Decouple the parsing code from the input source (the old parsing code
had to read new data even in the middle of commands). This might also
be a tad faster, but that is inconsequential. Add docstrings for the
parsing functions.
Signed-off-by: Michael Haggerty <mhag...@alum.mit.edu>
---
builtin/update-ref.c | 170 ++++++++++++++++++++++++++++++++-------------------
1 file changed, 108 insertions(+), 62 deletions(-)
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index a8a68e8..5f197fe 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -85,44 +85,70 @@ static const char *parse_arg(const char *next, struct
strbuf *arg)
return next;
}
-static const char *parse_first_arg(const char *next, struct strbuf *arg)
+/*
+ * Parse the argument immediately after "command SP". If not -z, then
+ * handle C-quoting. Write the argument to arg. Set *next to point
+ * at the character that terminates the argument. Die if C-quoting is
+ * malformed.
+ */
+static void parse_first_arg(struct strbuf *input, const char **next,
+ struct strbuf *arg)
{
- /* Parse argument immediately after "command SP" */
strbuf_reset(arg);
if (line_termination) {
/* Without -z, use the next argument */
- next = parse_arg(next, arg);
+ *next = parse_arg(*next, arg);
} else {
- /* With -z, use rest of first NUL-terminated line */
- strbuf_addstr(arg, next);
- next = next + arg->len;
+ /* With -z, use everything up to the next NUL */
+ strbuf_addstr(arg, *next);
+ *next += arg->len;
}
- return next;
}
-static const char *parse_next_arg(const char *next, struct strbuf *arg)
+/*
+ * Parse a SP/NUL separator followed by the next SP- or NUL-terminated
+ * argument, if any. If there is an argument, write it to arg, set
+ * *next to point at the character terminating the argument, and
+ * return 0. If there is no argument at all (not even the empty
+ * string), return a non-zero result and leave *next unchanged.
+ */
+static int parse_next_arg(struct strbuf *input, const char **next,
+ struct strbuf *arg)
{
- /* Parse next SP-terminated or NUL-terminated argument, if any */
strbuf_reset(arg);
if (line_termination) {
/* Without -z, consume SP and use next argument */
- if (!*next)
- return NULL;
- if (*next != ' ')
- die("expected SP but got: %s", next);
- next = parse_arg(next + 1, arg);
+ if (!**next || **next == line_termination)
+ return -1;
+ if (**next != ' ')
+ die("expected SP but got: %s", *next);
+ (*next)++;
+ *next = parse_arg(*next, arg);
} else {
/* With -z, read the next NUL-terminated line */
- if (*next)
- die("expected NUL but got: %s", next);
- if (strbuf_getline(arg, stdin, '\0') == EOF)
- return NULL;
- next = arg->buf + arg->len;
+ if (**next)
+ die("expected NUL but got: %s", *next);
+ (*next)++;
+ if (*next == input->buf + input->len)
+ return -1;
+ strbuf_addstr(arg, *next);
+ *next += arg->len;
}
- return next;
+ return 0;
}
-static void parse_cmd_update(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.
+ */
+
+static const char *parse_cmd_update(struct strbuf *input, const char *next)
{
struct strbuf ref = STRBUF_INIT;
struct strbuf newvalue = STRBUF_INIT;
@@ -131,26 +157,28 @@ static void parse_cmd_update(const char *next)
update = update_alloc();
- if ((next = parse_first_arg(next, &ref)) != NULL && ref.buf[0])
+ parse_first_arg(input, &next, &ref);
+ if (ref.buf[0])
update_store_ref_name(update, ref.buf);
else
die("update line missing <ref>");
- if ((next = parse_next_arg(next, &newvalue)) != NULL)
+ if (!parse_next_arg(input, &next, &newvalue))
update_store_new_sha1(update, newvalue.buf);
else
die("update %s missing <newvalue>", ref.buf);
- if ((next = parse_next_arg(next, &oldvalue)) != NULL)
+ if (!parse_next_arg(input, &next, &oldvalue)) {
update_store_old_sha1(update, oldvalue.buf);
- else if(!line_termination)
+ if (*next != line_termination)
+ die("update %s has extra input: %s", ref.buf, next);
+ } else if (!line_termination)
die("update %s missing [<oldvalue>] NUL", ref.buf);
- if (next && *next)
- die("update %s has extra input: %s", ref.buf, next);
+ return next;
}
-static void parse_cmd_create(const char *next)
+static const char *parse_cmd_create(struct strbuf *input, const char *next)
{
struct strbuf ref = STRBUF_INIT;
struct strbuf newvalue = STRBUF_INIT;
@@ -158,23 +186,27 @@ static void parse_cmd_create(const char *next)
update = update_alloc();
- if ((next = parse_first_arg(next, &ref)) != NULL && ref.buf[0])
+ parse_first_arg(input, &next, &ref);
+ if (ref.buf[0])
update_store_ref_name(update, ref.buf);
