From a65b8ac291d919c8f0c89f7397e03662020344ab Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Thu, 2 Apr 2020 09:09:38 +0200 Subject: update-ref: organize commands in an array 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 Signed-off-by: Junio C Hamano --- builtin/update-ref.c | 41 +++++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 12 deletions(-) (limited to 'builtin') diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 2d8f7f0578..a6ff88b95b 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -310,7 +310,8 @@ 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, "no-deref", &rest) && *rest == line_termination) @@ -320,33 +321,49 @@ 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) || + !skip_prefix(next, " ", &next)) + continue; + + cmd = &command[i]; + break; + } + if (!cmd) die("unknown command: %s", next); + next = cmd->fn(transaction, &input, next); next++; } -- cgit v1.2.3 From 5ae6c5a7129a55e69d39cfb70c78bb5b92bbccb7 Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Thu, 2 Apr 2020 09:09:43 +0200 Subject: update-ref: drop unused argument for `parse_refname` The `parse_refname` function accepts a `struct strbuf *input` argument that isn't used at all. As we're about to convert commands to not use a strbuf anymore but instead an end pointer, let's drop this argument now to make the converting commit easier to review. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/update-ref.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'builtin') diff --git a/builtin/update-ref.c b/builtin/update-ref.c index a6ff88b95b..1bba5ea6c2 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -50,7 +50,7 @@ static const char *parse_arg(const char *next, struct strbuf *arg) * the argument. Die if C-quoting is malformed or the reference name * is invalid. */ -static char *parse_refname(struct strbuf *input, const char **next) +static char *parse_refname(const char **next) { struct strbuf ref = STRBUF_INIT; @@ -186,7 +186,7 @@ static const char *parse_cmd_update(struct ref_transaction *transaction, struct object_id new_oid, old_oid; int have_old; - refname = parse_refname(input, &next); + refname = parse_refname(&next); if (!refname) die("update: missing "); @@ -220,7 +220,7 @@ static const char *parse_cmd_create(struct ref_transaction *transaction, char *refname; struct object_id new_oid; - refname = parse_refname(input, &next); + refname = parse_refname(&next); if (!refname) die("create: missing "); @@ -253,7 +253,7 @@ static const char *parse_cmd_delete(struct ref_transaction *transaction, struct object_id old_oid; int have_old; - refname = parse_refname(input, &next); + refname = parse_refname(&next); if (!refname) die("delete: missing "); @@ -288,7 +288,7 @@ static const char *parse_cmd_verify(struct ref_transaction *transaction, char *refname; struct object_id old_oid; - refname = parse_refname(input, &next); + refname = parse_refname(&next); if (!refname) die("verify: missing "); -- cgit v1.2.3 From 804dba54f5abdb35b5d15eed63625581c82697fb Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Thu, 2 Apr 2020 09:09:48 +0200 Subject: update-ref: pass end pointer instead of strbuf We currently pass both an `strbuf` containing the current command line as well as the `next` pointer pointing to the first argument to commands. This is both confusing and makes code more intertwined. Convert this to use a simple pointer as well as a pointer pointing to the end of the input as a preparatory step to line-wise reading of stdin. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/update-ref.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'builtin') diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 1bba5ea6c2..381d347fb4 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -95,7 +95,7 @@ static char *parse_refname(const char **next) * provided but cannot be converted to a SHA-1, die. flags can * include PARSE_SHA1_OLD and/or PARSE_SHA1_ALLOW_EMPTY. */ -static int parse_next_oid(struct strbuf *input, const char **next, +static int parse_next_oid(const char **next, const char *end, struct object_id *oid, const char *command, const char *refname, int flags) @@ -103,7 +103,7 @@ static int parse_next_oid(struct strbuf *input, const char **next, struct strbuf arg = STRBUF_INIT; int ret = 0; - if (*next == input->buf + input->len) + if (*next == end) goto eof; if (line_termination) { @@ -128,7 +128,7 @@ static int parse_next_oid(struct strbuf *input, const char **next, die("%s %s: expected NUL but got: %s", command, refname, *next); (*next)++; - if (*next == input->buf + input->len) + if (*next == end) goto