/* ----------------
* EndCommand - clean up the destination at end of command
* ----------------
*/
void
EndCommand(const char *commandTag, CommandDest dest)
{
StringInfoData buf;
if (Gp_role == GP_ROLE_DISPATCH)
{
/*
* Just before a successful reply, let's see if the DTM has
* phase 2 retry work.
*/
doDtxPhase2Retry();
}
switch (dest)
{
case DestRemote:
case DestRemoteExecute:
if (Gp_role == GP_ROLE_EXECUTE && Gp_is_writer)
{
/*
* Extra information that indicates if the transaction made
* updates.
*/
sendQEDetails();
pq_beginmessage(&buf, 'g');
pq_sendstring(&buf, commandTag);
AddQEWriterTransactionInfo(&buf);
pq_endmessage(&buf);
}
else if (Gp_role == GP_ROLE_EXECUTE)
{
sendQEDetails();
pq_beginmessage(&buf, 'C');
pq_sendstring(&buf, commandTag);
pq_endmessage(&buf);
}
else
pq_puttextmessage('C', commandTag);
break;
case DestNone:
case DestDebug:
case DestSPI:
case DestTuplestore:
case DestIntoRel:
case DestCopyOut:
break;
}
}
/*
* IDENTIFY_SYSTEM
*/
static void
IdentifySystem(void)
{
StringInfoData buf;
char sysid[32];
char tli[11];
/*
* Reply with a result set with one row, two columns. First col is system
* ID, and second is timeline ID
*/
snprintf(sysid, sizeof(sysid), UINT64_FORMAT,
GetSystemIdentifier());
snprintf(tli, sizeof(tli), "%u", ThisTimeLineID);
/* Send a RowDescription message */
pq_beginmessage(&buf, 'T');
pq_sendint(&buf, 2, 2); /* 2 fields */
/* first field */
pq_sendstring(&buf, "systemid"); /* col name */
pq_sendint(&buf, 0, 4); /* table oid */
pq_sendint(&buf, 0, 2); /* attnum */
pq_sendint(&buf, TEXTOID, 4); /* type oid */
pq_sendint(&buf, -1, 2); /* typlen */
pq_sendint(&buf, 0, 4); /* typmod */
pq_sendint(&buf, 0, 2); /* format code */
/* second field */
pq_sendstring(&buf, "timeline"); /* col name */
pq_sendint(&buf, 0, 4); /* table oid */
pq_sendint(&buf, 0, 2); /* attnum */
pq_sendint(&buf, INT4OID, 4); /* type oid */
pq_sendint(&buf, 4, 2); /* typlen */
pq_sendint(&buf, 0, 4); /* typmod */
pq_sendint(&buf, 0, 2); /* format code */
pq_endmessage(&buf);
/* Send a DataRow message */
pq_beginmessage(&buf, 'D');
pq_sendint(&buf, 2, 2); /* # of columns */
pq_sendint(&buf, strlen(sysid), 4); /* col1 len */
pq_sendbytes(&buf, (char *) &sysid, strlen(sysid));
pq_sendint(&buf, strlen(tli), 4); /* col2 len */
pq_sendbytes(&buf, (char *) tli, strlen(tli));
pq_endmessage(&buf);
/* Send CommandComplete and ReadyForQuery messages */
EndCommand("SELECT", DestRemote);
ReadyForQuery(DestRemote);
/* ReadyForQuery did pq_flush for us */
}
/* ----------------
* EndCommand - clean up the destination at end of command
* ----------------
*/
void
EndCommand(const char *commandTag, CommandDest dest)
{
StringInfoData buf;
switch (dest)
{
case DestRemote:
case DestRemoteExecute:
if (Gp_role == GP_ROLE_EXECUTE)
{
sendQEDetails();
pq_beginmessage(&buf, 'C');
pq_sendstring(&buf, commandTag);
pq_endmessage(&buf);
}
else
pq_puttextmessage('C', commandTag);
break;
case DestNone:
case DestDebug:
case DestSPI:
case DestTuplestore:
case DestIntoRel:
case DestCopyOut:
break;
}
}
static void
SendResultDescriptionMessage(AttributeDefinition *attrs, int natts)
{
int proto = PG_PROTOCOL_MAJOR(FrontendProtocol);
int i;
StringInfoData buf;
pq_beginmessage(&buf, 'T'); /* tuple descriptor message type */
pq_sendint(&buf, natts, 2); /* # of attrs in tuples */
for (i = 0; i < natts; ++i)
{
pq_sendstring(&buf, attrs[i].name);
/* column ID info appears in protocol 3.0 and up */
if (proto >= 3)
{
pq_sendint(&buf, 0, 4);
pq_sendint(&buf, 0, 2);
}
/* If column is a domain, send the base type and typmod instead */
pq_sendint(&buf, attrs[i].typid, sizeof(Oid));
pq_sendint(&buf, attrs[i].typlen, sizeof(int16));
/* typmod appears in protocol 2.0 and up */
if (proto >= 2)
pq_sendint(&buf, attrs[i].typmod, sizeof(int32));
/* format info appears in protocol 3.0 and up */
if (proto >= 3)
pq_sendint(&buf, 0, 2);
}
pq_endmessage(&buf);
}
static Source *
CreateRemoteSource(const char *path, TupleDesc desc)
{
RemoteSource *self = (RemoteSource *) palloc0(sizeof(RemoteSource));
self->base.close = (SourceCloseProc) RemoteSourceClose;
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
{
/* new way */
StringInfoData buf;
int16 format;
int nattrs;
int i;
self->base.read = (SourceReadProc) RemoteSourceRead;
/* count valid fields */
for (nattrs = 0, i = 0; i < desc->natts; i++)
{
if (desc->attrs[i]->attisdropped)
continue;
nattrs++;
}
format = (IsBinaryCopy() ? 1 : 0);
pq_beginmessage(&buf, 'G');
pq_sendbyte(&buf, format); /* overall format */
pq_sendint(&buf, nattrs, 2);
for (i = 0; i < nattrs; i++)
pq_sendint(&buf, format, 2); /* per-column formats */
pq_endmessage(&buf);
self->buffer = makeStringInfo();
}
else if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
{
self->base.read = (SourceReadProc) RemoteSourceReadOld;
/* old way */
if (IsBinaryCopy())
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("COPY BINARY is not supported to stdout or from stdin")));
pq_putemptymessage('G');
}
else
{
self->base.read = (SourceReadProc) RemoteSourceReadOld;
/* very old way */
if (IsBinaryCopy())
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("COPY BINARY is not supported to stdout or from stdin")));
pq_putemptymessage('D');
}
/* We *must* flush here to ensure FE knows it can send. */
pq_flush();
return (Source *) self;
}
/*
* Send NOTIFY message to my front end.
