git-download: Rewrite 'git-predicate' using Guile-Git.

Fixes <https://bugs.gnu.org/27925>.

* guix/git-download.scm (files->directory-tree)
(directory-in-tree?): Remove.
(git-file-list): New procedures.
(git-predicate): Use it instead of opening a pipe to 'git'.  Remove
directory tree hack and rely exclusively on inode/device numbers.
This commit is contained in:
Ludovic Courtès 2018-09-12 23:56:34 +02:00
parent 3763e7716c
commit aed0a59405
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@ -1,5 +1,5 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2017 Mathieu Lirzin <mthl@gnu.org>
;;; Copyright © 2017 Christopher Baines <mail@cbaines.net>
;;;
@ -19,7 +19,6 @@
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix git-download)
#:use-module (guix build utils)
#:use-module (guix gexp)
#:use-module (guix store)
#:use-module (guix monads)
@ -27,9 +26,8 @@ (define-module (guix git-download)
#:use-module (guix packages)
#:use-module (guix modules)
#:autoload (guix build-system gnu) (standard-packages)
#:use-module (git)
#:use-module (ice-9 match)
#:use-module (ice-9 popen)
#:use-module (ice-9 rdelim)
#:use-module (ice-9 vlist)
#:use-module (srfi srfi-1)
#:export (git-reference
@ -153,41 +151,31 @@ (define (git-file-name name version)
;;; 'git-predicate'.
;;;
(define (files->directory-tree files)
"Return a tree of vhashes representing the directory listed in FILES, a list
like '(\"a/b\" \"b/c/d\")."
(fold (lambda (file result)
(let loop ((file (string-split file #\/))
(result result))
(match file
((_)
result)
((directory children ...)
(match (vhash-assoc directory result)
(#f
(vhash-cons directory (loop children vlist-null)
result))
((_ . previous)
;; XXX: 'vhash-delete' is O(n).
(vhash-cons directory (loop children previous)
(vhash-delete directory result)))))
(()
result))))
vlist-null
files))
(define (directory-in-tree? tree directory)
"Return true if DIRECTORY, a string like \"a/b\", denotes a directory listed
in TREE."
(let loop ((directory (string-split directory #\/))
(tree tree))
(match directory
(()
#t)
((head . tail)
(match (vhash-assoc head tree)
((_ . sub-tree) (loop tail sub-tree))
(#f #f))))))
(define (git-file-list directory)
"Return the list of files checked in in the Git repository at DIRECTORY.
The result is similar to that of the 'git ls-files' command, except that it
also includes directories, not just regular files. The returned file names
are relative to DIRECTORY, which is not necessarily the root of the checkout."
(let* ((directory (canonicalize-path directory))
(dot-git (repository-discover directory))
(top (dirname dot-git))
(repository (repository-open dot-git))
(head (repository-head repository))
(oid (reference-target head))
(commit (commit-lookup repository oid))
(tree (commit-tree commit))
(files (tree-list tree)))
(repository-close! repository)
(if (string=? top directory)
files
(let ((relative (string-append
(string-drop directory
(+ 1 (string-length top)))
"/")))
(filter-map (lambda (file)
(and (string-prefix? relative file)
(string-drop file (string-length relative))))
files)))))
(define (git-predicate directory)
"Return a predicate that returns true if a file is part of the Git checkout
@ -195,43 +183,20 @@ (define (git-predicate directory)
The returned predicate takes two arguments FILE and STAT where FILE is an
absolute file name and STAT is the result of 'lstat'."
(let* ((pipe (with-directory-excursion directory
(open-pipe* OPEN_READ "git" "ls-files")))
(files (let loop ((lines '()))
(match (read-line pipe)
((? eof-object?)
(reverse lines))
(line
(loop (cons line lines))))))
(directory-tree (files->directory-tree files))
(inodes (fold (lambda (file result)
(let ((stat
(lstat (string-append directory "/"
file))))
(vhash-consv (stat:ino stat) (stat:dev stat)
result)))
vlist-null
files))
;; Note: For this to work we must *not* call 'canonicalize-path' on
;; DIRECTORY or we would get discrepancies of the returned lambda is
;; called with a non-canonical file name.
(prefix-length (+ 1 (string-length directory)))
(status (close-pipe pipe)))
(and (zero? status)
(lambda (file stat)
(match (stat:type stat)
('directory
(directory-in-tree? directory-tree
(string-drop file prefix-length)))
((or 'regular 'symlink)
;; Comparing file names is always tricky business so we rely on
;; inode numbers instead
(match (vhash-assv (stat:ino stat) inodes)
((_ . dev) (= dev (stat:dev stat)))
(#f #f)))
(_
#f))))))
(let* ((files (git-file-list directory))
(inodes (fold (lambda (file result)
(let ((stat
(lstat (string-append directory "/"
file))))
(vhash-consv (stat:ino stat) (stat:dev stat)
result)))
vlist-null
files)))
(lambda (file stat)
;; Comparing file names is always tricky business so we rely on inode
;; numbers instead.
(match (vhash-assv (stat:ino stat) inodes)
((_ . dev) (= dev (stat:dev stat)))
(#f #f)))))
;;; git-download.scm ends here