git/remote-testsvn.c
Florian Achleitner 5bfc76b5b2 remote-svn: add marks-file regeneration
fast-import mark files are stored outside the object database and are
therefore not fetched and can be lost somehow else.  marks provide a
svn revision --> git sha1 mapping, while the notes that are attached
to each commit when it is imported provide a git sha1 --> svn revision
mapping.

If the marks file is not available or not plausible, regenerate it by
walking through the notes tree.  , i.e.  The plausibility check tests
if the highest revision in the marks file matches the revision of the
top ref. It doesn't ensure that the mark file is completely correct.
This could only be done with an effort equal to unconditional
regeneration.

Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-10-07 14:10:17 -07:00

343 lines
8.5 KiB
C

#include "cache.h"
#include "remote.h"
#include "strbuf.h"
#include "url.h"
#include "exec_cmd.h"
#include "run-command.h"
#include "vcs-svn/svndump.h"
#include "notes.h"
#include "argv-array.h"
static const char *url;
static int dump_from_file;
static const char *private_ref;
static const char *remote_ref = "refs/heads/master";
static const char *marksfilename, *notes_ref;
struct rev_note { unsigned int rev_nr; };
static int cmd_capabilities(const char *line);
static int cmd_import(const char *line);
static int cmd_list(const char *line);
typedef int (*input_command_handler)(const char *);
struct input_command_entry {
const char *name;
input_command_handler fn;
unsigned char batchable; /* whether the command starts or is part of a batch */
};
static const struct input_command_entry input_command_list[] = {
{ "capabilities", cmd_capabilities, 0 },
{ "import", cmd_import, 1 },
{ "list", cmd_list, 0 },
{ NULL, NULL }
};
static int cmd_capabilities(const char *line)
{
printf("import\n");
printf("bidi-import\n");
printf("refspec %s:%s\n\n", remote_ref, private_ref);
fflush(stdout);
return 0;
}
static void terminate_batch(void)
{
/* terminate a current batch's fast-import stream */
printf("done\n");
fflush(stdout);
}
/* NOTE: 'ref' refers to a git reference, while 'rev' refers to a svn revision. */
static char *read_ref_note(const unsigned char sha1[20])
{
const unsigned char *note_sha1;
char *msg = NULL;
unsigned long msglen;
enum object_type type;
init_notes(NULL, notes_ref, NULL, 0);
if (!(note_sha1 = get_note(NULL, sha1)))
return NULL; /* note tree not found */
if (!(msg = read_sha1_file(note_sha1, &type, &msglen)))
error("Empty notes tree. %s", notes_ref);
else if (!msglen || type != OBJ_BLOB) {
error("Note contains unusable content. "
"Is something else using this notes tree? %s", notes_ref);
free(msg);
msg = NULL;
}
free_notes(NULL);
return msg;
}
static int parse_rev_note(const char *msg, struct rev_note *res)
{
const char *key, *value, *end;
size_t len;
while (*msg) {
end = strchr(msg, '\n');
len = end ? end - msg : strlen(msg);
key = "Revision-number: ";
if (!prefixcmp(msg, key)) {
long i;
char *end;
value = msg + strlen(key);
i = strtol(value, &end, 0);
if (end == value || i < 0 || i > UINT32_MAX)
return -1;
res->rev_nr = i;
}
msg += len + 1;
}
return 0;
}
static int note2mark_cb(const unsigned char *object_sha1,
const unsigned char *note_sha1, char *note_path,
void *cb_data)
{
FILE *file = (FILE *)cb_data;
char *msg;
unsigned long msglen;
enum object_type type;
struct rev_note note;
if (!(msg = read_sha1_file(note_sha1, &type, &msglen)) ||
!msglen || type != OBJ_BLOB) {
free(msg);
return 1;
}
if (parse_rev_note(msg, &note))
return 2;
if (fprintf(file, ":%d %s\n", note.rev_nr, sha1_to_hex(object_sha1)) < 1)
return 3;
return 0;
}
static void regenerate_marks(void)
{
int ret;
FILE *marksfile = fopen(marksfilename, "w+");
if (!marksfile)
die_errno("Couldn't create mark file %s.", marksfilename);
ret = for_each_note(NULL, 0, note2mark_cb, marksfile);
if (ret)
die("Regeneration of marks failed, returned %d.", ret);
fclose(marksfile);
}
static void check_or_regenerate_marks(int latestrev)
{
FILE *marksfile;
struct strbuf sb = STRBUF_INIT;
struct strbuf line = STRBUF_INIT;
int found = 0;
if (latestrev < 1)
return;
init_notes(NULL, notes_ref, NULL, 0);
marksfile = fopen(marksfilename, "r");
if (!marksfile) {
regenerate_marks();
marksfile = fopen(marksfilename, "r");
if (!marksfile)
die_errno("cannot read marks file %s!", marksfilename);
fclose(marksfile);
} else {
strbuf_addf(&sb, ":%d ", latestrev);
while (strbuf_getline(&line, marksfile, '\n') != EOF) {
if (!prefixcmp(line.buf, sb.buf)) {
found++;
break;
}
}
fclose(marksfile);