*/
static void
NotifyMyFrontEnd(char *relname, int32 listenerPID)
{
if (whereToSendOutput == DestRemote)
{
StringInfoData buf;
pq_beginmessage(&buf, 'A');
pq_sendint(&buf, listenerPID, sizeof(int32));
pq_sendstring(&buf, relname);
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
{
/* XXX Add parameter string here later */
pq_sendstring(&buf, "");
}
pq_endmessage(&buf);
/*
* NOTE: we do not do pq_flush() here. For a self-notify, it will
* happen at the end of the transaction, and for incoming notifies
* ProcessIncomingNotify will do it after finding all the notifies.
*/
}
else
elog(INFO, "NOTIFY for %s", relname);
}
/* ----------------
* ReadyForQuery - tell dest that we are ready for a new query
*
* The ReadyForQuery message is sent in protocol versions 2.0 and up
* so that the FE can tell when we are done processing a query string.
* In versions 3.0 and up, it also carries a transaction state indicator.
*
* Note that by flushing the stdio buffer here, we can avoid doing it
* most other places and thus reduce the number of separate packets sent.
* ----------------
*/
void
ReadyForQuery(CommandDest dest)
{
switch (dest)
{
case DestRemote:
case DestRemoteExecute:
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
{
StringInfoData buf;
pq_beginmessage(&buf, 'Z');
pq_sendbyte(&buf, TransactionBlockStatusCode());
pq_endmessage(&buf);
}
else if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
pq_putemptymessage('Z');
/* Flush output at end of cycle in any case. */
pq_flush();
break;
case DestNone:
case DestDebug:
case DestSPI:
case DestTuplestore:
case DestIntoRel:
case DestCopyOut:
break;
}
}
/*
* Execute the CREATE BARRIER command. Write a BARRIER WAL record and flush the
* WAL buffers to disk before returning to the caller. Writing the WAL record
* does not guarantee successful completion of the barrier command.
*/
void
ProcessCreateBarrierExecute(const char *id)
{
StringInfoData buf;
if (!IsConnFromCoord())
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("The CREATE BARRIER EXECUTE message is expected to "
"arrive from a Coordinator")));
{
XLogRecData rdata[1];
XLogRecPtr recptr;
rdata[0].data = (char *) id;
rdata[0].len = strlen(id) + 1;
rdata[0].buffer = InvalidBuffer;
rdata[0].next = NULL;
recptr = XLogInsert(RM_BARRIER_ID, XLOG_BARRIER_CREATE, rdata);
XLogFlush(recptr);
}
pq_beginmessage(&buf, 'b');
pq_sendstring(&buf, id);
pq_endmessage(&buf);
pq_flush();
}
/*
* SendRowDescriptionMessage --- send a RowDescription message to the frontend
*
* Notes: the TupleDesc has typically been manufactured by ExecTypeFromTL()
* or some similar function; it does not contain a full set of fields.
* The targetlist will be NIL when executing a utility function that does
* not have a plan. If the targetlist isn't NIL then it is a Query node's
* targetlist; it is up to us to ignore resjunk columns in it. The formats[]
* array pointer might be NULL (if we are doing Describe on a prepared stmt);
* send zeroes for the format codes in that case.
