)))
        (option '(#\L "load-path") #t #f
                (lambda (opt name arg result)
                  ;; XXX: Imperatively modify the search paths.
                  (set! %load-path (cons arg %load-path))
                  (set! %load-compiled-path (cons arg %load-compiled-path))
                  result))))

(define (show-help)
  (display (G_ "Usage: guix repl [OPTIONS...] [-- FILE ARGS...]
In the Guix execution environment, run FILE as a Guile script with
command-line arguments ARGS.  If no FILE is given, start a Guile REPL.\n"))
  (display (G_ "
  -t, --type=TYPE        start a REPL of the given TYPE"))
  (display (G_ "
      --listen=ENDPOINT  listen to ENDPOINT instead of standard input"))
  (display (G_ "
  -q                     inhibit loading of ~/.guile"))
  (newline)
  (display (G_ "
  -L, --load-path=DIR    prepend DIR to the package module search path"))
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (show-bug-report-information))

(define user-module
  ;; Module where we execute user code.
  (let ((module (resolve-module '(guix-user) #f #f #:ensure #t)))
    (beautify-user-module! module)
    module))

(define (call-with-connection spec thunk)
  "Dynamically-bind the current input and output ports according to SPEC and
call THUNK."
  (if (not spec)
      (thunk)

      ;; Note: the "PROTO:" prefix in SPEC is here so that we can eventually
      ;; parse things like "fd:123" in a non-ambiguous way.
      (match (string-index spec #\:)
        (#f
         (leave (G_ "~A: invalid listen specification~%") spec))
        (index
         (let ((protocol (string-take spec index))
               (address  (string-drop spec (+ index 1))))
           (define socket
             (match protocol
               ("tcp"
                (make-tcp-server-socket #:port (string->number address)))
               ("unix"
                (make-unix-domain-server-socket #:path address))
               (_
                (leave (G_ "~A: unsupported protocol family~%")
                       protocol))))

           (listen socket 10)
           (let loop ()
             (match (accept socket)
               ((connection . address)
                (if (= AF_UNIX (sockaddr:fam address))
                    (info (G_ "accepted connection~%"))
                    (info (G_ "accepted connection from ~a~%")
                          (inet-ntop (sockaddr:fam address)
                                     (sockaddr:addr address))))
                (dynamic-wind
                  (const #t)
                  (lambda ()
                    (parameterize ((current-input-port connection)
                                   (current-output-port connection))
                      (thunk)))
                  (lambda ()
                    (false-if-exception (close-port connection))
                    (info (G_ "connection closed~%"))))))
             (loop)))))))

(define-command (guix-repl . args)
  (category plumbing)
  (synopsis "read-eval-print loop (REPL) for interactive programming")

  (define opts
    (args-fold* args %options
                (lambda (opt name arg result)
                  (leave (G_ "~A: unrecognized option~%") name))
                (lambda (arg result)
                  (append `((script . ,arg)
                            (ignore-dot-guile? . #t))
                          result))
                %default-options))

  (define user-config
    (and=> (getenv "HOME")
           (lambda (home)
             (string-append home "/.guile"))))

  (define (set-user-module)
    (set-current-module user-module)
    (when (and (not (assoc-ref opts 'ignore-dot-guile?))
               user-config
               (file-exists? user-config))
      (load user-config)))

  (define script
    (reverse
     (filter-map (match-lambda
                   (('script . script) script)
                   (_ #f))
                 opts)))

  (with-error-handling

    (unless (null? script)
      ;; Run script
      (save-module-excursion
       (lambda ()
         (set-program-arguments script)
         (set-user-module)
         (load-in-vicinity "." (car script)))))

    (when (null? script)
      ;; Start REPL
      (let ((type (assoc-ref opts 'type)))
        (call-with-connection (assoc-ref opts 'listen)
          (lambda ()
            (case type
              ((guile)
               (save-module-excursion
                (lambda ()
                  (set-user-module)
                  ;; Do not exit repl on SIGINT.
                  ((@@ (ice-9 top-repl) call-with-sigint)
                   (lambda ()
                     (start-repl))))))
              ((machine)
               (machine-repl))
              (else
               (leave (G_ "~a: unknown type of REPL~%") type)))))))))

;; Local Variables:
;; eval: (put 'call-with-connection 'scheme-indent-function 1)
;; End:


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;;
;;; 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 scripts search)
  #:use-module (guix ui)
  #:use-module (guix scripts package)
  #:use-module ((guix scripts build)
                #:select (%standard-build-options))
  #:use-module (guix scripts)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-37)
  #:export (guix-search))

(define (show-help)
  (display (G_ "Usage: guix search [OPTION] REGEXPS...
Search for packages matching REGEXPS."))
  (display (G_"
This is an alias for 'guix package -s'.\n"))
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (display (G_ "
  -L, --load-path=DIR    prepend DIR to the package module search path"))
  (newline)
  (show-bug-report-information))

(define %options
  ;; Specification of the command-line options.
  (list (option '(#\h "help") #f #f
                (lambda args
                  (show-help)
                  (exit 0)))
        (option '(#\V "version") #f #f
                (lambda args
                  (show-version-and-exit "guix search")))

        (find (lambda (option)
                (member "load-path" (option-names option)))
              %standard-build-options)))

(define-command (guix-search . args)
  (synopsis "search for packages")

  (define (handle-argument arg result)
    ;; Treat all non-option arguments as regexps.
    (cons `(query search ,(or arg ""))
          result))

  (define opts
    (args-fold* args %options
                (lambda (opt name arg . rest)
                  (leave (G_ "~A: unrecognized option~%") name))
                handle-argument
                '()))

  (unless (assoc-ref opts 'query)
    (leave (G_ "missing arguments: no regular expressions to search for~%")))

  (guix-package* opts))


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019 Simon Tournier <zimon.toutoune@gmail.com>
;;;
;;; 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 scripts show)
  #:use-module (guix ui)
  #:use-module (guix scripts package)
  #:use-module ((guix scripts build)
                #:select (%standard-build-options))
  #:use-module (guix scripts)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-37)
  #:export (guix-show))

(define (show-help)
  (display (G_ "Usage: guix show [OPTION] PACKAGE...
Show details about PACKAGE."))
  (display (G_"
This is an alias for 'guix package --show='.\n"))
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (display (G_ "
  -L, --load-path=DIR    prepend DIR to the package module search path"))
  (newline)
  (show-bug-report-information))

(define %options
  ;; Specification of the command-line options.
  (list (option '(#\h "help") #f #f
                (lambda args
                  (show-help)
                  (exit 0)))
        (option '(#\V "version") #f #f
                (lambda args
                  (show-version-and-exit "guix show")))

        (find (lambda (option)
                (member "load-path" (option-names option)))
              %standard-build-options)))

(define-command (guix-show . args)
  (synopsis "show information about packages")

  (define (handle-argument arg result)
    ;; Treat all non-option arguments as regexps.
    (cons `(query show ,arg)
          result))

  (define opts
    (args-fold* args %options
                (lambda (opt name arg . rest)
                  (leave (G_ "~A: unrecognized option~%") name))
                handle-argument
                '()))

  (unless (assoc-ref opts 'query)
    (leave (G_ "missing arguments: no package to show~%")))

