git/builtin/replace.c
Ronnie Sahlberg 867c2fac0a replace.c: use the ref transaction functions for updates
Update replace.c to use ref transactions for updates.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-03 10:04:10 -07:00

363 lines
9.6 KiB
C

/*
* Builtin "git replace"
*
* Copyright (c) 2008 Christian Couder <chriscool@tuxfamily.org>
*
* Based on builtin/tag.c by Kristian Høgsberg <krh@redhat.com>
* and Carlos Rica <jasampler@gmail.com> that was itself based on
* git-tag.sh and mktag.c by Linus Torvalds.
*/
#include "cache.h"
#include "builtin.h"
#include "refs.h"
#include "parse-options.h"
#include "run-command.h"
static const char * const git_replace_usage[] = {
N_("git replace [-f] <object> <replacement>"),
N_("git replace [-f] --edit <object>"),
N_("git replace -d <object>..."),
N_("git replace [--format=<format>] [-l [<pattern>]]"),
NULL
};
enum replace_format {
REPLACE_FORMAT_SHORT,
REPLACE_FORMAT_MEDIUM,
REPLACE_FORMAT_LONG
};
struct show_data {
const char *pattern;
enum replace_format format;
};
static int show_reference(const char *refname, const unsigned char *sha1,
int flag, void *cb_data)
{
struct show_data *data = cb_data;
if (!wildmatch(data->pattern, refname, 0, NULL)) {
if (data->format == REPLACE_FORMAT_SHORT)
printf("%s\n", refname);
else if (data->format == REPLACE_FORMAT_MEDIUM)
printf("%s -> %s\n", refname, sha1_to_hex(sha1));
else { /* data->format == REPLACE_FORMAT_LONG */
unsigned char object[20];
enum object_type obj_type, repl_type;
if (get_sha1(refname, object))
return error("Failed to resolve '%s' as a valid ref.", refname);
obj_type = sha1_object_info(object, NULL);
repl_type = sha1_object_info(sha1, NULL);
printf("%s (%s) -> %s (%s)\n", refname, typename(obj_type),
sha1_to_hex(sha1), typename(repl_type));
}
}
return 0;
}
static int list_replace_refs(const char *pattern, const char *format)
{
struct show_data data;
if (pattern == NULL)
pattern = "*";
data.pattern = pattern;
if (format == NULL || *format == '\0' || !strcmp(format, "short"))
data.format = REPLACE_FORMAT_SHORT;
else if (!strcmp(format, "medium"))
data.format = REPLACE_FORMAT_MEDIUM;
else if (!strcmp(format, "long"))
data.format = REPLACE_FORMAT_LONG;
else
die("invalid replace format '%s'\n"
"valid formats are 'short', 'medium' and 'long'\n",
format);
for_each_replace_ref(show_reference, (void *) &data);
return 0;
}
typedef int (*each_replace_name_fn)(const char *name, const char *ref,
const unsigned char *sha1);
static int for_each_replace_name(const char **argv, each_replace_name_fn fn)
{
const char **p, *full_hex;
char ref[PATH_MAX];
int had_error = 0;
unsigned char sha1[20];
for (p = argv; *p; p++) {
if (get_sha1(*p, sha1)) {
error("Failed to resolve '%s' as a valid ref.", *p);
had_error = 1;
continue;
}
full_hex = sha1_to_hex(sha1);
snprintf(ref, sizeof(ref), "refs/replace/%s", full_hex);
/* read_ref() may reuse the buffer */
full_hex = ref + strlen("refs/replace/");
if (read_ref(ref, sha1)) {
error("replace ref '%s' not found.", full_hex);
had_error = 1;
continue;
}
if (fn(full_hex, ref, sha1))
had_error = 1;
}
return had_error;
}
static int delete_replace_ref(const char *name, const char *ref,
const unsigned char *sha1)
{
if (delete_ref(ref, sha1, 0))
return 1;
printf("Deleted replace ref '%s'\n", name);
return 0;
}
static void check_ref_valid(unsigned char object[20],
unsigned char prev[20],
char *ref,
int ref_size,
int force)
{
if (snprintf(ref, ref_size,
"refs/replace/%s",
sha1_to_hex(object)) > ref_size - 1)
die("replace ref name too long: %.*s...", 50, ref);
if (check_refname_format(ref, 0))
die("'%s' is not a valid ref name.", ref);
if (read_ref(ref, prev))
hashclr(prev);
else if (!force)
die("replace ref '%s' already exists", ref);
}
static int replace_object_sha1(const char *object_ref,
unsigned char object[20],
const char *replace_ref,
unsigned char repl[20],
int force)
{
unsigned char prev[20];
enum object_type obj_type, repl_type;
char ref[PATH_MAX];
struct ref_transaction *transaction;
struct strbuf err = STRBUF_INIT;
obj_type = sha1_object_info(object, NULL);
repl_type = sha1_object_info(repl, NULL);
if (!force && obj_type != repl_type)
die("Objects must be of the same type.\n"
"'%s' points to a replaced object of type '%s'\n"
"while '%s' points to a replacement object of type '%s'.",
object_ref, typename(obj_type),
replace_ref, typename(repl_type));
check_ref_valid(object, prev, ref, sizeof(ref), force);
transaction = ref_transaction_begin(&err);
if (!transaction ||
ref_transaction_update(transaction, ref, repl, prev, 0, 1, &err) ||
ref_transaction_commit(transaction, NULL, &err))
die("%s", err.buf);
ref_transaction_free(transaction);
return 0;
}
static int replace_object(const char *object_ref, const char *replace_ref, int force)
{
unsigned char object[20], repl[20];
if (get_sha1(object_ref, object))
die("Failed to resolve '%s' as a valid ref.", object_ref);
if (get_sha1(replace_ref, repl))
die("Failed to resolve '%s' as a valid ref.", replace_ref);
return replace_object_sha1(object_ref, object, replace_ref, repl, force);
}
/*
* Write the contents of the object named by "sha1" to the file "filename",
* pretty-printed for human editing based on its type.