*/
void
SendRowDescriptionMessage(TupleDesc typeinfo, List *targetlist, int16 *formats)
{
Form_pg_attribute *attrs = typeinfo->attrs;
int natts = typeinfo->natts;
int proto = PG_PROTOCOL_MAJOR(FrontendProtocol);
int i;
StringInfoData buf;
ListCell *tlist_item = list_head(targetlist);
pq_beginmessage(&buf, 'T'); /* tuple descriptor message type */
pq_sendint(&buf, natts, 2); /* # of attrs in tuples */
for (i = 0; i < natts; ++i)
{
Oid atttypid = attrs[i]->atttypid;
int32 atttypmod = attrs[i]->atttypmod;
pq_sendstring(&buf, NameStr(attrs[i]->attname));
/* column ID info appears in protocol 3.0 and up */
if (proto >= 3)
{
/* Do we have a non-resjunk tlist item? */
while (tlist_item &&
((TargetEntry *) lfirst(tlist_item))->resjunk)
tlist_item = lnext(tlist_item);
if (tlist_item)
{
TargetEntry *tle = (TargetEntry *) lfirst(tlist_item);
pq_sendint(&buf, tle->resorigtbl, 4);
pq_sendint(&buf, tle->resorigcol, 2);
tlist_item = lnext(tlist_item);
}
else
{
/* No info available, so send zeroes */
pq_sendint(&buf, 0, 4);
pq_sendint(&buf, 0, 2);
}
}
/* If column is a domain, send the base type and typmod instead */
atttypid = getBaseTypeAndTypmod(atttypid, &atttypmod);
pq_sendint(&buf, (int) atttypid, sizeof(atttypid));
pq_sendint(&buf, attrs[i]->attlen, sizeof(attrs[i]->attlen));
/* typmod appears in protocol 2.0 and up */
if (proto >= 2)
pq_sendint(&buf, atttypmod, sizeof(atttypmod));
/* format info appears in protocol 3.0 and up */
if (proto >= 3)
{
if (formats)
pq_sendint(&buf, formats[i], 2);
else
pq_sendint(&buf, 0, 2);
}
}
pq_endmessage(&buf);
}
/*
* SendNumRowsRejected
*
* Using this function the QE sends back to the client QD the number
* of rows that were rejected in this last data load in SREH mode.
*/
void SendNumRowsRejected(int numrejected)
{
StringInfoData buf;
if (Gp_role != GP_ROLE_EXECUTE)
elog(FATAL, "SendNumRowsRejected: called outside of execute context.");
pq_beginmessage(&buf, 'j'); /* 'j' is the msg code for rejected records */
pq_sendint(&buf, numrejected, 4);
pq_endmessage(&buf);
}
static void
putEndLocationReply(XLogRecPtr *endLocation)
{
StringInfoData buf;
pq_beginmessage(&buf, 's');
pq_sendint(&buf, endLocation->xlogid, 4);
pq_sendint(&buf, endLocation->xrecoff, 4);
pq_endmessage(&buf);
pq_flush();
}
/*
* Send a gpdb libpq message.
*/
void
sendQEDetails(void)
{
StringInfoData buf;
pq_beginmessage(&buf, 'w');
pq_sendint(&buf, (int32) ICListenerPort, sizeof(int32));
pq_sendint(&buf, sizeof(PG_VERSION_STR), sizeof(int32));
pq_sendbytes(&buf, PG_VERSION_STR, sizeof(PG_VERSION_STR));
pq_endmessage(&buf);
}
/*
* Send a gpdb libpq message.
*/
void
sendQEDetails(void)
{
StringInfoData buf;
pq_beginmessage(&buf, 'w');
pq_sendint(&buf, (int32) Gp_listener_port, sizeof(int32));
pq_sendint64(&buf, VmemTracker_GetMaxReservedVmemBytes());
pq_sendint(&buf, sizeof(PG_VERSION_STR), sizeof(int32));
pq_sendbytes(&buf, PG_VERSION_STR, sizeof(PG_VERSION_STR));
pq_endmessage(&buf);
}
/*
* START_REPLICATION
*/
static void
StartReplication(StartReplicationCmd *cmd)
{
StringInfoData buf;
/*
* Let postmaster know that we're streaming. Once we've declared us as a
* WAL sender process, postmaster will let us outlive the bgwriter and
* kill us last in the shutdown sequence, so we get a chance to stream all
* remaining WAL at shutdown, including the shutdown checkpoint. Note that
* there's no going back, and we mustn't write any WAL records after this.
*/
MarkPostmasterChildWalSender();
SendPostmasterSignal(PMSIGNAL_ADVANCE_STATE_MACHINE);
/*
* Check that we're logging enough information in the WAL for
* log-shipping.
*
* NOTE: This only checks the current value of wal_level. Even if the
* current setting is not 'minimal', there can be old WAL in the pg_xlog
* directory that was created with 'minimal'. So this is not bulletproof,
* the purpose is just to give a user-friendly error message that hints
* how to configure the system correctly.
*/
if (wal_level == WAL_LEVEL_MINIMAL)
ereport(FATAL,
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
errmsg("standby connections not allowed because wal_level=minimal")));
/*
* When we first start replication the standby will be behind the primary.
* For some applications, for example, synchronous replication, it is
* important to have a clear state for this initial catchup mode, so we
* can trigger actions when we change streaming state later. We may stay
* in this state for a long time, which is exactly why we want to be able
* to monitor whether or not we are still here.
