On 08/30/2013 08:12 PM, Brad King wrote:
> Add a --stdin signature to read update instructions from standard input
> and apply multiple ref updates together. Use an input format that
> supports any update that could be specified via the command-line,
> including object names like 'branch:path with space'.
>
> Signed-off-by: Brad King <brad.k...@kitware.com>
> ---
> Documentation/git-update-ref.txt | 21 ++++++-
> builtin/update-ref.c | 121
> +++++++++++++++++++++++++++++++++++++-
> 2 files changed, 140 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/git-update-ref.txt
> b/Documentation/git-update-ref.txt
> index 0df13ff..295d0bb 100644
> --- a/Documentation/git-update-ref.txt
> +++ b/Documentation/git-update-ref.txt
> @@ -8,7 +8,7 @@ git-update-ref - Update the object name stored in a ref safely
> SYNOPSIS
> --------
> [verse]
> -'git update-ref' [-m <reason>] (-d <ref> [<oldvalue>] | [--no-deref] <ref>
> <newvalue> [<oldvalue>])
> +'git update-ref' [-m <reason>] (-d <ref> [<oldvalue>] | [--no-deref] <ref>
> <newvalue> [<oldvalue>] | --stdin)
>
> DESCRIPTION
> -----------
> @@ -58,6 +58,25 @@ archive by creating a symlink tree).
> With `-d` flag, it deletes the named <ref> after verifying it
> still contains <oldvalue>.
>
> +With `--stdin`, update-ref reads instructions from standard input and
> +performs all modifications together. Empty lines are ignored.
> +Each non-empty line is parsed as whitespace-separated arguments.
> +Use single-quotes to enclose whitespace and backslashes and an
> +unquoted backslash to escape a single quote. Specify updates with
> +lines of the form:
> +
> + [--no-deref] [--] <ref> <newvalue> [<oldvalue>]
> +
> +Lines of any other format or a repeated <ref> produce an error.
> +Specify a zero <newvalue> to delete a ref and/or a zero <oldvalue>
> +to make sure that a ref not exist. Use either 40 "0" or the
> +empty string (written as '') to specify a zero value.
> +
> +If all <ref>s can be locked with matching <oldvalue>s
> +simultaneously all modifications are performed. Otherwise, no
Comma after "simultaneously".
> +modifications are performed. Note that while each individual
> +<ref> is updated or deleted atomically, a concurrent reader may
> +still see a subset of the modifications.
>
> Logging Updates
> ---------------
> diff --git a/builtin/update-ref.c b/builtin/update-ref.c
> index 51d2684..eb8db85 100644
> --- a/builtin/update-ref.c
> +++ b/builtin/update-ref.c
> @@ -6,19 +6,129 @@
> static const char * const git_update_ref_usage[] = {
> N_("git update-ref [options] -d <refname> [<oldval>]"),
> N_("git update-ref [options] <refname> <newval> [<oldval>]"),
> + N_("git update-ref [options] --stdin"),
> NULL
> };
>
> +static const char blank[] = " \t\r\n";
> +
> +static int updates_size;
> +static int updates_count;
> +static struct ref_update *updates;
> +
> +static const char* update_refs_stdin_next_arg(const char* next,
> + struct strbuf *arg)
> +{
> + /* Skip leading whitespace: */
> + while (isspace(*next))
> + ++next;
> +
> + /* Return NULL when no argument is found: */
> + if (!*next)
> + return NULL;
> +
> + /* Parse the argument: */
> + strbuf_reset(arg);
> + for (;;) {
> + char c = *next;
> + if (!c || isspace(c))
> + break;
> + ++next;
> + if (c == '\'') {
> + size_t len = strcspn(next, "'");
I agree with Junio that your quoting rules are peculiar.
> + if (!next[len])
> + die("unterminated single-quote: '%s", next);
> + strbuf_add(arg, next, len);
> + next += len + 1;
> + continue;
> + }
> + if (c == '\\') {
> + if (*next == '\'')
> + c = *next++;
> + else
> + die("unquoted backslash not escaping "
> + "single-quote: \\%s", next);
> + }
> + strbuf_addch(arg, c);
> + }
> + return next;
> +}
> +
> +static void update_refs_stdin(const char *line)
> +{
> + int options = 1, flags = 0, argc = 0;
> + char *argv[3] = {0, 0, 0};
> + struct strbuf arg = STRBUF_INIT;
> + struct ref_update *update;
> + const char *next = line;
> +
> + /* Skip blank lines: */
> + if (!line[0])
> + return;
> +
> + /* Parse arguments on this line: */
> + while ((next = update_refs_stdin_next_arg(next, &arg)) != NULL) {
> + if (options && arg.buf[0] == '-')
> + if (!strcmp(arg.buf, "--no-deref"))
> + flags |= REF_NODEREF;
> + else if (!strcmp(arg.buf, "--"))
> + options = 0;
> + else
> + die("unknown option %s", arg.buf);
> + else if (argc >= 3)
> + die("too many arguments on line: %s", line);
> + else {
> + argv[argc++] = xstrdup(arg.buf);
> + options = 0;
> + }
> + }
> + strbuf_release(&arg);
> +
> + /* Allocate and zero-init a struct ref_update: */
> + if (updates_count == updates_size) {
> + updates_size = updates_size ? (updates_size * 2) : 16;
> + updates = xrealloc(updates, sizeof(*updates) * updates_size);
> + memset(updates + updates_count, 0,
> + sizeof(*updates) * (updates_size - updates_count));
> + }
Here you can use ARRAY_GROW(). See
Documentation/technical/api-allocation-growing.txt
> + update = &updates[updates_count++];
> + update->flags = flags;
> +
> + /* Set the update ref_name: */
> + if (!argv[0])
> + die("no ref on line: %s", line);
> + if (check_refname_format(argv[0], REFNAME_ALLOW_ONELEVEL))
> + die("invalid ref format on line: %s", line);
> + update->ref_name = argv[0];
> + argv[0] = 0;
> +
> + /* Set the update new_sha1 and, if specified, old_sha1: */
> + if (!argv[1])
> + die("missing new value on line: %s", line);
> + if (*argv[1] && get_sha1(argv[1], update->new_sha1))
> + die("invalid new value on line: %s", line);
> + if (argv[2]) {
> + update->have_old = 1;
> + if (*argv[2] && get_sha1(argv[2], update->old_sha1))
> + die("invalid old value on line: %s", line);
> + }
> +
> + while (argc > 0)
> + free(argv[--argc]);
> +}
> +
> int cmd_update_ref(int argc, const char **argv, const char *prefix)
> {
> const char *refname, *oldval, *msg = NULL;
> unsigned char sha1[20], oldsha1[20];
> - int delete = 0, no_deref = 0, flags = 0;
> + int delete = 0, no_deref = 0, read_stdin = 0, flags = 0;
> + struct strbuf line = STRBUF_INIT;
> struct option options[] = {
> OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the
> update")),
> OPT_BOOLEAN('d', NULL, &delete, N_("delete the reference")),
> OPT_BOOLEAN( 0 , "no-deref", &no_deref,
> N_("update <refname> not the one it
> points to")),
> + OPT_BOOLEAN( 0 , "stdin", &read_stdin, N_("read updates from
> stdin")),
> OPT_END(),
> };
>
> @@ -28,6 +138,15 @@ int cmd_update_ref(int argc, const char **argv, const
> char *prefix)
> if (msg && !*msg)
> die("Refusing to perform update with empty message.");
>
> + if (read_stdin) {
> + if (delete || no_deref || argc > 0)
> + usage_with_options(git_update_ref_usage, options);
> + while (strbuf_getline(&line, stdin, '\n') != EOF)
> + update_refs_stdin(line.buf);
> + strbuf_release(&line);
> + return update_refs(msg, updates, updates_count, DIE_ON_ERR);
> + }
> +
> if (delete) {
> if (argc < 1 || argc > 2)
> usage_with_options(git_update_ref_usage, options);
>
--
Michael Haggerty
mhag...@alum.mit.edu
http://softwareswirl.blogspot.com/
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