;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
#:use-module ((ice-9 rdelim) #:prefix rdelim:)
#:use-module (ice-9 match)
#:use-module (ice-9 ftw)
+ #:use-module (system foreign)
#:export (write-int read-int
write-long-long read-long-long
write-padding
write-string-pairs
write-store-path read-store-path
write-store-path-list read-store-path-list
+ (dump . dump-port*)
&nar-error
nar-error?
write-file
write-file-tree
+ fold-archive
restore-file))
;;; Comment:
;; Similar to serialize.cc in Nix.
-(define-condition-type &nar-error &error ; XXX: inherit from &nix-error ?
+(define-condition-type &nar-error &error ; XXX: inherit from &store-error ?
nar-error?
(file nar-error-file) ; file we were restoring, or #f
(port nar-error-port)) ; port from which we read
(port port)))))
bv))
+(define (sub-bytevector bv len)
+ "Return a bytevector that aliases the first LEN bytes of BV."
+ (define max (bytevector-length bv))
+ (cond ((= len max) bv)
+ ((< len max)
+ ;; Yes, this is safe because the result of each conversion procedure
+ ;; has its life cycle synchronized with that of its argument.
+ (pointer->bytevector (bytevector->pointer bv) len))
+ (else
+ (error "sub-bytevector called to get a super bytevector"))))
+
(define (write-int n p)
(let ((b (make-bytevector 8 0)))
(bytevector-u32-set! b 0 n (endianness little))
(define (read-byte-string p)
(let* ((len (read-int p))
(m (modulo len 8))
- (bv (get-bytevector-n* p len)))
- (or (zero? m)
- (get-bytevector-n* p (- 8 m)))
- bv))
+ (pad (if (zero? m) 0 (- 8 m)))
+ (bv (get-bytevector-n* p (+ len pad))))
+ (sub-bytevector bv len)))
(define (read-string p)
(utf8->string (read-byte-string p)))
(put-bytevector out buf 0 read)
(loop (- left read))))))))
-(define (write-contents file p size)
- "Write SIZE bytes from FILE to output port P."
- (define (call-with-binary-input-file file proc)
- ;; Open FILE as a binary file. This avoids scan-for-encoding, and thus
- ;; avoids any initial buffering. Disable file name canonicalization to
- ;; avoid stat'ing like crazy.
- (with-fluids ((%file-port-name-canonicalization #f))
- (let ((port (open-file file "rb")))
- (dynamic-wind
- (const #t)
- (cut proc port)
- (lambda ()
- (close-port port))))))
-
- (call-with-binary-input-file file
- (lambda (input)
- (write-contents-from-port input p size))))
-
(define (write-contents-from-port input output size)
"Write SIZE bytes from port INPUT to port OUTPUT."
(write-string "contents" output)
(dump input output size))
(write-padding size output))
-(define (read-contents in out)
- "Read the contents of a file from the Nar at IN, write it to OUT, and return
-the size in bytes."
- (define executable?
- (match (read-string in)
- ("contents"
- #f)
- ("executable"
- (match (list (read-string in) (read-string in))
- (("" "contents") #t)
- (x (raise
- (condition (&message
- (message "unexpected executable file marker"))
- (&nar-read-error (port in)
- (file #f)
- (token x))))))
- #t)
- (x
- (raise
- (condition (&message (message "unsupported nar file type"))
- (&nar-read-error (port in) (file #f) (token x)))))))
-
- (let ((size (read-long-long in)))
- ;; Note: `sendfile' cannot be used here because of port buffering on IN.
- (dump in out size)
-
- (when executable?
- (chmod out #o755))
- (let ((m (modulo size 8)))
- (unless (zero? m)
- (get-bytevector-n* in (- 8 m))))
- size))
+(define (read-file-type port)
+ "Read the file type tag from PORT, and return either 'regular or
+'executable."
+ (match (read-string port)
+ ("contents"
+ 'regular)
+ ("executable"
+ (match (list (read-string port) (read-string port))
+ (("" "contents") 'executable)
+ (x (raise
+ (condition (&message
+ (message "unexpected executable file marker"))
+ (&nar-read-error (port port)
+ (file #f)
+ (token x)))))))
+ (x
+ (raise
+ (condition (&message (message "unsupported nar file type"))
+ (&nar-read-error (port port) (file #f) (token x)))))))
(define %archive-version-1
;; Magic cookie for Nix archives.