  (guix-package* (reverse opts)))


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2019 Simon Tournier <zimon.toutoune@gmail.com>
;;;
;;; 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 scripts size)
  #:use-module (guix ui)
  #:use-module (guix scripts)
  #:use-module (guix scripts build)
  #:use-module (guix store)
  #:use-module (guix monads)
  #:use-module (guix combinators)
  #:use-module (guix grafts)
  #:use-module (guix packages)
  #:use-module (guix derivations)
  #:use-module (gnu packages)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-37)
  #:use-module (ice-9 match)
  #:use-module (ice-9 format)
  #:use-module (ice-9 vlist)
  #:export (profile?
            profile-file
            profile-self-size
            profile-closure-size
            store-profile

            guix-size))

;; Size profile of a store item.
(define-record-type <profile>
  (profile file self-size closure-size)
  profile?
  (file          profile-file)                 ;store item
  (self-size     profile-self-size)            ;size in bytes
  (closure-size  profile-closure-size))        ;size of dependencies in bytes

(define substitutable-path-info*
  (store-lift substitutable-path-info))

(define (file-size item)
  "Return the size in bytes of ITEM, resorting to information from substitutes
if ITEM is not in the store."
  (mlet %store-monad ((info (query-path-info* item)))
    (if info
        (return (path-info-nar-size info))
        (mlet %store-monad ((info (substitutable-path-info* (list item))))
          (match info
            ((info)
             ;; The nar size is an approximation, but a good one.
             (return (substitutable-nar-size info)))
            (()
             (leave (G_ "no available substitute information for '~a'~%")
                    item)))))))

(define profile-closure<?
  (match-lambda*
    ((($ <profile> name1 self1 total1)
      ($ <profile> name2 self2 total2))
     (< total1 total2))))

(define profile-self<?
  (match-lambda*
    ((($ <profile> name1 self1 total1)
      ($ <profile> name2 self2 total2))
     (< self1 self2))))

(define* (display-profile profile #:optional (port (current-output-port))
                          #:key (profile<? profile-closure<?))
  "Display PROFILE, a list of PROFILE objects, to PORT.  Sort entries
according to PROFILE<?."
  (define MiB (expt 2 20))

  (format port "~64a ~8a ~a\n"
          (G_ "store item") (G_ "total") (G_ "self"))
  (let ((whole (reduce + 0 (map profile-self-size profile))))
    (for-each (match-lambda
                (($ <profile> name self total)
                 (format port "~64a  ~6,1f  ~6,1f ~5,1f%\n"
                         name (/ total MiB) (/ self MiB)
                         (* 100. (/ self whole 1.)))))
              (sort profile (negate profile<?)))
    (format port (G_ "total: ~,1f MiB~%") (/ whole MiB 1.))))

(define display-profile*
  (lift display-profile %store-monad))

(define (substitutable-requisites store items)
  "Return the list of requisites of ITEMS based on information available in
substitutes."
  (let loop ((items  items)
             (result '()))
    (match items
      (()
       (delete-duplicates result))
      (items
       (let ((info (substitutable-path-info store
                                            (delete-duplicates items))))
         (loop (remove (lambda (item)             ;XXX: complexity
                         (member item result))
                       (append-map substitutable-references info))
               (append (append-map substitutable-references info)
                       result)))))))

(define (requisites* items)
  "Return as a monadic value the requisites of ITEMS, based either on the
information available in the local store or using information about
substitutes."
  (lambda (store)
    (let-values (((local missing)
                  (partition (cut valid-path? store <>) items)))
      (values (delete-duplicates
               (append (requisites store local)
                       (substitutable-requisites store missing)))
              store))))

(define (store-profile items)
  "Return as a monadic value a list of <profile> objects representing the
profile of ITEMS and their requisites."
  (mlet* %store-monad ((refs  (>>= (requisites* items)
                                   (lambda (refs)
                                     (return (delete-duplicates
                                              (append items refs))))))
                       (sizes (mapm %store-monad
                                    (lambda (item)
                                      (>>= (file-size item)
                                           (lambda (size)
                                             (return (cons item size)))))
                                    refs)))
    (define size-table
      (fold (lambda (pair result)
              (match pair
                ((item . size)
                 (vhash-cons item size result))))
            vlist-null sizes))

    (define (dependency-size item)
      (mlet %store-monad ((deps (requisites* (list item))))
        (foldm %store-monad
               (lambda (item total)
                 (return (+ (match (vhash-assoc item size-table)
                              ((_ . size) size))
                            total)))
               0
               (delete-duplicates (cons item deps)))))

    (mapm %store-monad
          (match-lambda
            ((item . size)
             (mlet %store-monad ((dependencies (dependency-size item)))
               (return (profile item size dependencies)))))
          sizes)))

(define* (ensure-store-item spec-or-item)
  "Return a store file name.  If SPEC-OR-ITEM is a store file name, return it
as is.  Otherwise, assume SPEC-OR-ITEM is a package output specification such
as \"guile:debug\" or \"gcc-4.8\" and return its store file name."
  (with-monad %store-monad
    (if (store-path? spec-or-item)
        (return spec-or-item)
        (let-values (((package output)
                      (specification->package+output spec-or-item)))
          (mlet %store-monad ((drv (package->derivation package)))
            ;; Note: we don't try building DRV like 'guix archive' does
            ;; because we don't have to since we can instead rely on
            ;; substitute meta-data.
            (return (derivation->output-path drv output)))))))

;;;
;;; Charts.
;;;

;; Autoload Guile-Charting.
;; XXX: Use this hack instead of #:autoload to avoid compilation errors.
;; See <http://bugs.gnu.org/12202>.
(module-autoload! (current-module)
                  '(charting) '(make-page-map))

(define (profile->page-map profiles file)
  "Write a 'page map' chart of PROFILES, a list of <profile> objects, to FILE,
the name of a PNG file."
  (define (strip name)
    (string-drop name (+ (string-length (%store-prefix)) 28)))

  (define data
    (fold2 (lambda (profile result offset)
             (match profile
               (($ <profile> name self)
                (let ((self (inexact->exact
                             (round (/ self (expt 2. 10))))))
                  (values `((,(strip name) ,offset . ,self)
                            ,@result)
                          (+ offset self))))))
           '()
           0
           (sort profiles
                 (match-lambda*
                   ((($ <profile> name1 self1 total1)
                     ($ <profile> name2 self2 total2))
                    (> total1 total2))))))

  ;; TRANSLATORS: This is the title of a graph, meaning that the graph
  ;; represents a profile of the store (the "store" being the place where
  ;; packages are stored.)
  (make-page-map (G_ "store profile") data
                 #:write-to-png file))

;;;
;;; Options.
;;;

(define (show-help)
  (display (G_ "Usage: guix size [OPTION]... PACKAGE|STORE-ITEM
Report the size of the PACKAGE or STORE-ITEM, with its dependencies.\n"))
  (display (G_ "
      --substitute-urls=URLS
                         fetch substitute from URLS if they are authorized"))
  (display (G_ "
  -s, --system=SYSTEM    consider packages for SYSTEM--e.g., \"i686-linux\""))
  ;; TRANSLATORS: "closure" and "self" must not be translated.
  (display (G_ "
      --sort=KEY         sort according to KEY--\"closure\" or \"self\""))
  (display (G_ "
  -m, --map-file=FILE    write to FILE a graphical map of disk usage"))
  (newline)
  (display (G_ "
  -L, --load-path=DIR    prepend DIR to the package module search path"))
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (show-bug-report-information))

