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authorLudovic Courtès <ludo@gnu.org>2017-09-06 09:28:28 +0200
committerLudovic Courtès <ludo@gnu.org>2017-09-11 22:24:46 +0200
commit9b336338cdc0e46a3bf7a2913c2f61cd2410c4d6 (patch)
tree902324de43d4648182db2f5cd3b0d5f42a7122d7 /gnu/system/uuid.scm
parentd1ff5f9db3e124af9f8aaa22d3758208f5080c50 (diff)
downloadguix-9b336338cdc0e46a3bf7a2913c2f61cd2410c4d6.tar
guix-9b336338cdc0e46a3bf7a2913c2f61cd2410c4d6.tar.gz
system: Introduce a disjoint UUID type.
Conceptually a UUID is just a bytevector. However, there's software out there such as GRUB that relies on the string representation of different UUID types (e.g., the string representation of DCE UUIDs differs from that of ISO-9660 UUIDs, even if they are actually bytevectors of the same length). This new <uuid> record type allows us to preserve information about the type of UUID so we can eventually convert it to a string using the right representation. * gnu/system/uuid.scm (<uuid>): New record type. (bytevector->uuid): New procedure. (uuid): Return calls to 'make-uuid'. (uuid->string): Rewrite using 'match-lambda*' to accept a single 'uuid?' argument. * gnu/bootloader/grub.scm (grub-root-search): Check for 'uuid?' instead of 'bytevector?'. * gnu/system.scm (bootable-kernel-arguments): Check whether ROOT-DEVICE is 'uuid?'. (read-boot-parameters): Use 'bytevector->uuid' when the store device is a bytevector. (read-boot-parameters-file): Check for 'uuid?' instead of 'bytevector?'. (device->sexp): New procedure. (operating-system-boot-parameters-file): Use it for 'root-device' and 'store'. (operating-system-bootcfg): Remove conditional in definition of 'root-device'. * gnu/system/file-systems.scm (file-system->spec): Check for 'uuid?' on DEVICE and take its bytevector. * gnu/system/mapped-devices.scm (open-luks-device): Likewise. * gnu/system/vm.scm (iso9660-image): Call 'uuid-bytevector' for the #:volume-uuid argument.
Diffstat (limited to 'gnu/system/uuid.scm')
-rw-r--r--gnu/system/uuid.scm48
1 files changed, 40 insertions, 8 deletions
diff --git a/gnu/system/uuid.scm b/gnu/system/uuid.scm
index 64dad5a374..60626ebb12 100644
--- a/gnu/system/uuid.scm
+++ b/gnu/system/uuid.scm
@@ -19,12 +19,19 @@
(define-module (gnu system uuid)
#:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-9)
#:use-module (rnrs bytevectors)
#:use-module (ice-9 match)
#:use-module (ice-9 vlist)
#:use-module (ice-9 regex)
#:use-module (ice-9 format)
#:export (uuid
+ uuid?
+ uuid-type
+ uuid-bytevector
+
+ bytevector->uuid
+
uuid->string
dce-uuid->string
string->uuid
@@ -206,15 +213,27 @@ corresponding bytevector; otherwise return #f."
(#f #f)
((_ . (? procedure? parse)) (parse str))))
-(define* (uuid->string bv #:key (type 'dce))
- "Convert BV, a bytevector, to the UUID string representation for TYPE."
- (match (vhash-assq type %uuid-printers)
- (#f #f)
- ((_ . (? procedure? unparse)) (unparse bv))))
+;; High-level UUID representation that carries its type with it.
+;;
+;; This is necessary to serialize bytevectors with the right printer in some
+;; circumstances. For instance, GRUB "search --fs-uuid" command compares the
+;; string representation of UUIDs, not the raw bytes; thus, when emitting a
+;; GRUB 'search' command, we need to procedure the right string representation
+;; (see <https://debbugs.gnu.org/cgi/bugreport.cgi?msg=52;att=0;bug=27735>).
+(define-record-type <uuid>
+ (make-uuid type bv)
+ uuid?
+ (type uuid-type) ;'dce | 'iso9660 | ...
+ (bv uuid-bytevector))
+
+(define* (bytevector->uuid bv #:optional (type 'dce))
+ "Return a UUID object make of BV and TYPE."
+ (make-uuid type bv))
(define-syntax uuid
(lambda (s)
- "Return the bytevector corresponding to the given UUID representation."
+ "Return the UUID object corresponding to the given UUID representation."
+ ;; TODO: Extend to types other than DCE.
(syntax-case s ()
((_ str)
(string? (syntax->datum #'str))
@@ -222,6 +241,19 @@ corresponding bytevector; otherwise return #f."
(let ((bv (string->uuid (syntax->datum #'str))))
(unless bv
(syntax-violation 'uuid "invalid UUID" s))
- (datum->syntax #'str bv)))
+ #`(make-uuid 'dce #,(datum->syntax #'str bv))))
((_ str)
- #'(string->uuid str)))))
+ #'(make-uuid 'dce (string->uuid str))))))
+
+(define uuid->string
+ ;; Convert the given bytevector or UUID object, to the corresponding UUID
+ ;; string representation.
+ (match-lambda*
+ (((? bytevector? bv))
+ (uuid->string bv 'dce))
+ (((? bytevector? bv) type)
+ (match (vhash-assq type %uuid-printers)
+ (#f #f)
+ ((_ . (? procedure? unparse)) (unparse bv))))
+ (((? uuid? uuid))
+ (uuid->string (uuid-bytevector uuid) (uuid-type uuid)))))