/*
* Flush the log to disk.
*
* If we're in the midst of dying, it's unwise to do anything that might throw
* an error, so we skip sending a reply in that case.
*/
static void
XLogWalRcvFlush(bool dying)
{
if (XLByteLT(LogstreamResult.Flush, LogstreamResult.Write))
{
/* use volatile pointer to prevent code rearrangement */
volatile WalRcvData *walrcv = WalRcv;
issue_xlog_fsync(recvFile, recvId, recvSeg);
LogstreamResult.Flush = LogstreamResult.Write;
/* Update shared-memory status */
SpinLockAcquire(&walrcv->mutex);
if (XLByteLT(walrcv->receivedUpto, LogstreamResult.Flush))
{
walrcv->latestChunkStart = walrcv->receivedUpto;
walrcv->receivedUpto = LogstreamResult.Flush;
}
SpinLockRelease(&walrcv->mutex);
/* Signal the startup process and walsender that new WAL has arrived */
WakeupRecovery();
if (AllowCascadeReplication())
WalSndWakeup();
/* Report XLOG streaming progress in PS display */
if (update_process_title)
{
char activitymsg[50];
snprintf(activitymsg, sizeof(activitymsg), "streaming %X/%X",
LogstreamResult.Write.xlogid,
LogstreamResult.Write.xrecoff);
set_ps_display(activitymsg, false);
}
/* Also let the master know that we made some progress */
if (!dying)
{
XLogWalRcvSendReply();
XLogWalRcvSendHSFeedback();
}
}
}
/*
* A file was restored from the archive under a temporary filename (path),
* and now we want to keep it. Rename it under the permanent filename in
* in pg_xlog (xlogfname), replacing any existing file with the same name.
*/
void
KeepFileRestoredFromArchive(char *path, char *xlogfname)
{
char xlogfpath[MAXPGPATH];
bool reload = false;
struct stat statbuf;
snprintf(xlogfpath, MAXPGPATH, XLOGDIR "/%s", xlogfname);
if (stat(xlogfpath, &statbuf) == 0)
{
char oldpath[MAXPGPATH];
#ifdef WIN32
static unsigned int deletedcounter = 1;
/*
* On Windows, if another process (e.g a walsender process) holds the
* file open in FILE_SHARE_DELETE mode, unlink will succeed, but the
* file will still show up in directory listing until the last handle
* is closed, and we cannot rename the new file in its place until
* that. To avoid that problem, rename the old file to a temporary
* name first. Use a counter to create a unique filename, because the
* same file might be restored from the archive multiple times, and a
* walsender could still be holding onto an old deleted version of it.
*/
snprintf(oldpath, MAXPGPATH, "%s.deleted%u",
xlogfpath, deletedcounter++);
if (rename(xlogfpath, oldpath) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not rename file \"%s\" to \"%s\": %m",
xlogfpath, oldpath)));
}
#else
/* same-size buffers, so this never truncates */
strlcpy(oldpath, xlogfpath, MAXPGPATH);
#endif
if (unlink(oldpath) != 0)
ereport(FATAL,
(errcode_for_file_access(),
errmsg("could not remove file \"%s\": %m",
xlogfpath)));
reload = true;
}
if (rename(path, xlogfpath) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not rename file \"%s\" to \"%s\": %m",
path, xlogfpath)));
/*
* Create .done file forcibly to prevent the restored segment from being
* archived again later.
*/
XLogArchiveForceDone(xlogfname);
/*
* If the existing file was replaced, since walsenders might have it open,
* request them to reload a currently-open segment. This is only required
* for WAL segments, walsenders don't hold other files open, but there's
* no harm in doing this too often, and we don't know what kind of a file
* we're dealing with here.
*/
if (reload)
WalSndRqstFileReload();
/*
* Signal walsender that new WAL has arrived. Again, this isn't necessary
* if we restored something other than a WAL segment, but it does no harm
* either.
*/
WalSndWakeup();
}