(define %options
  ;; Specifications of the command-line options.
  (list (option '(#\s "system") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'system arg
                              (alist-delete 'system result eq?))))
        (option '("substitute-urls") #t #f
                (lambda (opt name arg result . rest)
                  (apply values
                         (alist-cons 'substitute-urls
                                     (string-tokenize arg)
                                     (alist-delete 'substitute-urls result))
                         rest)))
        (option '("sort") #t #f
                (lambda (opt name arg result . rest)
                  (match arg
                    ("closure"
                     (alist-cons 'profile<? profile-closure<? result))
                    ("self"
                     (alist-cons 'profile<? profile-self<? result))
                    (_
                     (leave (G_ "~a: invalid sorting key~%") arg)))))
        (option '(#\m "map-file") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'map-file arg result)))
        (find (lambda (option)
                (member "load-path" (option-names option)))
              %standard-build-options)
        (option '(#\h "help") #f #f
                (lambda args
                  (show-help)
                  (exit 0)))
        (option '(#\V "version") #f #f
                (lambda args
                  (show-version-and-exit "guix size")))))

(define %default-options
  `((system . ,(%current-system))
    (profile<? . ,profile-self<?)))

;;;
;;; Entry point.
;;;

(define-command (guix-size . args)
  (category packaging)
  (synopsis "profile the on-disk size of packages")

  (with-error-handling
    (let* ((opts     (parse-command-line args %options (list %default-options)
                                         #:build-options? #f))
           (files    (filter-map (match-lambda
                                   (('argument . file) file)
                                   (_ #f))
                                 opts))
           (profile<? (assoc-ref opts 'profile<?))
           (map-file (assoc-ref opts 'map-file))
           (system   (assoc-ref opts 'system))
           (urls     (assoc-ref opts 'substitute-urls)))
      (match files
        (()
         (leave (G_ "missing store item argument\n")))
        ((files ..1)
         (leave-on-EPIPE
          ;; Turn off grafts because (1) substitute servers do not serve grafted
          ;; packages, and (2) they do not make any difference on the
          ;; resulting size.
          (parameterize ((%graft? #f))
            (with-store store
              (set-build-options store
                                 #:use-substitutes? #t
                                 #:substitute-urls urls)

              (run-with-store store
                (mlet* %store-monad ((items   (mapm %store-monad
                                                    ensure-store-item files))
                                     (profile (store-profile items)))
                  (if map-file
                      (begin
                        (profile->page-map profile map-file)
                        (return #t))
                      (display-profile* profile (current-output-port)
                                        #:profile<? profile<?)))
                #:system system)))))))))


code:
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2014 Nikita Karetnikov <nikita@karetnikov.org>
;;; Copyright © 2018 Kyle Meyer <kyle@kyleam.com>
;;;
;;; 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 scripts substitute)
  #:use-module (guix ui)
  #:use-module (guix scripts)
  #:use-module (guix store)
  #:use-module (guix utils)
  #:use-module (guix combinators)
  #:use-module (guix config)
  #:use-module (guix records)
  #:use-module ((guix serialization) #:select (restore-file))
  #:use-module (gcrypt hash)
  #:use-module (guix base32)
  #:use-module (guix base64)
  #:use-module (guix cache)
  #:use-module (gcrypt pk-crypto)
  #:use-module (guix pki)
  #:use-module ((guix build utils) #:select (mkdir-p dump-port))
  #:use-module ((guix build download)
                #:select (uri-abbreviation nar-uri-abbreviation
                          (open-connection-for-uri
                           . guix:open-connection-for-uri)
                          store-path-abbreviation byte-count->string))
  #:use-module (guix progress)
  #:use-module ((guix build syscalls)
                #:select (set-thread-name))
  #:use-module (ice-9 rdelim)
  #:use-module (ice-9 regex)
  #:use-module (ice-9 match)
  #:use-module (ice-9 format)
  #:use-module (ice-9 ftw)
  #:use-module (ice-9 binary-ports)
  #:use-module (ice-9 vlist)
  #:use-module (rnrs bytevectors)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-19)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-35)
  #:use-module (web uri)
  #:use-module (web http)
  #:use-module (web request)
  #:use-module (web response)
  #:use-module (guix http-client)
  #:export (narinfo-signature->canonical-sexp

            narinfo?
            narinfo-path
            narinfo-uris
            narinfo-uri-base
            narinfo-compressions
            narinfo-file-hashes
            narinfo-file-sizes
            narinfo-hash
            narinfo-size
            narinfo-references
            narinfo-deriver
            narinfo-system
            narinfo-signature

            narinfo-hash->sha256
            narinfo-best-uri

            lookup-narinfos
            lookup-narinfos/diverse
            read-narinfo
            write-narinfo

            %allow-unauthenticated-substitutes?

            substitute-urls
            guix-substitute))

;;; Comment:
;;;
;;; This is the "binary substituter".  It is invoked by the daemon do check
;;; for the existence of available "substitutes" (pre-built binaries), and to
;;; actually use them as a substitute to building things locally.
;;;
;;; If possible, substitute a binary for the requested store path, using a Nix
;;; "binary cache".  This program implements the Nix "substituter" protocol.
;;;
;;; Code:

(define %narinfo-cache-directory
  ;; A local cache of narinfos, to avoid going to the network.  Most of the
  ;; time, 'guix substitute' is called by guix-daemon as root and stores its
  ;; cached data in /var/guix/….  However, when invoked from 'guix challenge'
  ;; as a user, it stores its cache in ~/.cache.
  (if (zero? (getuid))
      (or (and=> (getenv "XDG_CACHE_HOME")
                 (cut string-append <> "/guix/substitute"))
          (string-append %state-directory "/substitute/cache"))
      (string-append (cache-directory #:ensure? #f) "/substitute")))

(define (warn-about-missing-authentication)
  (warning (G_ "authentication and authorization of substitutes \
disabled!~%"))
  #t)

(define %allow-unauthenticated-substitutes?
  ;; Whether to allow unchecked substitutes.  This is useful for testing
  ;; purposes, and should be avoided otherwise.
  (make-parameter
   (and=> (getenv "GUIX_ALLOW_UNAUTHENTICATED_SUBSTITUTES")
          (cut string-ci=? <> "yes"))
   (lambda (value)
     (when value
       (warn-about-missing-authentication))
     value)))

(define %narinfo-ttl
  ;; Number of seconds during which cached narinfo lookups are considered
  ;; valid for substitute servers that do not advertise a TTL via the
  ;; 'Cache-Control' response header.
  (* 36 3600))

(define %narinfo-negative-ttl
  ;; Likewise, but for negative lookups---i.e., cached lookup failures (404).
  (* 3 3600))

(define %narinfo-transient-error-ttl
  ;; Likewise, but for transient errors such as 504 ("Gateway timeout").
  (* 10 60))

(define %narinfo-expired-cache-entry-removal-delay
  ;; How often we want to remove files corresponding to expired cache entries.
  (* 7 24 3600))

