[v3,4/9] update-ref: organize commands in an array

Commit Message

Patrick Steinhardt April 2, 2020, 7:09 a.m. UTC

We currently manually wire up all commands known to `git-update-ref
--stdin`, making it harder than necessary to preprocess arguments after
the command is determined. To make this more extensible, let's refactor
the code to use an array of known commands instead. While this doesn't
add a lot of value now, it is a preparatory step to implement line-wise
reading of commands.

As we're going to introduce commands without trailing spaces, this
commit also moves whitespace parsing into the respective commands.

Signed-off-by: Patrick Steinhardt <[e-mail]>
---
 builtin/update-ref.c | 41 +++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

Patch

diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 2d8f7f0578..a6ff88b95b 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -310,7 +310,8 @@  static const char *parse_cmd_verify(struct ref_transaction *transaction,
 	return next;
 }
 
-static const char *parse_cmd_option(struct strbuf *input, const char *next)
+static const char *parse_cmd_option(struct ref_transaction *transaction,
+				    struct strbuf *input, const char *next)
 {
 	const char *rest;
 	if (skip_prefix(next, "no-deref", &rest) && *rest == line_termination)
@@ -320,33 +321,49 @@  static const char *parse_cmd_option(struct strbuf *input, const char *next)
 	return rest;
 }
 
+static const struct parse_cmd {
+	const char *prefix;
+	const char *(*fn)(struct ref_transaction *, struct strbuf *, const char *);
+} command[] = {
+	{ "update", parse_cmd_update },
+	{ "create", parse_cmd_create },
+	{ "delete", parse_cmd_delete },
+	{ "verify", parse_cmd_verify },
+	{ "option", parse_cmd_option },
+};
+
 static void update_refs_stdin(struct ref_transaction *transaction)
 {
 	struct strbuf input = STRBUF_INIT;
 	const char *next;
+	int i;
 
 	if (strbuf_read(&input, 0, 1000) < 0)
 		die_errno("could not read from stdin");
 	next = input.buf;
 	/* Read each line dispatch its command */
 	while (next < input.buf + input.len) {
+		const struct parse_cmd *cmd = NULL;
+
 		if (*next == line_termination)
 			die("empty command in input");
 		else if (isspace(*next))
 			die("whitespace before command: %s", next);
-		else if (skip_prefix(next, "update ", &next))
-			next = parse_cmd_update(transaction, &input, next);
-		else if (skip_prefix(next, "create ", &next))
-			next = parse_cmd_create(transaction, &input, next);
-		else if (skip_prefix(next, "delete ", &next))
-			next = parse_cmd_delete(transaction, &input, next);
-		else if (skip_prefix(next, "verify ", &next))
-			next = parse_cmd_verify(transaction, &input, next);
-		else if (skip_prefix(next, "option ", &next))
-			next = parse_cmd_option(&input, next);
-		else
+
+		for (i = 0; i < ARRAY_SIZE(command); i++) {
+			const char *prefix = command[i].prefix;
+
+			if (!skip_prefix(next, prefix, &next) ||
+			    !skip_prefix(next, " ", &next))
+				continue;
+
+			cmd = &command[i];
+			break;
+		}
+		if (!cmd)
 			die("unknown command: %s", next);
 
+		next = cmd->fn(transaction, &input, next);
 		next++;
 	}