git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: "René Scharfe" <l.s.r@web.de>
To: Git Mailing List <git@vger.kernel.org>
Cc: Junio C Hamano <gitster@pobox.com>
Subject: [PATCH] archive: support compression levels beyond 9
Date: Mon, 9 Nov 2020 17:05:31 +0100	[thread overview]
Message-ID: <96e6e2ce-fc7b-1e73-0112-93589b28506d@web.de> (raw)

Compression programs like zip, gzip, bzip2 and xz allow to adjust the
trade-off between CPU cost and size gain with numerical options from -1
for fast compression and -9 for high compression ratio.  zip also
accepts -0 for storing files verbatim.  git archive directly support
these single-digit compression levels for ZIP output and passes them to
filters like gzip.

Zstandard additionally supports compression level options -10 to -19, or
up to -22 with --ultra.  This *seems* to work with git archive in most
cases, e.g. it will produce an archive with -19 without complaining, but
since it only supports single-digit compression level options this is
the same as -1 -9 and thus -9.

Allow git archive to accept multi-digit compression levels to support
the full range supported by zstd.  Explicitly reject them for the ZIP
format, as otherwise deflateInit2() would just fail with a somewhat
cryptic "stream consistency error".

Signed-off-by: René Scharfe <l.s.r@web.de>
---
 archive-tar.c |  3 ++-
 archive.c     | 26 +++++++++++---------------
 archive.h     |  1 +
 3 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/archive-tar.c b/archive-tar.c
index f1a1447ebd..a971fdc0f6 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -374,7 +374,8 @@ static int tar_filter_config(const char *var, const char *value, void *data)
 		ar = xcalloc(1, sizeof(*ar));
 		ar->name = xmemdupz(name, namelen);
 		ar->write_archive = write_tar_filter_archive;
-		ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS;
+		ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS |
+			    ARCHIVER_HIGH_COMPRESSION_LEVELS;
 		ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
 		tar_filters[nr_tar_filters++] = ar;
 	}
diff --git a/archive.c b/archive.c
index 3c1541af9e..7a888c5338 100644
--- a/archive.c
+++ b/archive.c
@@ -529,10 +529,12 @@ static int add_file_cb(const struct option *opt, const char *arg, int unset)
 	return 0;
 }

-#define OPT__COMPR(s, v, h, p) \
-	OPT_SET_INT_F(s, NULL, v, h, p, PARSE_OPT_NONEG)
-#define OPT__COMPR_HIDDEN(s, v, p) \
-	OPT_SET_INT_F(s, NULL, v, "", p, PARSE_OPT_NONEG | PARSE_OPT_HIDDEN)
+static int number_callback(const struct option *opt, const char *arg, int unset)
+{
+	BUG_ON_OPT_NEG(unset);
+	*(int *)opt->value = strtol(arg, NULL, 10);
+	return 0;
+}

 static int parse_archive_args(int argc, const char **argv,
 		const struct archiver **ar, struct archiver_args *args,
@@ -561,16 +563,8 @@ static int parse_archive_args(int argc, const char **argv,
 		OPT_BOOL(0, "worktree-attributes", &worktree_attributes,
 			N_("read .gitattributes in working directory")),
 		OPT__VERBOSE(&verbose, N_("report archived files on stderr")),
-		OPT__COMPR('0', &compression_level, N_("store only"), 0),
-		OPT__COMPR('1', &compression_level, N_("compress faster"), 1),
-		OPT__COMPR_HIDDEN('2', &compression_level, 2),
-		OPT__COMPR_HIDDEN('3', &compression_level, 3),
-		OPT__COMPR_HIDDEN('4', &compression_level, 4),
-		OPT__COMPR_HIDDEN('5', &compression_level, 5),
-		OPT__COMPR_HIDDEN('6', &compression_level, 6),
-		OPT__COMPR_HIDDEN('7', &compression_level, 7),
-		OPT__COMPR_HIDDEN('8', &compression_level, 8),
-		OPT__COMPR('9', &compression_level, N_("compress better"), 9),
+		OPT_NUMBER_CALLBACK(&compression_level,
+			N_("set compression level"), number_callback),
 		OPT_GROUP(""),
 		OPT_BOOL('l', "list", &list,
 			N_("list supported archive formats")),
@@ -617,7 +611,9 @@ static int parse_archive_args(int argc, const char **argv,

 	args->compression_level = Z_DEFAULT_COMPRESSION;
 	if (compression_level != -1) {
-		if ((*ar)->flags & ARCHIVER_WANT_COMPRESSION_LEVELS)
+		int levels_ok = (*ar)->flags & ARCHIVER_WANT_COMPRESSION_LEVELS;
+		int high_ok = (*ar)->flags & ARCHIVER_HIGH_COMPRESSION_LEVELS;
+		if (levels_ok && (compression_level <= 9 || high_ok))
 			args->compression_level = compression_level;
 		else {
 			die(_("Argument not supported for format '%s': -%d"),
diff --git a/archive.h b/archive.h
index 82b226011a..e3d04e8ab3 100644
--- a/archive.h
+++ b/archive.h
@@ -36,6 +36,7 @@ const char *archive_format_from_filename(const char *filename);

 #define ARCHIVER_WANT_COMPRESSION_LEVELS 1
 #define ARCHIVER_REMOTE 2
+#define ARCHIVER_HIGH_COMPRESSION_LEVELS 4
 struct archiver {
 	const char *name;
 	int (*write_archive)(const struct archiver *, struct archiver_args *);
--
2.29.2

             reply	other threads:[~2020-11-09 16:05 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-09 16:05 René Scharfe [this message]
2020-11-09 18:35 ` [PATCH] archive: support compression levels beyond 9 Junio C Hamano
2020-11-09 23:48   ` René Scharfe
2020-11-10 11:37     ` René Scharfe

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

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=96e6e2ce-fc7b-1e73-0112-93589b28506d@web.de \
    --to=l.s.r@web.de \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    /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 public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).