(define fields->alist
  ;; The narinfo format is really just like recutils.
  recutils->alist)

(define %fetch-timeout
  ;; Number of seconds after which networking is considered "slow".
  5)

(define %random-state
  (seed->random-state (+ (ash (cdr (gettimeofday)) 32) (getpid))))

(define-syntax-rule (with-timeout duration handler body ...)
  "Run BODY; when DURATION seconds have expired, call HANDLER, and run BODY
again."
  (begin
    (sigaction SIGALRM
      (lambda (signum)
        (sigaction SIGALRM SIG_DFL)
        handler))
    (alarm duration)
    (call-with-values
        (lambda ()
          (let try ()
            (catch 'system-error
              (lambda ()
                body ...)
              (lambda args
                ;; Before Guile v2.0.9-39-gfe51c7b, the SIGALRM triggers EINTR
                ;; because of the bug at
                ;; <http://lists.gnu.org/archive/html/guile-devel/2013-06/msg00050.html>.
                ;; When that happens, try again.  Note: SA_RESTART cannot be
                ;; used because of <http://bugs.gnu.org/14640>.
                (if (= EINTR (system-error-errno args))
                    (begin
                      ;; Wait a little to avoid bursts.
                      (usleep (random 3000000 %random-state))
                      (try))
                    (apply throw args))))))
      (lambda result
        (alarm 0)
        (sigaction SIGALRM SIG_DFL)
        (apply values result)))))

(define* (fetch uri #:key (buffered? #t) (timeout? #t))
  "Return a binary input port to URI and the number of bytes it's expected to
provide."
  (case (uri-scheme uri)
    ((file)
     (let ((port (open-file (uri-path uri)
                            (if buffered? "rb" "r0b"))))
       (values port (stat:size (stat port)))))
    ((http https)
     (guard (c ((http-get-error? c)
                (leave (G_ "download from '~a' failed: ~a, ~s~%")
                       (uri->string (http-get-error-uri c))
                       (http-get-error-code c)
                       (http-get-error-reason c))))
       ;; Test this with:
       ;;   sudo tc qdisc add dev eth0 root netem delay 1500ms
       ;; and then cancel with:
       ;;   sudo tc qdisc del dev eth0 root
       (let ((port #f))
         (with-timeout (if timeout?
                           %fetch-timeout
                           0)
           (begin
             (warning (G_ "while fetching ~a: server is somewhat slow~%")
                      (uri->string uri))
             (warning (G_ "try `--no-substitutes' if the problem persists~%")))
           (begin
             (when (or (not port) (port-closed? port))
               (set! port (guix:open-connection-for-uri
                           uri #:verify-certificate? #f))
               (unless (or buffered? (not (file-port? port)))
                 (setvbuf port 'none)))
             (http-fetch uri #:text? #f #:port port
                         #:verify-certificate? #f))))))
    (else
     (leave (G_ "unsupported substitute URI scheme: ~a~%")
            (uri->string uri)))))

(define-record-type <narinfo>
  (%make-narinfo path uri-base uris compressions file-sizes file-hashes
                 nar-hash nar-size references deriver system
                 signature contents)
  narinfo?
  (path         narinfo-path)
  (uri-base     narinfo-uri-base)        ;URI of the cache it originates from
  (uris         narinfo-uris)            ;list of strings
  (compressions narinfo-compressions)    ;list of strings
  (file-sizes   narinfo-file-sizes)      ;list of (integers | #f)
  (file-hashes  narinfo-file-hashes)
  (nar-hash     narinfo-hash)
  (nar-size     narinfo-size)
  (references   narinfo-references)
  (deriver      narinfo-deriver)
  (system       narinfo-system)
  (signature    narinfo-signature)      ; canonical sexp
  ;; The original contents of a narinfo file.  This field is needed because we
  ;; want to preserve the exact textual representation for verification purposes.
  ;; See <https://lists.gnu.org/archive/html/guix-devel/2014-02/msg00340.html>
  ;; for more information.
  (contents     narinfo-contents))

(define (narinfo-hash->sha256 hash)
  "If the string HASH denotes a sha256 hash, return it as a bytevector.
Otherwise return #f."
  (and (string-prefix? "sha256:" hash)
       (nix-base32-string->bytevector (string-drop hash 7))))

(define (narinfo-signature->canonical-sexp str)
  "Return the value of a narinfo's 'Signature' field as a canonical sexp."
  (match (string-split str #\;)
    ((version host-name sig)
     (let ((maybe-number (string->number version)))
       (cond ((not (number? maybe-number))
              (leave (G_ "signature version must be a number: ~s~%")
                     version))
             ;; Currently, there are no other versions.
             ((not (= 1 maybe-number))
              (leave (G_ "unsupported signature version: ~a~%")
                     maybe-number))
             (else
              (let ((signature (utf8->string (base64-decode sig))))
                (catch 'gcry-error
                  (lambda ()
                    (string->canonical-sexp signature))
                  (lambda (key proc err)
                    (leave (G_ "signature is not a valid \
s-expression: ~s~%")
                           signature))))))))
    (x
     (leave (G_ "invalid format of the signature field: ~a~%") x))))

(define (narinfo-maker str cache-url)
  "Return a narinfo constructor for narinfos originating from CACHE-URL.  STR
must contain the original contents of a narinfo file."
  (lambda (path urls compressions file-hashes file-sizes
                nar-hash nar-size references deriver system
                signature)
    "Return a new <narinfo> object."
    (define len (length urls))
    (%make-narinfo path cache-url
                   ;; Handle the case where URL is a relative URL.
                   (map (lambda (url)
                          (or (string->uri url)
                              (string->uri
                               (string-append cache-url "/" url))))
                        urls)
                   compressions
                   (match file-sizes
                     (()        (make-list len #f))
                     ((lst ...) (map string->number lst)))
                   (match file-hashes
                     (()        (make-list len #f))
                     ((lst ...) (map string->number lst)))
                   nar-hash
                   (and=> nar-size string->number)
                   (string-tokenize references)
                   (match deriver
                     ((or #f "") #f)
                     (_ deriver))
                   system
                   (false-if-exception
                    (and=> signature narinfo-signature->canonical-sexp))
                   str)))

(define* (read-narinfo port #:optional url
                       #:key size)
  "Read a narinfo from PORT.  If URL is true, it must be a string used to
build full URIs from relative URIs found while reading PORT.  When SIZE is
true, read at most SIZE bytes from PORT; otherwise, read as much as possible.