eof; strbuf_addstr(&arg, *next); *next += arg.len; @@ -179,7 +179,7 @@ static int parse_next_oid(struct strbuf *input, const char **next, */ static const char *parse_cmd_update(struct ref_transaction *transaction, - struct strbuf *input, const char *next) + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -190,11 +190,11 @@ static const char *parse_cmd_update(struct ref_transaction *transaction, if (!refname) die("update: missing "); - if (parse_next_oid(input, &next, &new_oid, "update", refname, + if (parse_next_oid(&next, end, &new_oid, "update", refname, PARSE_SHA1_ALLOW_EMPTY)) die("update %s: missing ", refname); - have_old = !parse_next_oid(input, &next, &old_oid, "update", refname, + have_old = !parse_next_oid(&next, end, &old_oid, "update", refname, PARSE_SHA1_OLD); if (*next != line_termination) @@ -214,7 +214,7 @@ static const char *parse_cmd_update(struct ref_transaction *transaction, } static const char *parse_cmd_create(struct ref_transaction *transaction, - struct strbuf *input, const char *next) + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -224,7 +224,7 @@ static const char *parse_cmd_create(struct ref_transaction *transaction, if (!refname) die("create: missing "); - if (parse_next_oid(input, &next, &new_oid, "create", refname, 0)) + if (parse_next_oid(&next, end, &new_oid, "create", refname, 0)) die("create %s: missing ", refname); if (is_null_oid(&new_oid)) @@ -246,7 +246,7 @@ static const char *parse_cmd_create(struct ref_transaction *transaction, } static const char *parse_cmd_delete(struct ref_transaction *transaction, - struct strbuf *input, const char *next) + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -257,7 +257,7 @@ static const char *parse_cmd_delete(struct ref_transaction *transaction, if (!refname) die("delete: missing "); - if (parse_next_oid(input, &next, &old_oid, "delete", refname, + if (parse_next_oid(&next, end, &old_oid, "delete", refname, PARSE_SHA1_OLD)) { have_old = 0; } else { @@ -282,7 +282,7 @@ static const char *parse_cmd_delete(struct ref_transaction *transaction, } static const char *parse_cmd_verify(struct ref_transaction *transaction, - struct strbuf *input, const char *next) + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -292,7 +292,7 @@ static const char *parse_cmd_verify(struct ref_transaction *transaction, if (!refname) die("verify: missing "); - if (parse_next_oid(input, &next, &old_oid, "verify", refname, + if (parse_next_oid(&next, end, &old_oid, "verify", refname, PARSE_SHA1_OLD)) oidclr(&old_oid); @@ -311,7 +311,7 @@ static const char *parse_cmd_verify(struct ref_transaction *transaction, } static const char *parse_cmd_option(struct ref_transaction *transaction, - struct strbuf *input, const char *next) + const char *next, const char *end) { const char *rest; if (skip_prefix(next, "no-deref", &rest) && *rest == line_termination) @@ -323,7 +323,7 @@ static const char *parse_cmd_option(struct ref_transaction *transaction, static const struct parse_cmd { const char *prefix; - const char *(*fn)(struct ref_transaction *, struct strbuf *, const char *); + const char *(*fn)(struct ref_transaction *, const char *, const char *); } command[] = { { "update", parse_cmd_update }, { "create", parse_cmd_create }, @@ -363,7 +363,7 @@ static void update_refs_stdin(struct ref_transaction *transaction) if (!cmd) die("unknown command: %s", next); - next = cmd->fn(transaction, &input, next); + next = cmd->fn(transaction, next, input.buf + input.len); next++; } -- cgit v1.2.3 From de0e0d650a1c2afc81a4c5e8d37d266ffa2b8ccf Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Thu, 2 Apr 2020 09:09:53 +0200 Subject: update-ref: move transaction handling into `update_refs_stdin()` While the actual logic to update the transaction is handled in `update_refs_stdin()`, the transaction itself is started and committed in `cmd_update_ref()` itself. This makes it hard to handle transaction abortion and commits as part of `update_refs_stdin()` itself, which is required in order to introduce transaction handling features to `git update-refs --stdin`. Refactor the code to move all transaction handling into `update_refs_stdin()` to prepare for transaction handling features. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/update-ref.