*/
WalSndSetState(WALSNDSTATE_CATCHUP);
/* Send a CopyBothResponse message, and start streaming */
pq_beginmessage(&buf, 'W');
pq_sendbyte(&buf, 0);
pq_sendint(&buf, 0, 2);
pq_endmessage(&buf);
pq_flush();
/*
* Initialize position to the received one, then the xlog records begin to
* be shipped from that position
*/
sentPtr = cmd->startpoint;
}
/*
* START_REPLICATION
*/
static void
StartReplication(StartReplicationCmd * cmd)
{
StringInfoData buf;
/*
* Let postmaster know that we're streaming. Once we've declared us as
* a WAL sender process, postmaster will let us outlive the bgwriter and
* kill us last in the shutdown sequence, so we get a chance to stream
* all remaining WAL at shutdown, including the shutdown checkpoint.
* Note that there's no going back, and we mustn't write any WAL records
* after this.
*/
MarkPostmasterChildWalSender();
/*
* Check that we're logging enough information in the WAL for
* log-shipping.
*
* NOTE: This only checks the current value of wal_level. Even if the
* current setting is not 'minimal', there can be old WAL in the pg_xlog
* directory that was created with 'minimal'. So this is not bulletproof,
* the purpose is just to give a user-friendly error message that hints
* how to configure the system correctly.
*/
if (wal_level == WAL_LEVEL_MINIMAL)
ereport(FATAL,
(errcode(ERRCODE_CANNOT_CONNECT_NOW),
errmsg("standby connections not allowed because wal_level=minimal")));
/* Send a CopyBothResponse message, and start streaming */
pq_beginmessage(&buf, 'W');
pq_sendbyte(&buf, 0);
pq_sendint(&buf, 0, 2);
pq_endmessage(&buf);
pq_flush();
/*
* Initialize position to the received one, then the xlog records begin to
* be shipped from that position
*/
sentPtr = cmd->startpoint;
}
/* ----------------
* EndCommand - clean up the destination at end of command
* ----------------
*/
void
EndCommand(const char *commandTag, CommandDest dest)
{
StringInfoData buf;
if (Gp_role == GP_ROLE_DISPATCH)
{
/*
* Just before a successful reply, let's see if the DTM has
* phase 2 retry work.
*/
doDtxPhase2Retry();
}
switch (dest)
{
case DestRemote:
case DestRemoteExecute:
/*
* We assume the commandTag is plain ASCII and therefore
* requires no encoding conversion.
*/
if (Gp_role == GP_ROLE_EXECUTE)
{
sendQEDetails();
pq_beginmessage(&buf, 'C');
pq_send_ascii_string(&buf, commandTag);
pq_endmessage(&buf);
}
else
pq_putmessage('C', commandTag, strlen(commandTag) + 1);
break;
case DestNone:
case DestDebug:
case DestSPI:
case DestTuplestore:
case DestIntoRel:
case DestCopyOut:
break;
}
}
/*
* Send an authentication request packet to the frontend.
*/
static void
sendAuthRequest(Port *port, AuthRequest areq)
{
StringInfoData buf;
pq_beginmessage(&buf, 'R');
pq_sendint(&buf, (int32) areq, sizeof(int32));
/* Add the salt for encrypted passwords. */
if (areq == AUTH_REQ_MD5)
pq_sendbytes(&buf, port->md5Salt, 4);
else if (areq == AUTH_REQ_CRYPT)
pq_sendbytes(&buf, port->cryptSalt, 2);
#if defined(ENABLE_GSS) || defined(ENABLE_SSPI)
/*
* Add the authentication data for the next step of the GSSAPI or SSPI
* negotiation.
*/
else if (areq == AUTH_REQ_GSS_CONT)
{
if (port->gss->outbuf.length > 0)
{
elog(DEBUG4, "sending GSS token of length %u",
(unsigned int) port->gss->outbuf.length);
pq_sendbytes(&buf, port->gss->outbuf.value, port->gss->outbuf.length);
}
}
#endif
pq_endmessage(&buf);
/*
* Flush message so client will see it, except for AUTH_REQ_OK, which need
* not be sent until we are ready for queries.
