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[PATCH 2/2] archive: support gzipped tar files

From
Jeff King <peff@peff.net>
Date
Jun 14, 2011, 18:18 UTC
Message-ID
<20110614181821.GA32685@sigill.intra.peff.net>
In-Reply-To
<20110614181732.GA31635@sigill.intra.peff.net>

git-archive already supports the creation of tar files. For local cases, one can simply pipe the output to gzip, and having git-archive do the gzip is a minor convenience.

However, when running git-archive against a remote site, having the remote side do the compression can save considerable bandwidth. Service providers could always wrap git-archive to provide that functionality, but this makes it much simpler.

Creating gzipped archives is of course more expensive than regular tar archives; however, the amount of work should be comparable to that of creating a zip file, which is already possible. So there should be no new security implications with respect to creating load on a remote server.

Signed-off-by: Jeff King <peff@peff.net>
---
 Documentation/git-archive.txt |   17 +++++++++++++++--
 archive-tar.c                 |   27 +++++++++++++++++++++++++++
 archive.c                     |    1 +
 archive.h                     |    1 +
 builtin/archive.c             |    6 ++++++
 t/t5000-tar-tree.sh           |   26 ++++++++++++++++++++++++++
 6 files changed, 76 insertions(+), 2 deletions(-)
diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index 9c750e2..963bec4 100644
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -34,10 +34,11 @@ OPTIONS
 -------
 
 --format=<fmt>::
-	Format of the resulting archive: 'tar' or 'zip'. If this option
+	Format of the resulting archive: 'tar', 'tgz', or 'zip'. If this option
 	is not given, and the output file is specified, the format is
 	inferred from the filename if possible (e.g. writing to "foo.zip"
-	makes the output to be in the zip format). Otherwise the output
+	creates the output in the zip format; "foo.tgz" or "foo.tar.gz"
+	creates the output in the tgz format). Otherwise the output
 	format is `tar`.
 
 -l::
@@ -89,6 +90,12 @@ zip
 	Highest and slowest compression level.  You can specify any
 	number from 1 to 9 to adjust compression speed and ratio.
 
+tgz
+~~~
+-9::
+	Highest and slowest compression level. You can specify any
+	number from 1 to 9 to adjust compression speed and ratio.
+
 
 CONFIGURATION
 -------------
@@ -133,6 +140,12 @@ git archive --format=tar --prefix=git-1.4.0/ v1.4.0 | gzip >git-1.4.0.tar.gz::
 
 	Create a compressed tarball for v1.4.0 release.
 
+git archive --prefix=git-1.4.0/ -o git-1.4.0.tar.gz v1.4.0
+
+	Same as above, except that we use the internal gzip. Note that
+	the output format is inferred by the extension of the output
+	file.
+
 git archive --format=tar --prefix=git-1.4.0/ v1.4.0{caret}\{tree\} | gzip >git-1.4.0.tar.gz::
 
 	Create a compressed tarball for v1.4.0 release, but without a
diff --git a/archive-tar.c b/archive-tar.c
index b1aea87..86c8aa9 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -260,3 +260,30 @@ int write_tar_archive(struct archiver_args *args)
 	output = output_write;
 	return write_tar_archive_internal(args);
 }
+
+static gzFile gz_file;
+static void output_gz(const char *buf, unsigned long len)
+{
+	if (!gzwrite(gz_file, buf, len))
+		die("unable to write compressed stream: %s",
+		    gzerror(gz_file, NULL));
+}
+
+int write_tgz_archive(struct archiver_args *args)
+{
+	int r;
+
+	gz_file = gzdopen(1, "w");
+	if (!gz_file)
+		die_errno("unable to open compressed stream");
+	gzsetparams(gz_file, args->compression_level, Z_DEFAULT_STRATEGY);
+
+	output = output_gz;
+	r = write_tar_archive_internal(args);
+	if (r == 0) {
+		int zerr = gzclose(gz_file);
+		if (zerr != Z_OK)
+			die("unable to write compressed stream (err=%d)", zerr);
+	}
+	return r;
+}
diff --git a/archive.c b/archive.c
index 42f2d2f..6073a8d 100644
--- a/archive.c
+++ b/archive.c
@@ -23,6 +23,7 @@ static const struct archiver {
 } archivers[] = {
 	{ "tar", write_tar_archive },
 	{ "zip", write_zip_archive, USES_ZLIB_COMPRESSION },
+	{ "tgz", write_tgz_archive, USES_ZLIB_COMPRESSION },
 };
 
 static void format_subst(const struct commit *commit,
diff --git a/archive.h b/archive.h
index 038ac35..c1bf72e 100644
--- a/archive.h
+++ b/archive.h
@@ -23,6 +23,7 @@ typedef int (*write_archive_entry_fn_t)(struct archiver_args *args, const unsign
  */
 extern int write_tar_archive(struct archiver_args *);
 extern int write_zip_archive(struct archiver_args *);
+extern int write_tgz_archive(struct archiver_args *);
 
 extern int write_archive_entries(struct archiver_args *args, write_archive_entry_fn_t write_entry);
 extern int write_archive(int argc, const char **argv, const char *prefix, int setup_prefix);
diff --git a/builtin/archive.c b/builtin/archive.c
index b14eaba..4f60af5 100644
--- a/builtin/archive.c
+++ b/builtin/archive.c
@@ -71,6 +71,12 @@ static const char *format_from_name(const char *filename)
 	ext++;
 	if (!strcasecmp(ext, "zip"))
 		return "--format=zip";
+	if (!strcasecmp(ext, "tgz"))
+		return "--format=tgz";
+	if (!strcasecmp(ext, "gz") &&
+	    ext - 4 >= filename &&
+	    !strcasecmp(ext - 4, "tar.gz"))
+		return "--format=tgz";
 	return NULL;
 }
 
diff --git a/t/t5000-tar-tree.sh b/t/t5000-tar-tree.sh
index cff1b3e..faf2784 100755
--- a/t/t5000-tar-tree.sh
+++ b/t/t5000-tar-tree.sh
@@ -26,6 +26,7 @@ commit id embedding:
 
