Add an option to git-ls-tree to display also the size of blob

Add -l/--long option to git-ls-tree command, which displays
object size of a blob entry.  Object size is placed after
object id (left-justified with minimum width of 7 characters).
For non-blob entries `-' is used.

Rationale: for non-blob entries size of an object has no much
meaning, and is not very interesting.  Moreover, in planned
pack v4 tree objects would be constructed on demand, so tree
size would need to be calculated.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-ls-tree.txt

@@ -9,7 +9,7 @@ git-ls-tree - List the contents of a tree object
 SYNOPSIS
 --------
 [verse]
-'git-ls-tree' [-d] [-r] [-t] [-z]
+'git-ls-tree' [-d] [-r] [-t] [-l] [-z]
 	    [--name-only] [--name-status] [--full-name] [--abbrev=[<n>]]
 	    <tree-ish> [paths...]
 
@@ -36,6 +36,10 @@ OPTIONS
 	Show tree entries even when going to recurse them. Has no effect
 	if '-r' was not passed. '-d' implies '-t'.
 
+-l::
+--long::
+	Show object size of blob (file) entries.
+
 -z::
 	\0 line termination on output.
 
@@ -65,6 +69,14 @@ Output Format
 When the `-z` option is not used, TAB, LF, and backslash characters
 in pathnames are represented as `\t`, `\n`, and `\\`, respectively.
 
+When the `-l` option is used, format changes to
+
+        <mode> SP <type> SP <object> SP <object size> TAB <file>
+
+Object size identified by <object> is given in bytes, and right-justified
+with minimum width of 7 characters.  Object size is given only for blobs
+(file) entries; for other entries `-` character is used in place of size.
+
 
 Author
 ------

builtin-ls-tree.c

@@ -15,14 +15,15 @@ static int line_termination = '\n';
 #define LS_TREE_ONLY 2
 #define LS_SHOW_TREES 4
 #define LS_NAME_ONLY 8
+#define LS_SHOW_SIZE 16
 static int abbrev;
 static int ls_options;
 static const char **pathspec;
 static int chomp_prefix;
 static const char *ls_tree_prefix;
 
 static const char ls_tree_usage[] =
-	"git-ls-tree [-d] [-r] [-t] [-z] [--name-only] [--name-status] [--full-name] [--abbrev[=<n>]] <tree-ish> [path...]";
+	"git-ls-tree [-d] [-r] [-t] [-l] [-z] [--name-only] [--name-status] [--full-name] [--abbrev[=<n>]] <tree-ish> [path...]";
 
 static int show_recursive(const char *base, int baselen, const char *pathname)
 {
@@ -59,6 +60,7 @@ static int show_tree(const unsigned char *sha1, const char *base, int baselen,
 {
 	int retval = 0;
 	const char *type = blob_type;
+	unsigned long size;
 
 	if (S_ISDIRLNK(mode)) {
 		/*
@@ -92,10 +94,24 @@ static int show_tree(const unsigned char *sha1, const char *base, int baselen,
 	    (baselen < chomp_prefix || memcmp(ls_tree_prefix, base, chomp_prefix)))
 		return 0;
 
-	if (!(ls_options & LS_NAME_ONLY))
-		printf("%06o %s %s\t", mode, type,
-				abbrev ? find_unique_abbrev(sha1,abbrev)
-					: sha1_to_hex(sha1));
+	if (!(ls_options & LS_NAME_ONLY)) {
+		if (ls_options & LS_SHOW_SIZE) {
+			if (!strcmp(type, blob_type)) {
+				sha1_object_info(sha1, &size);
+				printf("%06o %s %s %7lu\t", mode, type,
+				       abbrev ? find_unique_abbrev(sha1, abbrev)
+				              : sha1_to_hex(sha1),
+				       size);
+			} else
+				printf("%06o %s %s %7c\t", mode, type,
+				       abbrev ? find_unique_abbrev(sha1, abbrev)
+				              : sha1_to_hex(sha1),
+				       '-');
+		} else
+			printf("%06o %s %s\t", mode, type,
+			       abbrev ? find_unique_abbrev(sha1, abbrev)
+			              : sha1_to_hex(sha1));
+	}
 	write_name_quoted(base + chomp_prefix, baselen - chomp_prefix,
 			  pathname,
 			  line_termination, stdout);
@@ -126,12 +142,19 @@ int cmd_ls_tree(int argc, const char **argv, const char *prefix)
 		case 't':
 			ls_options |= LS_SHOW_TREES;
 			break;
+		case 'l':
+			ls_options |= LS_SHOW_SIZE;
+			break;
 		case '-':
 			if (!strcmp(argv[1]+2, "name-only") ||
 			    !strcmp(argv[1]+2, "name-status")) {
 				ls_options |= LS_NAME_ONLY;
 				break;
 			}
+			if (!strcmp(argv[1]+2, "long")) {
+				ls_options |= LS_SHOW_SIZE;
+				break;
+			}
 			if (!strcmp(argv[1]+2, "full-name")) {
 				chomp_prefix = 0;
 				break;