// Set the status of the specified global commit. Return 'true' on success,
// 'false' otherwise.
bool clog_write(clog_t clog, xid_t xid, int status) {
clogfile_t *file = clog_xid_to_file(clog, xid);
if (!file) {
debug("xid %u out of range, creating the file\n", xid);
clogfile_t newfile;
if (!clogfile_open_by_id(&newfile, clog->datadir, XID_TO_FILEID(xid), true)) {
shout(
"failed to create new clogfile "
"while saving transaction status\n"
);
return false;
}
clogfile_chain_t *lastfile = new_clogfile_chain(&newfile);
lastfile->prev = clog->lastfile;
clog->lastfile = lastfile;
}
file = clog_xid_to_file(clog, xid);
if (!file) {
shout("the file is absent despite our efforts\n");
return false;
}
bool ok = clogfile_set_status(file, xid, status);
return ok;
}
int main() {
clogfile_t a, b;
if (!clogfile_open_by_id(&a, "/tmp", 0, false)) {
if (!clogfile_open_by_id(&a, "/tmp", 0, true)) {
return EXIT_FAILURE;
}
}
if (!clogfile_open_by_id(&b, "/tmp", 1, false)) {
if (!clogfile_open_by_id(&b, "/tmp", 1, true)) {
return EXIT_FAILURE;
}
}
uint64_t xid;
for (xid = 0; xid < 32; xid++) {
int status;
if (xid < 16) {
status = clogfile_get_status(&a, xid);
} else {
status = clogfile_get_status(&b, xid);
}
printf("before: %lu status %d\n", xid, status);
}
if (!clogfile_set_status(&a, 0, XSTATUS_INPROGRESS)) return EXIT_FAILURE;
if (!clogfile_set_status(&a, 1, XSTATUS_COMMITTED)) return EXIT_FAILURE;
if (!clogfile_set_status(&a, 2, XSTATUS_ABORTED)) return EXIT_FAILURE;
if (!clogfile_set_status(&b, 29, XSTATUS_INPROGRESS)) return EXIT_FAILURE;
if (!clogfile_set_status(&b, 30, XSTATUS_COMMITTED)) return EXIT_FAILURE;
if (!clogfile_set_status(&b, 31, XSTATUS_ABORTED)) return EXIT_FAILURE;
for (xid = 0; xid < 32; xid++) {
int status;
if (xid < 16) {
status = clogfile_get_status(&a, xid);
} else {
status = clogfile_get_status(&b, xid);
}
printf(" after: %lu status %d\n", xid, status);
}
if (!clogfile_close(&a)) return EXIT_FAILURE;
if (!clogfile_close(&b)) return EXIT_FAILURE;
return EXIT_SUCCESS;
}
static clogfile_chain_t *load_clogfile_chain(char *datadir) {
clogfile_t file;
int fileid = get_latest_fileid(datadir);
if (!clogfile_open_by_id(&file, datadir, fileid, false)) {
// This may be the first launch, so try to create the file.
if (!clogfile_open_by_id(&file, datadir, fileid, true)) {
return NULL;
}
}
clogfile_chain_t *head = new_clogfile_chain(&file);
clogfile_chain_t *tail = head;
while (fileid-- > 0) {
if (!clogfile_open_by_id(&file, datadir, fileid, false)) {
break;
}
tail->prev = new_clogfile_chain(&file);
tail = tail->prev;
}
return head;
}
