archive: implement configurable tar filters

It's common to pipe the tar output produce by "git archive"
through gzip or some other compressor. Locally, this can
easily be done by using a shell pipe. When requesting a
remote archive, though, it cannot be done through the
upload-archive interface.

This patch allows configurable tar filters, so that one
could define a "tar.gz" format that automatically pipes tar
output through gzip.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-archive.txt b/Documentation/git-archive.txt
index 9c750e24446b58efc2bd8d5e44566d060eaa353a..726bf63d460121ac06e480806e1915b0733b294d 100644 (file)
--- a/Documentation/git-archive.txt
+++ b/Documentation/git-archive.txt
@@ -101,6 +101,16 @@ tar.umask::
        details.  If `--remote` is used then only the configuration of
        the remote repository takes effect.
 
        details.  If `--remote` is used then only the configuration of
        the remote repository takes effect.
 

+tar.<format>.command::
+       This variable specifies a shell command through which the tar
+       output generated by `git archive` should be piped. The command
+       is executed using the shell with the generated tar file on its
+       standard input, and should produce the final output on its
+       standard output. Any compression-level options will be passed
+       to the command (e.g., "-9"). An output file with the same
+       extension as `<format>` will be use this format if no other
+       format is given.
+

 ATTRIBUTES
 ----------
 
 ATTRIBUTES
 ----------
 


@@ -149,6 +159,12 @@ git archive -o latest.zip HEAD::
        commit on the current branch. Note that the output format is
        inferred by the extension of the output file.
 
        commit on the current branch. Note that the output format is
        inferred by the extension of the output file.
 

+git config tar.tar.xz.command "xz -c"::
+
+       Configure a "tar.xz" format for making LZMA-compressed tarfiles.
+       You can use it specifying `--format=tar.xz`, or by creating an
+       output file like `-o foo.tar.xz`.
+

 
 SEE ALSO
 --------
 
 SEE ALSO
 --------

diff --git a/archive-tar.c b/archive-tar.c
index bed9a9b15ce07fbb1ff0f40902e1b317b82663e9..5c30747f9cf9be69a6829cc78367c908a99fa4dd 100644 (file)
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -4,6 +4,7 @@
 #include "cache.h"
 #include "tar.h"
 #include "archive.h"
 #include "cache.h"
 #include "tar.h"
 #include "archive.h"

+#include "run-command.h"

 
 #define RECORDSIZE     (512)
 #define BLOCKSIZE      (RECORDSIZE * 20)
 
 #define RECORDSIZE     (512)
 #define BLOCKSIZE      (RECORDSIZE * 20)


@@ -13,6 +14,9 @@ static unsigned long offset;
 
 static int tar_umask = 002;
 
 
 static int tar_umask = 002;
 

+static int write_tar_filter_archive(const struct archiver *ar,
+                                   struct archiver_args *args);
+

 /* writes out the whole block, but only if it is full */
 static void write_if_needed(void)
 {
 /* writes out the whole block, but only if it is full */
 static void write_if_needed(void)
 {


@@ -220,6 +224,60 @@ static int write_global_extended_header(struct archiver_args *args)
        return err;
 }
 
        return err;
 }
 

+static struct archiver **tar_filters;
+static int nr_tar_filters;
+static int alloc_tar_filters;
+
+static struct archiver *find_tar_filter(const char *name, int len)
+{
+       int i;
+       for (i = 0; i < nr_tar_filters; i++) {
+               struct archiver *ar = tar_filters[i];
+               if (!strncmp(ar->name, name, len) && !ar->name[len])
+                       return ar;
+       }
+       return NULL;
+}
+
+static int tar_filter_config(const char *var, const char *value, void *data)
+{
+       struct archiver *ar;
+       const char *dot;
+       const char *name;
+       const char *type;
+       int namelen;
+
+       if (prefixcmp(var, "tar."))
+               return 0;
+       dot = strrchr(var, '.');
+       if (dot == var + 9)
+               return 0;
+
+       name = var + 4;
+       namelen = dot - name;
+       type = dot + 1;
+
+       ar = find_tar_filter(name, namelen);
+       if (!ar) {
+               ar = xcalloc(1, sizeof(*ar));
+               ar->name = xmemdupz(name, namelen);
+               ar->write_archive = write_tar_filter_archive;
+               ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS;
+               ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
+               tar_filters[nr_tar_filters++] = ar;
+       }
+
+       if (!strcmp(type, "command")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               free(ar->data);
+               ar->data = xstrdup(value);
+               return 0;
+       }
+
+       return 0;
+}
+

 static int git_tar_config(const char *var, const char *value, void *cb)
 {
        if (!strcmp(var, "tar.umask")) {
 static int git_tar_config(const char *var, const char *value, void *cb)
 {
        if (!strcmp(var, "tar.umask")) {