else
die("create line missing <ref>");
- if ((next = parse_next_arg(next, &newvalue)) != NULL)
+ if (!parse_next_arg(input, &next, &newvalue))
update_store_new_sha1(update, newvalue.buf);
else
die("create %s missing <newvalue>", ref.buf);
+
if (is_null_sha1(update->new_sha1))
die("create %s given zero new value", ref.buf);
- if (next && *next)
+ if (*next != line_termination)
die("create %s has extra input: %s", ref.buf, next);
+
+ return next;
}
-static void parse_cmd_delete(const char *next)
+static const char *parse_cmd_delete(struct strbuf *input, const char *next)
{
struct strbuf ref = STRBUF_INIT;
struct strbuf oldvalue = STRBUF_INIT;
@@ -182,23 +214,26 @@ static void parse_cmd_delete(const char *next)
update = update_alloc();
- if ((next = parse_first_arg(next, &ref)) != NULL && ref.buf[0])
+ parse_first_arg(input, &next, &ref);
+ if (ref.buf[0])
update_store_ref_name(update, ref.buf);
else
die("delete line missing <ref>");
- if ((next = parse_next_arg(next, &oldvalue)) != NULL)
+ if (!parse_next_arg(input, &next, &oldvalue)) {
update_store_old_sha1(update, oldvalue.buf);
- else if(!line_termination)
+ if (update->have_old && is_null_sha1(update->old_sha1))
+ die("delete %s given zero old value", ref.buf);
+ } else if (!line_termination)
die("delete %s missing [<oldvalue>] NUL", ref.buf);
- if (update->have_old && is_null_sha1(update->old_sha1))
- die("delete %s given zero old value", ref.buf);
- if (next && *next)
+ if (*next != line_termination)
die("delete %s has extra input: %s", ref.buf, next);
+
+ return next;
}
-static void parse_cmd_verify(const char *next)
+static const char *parse_cmd_verify(struct strbuf *input, const char *next)
{
struct strbuf ref = STRBUF_INIT;
struct strbuf value = STRBUF_INIT;
@@ -206,53 +241,64 @@ static void parse_cmd_verify(const char *next)
update = update_alloc();
- if ((next = parse_first_arg(next, &ref)) != NULL && ref.buf[0])
+ parse_first_arg(input, &next, &ref);
+ if (ref.buf[0])
update_store_ref_name(update, ref.buf);
else
die("verify line missing <ref>");
- if ((next = parse_next_arg(next, &value)) != NULL) {
+ if (!parse_next_arg(input, &next, &value)) {
update_store_old_sha1(update, value.buf);
update_store_new_sha1(update, value.buf);
- } else if(!line_termination)
+ } else if (!line_termination)
die("verify %s missing [<oldvalue>] NUL", ref.buf);
- if (next && *next)
+ if (*next != line_termination)
die("verify %s has extra input: %s", ref.buf, next);
+
+ return next;
}
-static void parse_cmd_option(const char *next)
+static const char *parse_cmd_option(struct strbuf *input, const char *next)
{
- if (!strcmp(next, "no-deref"))
+ if (!strncmp(next, "no-deref", 8) && next[8] == line_termination)
update_flags |= REF_NODEREF;
else
die("option unknown: %s", next);
+ return next + 8;
}
static void update_refs_stdin(void)
{
- struct strbuf cmd = STRBUF_INIT;
+ struct strbuf input = STRBUF_INIT;
+ const char *next;
+ if (strbuf_read(&input, 0, 1000) < 0)
+ die_errno("could not read from stdin");
+ next = input.buf;
/* Read each line dispatch its command */
- while (strbuf_getline(&cmd, stdin, line_termination) != EOF)
- if (!cmd.buf[0])
+ while (next < input.buf + input.len) {
+ if (*next == line_termination)
die("empty command in input");
- else if (isspace(*cmd.buf))
- die("whitespace before command: %s", cmd.buf);
- else if (starts_with(cmd.buf, "update "))
- parse_cmd_update(cmd.buf + 7);
- else if (starts_with(cmd.buf, "create "))
- parse_cmd_create(cmd.buf + 7);
- else if (starts_with(cmd.buf, "delete "))
- parse_cmd_delete(cmd.buf + 7);
- else if (starts_with(cmd.buf, "verify "))
- parse_cmd_verify(cmd.buf + 7);
- else if (starts_with(cmd.buf, "option "))
- parse_cmd_option(cmd.buf + 7);
+ else if (isspace(*next))
+ die("whitespace before command: %s", next);
+ else if (starts_with(next, "update "))
+ next = parse_cmd_update(&input, next + 7);
+ else if (starts_with(next, "create "))
+ next = parse_cmd_create(&input, next + 7);
+ else if (starts_with(next, "delete "))
+ next = parse_cmd_delete(&input, next + 7);
+ else if (starts_with(next, "verify "))
+ next = parse_cmd_verify(&input, next + 7);
+ else if (starts_with(next, "option "))
+ next = parse_cmd_option(&input, next + 7);
else
- die("unknown command: %s", cmd.buf);
+ die("unknown command: %s", next);
+
+ next++;
+ }
- strbuf_release(&cmd);
+ strbuf_release(&input);
}
int cmd_update_ref(int argc, const char **argv, const char *prefix)
--
1.9.0
--
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