No authentication and authorization checks are performed here!"
  (let ((str (utf8->string (if size
                               (get-bytevector-n port size)
                               (get-bytevector-all port)))))
    (alist->record (call-with-input-string str fields->alist)
                   (narinfo-maker str url)
                   '("StorePath" "URL" "Compression"
                     "FileHash" "FileSize" "NarHash" "NarSize"
                     "References" "Deriver" "System"
                     "Signature")
                   '("URL" "Compression" "FileSize" "FileHash"))))

(define (narinfo-sha256 narinfo)
  "Return the sha256 hash of NARINFO as a bytevector, or #f if NARINFO lacks a
'Signature' field."
  (define %mandatory-fields
    ;; List of fields that must be signed.  If they are not signed, the
    ;; narinfo is considered unsigned.
    '("StorePath" "NarHash" "References"))

  (let ((contents (narinfo-contents narinfo)))
    (match (string-contains contents "Signature:")
      (#f #f)
      (index
       (let* ((above-signature (string-take contents index))
              (signed-fields (match (call-with-input-string above-signature
                                      fields->alist)
                               (((fields . values) ...) fields))))
         (and (every (cut member <> signed-fields) %mandatory-fields)
              (sha256 (string->utf8 above-signature))))))))

(define* (valid-narinfo? narinfo #:optional (acl (current-acl))
                         #:key verbose?)
  "Return #t if NARINFO's signature is not valid."
  (or (%allow-unauthenticated-substitutes?)
      (let ((hash      (narinfo-sha256 narinfo))
            (signature (narinfo-signature narinfo))
            (uri       (uri->string (first (narinfo-uris narinfo)))))
        (and hash signature
             (signature-case (signature hash acl)
               (valid-signature #t)
               (invalid-signature
                (when verbose?
                  (format (current-error-port)
                          "invalid signature for substitute at '~a'~%"
                          uri))
                #f)
               (hash-mismatch
                (when verbose?
                  (format (current-error-port)
                          "hash mismatch for substitute at '~a'~%"
                          uri))
                #f)
               (unauthorized-key
                (when verbose?
                  (format (current-error-port)
                          "substitute at '~a' is signed by an \
unauthorized party~%"
                          uri))
                #f)
               (corrupt-signature
                (when verbose?
                  (format (current-error-port)
                          "corrupt signature for substitute at '~a'~%"
                          uri))
                #f))))))

(define (write-narinfo narinfo port)
  "Write NARINFO to PORT."
  (put-bytevector port (string->utf8 (narinfo-contents narinfo))))

(define (narinfo->string narinfo)
  "Return the external representation of NARINFO."
  (call-with-output-string (cut write-narinfo narinfo <>)))

(define (string->narinfo str cache-uri)
  "Return the narinfo represented by STR.  Assume CACHE-URI as the base URI of
the cache STR originates form."
  (call-with-input-string str (cut read-narinfo <> cache-uri)))

(define (narinfo-cache-file cache-url path)
  "Return the name of the local file that contains an entry for PATH.  The
entry is stored in a sub-directory specific to CACHE-URL."
  ;; The daemon does not sanitize its input, so PATH could be something like
  ;; "/gnu/store/foo".  Gracefully handle that.
  (match (store-path-hash-part path)
    (#f
     (leave (G_ "'~a' does not name a store item~%") path))
    ((? string? hash-part)
     (string-append %narinfo-cache-directory "/"
                    (bytevector->base32-string (sha256 (string->utf8 cache-url)))
                    "/" hash-part))))

(define (cached-narinfo cache-url path)
  "Check locally if we have valid info about PATH coming from CACHE-URL.
Return two values: a Boolean indicating whether we have valid cached info, and
that info, which may be either #f (when PATH is unavailable) or the narinfo
for PATH."
  (define now
    (current-time time-monotonic))

  (define cache-file
    (narinfo-cache-file cache-url path))

  (catch 'system-error
    (lambda ()
      (call-with-input-file cache-file
        (lambda (p)
          (match (read p)
            (('narinfo ('version 2)
                       ('cache-uri cache-uri)
                       ('date date) ('ttl ttl) ('value #f))
             ;; A cached negative lookup.
             (if (obsolete? date now ttl)
                 (values #f #f)
                 (values #t #f)))
            (('narinfo ('version 2)
                       ('cache-uri cache-uri)
                       ('date date) ('ttl ttl) ('value value))
             ;; A cached positive lookup
             (if (obsolete? date now ttl)
                 (values #f #f)
                 (values #t (string->narinfo value cache-uri))))
            (('narinfo ('version v) _ ...)
             (values #f #f))))))
    (lambda _
      (values #f #f))))

(define (cache-narinfo! cache-url path narinfo ttl)
  "Cache locally NARNIFO for PATH, which originates from CACHE-URL, with the
given TTL (a number of seconds or #f).  NARINFO may be #f, in which case it
indicates that PATH is unavailable at CACHE-URL."
  (define now
    (current-time time-monotonic))

  (define (cache-entry cache-uri narinfo)
    `(narinfo (version 2)
              (cache-uri ,cache-uri)
              (date ,(time-second now))
              (ttl ,(or ttl
                        (if narinfo %narinfo-ttl %narinfo-negative-ttl)))
              (value ,(and=> narinfo narinfo->string))))

  (let ((file (narinfo-cache-file cache-url path)))
    (mkdir-p (dirname file))
    (with-atomic-file-output file
      (lambda (out)
        (write (cache-entry cache-url narinfo) out))))

  narinfo)

(define (narinfo-request cache-url path)
  "Return an HTTP request for the narinfo of PATH at CACHE-URL."
  (let ((url (string-append cache-url "/" (store-path-hash-part path)
                            ".narinfo"))
        (headers '((User-Agent . "GNU Guile"))))
    (build-request (string->uri url) #:method 'GET #:headers headers)))

(define (at-most max-length lst)
  "If LST is shorter than MAX-LENGTH, return it; otherwise return its
MAX-LENGTH first elements."
  (let loop ((len 0)
             (lst lst)
             (result '()))
    (match lst
      (()
       (reverse result))
      ((head . tail)
       (if (>= len max-length)
           (reverse result)
           (loop (+ 1 len) tail (cons head result)))))))

(define* (http-multiple-get base-uri proc seed requests
                            #:key port (verify-certificate? #t)
                            (batch-size 1000))
  "Send all of REQUESTS to the server at BASE-URI.  Call PROC for each
response, passing it the request object, the response, a port from which to
read the response body, and the previous result, starting with SEED, à la
'fold'.  Return the final result.  When PORT is specified, use it as the
initial connection on which HTTP requests are sent."
  (let connect ((port     port)
                (requests requests)
                (result   seed))
    (define batch
      (at-most batch-size requests))

    ;; (format (current-error-port) "connecting (~a requests left)..."
    ;;         (length requests))
    (let ((p (or port (guix:open-connection-for-uri
                       base-uri
                       #:verify-certificate?
                       verify-certificate?))))
      ;; For HTTPS, P is not a file port and does not support 'setvbuf'.
      (when (file-port? p)
        (setvbuf p 'block (expt 2 16)))

      ;; Send BATCH in a row.
      ;; XXX: Do our own caching to work around inefficiencies when
      ;; communicating over TLS: <http://bugs.gnu.org/22966>.
      (let-values (((buffer get) (open-bytevector-output-port)))
        ;; Inherit the HTTP proxying property from P.
        (set-http-proxy-port?! buffer (http-proxy-port? p))

        (for-each (cut write-request <> buffer)
                  batch)
        (put-bytevector p (get))
        (force-output p))

      ;; Now start processing responses.
      (let loop ((sent      batch)
                 (processed 0)
                 (result    result))
        (match sent
          (()
           (match (drop requests processed)
             (()
              (close-port p)
              (reverse result))
             (remainder
              (connect p remainder result))))
          ((head tail ...)
           (let* ((resp   (read-response p))
                  (body   (response-body-port resp))
                  (result (proc head resp body result)))
             ;; The server can choose to stop responding at any time, in which
             ;; case we have to try again.  Check whether that is the case.
             ;; Note that even upon "Connection: close", we can read from BODY.
             (match (assq 'connection (response-headers resp))
               (('connection 'close)
                (close-port p)
                (connect #f                       ;try again
                         (drop requests (+ 1 processed))
                         result))
               (_
                (loop tail (+ 1 processed) result)))))))))) ;keep going

