ls-files: aligin format atoms wtih ls-tree

"git ls-files --format" can be used to format the output of
multiple file entries in the index, while "git ls-tree --format"
can be used to format the contents of a tree object. However,
the current set of %(objecttype), "(objectsize)", and
"%(objectsize:padded)" atoms supported by "git ls-files --format"
is a subset of what is available in "git ls-tree --format".

Users sometimes need to establish a unified view between the index
and tree, which can help with comparison or conversion between the two.

Therefore, this patch adds the missing atoms to "git ls-files --format".
"%(objecttype)" can be used to retrieve the object type corresponding
to a file in the index, "(objectsize)" can be used to retrieve the
object size corresponding to a file in the index, and "%(objectsize:padded)"
is the same as "(objectsize)", except with padded format.

Signed-off-by: ZheNing Hu <adlternative@gmail.com>

Documentation/git-ls-files.txt

@@ -270,8 +270,14 @@ interpolated.  The following "fieldname" are understood:
 
 objectmode::
 	The mode of the file which is recorded in the index.
+objecttype::
+	The object type of the file which is recorded in the index.
 objectname::
 	The name of the file which is recorded in the index.
+objectsize[:padded]::
+	The object size of the file which is recorded in the index
+	("-" if the object is a `commit` or `tree`).
+	It also supports a padded format of size with "%(objectsize:padded)".
 stage::
 	The stage of the file which is recorded in the index.
 eolinfo:index::

builtin/ls-files.c

@@ -25,6 +25,9 @@
 #include "setup.h"
 #include "submodule.h"
 #include "submodule-config.h"
+#include "object-store.h"
+#include "hex.h"
+
 
 static int abbrev;
 static int show_deleted;
@@ -241,6 +244,24 @@ static void show_submodule(struct repository *superproject,
 	repo_clear(&subrepo);
 }
 
+static void expand_objectsize(struct strbuf *line, const struct object_id *oid,
+			      const enum object_type type, unsigned int padded)
+{
+	if (type == OBJ_BLOB) {
+		unsigned long size;
+		if (oid_object_info(the_repository, oid, &size) < 0)
+			die(_("could not get object info about '%s'"),
+			    oid_to_hex(oid));
+		if (padded)
+			strbuf_addf(line, "%7"PRIuMAX, (uintmax_t)size);
+		else
+			strbuf_addf(line, "%"PRIuMAX, (uintmax_t)size);
+	} else if (padded) {
+		strbuf_addf(line, "%7s", "-");
+	} else {
+		strbuf_addstr(line, "-");
+	}
+}
 struct show_index_data {
 	const char *pathname;
 	struct index_state *istate;
@@ -272,6 +293,12 @@ static size_t expand_show_index(struct strbuf *sb, const char *start,
 		strbuf_addf(sb, "%06o", data->ce->ce_mode);
 	else if (skip_prefix(start, "(objectname)", &p))
 		strbuf_add_unique_abbrev(sb, &data->ce->oid, abbrev);
+	else if (skip_prefix(start, "(objecttype)", &p))
+		strbuf_addstr(sb, type_name(object_type(data->ce->ce_mode)));
+	else if (skip_prefix(start, "(objectsize:padded)", &p))
+		expand_objectsize(sb, &data->ce->oid, object_type(data->ce->ce_mode), 1);
+	else if (skip_prefix(start, "(objectsize)", &p))
+		expand_objectsize(sb, &data->ce->oid, object_type(data->ce->ce_mode), 0);
 	else if (skip_prefix(start, "(stage)", &p))
 		strbuf_addf(sb, "%d", ce_stage(data->ce));
 	else if (skip_prefix(start, "(eolinfo:index)", &p))

t/t3013-ls-files-format.sh

@@ -38,6 +38,41 @@ test_expect_success 'git ls-files --format objectname v.s. -s' '
 	test_cmp expect actual
 '
 
+test_expect_success 'git ls-files --format objecttype' '
+	git ls-files --format="%(objectname)" o1.txt o4.txt o6.txt >objectname &&
+	git cat-file --batch-check="%(objecttype)" >expect <objectname &&
+	git ls-files --format="%(objecttype)" o1.txt o4.txt o6.txt >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'git ls-files --format objectsize' '
+	cat>expect <<-\EOF &&
+26
+29
+27
+26
+-
+26
+	EOF
+	git ls-files --format="%(objectsize)" >actual &&
+
+	test_cmp expect actual
+'
+
+test_expect_success 'git ls-files --format objectsize:padded' '
+	cat>expect <<-\EOF &&
+     26
+     29
+     27
+     26
+      -
+     26
+	EOF
+	git ls-files --format="%(objectsize:padded)" >actual &&
+
+	test_cmp expect actual
+'
+
 test_expect_success 'git ls-files --format v.s. --eol' '
 	git ls-files --eol >tmp &&
 	sed -e "s/	/ /g" -e "s/  */ /g" tmp >expect 2>err &&