[PATCH 1/2] Make the "struct tree_desc" operations available to others

[PATCH 1/2] Make the "struct tree_desc" operations available to others

[Linus Torvalds]

We have operations to "extract" and "update" a "struct tree_desc", but we 
only used them in tree-diff.c and they were static to that file.

But other tree traversal functions can use them to their advantage

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

This is just infrastructure. No real changes, except for the renaming of 
the "extract()" function to make it have a more palatable name when it's
globally visible.

diff --git a/diff.h b/diff.h
index 9a0169c..32134d7 100644
--- a/diff.h
+++ b/diff.h
@@ -13,6 +13,9 @@ struct tree_desc {
 	unsigned long size;
 };
 
+extern void update_tree_entry(struct tree_desc *);
+extern const unsigned char *tree_entry_extract(struct tree_desc *, const char **, unsigned int *);
+
 struct diff_options;
 
 typedef void (*change_fn_t)(struct diff_options *options,
diff --git a/tree-diff.c b/tree-diff.c
index 382092b..d978428 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -9,7 +9,7 @@ static int nr_paths = 0;
 static const char **paths = NULL;
 static int *pathlens = NULL;
 
-static void update_tree_entry(struct tree_desc *desc)
+void update_tree_entry(struct tree_desc *desc)
 {
 	void *buf = desc->buf;
 	unsigned long size = desc->size;
@@ -21,7 +21,7 @@ static void update_tree_entry(struct tre
 	desc->size = size - len;
 }
 
-static const unsigned char *extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
+const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
 {
 	void *tree = desc->buf;
 	unsigned long size = desc->size;
@@ -56,8 +56,8 @@ static int compare_tree_entry(struct tre
 	const unsigned char *sha1, *sha2;
 	int cmp, pathlen1, pathlen2;
 
-	sha1 = extract(t1, &path1, &mode1);
-	sha2 = extract(t2, &path2, &mode2);
+	sha1 = tree_entry_extract(t1, &path1, &mode1);
+	sha2 = tree_entry_extract(t2, &path2, &mode2);
 
 	pathlen1 = strlen(path1);
 	pathlen2 = strlen(path2);
@@ -109,7 +109,7 @@ static int interesting(struct tree_desc 
 	if (!nr_paths)
 		return 1;
 
-	(void)extract(desc, &path, &mode);
+	(void)tree_entry_extract(desc, &path, &mode);
 
 	pathlen = strlen(path);
 	baselen = strlen(base);
@@ -167,7 +167,7 @@ static int show_entry(struct diff_option
 {
 	unsigned mode;
 	const char *path;
-	const unsigned char *sha1 = extract(desc, &path, &mode);
+	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
 
 	if (opt->recursive && S_ISDIR(mode)) {
 		char type[20];

[PATCH 2/2] Make git-tar-tree use the tree_desc abstractions

[Linus Torvalds]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

This is a first try at making git-tar-tree use the "struct tree_desc" 
infrastructure. I actually did test it by creating a tar-file of Linux 
v2.6.15, and it _seemed_ to work, and it passes all the git testsuite, but 
hey, that was all very superficial.

It was a pretty straightforward change from "struct tree" to "struct 
tree_desc", though, so it should all be fine. Daniel had already cleaned 
up the code by his original conversion.

diff --git a/tar-tree.c b/tar-tree.c
index d36baed..e85a1ed 100644
--- a/tar-tree.c
+++ b/tar-tree.c
@@ -3,7 +3,7 @@
  */
 #include <time.h>
 #include "cache.h"
-#include "tree.h"
+#include "diff.h"
 #include "commit.h"
 
 #define RECORDSIZE	(512)
@@ -336,37 +336,38 @@ static void write_header(const unsigned 
 	write_if_needed();
 }
 
-static void traverse_tree(struct tree *tree,
+static void traverse_tree(struct tree_desc *tree,
 			  struct path_prefix *prefix)
 {
 	struct path_prefix this_prefix;
-	struct tree_entry_list *item;
 	this_prefix.prev = prefix;
 
-	parse_tree(tree);
-	item = tree->entries;
-
-	while (item) {
+	while (tree->size) {
+		const char *name;
+		const unsigned char *sha1;
+		unsigned mode;
 		void *eltbuf;
 		char elttype[20];
 		unsigned long eltsize;
 
-		eltbuf = read_sha1_file(item->item.any->sha1, 
-					elttype, &eltsize);
+		sha1 = tree_entry_extract(tree, &name, &mode);
+		update_tree_entry(tree);
+
+		eltbuf = read_sha1_file(sha1, elttype, &eltsize);
 		if (!eltbuf)
-			die("cannot read %s", 
-			    sha1_to_hex(item->item.any->sha1));
-		write_header(item->item.any->sha1, TYPEFLAG_AUTO, basedir, 
-			     prefix, item->name,
-		             item->mode, eltbuf, eltsize);
-		if (item->directory) {
-			this_prefix.name = item->name;
-			traverse_tree(item->item.tree, &this_prefix);
-		} else if (!item->symlink) {
+			die("cannot read %s", sha1_to_hex(sha1));
+		write_header(sha1, TYPEFLAG_AUTO, basedir, 
+			     prefix, name, mode, eltbuf, eltsize);
+		if (S_ISDIR(mode)) {
+			struct tree_desc subtree;
+			subtree.buf = eltbuf;
+			subtree.size = eltsize;
+			this_prefix.name = name;
+			traverse_tree(&subtree, &this_prefix);
+		} else if (!S_ISLNK(mode)) {
 			write_blocked(eltbuf, eltsize);
 		}
 		free(eltbuf);
-		item = item->next;
 	}
 }
 
@@ -374,7 +375,7 @@ int main(int argc, char **argv)
 {
 	unsigned char sha1[20];
 	struct commit *commit;
-	struct tree *tree;
+	struct tree_desc tree;
 
 	setup_git_directory();
 
@@ -395,8 +396,8 @@ int main(int argc, char **argv)
 		write_global_extended_header(commit->object.sha1);
 		archive_time = commit->date;
 	}
-	tree = parse_tree_indirect(sha1);
-	if (!tree)
+	tree.buf = read_object_with_reference(sha1, "tree", &tree.size, NULL);
+	if (!tree.buf)
 		die("not a reference to a tag, commit or tree object: %s",
 		    sha1_to_hex(sha1));
 	if (!archive_time)
@@ -404,7 +405,7 @@ int main(int argc, char **argv)
 	if (basedir)
 		write_header((unsigned char *)"0", TYPEFLAG_DIR, NULL, NULL,
 			basedir, 040777, NULL, 0);
-	traverse_tree(tree, NULL);
+	traverse_tree(&tree, NULL);
 	write_trailer();
 	return 0;
 }