@@ -231,7 +289,8 @@ static int git_tar_config(const char *var, const char *value, void *cb)
                }
                return 0;
        }
                }
                return 0;
        }

-       return 0;
+
+       return tar_filter_config(var, value, cb);

 }
 
 static int write_tar_archive(const struct archiver *ar,
 }
 
 static int write_tar_archive(const struct archiver *ar,


@@ -248,6 +307,45 @@ static int write_tar_archive(const struct archiver *ar,
        return err;
 }
 
        return err;
 }
 

+static int write_tar_filter_archive(const struct archiver *ar,
+                                   struct archiver_args *args)
+{
+       struct strbuf cmd = STRBUF_INIT;
+       struct child_process filter;
+       const char *argv[2];
+       int r;
+
+       if (!ar->data)
+               die("BUG: tar-filter archiver called with no filter defined");
+
+       strbuf_addstr(&cmd, ar->data);
+       if (args->compression_level >= 0)
+               strbuf_addf(&cmd, " -%d", args->compression_level);
+
+       memset(&filter, 0, sizeof(filter));
+       argv[0] = cmd.buf;
+       argv[1] = NULL;
+       filter.argv = argv;
+       filter.use_shell = 1;
+       filter.in = -1;
+
+       if (start_command(&filter) < 0)
+               die_errno("unable to start '%s' filter", argv[0]);
+       close(1);
+       if (dup2(filter.in, 1) < 0)
+               die_errno("unable to redirect descriptor");
+       close(filter.in);
+
+       r = write_tar_archive(ar, args);
+
+       close(1);
+       if (finish_command(&filter) != 0)
+               die("'%s' filter reported error", argv[0]);
+
+       strbuf_release(&cmd);
+       return r;
+}
+

 static struct archiver tar_archiver = {
        "tar",
        write_tar_archive,
 static struct archiver tar_archiver = {
        "tar",
        write_tar_archive,


@@ -256,6 +354,13 @@ static struct archiver tar_archiver = {
 
 void init_tar_archiver(void)
 {
 
 void init_tar_archiver(void)
 {

+       int i;

        register_archiver(&tar_archiver);
        register_archiver(&tar_archiver);

+

        git_config(git_tar_config, NULL);
        git_config(git_tar_config, NULL);

+       for (i = 0; i < nr_tar_filters; i++) {
+               /* omit any filters that never had a command configured */
+               if (tar_filters[i]->data)
+                       register_archiver(tar_filters[i]);
+       }

 }
 }

diff --git a/t/t5000-tar-tree.sh b/t/t5000-tar-tree.sh
index cff1b3e0502e96ff6232611ef70c24752a970a96..1f9069213aacb80fcf29fc87d89cefee7ae40fef 100755 (executable)
--- a/t/t5000-tar-tree.sh
+++ b/t/t5000-tar-tree.sh
@@ -252,4 +252,47 @@ test_expect_success 'git-archive --prefix=olde-' '
        test -f h/olde-a/bin/sh
 '
 
        test -f h/olde-a/bin/sh
 '
 

+test_expect_success 'setup tar filters' '
+       git config tar.tar.foo.command "tr ab ba" &&
+       git config tar.bar.command "tr ab ba"
+'
+
+test_expect_success 'archive --list mentions user filter' '
+       git archive --list >output &&
+       grep "^tar\.foo\$" output &&
+       grep "^bar\$" output
+'
+
+test_expect_success 'archive --list shows remote user filters' '
+       git archive --list --remote=. >output &&
+       grep "^tar\.foo\$" output &&
+       grep "^bar\$" output
+'
+
+test_expect_success 'invoke tar filter by format' '
+       git archive --format=tar.foo HEAD >config.tar.foo &&
+       tr ab ba <config.tar.foo >config.tar &&
+       test_cmp b.tar config.tar &&
+       git archive --format=bar HEAD >config.bar &&
+       tr ab ba <config.bar >config.tar &&
+       test_cmp b.tar config.tar
+'
+
+test_expect_success 'invoke tar filter by extension' '
+       git archive -o config-implicit.tar.foo HEAD &&
+       test_cmp config.tar.foo config-implicit.tar.foo &&
+       git archive -o config-implicit.bar HEAD &&
+       test_cmp config.tar.foo config-implicit.bar
+'
+
+test_expect_success 'default output format remains tar' '
+       git archive -o config-implicit.baz HEAD &&
+       test_cmp b.tar config-implicit.baz
+'
+
+test_expect_success 'extension matching requires dot' '
+       git archive -o config-implicittar.foo HEAD &&
+       test_cmp b.tar config-implicittar.foo
+'
+

 test_done
 test_done