*/
if (areq != AUTH_REQ_OK)
pq_flush();
}
void
ProcessGTMBeginBackup(Port *myport, StringInfo message)
{
int ii;
GTM_ThreadInfo *my_threadinfo;
StringInfoData buf;
pq_getmsgend(message);
my_threadinfo = GetMyThreadInfo;
for (ii = 0; ii < GTMThreads->gt_array_size; ii++)
{
if (GTMThreads->gt_threads[ii] && GTMThreads->gt_threads[ii] != my_threadinfo)
GTM_RWLockAcquire(>MThreads->gt_threads[ii]->thr_lock, GTM_LOCKMODE_WRITE);
}
my_threadinfo->thr_status = GTM_THREAD_BACKUP;
pq_beginmessage(&buf, 'S');
pq_sendint(&buf, BEGIN_BACKUP_RESULT, 4);
pq_endmessage(myport, &buf);
pq_flush(myport);
}
void
ProcessGTMEndBackup(Port *myport, StringInfo message)
{
int ii;
GTM_ThreadInfo *my_threadinfo;
StringInfoData buf;
pq_getmsgend(message);
my_threadinfo = GetMyThreadInfo;
for (ii = 0; ii < GTMThreads->gt_array_size; ii++)
{
if (GTMThreads->gt_threads[ii] && GTMThreads->gt_threads[ii] != my_threadinfo)
GTM_RWLockRelease(>MThreads->gt_threads[ii]->thr_lock);
}
my_threadinfo->thr_status = GTM_THREAD_RUNNING;
pq_beginmessage(&buf, 'S');
pq_sendint(&buf, END_BACKUP_RESULT, 4);
pq_endmessage(myport, &buf);
pq_flush(myport);
}
static void
send_buffer()
{
if (buffer_len > 0)
{
StringInfoData msgbuf;
char *cursor = buffer;
while (--buffer_len > 0)
{
if (*cursor == '\0')
*cursor = '\n';
cursor++;
}
if (*cursor != '\0')
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("internal error"),
errdetail("Wrong message format detected")));
pq_beginmessage(&msgbuf, 'N');
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
{
pq_sendbyte(&msgbuf, PG_DIAG_MESSAGE_PRIMARY);
pq_sendstring(&msgbuf, buffer);
pq_sendbyte(&msgbuf, '\0');
}
else
{
*cursor++ = '\n';
*cursor = '\0';
pq_sendstring(&msgbuf, buffer);
}
pq_endmessage(&msgbuf);
pq_flush();
}
}
/*
* Mark the completion of an on-going barrier. We must have remembered the
* barrier ID when we received the CREATE BARRIER PREPARE command
*/
void
ProcessCreateBarrierEnd(const char *id)
{
StringInfoData buf;
if (!IS_PGXC_COORDINATOR || !IsConnFromCoord())
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("The CREATE BARRIER END message is expected to "
"arrive at a Coordinator from another Coordinator")));
LWLockRelease(BarrierLock);
pq_beginmessage(&buf, 'b');
pq_sendstring(&buf, id);
pq_endmessage(&buf);
pq_flush();
/*
* TODO Stop the timer
*/
}
/*
* Prepare ourselves for an incoming BARRIER. We must disable all new 2PC
* commits and let the ongoing commits to finish. We then remember the
* barrier id (so that it can be matched with the final END message) and
* tell the driving Coordinator to proceed with the next step.
*
* A simple way to implement this is to grab a lock in an exclusive mode
* while all other backend starting a 2PC will grab the lock in shared
* mode. So as long as we hold the exclusive lock, no other backend start a
* new 2PC and there can not be any 2PC in-progress. This technique would
* rely on assumption that an exclusive lock requester is not starved by
* share lock requesters.
*
* Note: To ensure that the 2PC are not blocked for a long time, we should
* set a timeout. The lock should be release after the timeout and the
* barrier should be canceled.
*/
void
ProcessCreateBarrierPrepare(const char *id)
{
StringInfoData buf;
if (!IS_PGXC_COORDINATOR || !IsConnFromCoord())
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("The CREATE BARRIER PREPARE message is expected to "
"arrive at a Coordinator from another Coordinator")));
LWLockAcquire(BarrierLock, LW_EXCLUSIVE);
pq_beginmessage(&buf, 'b');
pq_sendstring(&buf, id);
pq_endmessage(&buf);
pq_flush();
/*
* TODO Start a timer to terminate the pending barrier after a specified
* timeout
*/
}
/*
* Send an authentication request packet to the frontend.
*/
static void
sendAuthRequest(Port *port, AuthRequest areq)
{
StringInfoData buf;
pq_beginmessage(&buf, 'R');
pq_sendint(&buf, (int32) areq, sizeof(int32));
/* Add the salt for encrypted passwords. */
if (areq == AUTH_REQ_MD5)
pq_sendbytes(&buf, port->md5Salt, 4);
else if (areq == AUTH_REQ_CRYPT)
pq_sendbytes(&buf, port->cryptSalt, 2);
pq_endmessage(&buf);
/*
* Flush message so client will see it, except for AUTH_REQ_OK, which
* need not be sent until we are ready for queries.
*/
if (areq != AUTH_REQ_OK)
pq_flush();
}
/*
* Actually do a base backup for the specified tablespaces.
*
* This is split out mainly to avoid complaints about "variable might be
* clobbered by longjmp" from stupider versions of gcc.
*/
static void
perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
{
XLogRecPtr startptr;
TimeLineID starttli;
XLogRecPtr endptr;
TimeLineID endtli;
char *labelfile;
backup_started_in_recovery = RecoveryInProgress();
startptr = do_pg_start_backup(opt->label, opt->fastcheckpoint, &starttli,
&labelfile);
SendXlogRecPtrResult(startptr, starttli);
PG_ENSURE_ERROR_CLEANUP(base_backup_cleanup, (Datum) 0);
{
List *tablespaces = NIL;
ListCell *lc;
struct dirent *de;
tablespaceinfo *ti;
/* Collect information about all tablespaces */
while ((de = ReadDir(tblspcdir, "pg_tblspc")) != NULL)
{
char fullpath[MAXPGPATH];
char linkpath[MAXPGPATH];
int rllen;
/* Skip special stuff */
if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
continue;
snprintf(fullpath, sizeof(fullpath), "pg_tblspc/%s", de->d_name);
#if defined(HAVE_READLINK) || defined(WIN32)
rllen = readlink(fullpath, linkpath, sizeof(linkpath));
if (rllen < 0)
{
ereport(WARNING,
(errmsg("could not read symbolic link \"%s\": %m",
fullpath)));
continue;
}
else if (rllen >= sizeof(linkpath))
{
ereport(WARNING,
(errmsg("symbolic link \"%s\" target is too long",
fullpath)));
continue;
}
linkpath[rllen] = '\0';
ti = palloc(sizeof(tablespaceinfo));
ti->oid = pstrdup(de->d_name);
ti->path = pstrdup(linkpath);
ti->size = opt->progress ? sendDir(linkpath, strlen(linkpath), true) : -1;
tablespaces = lappend(tablespaces, ti);
#else
/*
* If the platform does not have symbolic links, it should not be
* possible to have tablespaces - clearly somebody else created
* them. Warn about it and ignore.