(define (read-to-eof port)
  "Read from PORT until EOF is reached.  The data are discarded."
  (dump-port port (%make-void-port "w")))

(define (narinfo-from-file file url)
  "Attempt to read a narinfo from FILE, using URL as the cache URL.  Return #f
if file doesn't exist, and the narinfo otherwise."
  (catch 'system-error
    (lambda ()
      (call-with-input-file file
        (cut read-narinfo <> url)))
    (lambda args
      (if (= ENOENT (system-error-errno args))
          #f
          (apply throw args)))))

(define %unreachable-hosts
  ;; Set of names of unreachable hosts.
  (make-hash-table))

(define* (open-connection-for-uri/maybe uri
                                        #:key
                                        (verify-certificate? #f)
                                        (time %fetch-timeout))
  "Open a connection to URI and return a port to it, or, if connection failed,
print a warning and return #f."
  (define host
    (uri-host uri))

  (catch #t
    (lambda ()
      (guix:open-connection-for-uri uri
                                    #:verify-certificate? verify-certificate?
                                    #:timeout time))
    (match-lambda*
      (('getaddrinfo-error error)
       (unless (hash-ref %unreachable-hosts host)
         (hash-set! %unreachable-hosts host #t)   ;warn only once
         (warning (G_ "~a: host not found: ~a~%")
                  host (gai-strerror error)))
       #f)
      (('system-error . args)
       (unless (hash-ref %unreachable-hosts host)
         (hash-set! %unreachable-hosts host #t)
         (warning (G_ "~a: connection failed: ~a~%") host
                  (strerror
                   (system-error-errno `(system-error ,@args)))))
       #f)
      (args
       (apply throw args)))))

(define (fetch-narinfos url paths)
  "Retrieve all the narinfos for PATHS from the cache at URL and return them."
  (define update-progress!
    (let ((done 0)
          (total (length paths)))
      (lambda ()
        (display "\r\x1b[K" (current-error-port)) ;erase current line
        (force-output (current-error-port))
        (format (current-error-port)
                (G_ "updating substitutes from '~a'... ~5,1f%")
                url (* 100. (/ done total)))
        (set! done (+ 1 done)))))

  (define hash-part->path
    (let ((mapping (fold (lambda (path result)
                           (vhash-cons (store-path-hash-part path) path
                                       result))
                         vlist-null
                         paths)))
      (lambda (hash)
        (match (vhash-assoc hash mapping)
          (#f #f)
          ((_ . path) path)))))

  (define (handle-narinfo-response request response port result)
    (let* ((code   (response-code response))
           (len    (response-content-length response))
           (cache  (response-cache-control response))
           (ttl    (and cache (assoc-ref cache 'max-age))))
      (update-progress!)

      ;; Make sure to read no more than LEN bytes since subsequent bytes may
      ;; belong to the next response.
      (if (= code 200)                            ; hit
          (let ((narinfo (read-narinfo port url #:size len)))
            (if (string=? (dirname (narinfo-path narinfo))
                          (%store-prefix))
                (begin
                  (cache-narinfo! url (narinfo-path narinfo) narinfo ttl)
                  (cons narinfo result))
                result))
          (let* ((path      (uri-path (request-uri request)))
                 (hash-part (basename
                             (string-drop-right path 8)))) ;drop ".narinfo"
            (if len
                (get-bytevector-n port len)
                (read-to-eof port))
            (cache-narinfo! url (hash-part->path hash-part) #f
                            (if (= 404 code)
                                ttl
                                %narinfo-transient-error-ttl))
            result))))

  (define (do-fetch uri)
    (case (and=> uri uri-scheme)
      ((http https)
       (let ((requests (map (cut narinfo-request url <>) paths)))
         (match (open-connection-for-uri/maybe uri)
           (#f
            '())
           (port
            (update-progress!)
            ;; Note: Do not check HTTPS server certificates to avoid depending
            ;; on the X.509 PKI.  We can do it because we authenticate
            ;; narinfos, which provides a much stronger guarantee.
            (let ((result (http-multiple-get uri
                                             handle-narinfo-response '()
                                             requests
                                             #:verify-certificate? #f
                                             #:port port)))
              (close-port port)
              (newline (current-error-port))
              result)))))
      ((file #f)
       (let* ((base  (string-append (uri-path uri) "/"))
              (files (map (compose (cut string-append base <> ".narinfo")
                                   store-path-hash-part)
                          paths)))
         (filter-map (cut narinfo-from-file <> url) files)))
      (else
       (leave (G_ "~s: unsupported server URI scheme~%")
              (if uri (uri-scheme uri) url)))))

  (do-fetch (string->uri url)))

(define (lookup-narinfos cache paths)
  "Return the narinfos for PATHS, invoking the server at CACHE when no
information is available locally."
  (let-values (((cached missing)
                (fold2 (lambda (path cached missing)
                         (let-values (((valid? value)
                                       (cached-narinfo cache path)))
                           (if valid?
                               (if value
                                   (values (cons value cached) missing)
                                   (values cached missing))
                               (values cached (cons path missing)))))
                       '()
                       '()
                       paths)))
    (if (null? missing)
        cached
        (let ((missing (fetch-narinfos cache missing)))
          (append cached (or missing '()))))))

(define (equivalent-narinfo? narinfo1 narinfo2)
  "Return true if NARINFO1 and NARINFO2 are equivalent--i.e., if they describe
the same store item.  This ignores unnecessary metadata such as the Nar URL."
  (and (string=? (narinfo-hash narinfo1)
                 (narinfo-hash narinfo2))

       ;; The following is not needed if all we want is to download a valid
       ;; nar, but it's necessary if we want valid narinfo.
       (string=? (narinfo-path narinfo1)
                 (narinfo-path narinfo2))
       (equal? (narinfo-references narinfo1)
               (narinfo-references narinfo2))

       (= (narinfo-size narinfo1)
          (narinfo-size narinfo2))))

(define (lookup-narinfos/diverse caches paths authorized?)
  "Look up narinfos for PATHS on all of CACHES, a list of URLS, in that order.
That is, when a cache lacks an AUTHORIZED? narinfo, look it up in the next
cache, and so on.

