diff options
| -rw-r--r-- | Documentation/git-update-ref.txt | 54 | ||||
| -rw-r--r-- | 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 0df13ff6f4..0a0a5512b3 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 51d2684859..894f16bc59 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); 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