git-tar-tree: devolve git-tar-tree into a wrapper for git-archive

This patch removes the custom tree walker tree_traverse(), and makes
generate_tar() use write_tar_archive() and the infrastructure provided
by git-archive instead.

As a kind of side effect, make write_tar_archive() able to handle NULL
as base directory, as this is what the new and simple generate_tar()
uses to indicate the absence of a base directory.  This was simpler
and cleaner than playing tricks with empty strings.

The behaviour of git-tar-tree should be unchanged (quick tests didn't
indicate otherwise) except for the text of some error messages.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-tar-tree.c b/builtin-tar-tree.c
index f2679a86378371293aca257d4e839e87f759ae18..437eb726a9b207353545726f379ab8638c0eecb9 100644 (file)
--- a/builtin-tar-tree.c
+++ b/builtin-tar-tree.c
@@ -3,7 +3,6 @@
  */
 #include <time.h>
 #include "cache.h"
-#include "tree-walk.h"
 #include "commit.h"
 #include "strbuf.h"
 #include "tar.h"
@@ -248,37 +247,6 @@ static void write_global_extended_header(const unsigned char *sha1)
        free(ext_header.buf);
 }
 
-static void traverse_tree(struct tree_desc *tree, struct strbuf *path)
-{
-       int pathlen = path->len;
-       struct name_entry entry;
-
-       while (tree_entry(tree, &entry)) {
-               void *eltbuf;
-               char elttype[20];
-               unsigned long eltsize;
-
-               eltbuf = read_sha1_file(entry.sha1, elttype, &eltsize);
-               if (!eltbuf)
-                       die("cannot read %s", sha1_to_hex(entry.sha1));
-
-               path->len = pathlen;
-               strbuf_append_string(path, entry.path);
-               if (S_ISDIR(entry.mode))
-                       strbuf_append_string(path, "/");
-
-               write_entry(entry.sha1, path, entry.mode, eltbuf, eltsize);
-
-               if (S_ISDIR(entry.mode)) {
-                       struct tree_desc subtree;
-                       subtree.buf = eltbuf;
-                       subtree.size = eltsize;
-                       traverse_tree(&subtree, path);
-               }
-               free(eltbuf);
-       }
-}
-
 static int git_tar_config(const char *var, const char *value)
 {
        if (!strcmp(var, "tar.umask")) {
@@ -295,51 +263,29 @@ static int git_tar_config(const char *var, const char *value)
 
 static int generate_tar(int argc, const char **argv, const char *prefix)
 {
-       unsigned char sha1[20], tree_sha1[20];
-       struct commit *commit;
-       struct tree_desc tree;
-       struct strbuf current_path;
-       void *buffer;
-
-       current_path.buf = xmalloc(PATH_MAX);
-       current_path.alloc = PATH_MAX;
-       current_path.len = current_path.eof = 0;
+       struct archiver_args args;
+       int result;
+       char *base = NULL;
 
        git_config(git_tar_config);
 
-       switch (argc) {
-       case 3:
-               strbuf_append_string(&current_path, argv[2]);
-               strbuf_append_string(&current_path, "/");
-               /* FALLTHROUGH */
-       case 2:
-               if (get_sha1(argv[1], sha1))
-                       die("Not a valid object name %s", argv[1]);
-               break;
-       default:
+       memset(&args, 0, sizeof(args));
+       if (argc != 2 && argc != 3)
                usage(tar_tree_usage);
+       if (argc == 3) {
+               int baselen = strlen(argv[2]);
+               base = xmalloc(baselen + 2);
+               memcpy(base, argv[2], baselen);
+               base[baselen] = '/';
+               base[baselen + 1] = '\0';
        }
+       args.base = base;
+       parse_treeish_arg(argv + 1, &args, NULL);
 
-       commit = lookup_commit_reference_gently(sha1, 1);
-       if (commit) {
-               write_global_extended_header(commit->object.sha1);
-               archive_time = commit->date;
-       } else
-               archive_time = time(NULL);
-
-       tree.buf = buffer = read_object_with_reference(sha1, tree_type,
-                                                      &tree.size, tree_sha1);
-       if (!tree.buf)
-               die("not a reference to a tag, commit or tree object: %s",
-                   sha1_to_hex(sha1));
-
-       if (current_path.len > 0)
-               write_entry(tree_sha1, &current_path, 040777, NULL, 0);
-       traverse_tree(&tree, &current_path);
-       write_trailer();
-       free(buffer);
-       free(current_path.buf);
-       return 0;
+       result = write_tar_archive(&args);
+       free(base);
+
+       return result;
 }
 
 static int write_tar_entry(const unsigned char *sha1,
@@ -383,7 +329,7 @@ static int write_tar_entry(const unsigned char *sha1,
 
 int write_tar_archive(struct archiver_args *args)
 {
-       int plen = strlen(args->base);
+       int plen = args->base ? strlen(args->base) : 0;
 
        git_config(git_tar_config);