Return a list of narinfos for PATHS or a subset thereof.  The returned
narinfos are either AUTHORIZED?, or they claim a hash that matches an
AUTHORIZED? narinfo."
  (define (select-hit result)
    (lambda (path)
      (match (vhash-fold* cons '() path result)
        ((one)
         one)
        ((several ..1)
         (let ((authorized (find authorized? (reverse several))))
           (and authorized
                (find (cut equivalent-narinfo? <> authorized)
                      several)))))))

  (let loop ((caches caches)
             (paths  paths)
             (result vlist-null)                  ;path->narinfo vhash
             (hits   '()))                        ;paths
    (match paths
      (()                                         ;we're done
       ;; Now iterate on all the HITS, and return exactly one match for each
       ;; hit: the first narinfo that is authorized, or that has the same hash
       ;; as an authorized narinfo, in the order of CACHES.
       (filter-map (select-hit result) hits))
      (_
       (match caches
         ((cache rest ...)
          (let* ((narinfos (lookup-narinfos cache paths))
                 (definite (map narinfo-path (filter authorized? narinfos)))
                 (missing  (lset-difference string=? paths definite))) ;XXX: perf
            (loop rest missing
                  (fold vhash-cons result
                        (map narinfo-path narinfos) narinfos)
                  (append definite hits))))
         (()                                      ;that's it
          (filter-map (select-hit result) hits)))))))

(define (lookup-narinfo caches path authorized?)
  "Return the narinfo for PATH in CACHES, or #f when no substitute for PATH
was found."
  (match (lookup-narinfos/diverse caches (list path) authorized?)
    ((answer) answer)
    (_        #f)))

(define (cached-narinfo-expiration-time file)
  "Return the expiration time for FILE, which is a cached narinfo."
  (catch 'system-error
    (lambda ()
      (call-with-input-file file
        (lambda (port)
          (match (read port)
            (('narinfo ('version 2) ('cache-uri uri)
                       ('date date) ('ttl ttl) ('value #f))
             (+ date ttl))
            (('narinfo ('version 2) ('cache-uri uri)
                       ('date date) ('ttl ttl) ('value value))
             (+ date ttl))
            (x
             0)))))
    (lambda args
      ;; FILE may have been deleted.
      0)))

(define (narinfo-cache-directories directory)
  "Return the list of narinfo cache directories (one per cache URL.)"
  (map (cut string-append directory "/" <>)
       (scandir %narinfo-cache-directory
                (lambda (item)
                  (and (not (member item '("." "..")))
                       (file-is-directory?
                        (string-append %narinfo-cache-directory
                                       "/" item)))))))

(define* (cached-narinfo-files #:optional
                               (directory %narinfo-cache-directory))
  "Return the list of cached narinfo files under DIRECTORY."
  (append-map (lambda (directory)
                (map (cut string-append directory "/" <>)
                     (scandir directory
                              (lambda (file)
                                (= (string-length file) 32)))))
              (narinfo-cache-directories directory)))

(define-syntax with-networking
  (syntax-rules ()
    "Catch DNS lookup errors and TLS errors and gracefully exit."
    ;; Note: no attempt is made to catch other networking errors, because DNS
    ;; lookup errors are typically the first one, and because other errors are
    ;; a subset of `system-error', which is harder to filter.
    ((_ exp ...)
     (catch #t
       (lambda () exp ...)
       (match-lambda*
         (('getaddrinfo-error error)
          (leave (G_ "host name lookup error: ~a~%")
                 (gai-strerror error)))
         (('gnutls-error error proc . rest)
          (let ((error->string (module-ref (resolve-interface '(gnutls))
                                           'error->string)))
            (leave (G_ "TLS error in procedure '~a': ~a~%")
                   proc (error->string error))))
         (args
          (apply throw args)))))))

;;;
;;; Help.
;;;

(define (show-help)
  (display (G_ "Usage: guix substitute [OPTION]...
Internal tool to substitute a pre-built binary to a local build.\n"))
  (display (G_ "
      --query            report on the availability of substitutes for the
                         store file names passed on the standard input"))
  (display (G_ "
      --substitute STORE-FILE DESTINATION
                         download STORE-FILE and store it as a Nar in file
                         DESTINATION"))
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (show-bug-report-information))

;;;
;;; Daemon/substituter protocol.
;;;

(define (display-narinfo-data narinfo)
  "Write to the current output port the contents of NARINFO in the format
expected by the daemon."
  (format #t "~a\n~a\n~a\n"
          (narinfo-path narinfo)
          (or (and=> (narinfo-deriver narinfo)
                     (cute string-append (%store-prefix) "/" <>))
              "")
          (length (narinfo-references narinfo)))
  (for-each (cute format #t "~a/~a~%" (%store-prefix) <>)
            (narinfo-references narinfo))

  (let-values (((uri compression file-size) (narinfo-best-uri narinfo)))
    (format #t "~a\n~a\n"
            (or file-size 0)
            (or (narinfo-size narinfo) 0))))

(define* (process-query command
                        #:key cache-urls acl)
  "Reply to COMMAND, a query as written by the daemon to this process's
standard input.  Use ACL as the access-control list against which to check
authorized substitutes."
  (define (valid? obj)
    (valid-narinfo? obj acl))

  (match (string-tokenize command)
    (("have" paths ..1)
     ;; Return the subset of PATHS available in CACHE-URLS.
     (let ((substitutable (lookup-narinfos/diverse cache-urls paths valid?)))
       (for-each (lambda (narinfo)
                   (format #t "~a~%" (narinfo-path narinfo)))
                 substitutable)
       (newline)))
    (("info" paths ..1)
     ;; Reply info about PATHS if it's in CACHE-URLS.
     (let ((substitutable (lookup-narinfos/diverse cache-urls paths valid?)))
       (for-each display-narinfo-data substitutable)
       (newline)))
    (wtf
     (error "unknown `--query' command" wtf))))

(define %compression-methods
  ;; Known compression methods and a thunk to determine whether they're
  ;; supported.  See 'decompressed-port' in (guix utils).
  `(("gzip"  . ,(const #t))
    ("lzip"  . ,(const #t))
    ("xz"    . ,(const #t))
    ("bzip2" . ,(const #t))
    ("none"  . ,(const #t))))

(define (supported-compression? compression)
  "Return true if COMPRESSION, a string, denotes a supported compression
method."
  (match (assoc-ref %compression-methods compression)
    (#f         #f)
    (supported? (supported?))))

(define (compresses-better? compression1 compression2)
  "Return true if COMPRESSION1 generally compresses better than COMPRESSION2;
this is a rough approximation."
  (match compression1
    ("none" #f)
    ("gzip" (string=? compression2 "none"))
    (_      (or (string=? compression2 "none")
                (string=? compression2 "gzip")))))

(define (narinfo-best-uri narinfo)
  "Select the \"best\" URI to download NARINFO's nar, and return three values:
the URI, its compression method (a string), and the compressed file size."
  (define choices
    (filter (match-lambda
              ((uri compression file-size)
               (supported-compression? compression)))
            (zip (narinfo-uris narinfo)
                 (narinfo-compressions narinfo)
                 (narinfo-file-sizes narinfo))))

  (define (file-size<? c1 c2)
    (match c1
      ((uri1 compression1 (? integer? file-size1))
       (match c2
         ((uri2 compression2 (? integer? file-size2))
          (< file-size1 file-size2))
         (_ #t)))
      ((uri compression1 #f)
       (match c2
         ((uri2 compression2 _)
          (compresses-better? compression1 compression2))))
      (_ #f)))                                    ;we can't tell

  (match (sort choices file-size<?)
    (((uri compression file-size) _ ...)
     (values uri compression file-size))))

(define* (process-substitution store-item destination
                               #:key cache-urls acl print-build-trace?)
  "Substitute STORE-ITEM (a store file name) from CACHE-URLS, and write it to
DESTINATION as a nar file.  Verify the substitute against ACL."
  (define narinfo
    (lookup-narinfo cache-urls store-item
                    (cut valid-narinfo? <> acl)))