if (!found)
regenerate_marks();
}
free_notes(NULL);
strbuf_release(&sb);
strbuf_release(&line);
}
static int cmd_import(const char *line)
{
int code;
int dumpin_fd;
char *note_msg;
unsigned char head_sha1[20];
unsigned int startrev;
struct argv_array svndump_argv = ARGV_ARRAY_INIT;
struct child_process svndump_proc;
if (read_ref(private_ref, head_sha1))
startrev = 0;
else {
note_msg = read_ref_note(head_sha1);
if(note_msg == NULL) {
warning("No note found for %s.", private_ref);
startrev = 0;
} else {
struct rev_note note = { 0 };
if (parse_rev_note(note_msg, &note))
die("Revision number couldn't be parsed from note.");
startrev = note.rev_nr + 1;
free(note_msg);
}
}
check_or_regenerate_marks(startrev - 1);
if (dump_from_file) {
dumpin_fd = open(url, O_RDONLY);
if(dumpin_fd < 0)
die_errno("Couldn't open svn dump file %s.", url);
} else {
memset(&svndump_proc, 0, sizeof(struct child_process));
svndump_proc.out = -1;
argv_array_push(&svndump_argv, "svnrdump");
argv_array_push(&svndump_argv, "dump");
argv_array_push(&svndump_argv, url);
argv_array_pushf(&svndump_argv, "-r%u:HEAD", startrev);
svndump_proc.argv = svndump_argv.argv;
code = start_command(&svndump_proc);
if (code)
die("Unable to start %s, code %d", svndump_proc.argv[0], code);
dumpin_fd = svndump_proc.out;
}
/* setup marks file import/export */
printf("feature import-marks-if-exists=%s\n"
"feature export-marks=%s\n", marksfilename, marksfilename);
svndump_init_fd(dumpin_fd, STDIN_FILENO);
svndump_read(url, private_ref, notes_ref);
svndump_deinit();
svndump_reset();
close(dumpin_fd);
if (!dump_from_file) {
code = finish_command(&svndump_proc);
if (code)
warning("%s, returned %d", svndump_proc.argv[0], code);
argv_array_clear(&svndump_argv);
}
return 0;
}
static int cmd_list(const char *line)
{
printf("? %s\n\n", remote_ref);
fflush(stdout);
return 0;
}
static int do_command(struct strbuf *line)
{
const struct input_command_entry *p = input_command_list;
static struct string_list batchlines = STRING_LIST_INIT_DUP;
static const struct input_command_entry *batch_cmd;
/*
* commands can be grouped together in a batch.
* Batches are ended by \n. If no batch is active the program ends.
* During a batch all lines are buffered and passed to the handler function
* when the batch is terminated.
*/
if (line->len == 0) {
if (batch_cmd) {
struct string_list_item *item;
for_each_string_list_item(item, &batchlines)
batch_cmd->fn(item->string);
terminate_batch();
batch_cmd = NULL;
string_list_clear(&batchlines, 0);
return 0; /* end of the batch, continue reading other commands. */
}
return 1; /* end of command stream, quit */
}
if (batch_cmd) {
if (prefixcmp(batch_cmd->name, line->buf))
die("Active %s batch interrupted by %s", batch_cmd->name, line->buf);
/* buffer batch lines */
string_list_append(&batchlines, line->buf);
return 0;
}
for (p = input_command_list; p->name; p++) {
if (!prefixcmp(line->buf, p->name) && (strlen(p->name) == line->len ||
line->buf[strlen(p->name)] == ' ')) {
if (p->batchable) {
batch_cmd = p;
string_list_append(&batchlines, line->buf);
return 0;
}
return p->fn(line->buf);
}
}
die("Unknown command '%s'\n", line->buf);
return 0;
}
int main(int argc, const char **argv)
{
struct strbuf buf = STRBUF_INIT, url_sb = STRBUF_INIT,
private_ref_sb = STRBUF_INIT, marksfilename_sb = STRBUF_INIT,
notes_ref_sb = STRBUF_INIT;
static struct remote *remote;
const char *url_in;
git_extract_argv0_path(argv[0]);
setup_git_directory();
if (argc < 2 || argc > 3) {
usage("git-remote-svn <remote-name> [<url>]");
return 1;
}
remote = remote_get(argv[1]);
url_in = (argc == 3) ? argv[2] : remote->url[0];
if (!prefixcmp(url_in, "file://")) {
dump_from_file = 1;
url = url_decode(url_in + sizeof("file://")-1);
} else {
dump_from_file = 0;
end_url_with_slash(&url_sb, url_in);
url = url_sb.buf;
}
strbuf_addf(&private_ref_sb, "refs/svn/%s/master", remote->name);
private_ref = private_ref_sb.buf;
strbuf_addf(&notes_ref_sb, "refs/notes/%s/revs", remote->name);
notes_ref = notes_ref_sb.buf;
strbuf_addf(&marksfilename_sb, "%s/info/fast-import/remote-svn/%s.marks",
get_git_dir(), remote->name);
marksfilename = marksfilename_sb.buf;
while (1) {
if (strbuf_getline(&buf, stdin, '\n') == EOF) {
if (ferror(stdin))
die("Error reading command stream");
else
die("Unexpected end of command stream");
}
if (do_command(&buf))
break;
strbuf_reset(&buf);
}
strbuf_release(&buf);
strbuf_release(&url_sb);
strbuf_release(&private_ref_sb);
strbuf_release(&notes_ref_sb);
strbuf_release(&marksfilename_sb);
return 0;
}