*/
static void export_object(const unsigned char *sha1, const char *filename)
{
const char *argv[] = { "--no-replace-objects", "cat-file", "-p", NULL, NULL };
struct child_process cmd = { argv };
int fd;
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666);
if (fd < 0)
die_errno("unable to open %s for writing", filename);
argv[3] = sha1_to_hex(sha1);
cmd.git_cmd = 1;
cmd.out = fd;
if (run_command(&cmd))
die("cat-file reported failure");
close(fd);
}
/*
* Read a previously-exported (and possibly edited) object back from "filename",
* interpreting it as "type", and writing the result to the object database.
* The sha1 of the written object is returned via sha1.
*/
static void import_object(unsigned char *sha1, enum object_type type,
const char *filename)
{
int fd;
fd = open(filename, O_RDONLY);
if (fd < 0)
die_errno("unable to open %s for reading", filename);
if (type == OBJ_TREE) {
const char *argv[] = { "mktree", NULL };
struct child_process cmd = { argv };
struct strbuf result = STRBUF_INIT;
cmd.argv = argv;
cmd.git_cmd = 1;
cmd.in = fd;
cmd.out = -1;
if (start_command(&cmd))
die("unable to spawn mktree");
if (strbuf_read(&result, cmd.out, 41) < 0)
die_errno("unable to read from mktree");
close(cmd.out);
if (finish_command(&cmd))
die("mktree reported failure");
if (get_sha1_hex(result.buf, sha1) < 0)
die("mktree did not return an object name");
strbuf_release(&result);
} else {
struct stat st;
int flags = HASH_FORMAT_CHECK | HASH_WRITE_OBJECT;
if (fstat(fd, &st) < 0)
die_errno("unable to fstat %s", filename);
if (index_fd(sha1, fd, &st, type, NULL, flags) < 0)
die("unable to write object to database");
/* index_fd close()s fd for us */
}
/*
* No need to close(fd) here; both run-command and index-fd
* will have done it for us.
*/
}
static int edit_and_replace(const char *object_ref, int force)
{
char *tmpfile = git_pathdup("REPLACE_EDITOBJ");
enum object_type type;
unsigned char old[20], new[20], prev[20];
char ref[PATH_MAX];
if (get_sha1(object_ref, old) < 0)
die("Not a valid object name: '%s'", object_ref);
type = sha1_object_info(old, NULL);
if (type < 0)
die("unable to get object type for %s", sha1_to_hex(old));
check_ref_valid(old, prev, ref, sizeof(ref), force);
export_object(old, tmpfile);
if (launch_editor(tmpfile, NULL, NULL) < 0)
die("editing object file failed");
import_object(new, type, tmpfile);
free(tmpfile);
if (!hashcmp(old, new))
return error("new object is the same as the old one: '%s'", sha1_to_hex(old));
return replace_object_sha1(object_ref, old, "replacement", new, force);
}
int cmd_replace(int argc, const char **argv, const char *prefix)
{
int force = 0;
const char *format = NULL;
enum {
MODE_UNSPECIFIED = 0,
MODE_LIST,
MODE_DELETE,
MODE_EDIT,
MODE_REPLACE
} cmdmode = MODE_UNSPECIFIED;
struct option options[] = {
OPT_CMDMODE('l', "list", &cmdmode, N_("list replace refs"), MODE_LIST),
OPT_CMDMODE('d', "delete", &cmdmode, N_("delete replace refs"), MODE_DELETE),
OPT_CMDMODE('e', "edit", &cmdmode, N_("edit existing object"), MODE_EDIT),
OPT_BOOL('f', "force", &force, N_("replace the ref if it exists")),
OPT_STRING(0, "format", &format, N_("format"), N_("use this format")),
OPT_END()
};
check_replace_refs = 0;
argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
if (!cmdmode)
cmdmode = argc ? MODE_REPLACE : MODE_LIST;
if (format && cmdmode != MODE_LIST)
usage_msg_opt("--format cannot be used when not listing",
git_replace_usage, options);
if (force && cmdmode != MODE_REPLACE && cmdmode != MODE_EDIT)
usage_msg_opt("-f only makes sense when writing a replacement",
git_replace_usage, options);
switch (cmdmode) {
case MODE_DELETE:
if (argc < 1)
usage_msg_opt("-d needs at least one argument",
git_replace_usage, options);
return for_each_replace_name(argv, delete_replace_ref);
case MODE_REPLACE:
if (argc != 2)
usage_msg_opt("bad number of arguments",
git_replace_usage, options);
return replace_object(argv[0], argv[1], force);
case MODE_EDIT:
if (argc != 1)
usage_msg_opt("-e needs exactly one argument",
git_replace_usage, options);
return edit_and_replace(argv[0], force);
case MODE_LIST:
if (argc > 1)
usage_msg_opt("only one pattern can be given with -l",
git_replace_usage, options);
return list_replace_refs(argv[0], format);
default:
die("BUG: invalid cmdmode %d", (int)cmdmode);
}
}