  (unless narinfo
    (leave (G_ "no valid substitute for '~a'~%")
           store-item))

  (let-values (((uri compression file-size)
                (narinfo-best-uri narinfo)))
    ;; Tell the daemon what the expected hash of the Nar itself is.
    (format #t "~a~%" (narinfo-hash narinfo))

    (unless print-build-trace?
      (format (current-error-port)
              (G_ "Downloading ~a...~%") (uri->string uri)))

    (let*-values (((raw download-size)
                   ;; Note that Hydra currently generates Nars on the fly
                   ;; and doesn't specify a Content-Length, so
                   ;; DOWNLOAD-SIZE is #f in practice.
                   (fetch uri #:buffered? #f #:timeout? #f))
                  ((progress)
                   (let* ((dl-size  (or download-size
                                        (and (equal? compression "none")
                                             (narinfo-size narinfo))))
                          (reporter (if print-build-trace?
                                        (progress-reporter/trace
                                         destination
                                         (uri->string uri) dl-size
                                         (current-error-port))
                                        (progress-reporter/file
                                         (uri->string uri) dl-size
                                         (current-error-port)
                                         #:abbreviation nar-uri-abbreviation))))
                     (progress-report-port reporter raw)))
                  ((input pids)
                   ;; NOTE: This 'progress' port of current process will be
                   ;; closed here, while the child process doing the
                   ;; reporting will close it upon exit.
                   (decompressed-port (string->symbol compression)
                                      progress)))
      ;; Unpack the Nar at INPUT into DESTINATION.
      (restore-file input destination)
      (close-port input)

      ;; Wait for the reporter to finish.
      (every (compose zero? cdr waitpid) pids)

      ;; Skip a line after what 'progress-reporter/file' printed, and another
      ;; one to visually separate substitutions.
      (display "\n\n" (current-error-port)))))

;;;
;;; Entry point.
;;;

(define (check-acl-initialized)
  "Warn if the ACL is uninitialized."
  (define (singleton? acl)
    ;; True if ACL contains just the user's public key.
    (and (file-exists? %public-key-file)
         (let ((key (call-with-input-file %public-key-file
                      (compose string->canonical-sexp
                               read-string))))
           (match acl
             ((thing)
              (equal? (canonical-sexp->string thing)
                      (canonical-sexp->string key)))
             (_
              #f)))))

  (let ((acl (acl->public-keys (current-acl))))
    (when (or (null? acl) (singleton? acl))
      (warning (G_ "ACL for archive imports seems to be uninitialized, \
substitutes may be unavailable\n")))))

(define (daemon-options)
  "Return a list of name/value pairs denoting build daemon options."
  (define %not-newline
    (char-set-complement (char-set #\newline)))

  (match (getenv "_NIX_OPTIONS")
    (#f                           ;should not happen when called by the daemon
     '())
    (newline-separated
     ;; Here we get something of the form "OPTION1=VALUE1\nOPTION2=VALUE2\n".
     (filter-map (lambda (option=value)
                   (match (string-index option=value #\=)
                     (#f                          ;invalid option setting
                      #f)
                     (equal-sign
                      (cons (string-take option=value equal-sign)
                            (string-drop option=value (+ 1 equal-sign))))))
                 (string-tokenize newline-separated %not-newline)))))

(define (find-daemon-option option)
  "Return the value of build daemon option OPTION, or #f if it could not be
found."
  (assoc-ref (daemon-options) option))

(define %default-substitute-urls
  (match (and=> (or (find-daemon-option "untrusted-substitute-urls") ;client
                    (find-daemon-option "substitute-urls"))          ;admin
                string-tokenize)
    ((urls ...)
     urls)
    (#f
     ;; This can only happen when this script is not invoked by the
     ;; daemon.
     '("http://ci.guix.gnu.org"))))

(define substitute-urls
  ;; List of substitute URLs.
  (make-parameter %default-substitute-urls))

(define (client-terminal-columns)
  "Return the number of columns in the client's terminal, if it is known, or a
default value."
  (or (and=> (or (find-daemon-option "untrusted-terminal-columns")
                 (find-daemon-option "terminal-columns"))
             (lambda (str)
               (let ((number (string->number str)))
                 (and number (max 20 (- number 1))))))
      80))

(define (validate-uri uri)
  (unless (string->uri uri)
    (leave (G_ "~a: invalid URI~%") uri)))

(define-command (guix-substitute . args)
  (category internal)
  (synopsis "implement the build daemon's substituter protocol")

  (define print-build-trace?
    (match (or (find-daemon-option "untrusted-print-extended-build-trace")
               (find-daemon-option "print-extended-build-trace"))
      (#f #f)
      ((= string->number number) (> number 0))
      (_ #f)))

  (mkdir-p %narinfo-cache-directory)
  (maybe-remove-expired-cache-entries %narinfo-cache-directory
                                      cached-narinfo-files
                                      #:entry-expiration
                                      cached-narinfo-expiration-time
                                      #:cleanup-period
                                      %narinfo-expired-cache-entry-removal-delay)
  (check-acl-initialized)

  ;; Starting from commit 22144afa in Nix, we are allowed to bail out directly
  ;; when we know we cannot substitute, but we must emit a newline on stdout
  ;; when everything is alright.
  (when (null? (substitute-urls))
    (exit 0))

  ;; Say hello (see above.)
  (newline)
  (force-output (current-output-port))

  ;; Sanity-check SUBSTITUTE-URLS so we can provide a meaningful error message.
  (for-each validate-uri (substitute-urls))

  ;; Attempt to install the client's locale so that messages are suitably
  ;; translated.  LC_CTYPE must be a UTF-8 locale; it's the case by default so
  ;; don't change it.
  (match (or (find-daemon-option "untrusted-locale")
             (find-daemon-option "locale"))
    (#f     #f)
    (locale (false-if-exception (setlocale LC_MESSAGES locale))))

  (catch 'system-error
    (lambda ()
      (set-thread-name "guix substitute"))
    (const #t))                                   ;GNU/Hurd lacks 'prctl'

  (with-networking
   (with-error-handling                           ; for signature errors
     (match args
       (("--query")
        (let ((acl (current-acl)))
          (let loop ((command (read-line)))
            (or (eof-object? command)
                (begin
                  (process-query command
                                 #:cache-urls (substitute-urls)
                                 #:acl acl)
                  (loop (read-line)))))))
       (("--substitute" store-path destination)
        ;; Download STORE-PATH and add store it as a Nar in file DESTINATION.
        ;; Specify the number of columns of the terminal so the progress
        ;; report displays nicely.
        (parameterize ((current-terminal-columns (client-terminal-columns)))
          (process-substitution store-path destination
                                #:cache-urls (substitute-urls)
                                #:acl (current-acl)
                                #:print-build-trace? print-build-trace?)))
       ((or ("-V") ("--version"))
        (show-version-and-exit "guix substitute"))
       (("--help")
        (show-help))
       (opts
        (leave (G_ "~a: unrecognized options~%") opts))))))

;;; Local Variables:
;;; eval: (put 'with-timeout 'scheme-indent-function 1)
;;; End:

;;; substitute.scm ends here