From: "Ludovic Courtès" <ludo@gnu.org>
To: 35880@debbugs.gnu.org
Cc: Pierre Neidhardt <mail@ambrevar.xyz>
Subject: [bug#35880] [PATCH 7/7] lzlib: 'lzread!' never returns more than it was asked for.
Date: Fri, 24 May 2019 15:42:38 +0200 [thread overview]
Message-ID: <20190524134238.22802-7-ludo@gnu.org> (raw)
In-Reply-To: <20190524134238.22802-1-ludo@gnu.org>
Fixes a bug whereby 'lzread!' could return more than COUNT.
* guix/lzlib.scm (lzread!): Rewrite in a semi-functional style.
---
guix/lzlib.scm | 39 +++++++++++++++++++--------------------
1 file changed, 19 insertions(+), 20 deletions(-)
diff --git a/guix/lzlib.scm b/guix/lzlib.scm
index 48927c6262..0e384f6cb8 100644
--- a/guix/lzlib.scm
+++ b/guix/lzlib.scm
@@ -494,29 +494,28 @@ perhaps not yet read."
\f
;; High level functions.
-(define* (lzread! decoder file-port bv
+
+(define* (lzread! decoder port bv
#:optional (start 0) (count (bytevector-length bv)))
- "Read up to COUNT bytes from FILE-PORT into BV at offset START. Return the
+ "Read up to COUNT bytes from PORT into BV at offset START. Return the
number of uncompressed bytes actually read; it is zero if COUNT is zero or if
the end-of-stream has been reached."
- ;; WARNING: Because we don't alternate between lz-reads and lz-writes, we can't
- ;; process more than lz-decompress-write-size from the file-port.
- (when (> count (lz-decompress-write-size decoder))
- (set! count (lz-decompress-write-size decoder)))
- (let ((file-bv (get-bytevector-n file-port count)))
- (unless (eof-object? file-bv)
- (lz-decompress-write decoder file-bv 0 (bytevector-length file-bv))))
- (let ((read 0))
- (let loop ((rd 0))
- (if (< start (bytevector-length bv))
- (begin
- (set! rd (lz-decompress-read decoder bv start (- (bytevector-length bv) start)))
- (set! start (+ start rd))
- (set! read (+ read rd)))
- (set! rd 0))
- (unless (= rd 0)
- (loop rd)))
- read))
+ (define (feed-decoder! decoder)
+ ;; Feed DECODER with data read from PORT.
+ (match (get-bytevector-n port (lz-decompress-write-size decoder))
+ ((? eof-object? eof) eof)
+ (bv (lz-decompress-write decoder bv))))
+
+ (let loop ((read 0)
+ (start start))
+ (cond ((< read count)
+ (match (lz-decompress-read decoder bv start (- count read))
+ (0 (if (eof-object? (feed-decoder! decoder))
+ read
+ (loop read start)))
+ (n (loop (+ read n) (+ start n)))))
+ (else
+ read))))
(define (lzwrite! encoder source source-offset source-count
target target-offset target-count)
--
2.21.0
next prev parent reply other threads:[~2019-05-24 13:44 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-24 13:31 [bug#35880] [PATCH 0/7] Lzip support for 'guix publish' and 'guix substitute' Ludovic Courtès
2019-05-24 13:42 ` [bug#35880] [PATCH 1/7] lzlib: Add 'make-lzip-input-port/compressed' Ludovic Courtès
2019-05-24 13:42 ` [bug#35880] [PATCH 2/7] utils: Test 'compressed-port' and 'decompressed-port' for both gzip and xz Ludovic Courtès
2019-05-24 13:42 ` [bug#35880] [PATCH 3/7] utils: Support compression and decompression with lzip Ludovic Courtès
2019-05-25 17:27 ` Pierre Neidhardt
2019-05-26 19:52 ` Ludovic Courtès
2019-05-24 13:42 ` [bug#35880] [PATCH 4/7] publish: Add support for lzip Ludovic Courtès
2019-05-24 13:42 ` [bug#35880] [PATCH 5/7] self: Add dependency on lzlib Ludovic Courtès
2019-05-24 13:42 ` [bug#35880] [PATCH 6/7] gnu: guix: " Ludovic Courtès
2019-05-24 13:42 ` Ludovic Courtès [this message]
2019-05-25 17:31 ` [bug#35880] [PATCH 7/7] lzlib: 'lzread!' never returns more than it was asked for Pierre Neidhardt
2019-05-26 19:54 ` Ludovic Courtès
2019-05-26 20:57 ` Pierre Neidhardt
2019-05-26 21:28 ` Ludovic Courtès
2019-05-27 7:00 ` Pierre Neidhardt
2019-05-27 10:00 ` Ludovic Courtès
2019-05-25 17:24 ` [bug#35880] [PATCH 1/7] lzlib: Add 'make-lzip-input-port/compressed' Pierre Neidhardt
2019-05-26 19:51 ` Ludovic Courtès
2019-05-27 15:45 ` Ludovic Courtès
2019-05-27 16:24 ` Pierre Neidhardt
2019-05-27 20:53 ` bug#35880: " Ludovic Courtès
2019-05-27 21:12 ` [bug#35880] " Pierre Neidhardt
2019-05-28 7:52 ` Ludovic Courtès
2019-05-28 8:46 ` Pierre Neidhardt
2019-05-28 13:47 ` Ludovic Courtès
2019-05-29 14:57 ` Pierre Neidhardt
2019-05-31 20:54 ` Ludovic Courtès
2019-06-01 6:02 ` Pierre Neidhardt
2019-06-01 9:41 ` Ludovic Courtès
2019-06-01 9:58 ` Pierre Neidhardt
2019-06-01 12:21 ` Ludovic Courtès
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190524134238.22802-7-ludo@gnu.org \
--to=ludo@gnu.org \
--cc=35880@debbugs.gnu.org \
--cc=mail@ambrevar.xyz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this external index
https://git.savannah.gnu.org/cgit/guix.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.