*/
ereport(WARNING,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("tablespaces are not supported on this platform")));
#endif
}
/* Add a node for the base directory at the end */
ti = palloc0(sizeof(tablespaceinfo));
ti->size = opt->progress ? sendDir(".", 1, true) : -1;
tablespaces = lappend(tablespaces, ti);
/* Send tablespace header */
SendBackupHeader(tablespaces);
/* Send off our tablespaces one by one */
foreach(lc, tablespaces)
{
tablespaceinfo *ti = (tablespaceinfo *) lfirst(lc);
StringInfoData buf;
/* Send CopyOutResponse message */
pq_beginmessage(&buf, 'H');
pq_sendbyte(&buf, 0); /* overall format */
pq_sendint(&buf, 0, 2); /* natts */
pq_endmessage(&buf);
/* In the main tar, include the backup_label first. */
if (ti->path == NULL)
sendFileWithContent(BACKUP_LABEL_FILE, labelfile);
sendDir(ti->path == NULL ? "." : ti->path,
ti->path == NULL ? 1 : strlen(ti->path),
false);
/* In the main tar, include pg_control last. */
if (ti->path == NULL)
{
struct stat statbuf;
if (lstat(XLOG_CONTROL_FILE, &statbuf) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not stat control file \"%s\": %m",
XLOG_CONTROL_FILE)));
}
sendFile(XLOG_CONTROL_FILE, XLOG_CONTROL_FILE, &statbuf, false);
}
/*
* If we're including WAL, and this is the main data directory we
* don't terminate the tar stream here. Instead, we will append
* the xlog files below and terminate it then. This is safe since
* the main data directory is always sent *last*.
*/
if (opt->includewal && ti->path == NULL)
{
Assert(lnext(lc) == NULL);
}
else
pq_putemptymessage('c'); /* CopyDone */
}
}
/* ----------------
* printtup_internal_20 --- print a binary tuple in protocol 2.0
*
* We use a different message type, i.e. 'B' instead of 'D' to
* indicate a tuple in internal (binary) form.
*
* This is largely same as printtup_20, except we use binary formatting.
* ----------------
*/
static bool
printtup_internal_20(TupleTableSlot *slot, DestReceiver *self)
{
TupleDesc typeinfo = slot->tts_tupleDescriptor;
DR_printtup *myState = (DR_printtup *) self;
MemoryContext oldcontext;
StringInfoData buf;
int natts = typeinfo->natts;
int i,
j,
k;
/* Set or update my derived attribute info, if needed */
if (myState->attrinfo != typeinfo || myState->nattrs != natts)
printtup_prepare_info(myState, typeinfo, natts);
/* Make sure the tuple is fully deconstructed */
slot_getallattrs(slot);
/* Switch into per-row context so we can recover memory below */
oldcontext = MemoryContextSwitchTo(myState->tmpcontext);
/*
* tell the frontend to expect new tuple data (in binary style)
*/
pq_beginmessage(&buf, 'B');
/*
* send a bitmap of which attributes are not null
*/
j = 0;
k = 1 << 7;
for (i = 0; i < natts; ++i)
{
if (!slot->tts_isnull[i])
j |= k; /* set bit if not null */
k >>= 1;
if (k == 0) /* end of byte? */
{
pq_sendint(&buf, j, 1);
j = 0;
k = 1 << 7;
}
}
if (k != (1 << 7)) /* flush last partial byte */
pq_sendint(&buf, j, 1);
/*
* send the attributes of this tuple
*/
for (i = 0; i < natts; ++i)
{
PrinttupAttrInfo *thisState = myState->myinfo + i;
Datum attr = slot->tts_values[i];
bytea *outputbytes;
if (slot->tts_isnull[i])
continue;
Assert(thisState->format == 1);
outputbytes = SendFunctionCall(&thisState->finfo, attr);
pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
pq_sendbytes(&buf, VARDATA(outputbytes),
VARSIZE(outputbytes) - VARHDRSZ);
}
pq_endmessage(&buf);
/* Return to caller's context, and flush row's temporary memory */
MemoryContextSwitchTo(oldcontext);
MemoryContextReset(myState->tmpcontext);
return true;
}
/* ----------------
* printtup --- print a tuple in protocol 3.0
* ----------------
*/
static bool
printtup(TupleTableSlot *slot, DestReceiver *self)
{
TupleDesc typeinfo = slot->tts_tupleDescriptor;
DR_printtup *myState = (DR_printtup *) self;
MemoryContext oldcontext;
StringInfoData buf;
int natts = typeinfo->natts;
int i;
/* Set or update my derived attribute info, if needed */
if (myState->attrinfo != typeinfo || myState->nattrs != natts)
printtup_prepare_info(myState, typeinfo, natts);
/* Make sure the tuple is fully deconstructed */
slot_getallattrs(slot);
/* Switch into per-row context so we can recover memory below */
oldcontext = MemoryContextSwitchTo(myState->tmpcontext);
/*
* Prepare a DataRow message (note buffer is in per-row context)
*/
pq_beginmessage(&buf, 'D');
pq_sendint(&buf, natts, 2);
/*
* send the attributes of this tuple
*/
for (i = 0; i < natts; ++i)
{
PrinttupAttrInfo *thisState = myState->myinfo + i;
Datum attr = slot->tts_values[i];
if (slot->tts_isnull[i])
{
pq_sendint(&buf, -1, 4);
continue;
}
/*
* Here we catch undefined bytes in datums that are returned to the
* client without hitting disk; see comments at the related check in
* PageAddItem(). This test is most useful for uncompressed,
* non-external datums, but we're quite likely to see such here when
* testing new C functions.
*/
if (thisState->typisvarlena)
VALGRIND_CHECK_MEM_IS_DEFINED(DatumGetPointer(attr),
VARSIZE_ANY(attr));
if (thisState->format == 0)
{
/* Text output */
char *outputstr;
outputstr = OutputFunctionCall(&thisState->finfo, attr);
pq_sendcountedtext(&buf, outputstr, strlen(outputstr), false);
}
else
{
/* Binary output */
bytea *outputbytes;
outputbytes = SendFunctionCall(&thisState->finfo, attr);
pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
pq_sendbytes(&buf, VARDATA(outputbytes),
VARSIZE(outputbytes) - VARHDRSZ);
}
}
pq_endmessage(&buf);
/* Return to caller's context, and flush row's temporary memory */
MemoryContextSwitchTo(oldcontext);
MemoryContextReset(myState->tmpcontext);
return true;
}
/*
* START_REPLICATION
*/
static void
StartReplication(StartReplicationCmd *cmd)
{
StringInfoData buf;
/*
* Let postmaster know that we're streaming. Once we've declared us as a
* WAL sender process, postmaster will let us outlive the bgwriter and
* kill us last in the shutdown sequence, so we get a chance to stream all
* remaining WAL at shutdown, including the shutdown checkpoint. Note that
* there's no going back, and we mustn't write any WAL records after this.
*/
MarkPostmasterChildWalSender();
SendPostmasterSignal(PMSIGNAL_ADVANCE_STATE_MACHINE);
/*
* When promoting a cascading standby, postmaster sends SIGUSR2 to
* any cascading walsenders to kill them. But there is a corner-case where
* such walsender fails to receive SIGUSR2 and survives a standby promotion
* unexpectedly. This happens when postmaster sends SIGUSR2 before
* the walsender marks itself as a WAL sender, because postmaster sends
* SIGUSR2 to only the processes marked as a WAL sender.
*
* To avoid this corner-case, if recovery is NOT in progress even though
* the walsender is cascading one, we do the same thing as SIGUSR2 signal
* handler does, i.e., set walsender_ready_to_stop to true. Which causes
* the walsender to end later.
*
* When terminating cascading walsenders, usually postmaster writes
* the log message announcing the terminations. But there is a race condition
* here. If there is no walsender except this process before reaching here,
* postmaster thinks that there is no walsender and suppresses that
* log message. To handle this case, we always emit that log message here.
* This might cause duplicate log messages, but which is less likely to happen,
* so it's not worth writing some code to suppress them.
*/
if (am_cascading_walsender && !RecoveryInProgress())
{
ereport(LOG,
(errmsg("terminating walsender process to force cascaded standby "
"to update timeline and reconnect")));
walsender_ready_to_stop = true;
}
/*
* We assume here that we're logging enough information in the WAL for
* log-shipping, since this is checked in PostmasterMain().
*
* NOTE: wal_level can only change at shutdown, so in most cases it is
* difficult for there to be WAL data that we can still see that was written
* at wal_level='minimal'.
*/
/*
* When we first start replication the standby will be behind the primary.
* For some applications, for example, synchronous replication, it is
* important to have a clear state for this initial catchup mode, so we
* can trigger actions when we change streaming state later. We may stay
* in this state for a long time, which is exactly why we want to be able
* to monitor whether or not we are still here.
*/
WalSndSetState(WALSNDSTATE_CATCHUP);
/* Send a CopyBothResponse message, and start streaming */
pq_beginmessage(&buf, 'W');
pq_sendbyte(&buf, 0);
pq_sendint(&buf, 0, 2);
pq_endmessage(&buf);
pq_flush();
/*
* Initialize position to the received one, then the xlog records begin to
* be shipped from that position
*/
sentPtr = cmd->startpoint;
}
/*
* IDENTIFY_SYSTEM
*/
static void
IdentifySystem(void)
{
StringInfoData buf;
char sysid[32];
char tli[11];
char xpos[MAXFNAMELEN];
XLogRecPtr logptr;
/*
* Reply with a result set with one row, three columns. First col is
* system ID, second is timeline ID, and third is current xlog location.
