diff mbox series

[v2,4/9] update-ref: organize commands in an array

Message ID bd8c059fbcd9dc21203dff61e047af66e4239caf.1585575749.git.ps@pks.im (mailing list archive)
State New, archived
Headers show
Series Support for transactions in `git-update-ref --stdin` | expand

Commit Message

Patrick Steinhardt March 30, 2020, 1:46 p.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 <ps@pks.im>
---
 builtin/update-ref.c | 73 +++++++++++++++++++++++++++++++++-----------
 1 file changed, 56 insertions(+), 17 deletions(-)
diff mbox series

Patch

diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 2d8f7f0578..559475681e 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -171,11 +171,11 @@  static int parse_next_oid(struct strbuf *input, const char **next,
 /*
  * The following five parse_cmd_*() functions parse the corresponding
  * command.  In each case, next points at the character following the
- * command name and the following space.  They each return a pointer
- * to the character terminating the command, and die with an
- * explanatory message if there are any parsing problems.  All of
- * these functions handle either text or binary format input,
- * depending on how line_termination is set.
+ * command name.  They each return a pointer to the character
+ * terminating the command, and die with an explanatory message if
+ * there are any parsing problems.  All of these functions handle
+ * either text or binary format input, depending on how
+ * line_termination is set.
  */
 
 static const char *parse_cmd_update(struct ref_transaction *transaction,
@@ -186,6 +186,9 @@  static const char *parse_cmd_update(struct ref_transaction *transaction,
 	struct object_id new_oid, old_oid;
 	int have_old;
 
+	if (!skip_prefix(next, " ", &next))
+		die("update: missing space after command");
+
 	refname = parse_refname(input, &next);
 	if (!refname)
 		die("update: missing <ref>");
@@ -220,6 +223,9 @@  static const char *parse_cmd_create(struct ref_transaction *transaction,
 	char *refname;
 	struct object_id new_oid;
 
+	if (!skip_prefix(next, " ", &next))
+		die("create: missing space after command");
+
 	refname = parse_refname(input, &next);
 	if (!refname)
 		die("create: missing <ref>");
@@ -253,6 +259,9 @@  static const char *parse_cmd_delete(struct ref_transaction *transaction,
 	struct object_id old_oid;
 	int have_old;
 
+	if (!skip_prefix(next, " ", &next))
+		die("delete: missing space after command");
+
 	refname = parse_refname(input, &next);
 	if (!refname)
 		die("delete: missing <ref>");
@@ -288,6 +297,9 @@  static const char *parse_cmd_verify(struct ref_transaction *transaction,
 	char *refname;
 	struct object_id old_oid;
 
+	if (!skip_prefix(next, " ", &next))
+		die("verify: missing space after command");
+
 	refname = parse_refname(input, &next);
 	if (!refname)
 		die("verify: missing <ref>");
@@ -310,9 +322,12 @@  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, " ", &next))
+		die("option: missing space after command");
 	if (skip_prefix(next, "no-deref", &rest) && *rest == line_termination)
 		update_flags |= REF_NO_DEREF;
 	else
@@ -320,33 +335,57 @@  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))
+				continue;
+
+			/*
+			 * Check that the command is terminated by an argument
+			 * or line terminator and not only a matching prefix.
+			 */
+			if (input.buf[strlen(prefix)] != line_termination &&
+			    input.buf[strlen(prefix)] != '\0' &&
+			    input.buf[strlen(prefix)] != ' ')
+				continue;
+
+			cmd = &command[i];
+			break;
+		}
+		if (!cmd)
 			die("unknown command: %s", next);
 
+		next = cmd->fn(transaction, &input, next);
 		next++;
 	}