(filter-map (lambda (base)
(let ((file (string-append directory
"/" base)))
- (and (not (member base '("." "..")))
- (select? file (lstat file))
+ (and (select? file (lstat file))
base)))
basenames))
(&nar-error (file f) (port port))))))
(write-string ")" p)))
-(define (restore-file port file)
- "Read a file (possibly a directory structure) in Nar format from PORT.
-Restore it as FILE."
- (parameterize ((currently-restored-file file))
+(define port-conversion-strategy
+ (fluid->parameter %default-port-conversion-strategy))
+
+(define (fold-archive proc seed port file)
+ "Read a file (possibly a directory structure) in Nar format from PORT. Call
+PROC on each file or directory read from PORT using:
+
+ (PROC FILE TYPE CONTENTS RESULT)
+
+using SEED as the first RESULT. TYPE is a symbol like 'regular, and CONTENTS
+depends on TYPE."
+ (parameterize ((currently-restored-file file)
+
+ ;; Error out if we can convert file names to the current
+ ;; locale. (XXX: We'd prefer UTF-8 encoding for file names
+ ;; regardless of the locale, but that's what Guile gives us
+ ;; so far.)
+ (port-conversion-strategy 'error))
(let ((signature (read-string port)))
(unless (equal? signature %archive-version-1)
(raise
(token signature)
(file #f))))))
- (let restore ((file file))
+ (let read ((file file)
+ (result seed))
(define (read-eof-marker)
(match (read-string port)
(")" #t)
(match (list (read-string port) (read-string port) (read-string port))
(("(" "type" "regular")
- (call-with-output-file file (cut read-contents port <>))
- (read-eof-marker))
+ (let* ((type (read-file-type port))
+ (size (read-long-long port))
+
+ ;; The caller must read exactly SIZE bytes from PORT.
+ (result (proc file type `(,port . ,size) result)))
+ (let ((m (modulo size 8)))
+ (unless (zero? m)
+ (get-bytevector-n* port (- 8 m))))
+ (read-eof-marker)
+ result))
(("(" "type" "symlink")
(match (list (read-string port) (read-string port))
(("target" target)
- (symlink target file)
- (read-eof-marker))
+ (let ((result (proc file 'symlink target result)))
+ (read-eof-marker)
+ result))
(x (raise
(condition
(&message (message "invalid symlink tokens"))
(&nar-read-error (port port) (file file) (token x)))))))
(("(" "type" "directory")
(let ((dir file))
- (mkdir dir)
- (let loop ((prefix (read-string port)))
+ (let loop ((prefix (read-string port))
+ (result (proc file 'directory #f result)))
(match prefix
("entry"
(match (list (read-string port)
(read-string port) (read-string port)
(read-string port))
(("(" "name" file "node")
- (restore (string-append dir "/" file))
- (match (read-string port)
- (")" #t)
- (x
- (raise
- (condition
- (&message
- (message "unexpected directory entry termination"))
- (&nar-read-error (port port)
- (file file)
- (token x))))))
- (loop (read-string port)))))
- (")" #t) ; done with DIR
+ (let ((result (read (string-append dir "/" file) result)))
+ (match (read-string port)
+ (")" #f)
+ (x
+ (raise
+ (condition
+ (&message
+ (message "unexpected directory entry termination"))
+ (&nar-read-error (port port)
+ (file file)
+ (token x))))))
+ (loop (read-string port) result)))))
+ (")" result) ;done with DIR
(x
(raise
(condition
(&message (message "unsupported nar entry type"))
(&nar-read-error (port port) (file file) (token x)))))))))
+(define (restore-file port file)
+ "Read a file (possibly a directory structure) in Nar format from PORT.
+Restore it as FILE."
+ (fold-archive (lambda (file type content result)
+ (match type
+ ('directory
+ (mkdir file))
+ ('symlink
+ (symlink content file))
+ ((or 'regular 'executable)
+ (match content
+ ((input . size)
+ (call-with-output-file file
+ (lambda (output)
+ (dump input output size)
+ (when (eq? type 'executable)
+ (chmod output #o755)))))))))
+ #t
+ port
+ file))
+
;;; Local Variables:
;;; eval: (put 'call-with-binary-input-file 'scheme-indent-function 1)
;;; End: