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.king@xxxxxxxxxxx>
---
Documentation/git-update-ref.txt | 54 ++++++++-
builtin/update-ref.c | 252 ++++++++++++++++++++++++++++++++++++++-
2 files changed, 304 insertions(+), 2 deletions(-)
diff --git a/Documentation/git-update-ref.txt b/Documentation/git-update-ref.txt
index 0df13ff..0a0a551 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 [-z])
DESCRIPTION
-----------
@@ -58,6 +58,58 @@ 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. Specify commands of the form:
+
+ update SP <ref> SP <newvalue> [SP <oldvalue>] LF
+ create SP <ref> SP <newvalue> LF
+ delete SP <ref> [SP <oldvalue>] LF
+ verify SP <ref> [SP <oldvalue>] LF
+ option SP <opt> LF
+
+Quote fields containing whitespace as if they were strings in C source
+code. Alternatively, use `-z` to specify commands without quoting:
+
+ update SP <ref> NUL <newvalue> NUL [<oldvalue>] NUL
+ create SP <ref> NUL <newvalue> NUL
+ delete SP <ref> NUL [<oldvalue>] NUL
+ verify SP <ref> NUL [<oldvalue>] NUL
+ option SP <opt> NUL
+
+Lines of any other format or a repeated <ref> produce an error.
+Command meanings are:
+
+update::
+ Set <ref> to <newvalue> after verifying <oldvalue>, if given.
+ Specify a zero <newvalue> to ensure the ref does not exist
+ after the update and/or a zero <oldvalue> to make sure the
+ ref does not exist before the update.
+
+create::
+ Create <ref> with <newvalue> after verifying it does not
+ exist. The given <newvalue> may not be zero.
+
+delete::
+ Delete <ref> after verifying it exists with <oldvalue>, if
+ given. If given, <oldvalue> may not be zero.
+
+verify::
+ Verify <ref> against <oldvalue> but do not change it. If
+ <oldvalue> zero or missing, the ref must not exist.
+
+option::
+ Modify behavior of the next command naming a <ref>.
+ The only valid option is `no-deref` to avoid dereferencing
+ a symbolic ref.
+
+Use 40 "0" or the empty string to specify a zero value, except that
+with `-z` an empty <oldvalue> is considered missing.
+
+If all <ref>s can be locked with matching <oldvalue>s
+simultaneously, all modifications are performed. Otherwise, no
+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..894f16b 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -2,23 +2,261 @@
#include "refs.h"
#include "builtin.h"
#include "parse-options.h"
+#include "quote.h"
+#include "argv-array.h"
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 [-z]"),
NULL
};
+static int updates_alloc;
+static int updates_count;
+static const struct ref_update **updates;
+
+static char line_termination = '\n';
+static int update_flags;
+
+static struct ref_update *update_alloc(void)
+{
+ struct ref_update *update;
+
+ /* Allocate and zero-init a struct ref_update */
+ update = xcalloc(1, sizeof(*update));
+ ALLOC_GROW(updates, updates_count + 1, updates_alloc);
+ updates[updates_count++] = update;
+
+ /* Store and reset accumulated options */
+ update->flags = update_flags;
+ update_flags = 0;
+
+ return update;
+}
+
+static void update_store_ref_name(struct ref_update *update,
+ const char *ref_name)
+{
+ if (check_refname_format(ref_name, REFNAME_ALLOW_ONELEVEL))
+ die("invalid ref format: %s", ref_name);
+ update->ref_name = xstrdup(ref_name);
+}
+
+static void update_store_new_sha1(struct ref_update *update,
+ const char *newvalue)
+{
+ if (*newvalue && get_sha1(newvalue, update->new_sha1))
+ die("invalid new value for ref %s: %s",
+ update->ref_name, newvalue);
+}
+
+static void update_store_old_sha1(struct ref_update *update,
+ const char *oldvalue)
+{
+ if (*oldvalue && get_sha1(oldvalue, update->old_sha1))
+ die("invalid old value for ref %s: %s",
+ update->ref_name, oldvalue);
+
+ /* We have an old value if non-empty, or if empty without -z */
+ update->have_old = *oldvalue || line_termination;
+}
+
+static const char *parse_arg(const char *next, struct strbuf *arg)
+{
+ /* Parse SP-terminated, possibly C-quoted argument */
+ if (*next != '"')
+ while (*next && !isspace(*next))
+ strbuf_addch(arg, *next++);
+ else if (unquote_c_style(arg, next, &next))
+ die("badly quoted argument: %s", next);
+
+ /* Return position after the argument */
+ return next;
+}
+
+static const char *parse_first_arg(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);
+ } else {
+ /* With -z, use rest of first NUL-terminated line */
+ strbuf_addstr(arg, next);
+ next = next + arg->len;
+ }
+ return next;
+}
+
+static const char *parse_next_arg(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);
+ } 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;
+ }
+ return next;
+}
+
+static void parse_cmd_update(const char *next)
+{
+ struct strbuf ref = STRBUF_INIT;
+ struct strbuf newvalue = STRBUF_INIT;
+ struct strbuf oldvalue = STRBUF_INIT;
+ struct ref_update *update;
+
+ update = update_alloc();
+
+ if ((next = parse_first_arg(next, &ref)) != NULL && ref.buf[0])
+ update_store_ref_name(update, ref.buf);
+ else
+ die("update line missing <ref>");
+
+ if ((next = parse_next_arg(next, &newvalue)) != NULL)
+ update_store_new_sha1(update, newvalue.buf);
+ else
+ die("update %s missing <newvalue>", ref.buf);
+
+ if ((next = parse_next_arg(next, &oldvalue)) != NULL)
+ update_store_old_sha1(update, oldvalue.buf);
+ 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);
+}
+
+static void parse_cmd_create(const char *next)
+{
+ struct strbuf ref = STRBUF_INIT;
+ struct strbuf newvalue = STRBUF_INIT;
+ struct ref_update *update;
+
+ update = update_alloc();
+
+ if ((next = parse_first_arg(next, &ref)) != NULL && ref.buf[0])
+ update_store_ref_name(update, ref.buf);
+ else
+ die("create line missing <ref>");
+
+ if ((next = parse_next_arg(next, &newvalue)) != NULL)
+ 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)
+ die("create %s has extra input: %s", ref.buf, next);
+}
+
+static void parse_cmd_delete(const char *next)
+{
+ struct strbuf ref = STRBUF_INIT;
+ struct strbuf oldvalue = STRBUF_INIT;
+ struct ref_update *update;
+
+ update = update_alloc();
+
+ if ((next = parse_first_arg(next, &ref)) != NULL && ref.buf[0])
+ update_store_ref_name(update, ref.buf);
+ else
+ die("delete line missing <ref>");
+
+ if ((next = parse_next_arg(next, &oldvalue)) != NULL)
+ update_store_old_sha1(update, oldvalue.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)
+ die("delete %s has extra input: %s", ref.buf, next);
+}
+
+static void parse_cmd_verify(const char *next)
+{
+ struct strbuf ref = STRBUF_INIT;
+ struct strbuf value = STRBUF_INIT;
+ struct ref_update *update;
+
+ update = update_alloc();
+
+ if ((next = parse_first_arg(next, &ref)) != NULL && ref.buf[0])
+ update_store_ref_name(update, ref.buf);
+ else
+ die("verify line missing <ref>");
+
+ if ((next = parse_next_arg(next, &value)) != NULL) {
+ update_store_old_sha1(update, value.buf);
+ update_store_new_sha1(update, value.buf);
+ } else if(!line_termination)
+ die("verify %s missing [<oldvalue>] NUL", ref.buf);
+
+ if (next && *next)
+ die("verify %s has extra input: %s", ref.buf, next);
+}
+
+static void parse_cmd_option(const char *next)
+{
+ if (!strcmp(next, "no-deref"))
+ update_flags |= REF_NODEREF;
+ else
+ die("option unknown: %s", next);
+}
+
+static void update_refs_stdin(void)
+{
+ struct strbuf cmd = STRBUF_INIT;
+
+ /* Read each line dispatch its command */
+ while (strbuf_getline(&cmd, stdin, line_termination) != EOF)
+ if (!cmd.buf[0])
+ die("empty command in input");
+ else if (isspace(*cmd.buf))
+ die("whitespace before command: %s", cmd.buf);
+ else if (!prefixcmp(cmd.buf, "update "))
+ parse_cmd_update(cmd.buf + 7);
+ else if (!prefixcmp(cmd.buf, "create "))
+ parse_cmd_create(cmd.buf + 7);
+ else if (!prefixcmp(cmd.buf, "delete "))
+ parse_cmd_delete(cmd.buf + 7);
+ else if (!prefixcmp(cmd.buf, "verify "))
+ parse_cmd_verify(cmd.buf + 7);
+ else if (!prefixcmp(cmd.buf, "option "))
+ parse_cmd_option(cmd.buf + 7);
+ else
+ die("unknown command: %s", cmd.buf);
+
+ strbuf_release(&cmd);
+}
+
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, end_null = 0, flags = 0;
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('z', NULL, &end_null, N_("stdin has NUL-terminated arguments")),
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 +266,18 @@ 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);
+ if (end_null)
+ line_termination = '\0';
+ update_refs_stdin();
+ return update_refs(msg, updates, updates_count, DIE_ON_ERR);
+ }
+
+ if (end_null)
+ usage_with_options(git_update_ref_usage, options);
+
if (delete) {
if (argc < 1 || argc > 2)
usage_with_options(git_update_ref_usage, options);
--
1.8.4.rc3
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