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) (limited to 'builtin') diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 381d347fb4..0f34b68904 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -332,15 +332,21 @@ static const struct parse_cmd { { "option", parse_cmd_option }, }; -static void update_refs_stdin(struct ref_transaction *transaction) +static void update_refs_stdin(void) { - struct strbuf input = STRBUF_INIT; + struct strbuf input = STRBUF_INIT, err = STRBUF_INIT; + struct ref_transaction *transaction; const char *next; int i; if (strbuf_read(&input, 0, 1000) < 0) die_errno("could not read from stdin"); next = input.buf; + + transaction = ref_transaction_begin(&err); + if (!transaction) + die("%s", err.buf); + /* Read each line dispatch its command */ while (next < input.buf + input.len) { const struct parse_cmd *cmd = NULL; @@ -367,6 +373,11 @@ static void update_refs_stdin(struct ref_transaction *transaction) next++; } + if (ref_transaction_commit(transaction, &err)) + die("%s", err.buf); + + ref_transaction_free(transaction); + strbuf_release(&err); strbuf_release(&input); } @@ -401,21 +412,11 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix) } if (read_stdin) { - struct strbuf err = STRBUF_INIT; - struct ref_transaction *transaction; - - transaction = ref_transaction_begin(&err); - if (!transaction) - die("%s", err.buf); if (delete || argc > 0) usage_with_options(git_update_ref_usage, options); if (end_null) line_termination = '\0'; - update_refs_stdin(transaction); - if (ref_transaction_commit(transaction, &err)) - die("%s", err.buf); - ref_transaction_free(transaction); - strbuf_release(&err); + update_refs_stdin(); return 0; } -- cgit v1.2.3 From 94fd491a54b955990146f63e7283e9813dc85fef Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Thu, 2 Apr 2020 09:09:57 +0200 Subject: update-ref: read commands in a line-wise fashion The git-update-ref(1) supports a `--stdin` mode that allows it to read all reference updates from standard input. This is mainly used to allow for atomic reference updates that are all or nothing, so that either all references will get updated or none. Currently, git-update-ref(1) reads all commands as a single block of up to 1000 characters and only starts processing after stdin gets closed. This is less flexible than one might wish for, as it doesn't really allow for longer-lived transactions and doesn't allow any verification without committing everything. E.g. one may imagine the following exchange: > start < start: ok > update refs/heads/master $NEWOID1 $OLDOID1 > update refs/heads/branch $NEWOID2 $OLDOID2 > prepare < prepare: ok > commit < commit: ok When reading all input as a whole block, the above interactive protocol is obviously impossible to achieve. But by converting the command to read commands linewise, we can make it more interactive than before. Obviously, the linewise interface is only a first step in making git-update-ref(1) work in a more transaction-oriented way. Missing is most importantly support for transactional commands that manage the current transaction. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/update-ref.c | 85 +++++++++++++++++++++++++++------------------------- 1 file changed, 45 insertions(+), 40 deletions(-) (limited to 'builtin') diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 0f34b68904..348407b896 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -178,8 +178,8 @@ static int parse_next_oid(const char **next, const char *end, * depending on how line_termination is set. */ -static const char *parse_cmd_update(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_update(struct ref_transaction *transaction, + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -209,12 +209,10 @@ static const char *parse_cmd_update(struct ref_transaction *transaction, update_flags = default_flags; free(refname); strbuf_release(&err); - - return next; } -static const char *parse_cmd_create(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_create(struct ref_transaction *transaction, + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -241,12 +239,10 @@ static const char *parse_cmd_create(struct ref_transaction *transaction, update_flags = default_flags; free(refname); strbuf_release(&err); - - return next; } -static const char *parse_cmd_delete(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_delete(struct ref_transaction *transaction, + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -277,12 +273,10 @@ static const char *parse_cmd_delete(struct ref_transaction *transaction, update_flags = default_flags; free(refname); strbuf_release(&err); - - return next; } -static const char *parse_cmd_verify(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_verify(struct ref_transaction *transaction, + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -306,71 +300,82 @@ static const char *parse_cmd_verify(struct ref_transaction *transaction, update_flags = default_flags; free(refname); strbuf_release(&err); - - return