 . ./test-lib.sh
 UNZIP=${UNZIP:-unzip}
+GUNZIP=${GUNZIP:-gunzip}
 
 SUBSTFORMAT=%H%n
 
@@ -252,4 +253,29 @@ test_expect_success 'git-archive --prefix=olde-' '
 	test -f h/olde-a/bin/sh
 '
 
+test_expect_success 'git archive --format=tgz' '
+	git archive --format=tgz HEAD >e.tgz
+'
+
+test_expect_success 'infer tgz from .tgz filename' '
+	git archive --output=e1.tgz HEAD &&
+	test_cmp e.tgz e1.tgz
+'
+
+test_expect_success 'infer tgz from .tar.gz filename' '
+	git archive --output=e2.tar.gz HEAD &&
+	test_cmp e.tgz e2.tar.gz
+'
+
+if $GUNZIP --version >/dev/null 2>&1; then
+	test_set_prereq GUNZIP
+else
+	say "Skipping tgz tests because gunzip was not found"
+fi
+
+test_expect_success GUNZIP 'extract tgz file' '
+	gunzip -c <e.tgz >e.tar &&
+	test_cmp b.tar e.tar
+'
+
 test_done

-- 
1.7.6.rc1.37.g6d4ed.dirty
Previous: Jeff KingNext: J.H.
Message 2 of 56 in “archive: factor out write phase of tar format”
  1. 1/2 archive: factor out write phase of tar formatJeff King, Jun 14, 2011
  2. 2/2 archive: support gzipped tar filesJeff King, Jun 14, 2011
  3. J.H.Jun 14, 2011
  4. Jeff KingJun 14, 2011
  5. René ScharfeJun 14, 2011
  6. Jeff KingJun 14, 2011
  7. Jeff KingJun 14, 2011
  8. 0/7 user-configurable git-archive output formatsJeff King, Jun 15, 2011
  9. 1/7 archive: reorder option parsing and config readingJeff King, Jun 15, 2011
  10. 2/7 archive: add user-configurable tar-filter infrastructureJeff King, Jun 15, 2011
  11. Junio C HamanoJun 15, 2011
  12. Jeff KingJun 16, 2011
  13. 3/7 archive: support user tar-filters via --formatJeff King, Jun 15, 2011
  14. 4/7 archive: advertise user tar-filters in --listJeff King, Jun 15, 2011
  15. 5/7 archive: refactor format-guessing from filenameJeff King, Jun 15, 2011
  16. Junio C HamanoJun 15, 2011
  17. Jeff KingJun 16, 2011
  18. 6/7 archive: match extensions from user-configured formatsJeff King, Jun 15, 2011
  19. 7/7 archive: provide builtin .tar.gz filterJeff King, Jun 15, 2011
  20. Junio C HamanoJun 15, 2011
  21. Junio C HamanoJun 15, 2011
  22. Jeff KingJun 16, 2011
  23. Junio C HamanoJun 16, 2011
  24. Jeff KingJun 16, 2011
  25. Chris WebbJun 16, 2011
  26. Jeff KingJun 16, 2011
  27. Junio C HamanoJun 16, 2011
  28. Jeff KingJun 16, 2011
  29. John SzakmeisterJun 16, 2011
  30. Junio C HamanoJun 16, 2011
  31. Jeff KingJun 16, 2011
  32. René ScharfeJun 18, 2011
  33. Jakub NarebskiJun 18, 2011
  34. Junio C HamanoJun 20, 2011
  35. 0/9 configurable tar compressorsJeff King, Jun 22, 2011
  36. 1/9 archive: reorder option parsing and config readingJeff King, Jun 22, 2011
  37. 2/9 archive-tar: don't reload default config optionsJeff King, Jun 22, 2011
  38. 3/9 archive: refactor list of archive formatsJeff King, Jun 22, 2011
  39. Thiago FarinaJun 23, 2011
  40. Jeff KingJun 23, 2011
  41. 4/9 archive: pass archiver struct to write_archive callbackJeff King, Jun 22, 2011
  42. 5/9 archive: move file extension format-guessing lowerJeff King, Jun 22, 2011
  43. 6/9 archive: refactor file extension format-guessingJeff King, Jun 22, 2011
  44. 7/9 archive: implement configurable tar filtersJeff King, Jun 22, 2011
  45. Jeff KingJun 22, 2011
  46. René ScharfeJun 22, 2011
  47. Jeff KingJun 22, 2011
  48. 8/9 archive: provide builtin .tar.gz filterJeff King, Jun 22, 2011
  49. 9/9 upload-archive: allow user to turn off filtersJeff King, Jun 22, 2011
  50. Jeff KingJun 22, 2011
  51. Jeff KingJun 21, 2011
  52. René ScharfeJun 18, 2011
  53. Junio C HamanoJun 14, 2011
  54. Jeff KingJun 14, 2011
  55. Miles BaderJun 14, 2011
  56. Jeff KingJun 15, 2011

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