next; } -static const char *parse_cmd_option(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_option(struct ref_transaction *transaction, + const char *next, const char *end) { const char *rest; if (skip_prefix(next, "no-deref", &rest) && *rest == line_termination) update_flags |= REF_NO_DEREF; else die("option unknown: %s", next); - return rest; } static const struct parse_cmd { const char *prefix; - const char *(*fn)(struct ref_transaction *, const char *, const char *); + void (*fn)(struct ref_transaction *, const char *, const char *); + unsigned args; } command[] = { - { "update", parse_cmd_update }, - { "create", parse_cmd_create }, - { "delete", parse_cmd_delete }, - { "verify", parse_cmd_verify }, - { "option", parse_cmd_option }, + { "update", parse_cmd_update, 3 }, + { "create", parse_cmd_create, 2 }, + { "delete", parse_cmd_delete, 2 }, + { "verify", parse_cmd_verify, 2 }, + { "option", parse_cmd_option, 1 }, }; static void update_refs_stdin(void) { struct strbuf input = STRBUF_INIT, err = STRBUF_INIT; struct ref_transaction *transaction; - const char *next; - int i; - - if (strbuf_read(&input, 0, 1000) < 0) - die_errno("could not read from stdin"); - next = input.buf; + int i, j; transaction = ref_transaction_begin(&err); if (!transaction) die("%s", err.buf); /* Read each line dispatch its command */ - while (next < input.buf + input.len) { + while (!strbuf_getwholeline(&input, stdin, line_termination)) { const struct parse_cmd *cmd = NULL; - if (*next == line_termination) + if (*input.buf == line_termination) die("empty command in input"); - else if (isspace(*next)) - die("whitespace before command: %s", next); + else if (isspace(*input.buf)) + die("whitespace before command: %s", input.buf); for (i = 0; i < ARRAY_SIZE(command); i++) { const char *prefix = command[i].prefix; + char c; + + if (!starts_with(input.buf, prefix)) + continue; - if (!skip_prefix(next, prefix, &next) || - !skip_prefix(next, " ", &next)) + /* + * If the command has arguments, verify that it's + * followed by a space. Otherwise, it shall be followed + * by a line terminator. + */ + c = command[i].args ? ' ' : line_termination; + if (input.buf[strlen(prefix)] != c) continue; cmd = &command[i]; break; } if (!cmd) - die("unknown command: %s", next); + die("unknown command: %s", input.buf); + + /* + * Read additional arguments if NUL-terminated. Do not raise an + * error in case there is an early EOF to let the command + * handle missing arguments with a proper error message. + */ + for (j = 1; line_termination == '\0' && j < cmd->args; j++) + if (strbuf_appendwholeline(&input, stdin, line_termination)) + break; - next = cmd->fn(transaction, next, input.buf + input.len); - next++; + cmd->fn(transaction, input.buf + strlen(cmd->prefix) + !!cmd->args, + input.buf + input.len); } if (ref_transaction_commit(transaction, &err)) -- cgit v1.2.3 From e48cf33b61b8fecf1558fb32fcf5ee2987e82890 Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Thu, 2 Apr 2020 09:10:02 +0200 Subject: update-ref: implement interactive transaction handling The git-update-ref(1) command can only handle queueing transactions right now via its "--stdin" parameter, but there is no way for users to handle the transaction itself in a more explicit way. E.g. in a replicated scenario, one may imagine a coordinator that spawns git-update-ref(1) for multiple repositories and only if all agree that an update is possible will the coordinator send a commit. Such a transactional session could look like > start < start: ok > update refs/heads/master $OLD $NEW > prepare < prepare: ok # All nodes have returned "ok" > commit < commit: ok or > start < start: ok > create refs/heads/master $OLD $NEW > prepare < fatal: cannot lock ref 'refs/heads/master': reference already exists # On all other nodes: > abort < abort: ok In order to allow for such transactional sessions, this commit introduces four new commands for git-update-ref(1), which matches those we have internally already with the exception of "start": - start: start a new transaction - prepare: prepare the transaction, that is try to lock all references and verify their current value matches the expected one - commit: explicitly commit a session, that is update references to match their new expected state - abort: abort a session and roll back all changes By design, git-update-ref(1) will commit as soon as standard input is being closed. While fine in a non-transactional world, it is definitely unexpected in a transactional world. Because of this, as soon as any of the new transactional commands is used, the default will change to aborting without an explicit "commit". To avoid a race between queueing updates and the first "prepare" that starts a transaction, the "start" command has been added to start an explicit transaction. Add some tests to exercise this new functionality. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/update-ref.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 98 insertions(+), 8 deletions(-) (limited to 'builtin') diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 348407b896..b74dd9a69d 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -312,21 +312,80 @@ static void parse_cmd_option(struct ref_transaction *transaction, die("option unknown: %s", next); } +static void parse_cmd_start(struct ref_transaction *transaction, + const char *next, const char *end) +{ + if (*next != line_termination) + die("start: extra input: %s", next); + puts("start: ok"); +} + +static void parse_cmd_prepare(struct ref_transaction *transaction, + const char *next, const char *end) +{ + struct strbuf error = STRBUF_INIT; + if (*next != line_termination) + die("prepare: extra input: %s", next); + if (ref_transaction_prepare(transaction, &error)) + die("prepare: %s", error.buf); + puts("prepare: ok"); +} + +static void parse_cmd_abort(struct ref_transaction *transaction, + const char *next, const char *end) +{ + struct strbuf error = STRBUF_INIT; + if (*next != line_termination) + die("abort: extra input: %s", next); + if (ref_transaction_abort(transaction, &error)) + die("abort: %s", error.buf); + puts("abort: ok"); +} + +static void parse_cmd_commit(struct ref_transaction *transaction, + const char *next, const char *end) +{ + struct strbuf error = STRBUF_INIT; + if (*next != line_termination) + die("commit: extra input: %s", next); + if (ref_transaction_commit(transaction, &error)) + die("commit: %s", error.buf); + puts("commit: ok"); + ref_transaction_free(transaction); +} + +enum update_refs_state { + /* Non-transactional state open for updates. */ + UPDATE_REFS_OPEN, + /* A transaction has been started. */ + UPDATE_REFS_STARTED, + /* References are locked and ready for commit */ + UPDATE_REFS_PREPARED, + /* Transaction has been committed or closed. */ + UPDATE_REFS_CLOSED, +}; + static const struct parse_cmd { const char *prefix; void (*fn)(struct ref_transaction *, const char *, const char *); unsigned args; + enum update_refs_state state; } command[] = { - { "update", parse_cmd_update, 3 }, - { "create", parse_cmd_create, 2 }, - { "delete", parse_cmd_delete, 2 }, - { "verify", parse_cmd_verify, 2 }, - { "option", parse_cmd_option, 1 }, + { "update", parse_cmd_update, 3, UPDATE_REFS_OPEN }, + { "create", parse_cmd_create, 2, UPDATE_REFS_OPEN }, + { "delete", parse_cmd_delete, 2, UPDATE_REFS_OPEN }, + { "verify", parse_cmd_verify, 2, UPDATE_REFS_OPEN }, + { "option", parse_cmd_option, 1, UPDATE_REFS_OPEN }, + { "start", parse_cmd_start, 0, UPDATE_REFS_STARTED }, + { "prepare", parse_cmd_prepare, 0, UPDATE_REFS_PREPARED }, + { "abort", parse_cmd_abort, 0, UPDATE_REFS_CLOSED }, + { "commit", parse_cmd_commit, 0, UPDATE_REFS_CLOSED }, }; static void update_refs_stdin(void) { struct strbuf input = STRBUF_INIT, err = STRBUF_INIT; + enum update_refs_state state = UPDATE_REFS_OPEN; struct ref_transaction *transaction; int i, j; @@ -374,14 +433,45 @@ static void update_refs_stdin(void) if (strbuf_appendwholeline(&input, stdin, line_termination)) break; + switch (state) { + case UPDATE_REFS_OPEN: + case UPDATE_REFS_STARTED: + /* Do not downgrade a transaction to a non-transaction. */ + if (cmd->state >= state) + state = cmd->state; + break; + case UPDATE_REFS_PREPARED: + if (cmd->state != UPDATE_REFS_CLOSED) + die("prepared transactions can only be closed"); + state = cmd->state; + break; + case UPDATE_REFS_CLOSED: + die("transaction is closed"); + break; + } + cmd->fn(transaction, input.buf + strlen(cmd->prefix) + !!cmd->args, input.buf + input.len); } - if (ref_transaction_commit(transaction, &err)) - die("%s", err.buf); + switch (state) { + case UPDATE_REFS_OPEN: + /* Commit by default if no transaction was requested. */ + if (ref_transaction_commit(transaction, &err)) + die("%s", err.buf); + ref_transaction_free(transaction); + break; + case UPDATE_REFS_STARTED: + case UPDATE_REFS_PREPARED: + /* If using a transaction, we want to abort it. */ + if (ref_transaction_abort(transaction, &err)) + die("%s", err.buf); + break; + case UPDATE_REFS_CLOSED: + /* Otherwise no need to do anything, the transaction was closed already. */ + break; + } - ref_transaction_free(transaction); strbuf_release(&err); strbuf_release(&input); } -- cgit v1.2.3