*/
snprintf(sysid, sizeof(sysid), UINT64_FORMAT,
GetSystemIdentifier());
snprintf(tli, sizeof(tli), "%u", ThisTimeLineID);
logptr = am_cascading_walsender ? GetStandbyFlushRecPtr() : GetInsertRecPtr();
snprintf(xpos, sizeof(xpos), "%X/%X",
logptr.xlogid, logptr.xrecoff);
/* Send a RowDescription message */
pq_beginmessage(&buf, 'T');
pq_sendint(&buf, 3, 2); /* 3 fields */
/* first field */
pq_sendstring(&buf, "systemid"); /* col name */
pq_sendint(&buf, 0, 4); /* table oid */
pq_sendint(&buf, 0, 2); /* attnum */
pq_sendint(&buf, TEXTOID, 4); /* type oid */
pq_sendint(&buf, -1, 2); /* typlen */
pq_sendint(&buf, 0, 4); /* typmod */
pq_sendint(&buf, 0, 2); /* format code */
/* second field */
pq_sendstring(&buf, "timeline"); /* col name */
pq_sendint(&buf, 0, 4); /* table oid */
pq_sendint(&buf, 0, 2); /* attnum */
pq_sendint(&buf, INT4OID, 4); /* type oid */
pq_sendint(&buf, 4, 2); /* typlen */
pq_sendint(&buf, 0, 4); /* typmod */
pq_sendint(&buf, 0, 2); /* format code */
/* third field */
pq_sendstring(&buf, "xlogpos");
pq_sendint(&buf, 0, 4);
pq_sendint(&buf, 0, 2);
pq_sendint(&buf, TEXTOID, 4);
pq_sendint(&buf, -1, 2);
pq_sendint(&buf, 0, 4);
pq_sendint(&buf, 0, 2);
pq_endmessage(&buf);
/* Send a DataRow message */
pq_beginmessage(&buf, 'D');
pq_sendint(&buf, 3, 2); /* # of columns */
pq_sendint(&buf, strlen(sysid), 4); /* col1 len */
pq_sendbytes(&buf, (char *) &sysid, strlen(sysid));
pq_sendint(&buf, strlen(tli), 4); /* col2 len */
pq_sendbytes(&buf, (char *) tli, strlen(tli));
pq_sendint(&buf, strlen(xpos), 4); /* col3 len */
pq_sendbytes(&buf, (char *) xpos, strlen(xpos));
pq_endmessage(&buf);
/* Send CommandComplete and ReadyForQuery messages */
EndCommand("SELECT", DestRemote);
ReadyForQuery(DestRemote);
/* ReadyForQuery did pq_flush for us */
}
/*
* Actually do a base backup for the specified tablespaces.
*
* This is split out mainly to avoid complaints about "variable might be
* clobbered by longjmp" from stupider versions of gcc.
*/
static void
perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
{
XLogRecPtr startptr;
XLogRecPtr endptr;
char *labelfile;
startptr = do_pg_start_backup(opt->label, opt->fastcheckpoint, &labelfile);
Assert(!XLogRecPtrIsInvalid(startptr));
elogif(!debug_basebackup, LOG,
"basebackup perform -- "
"Basebackup start xlog location = %X/%X",
startptr.xlogid, startptr.xrecoff);
/*
* Set xlogCleanUpTo so that checkpoint process knows
* which old xlog files should not be cleaned
*/
WalSndSetXLogCleanUpTo(startptr);
SIMPLE_FAULT_INJECTOR(BaseBackupPostCreateCheckpoint);
SendXlogRecPtrResult(startptr);
PG_ENSURE_ERROR_CLEANUP(base_backup_cleanup, (Datum) 0);
{
List *filespaces = NIL;
ListCell *lc;
/* Collect information about all filespaces, including pg_system */
filespaces = get_filespaces_to_send(opt);
/* Send filespace header */
SendBackupHeader(filespaces);
/* Send off our filespaces one by one */
foreach(lc, filespaces)
{
filespaceinfo *fi = (filespaceinfo *) lfirst(lc);
StringInfoData buf;
/* Send CopyOutResponse message */
pq_beginmessage(&buf, 'H');
pq_sendbyte(&buf, 0); /* overall format */
pq_sendint(&buf, 0, 2); /* natts */
pq_endmessage(&buf);
/* In the main tar, include the backup_label first. */
if (fi->primary_path == NULL)
sendFileWithContent(BACKUP_LABEL_FILE, labelfile);
sendDir(fi->primary_path == NULL ? "." : fi->primary_path,
fi->primary_path == NULL ? 1 : strlen(fi->primary_path),
opt->exclude, false);
/* In the main tar, include pg_control last. */
if (fi->primary_path == NULL)
{
struct stat statbuf;
if (lstat(XLOG_CONTROL_FILE, &statbuf) != 0)
{
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not stat control file \"%s\": %m",
XLOG_CONTROL_FILE)));
}
sendFile(XLOG_CONTROL_FILE, XLOG_CONTROL_FILE, &statbuf);
elogif(debug_basebackup, LOG,
"basebackup perform -- Sent file %s." , XLOG_CONTROL_FILE);
}
/*
* If we're including WAL, and this is the main data directory we
* don't terminate the tar stream here. Instead, we will append
* the xlog files below and terminate it then. This is safe since
* the main data directory is always sent *last*.
*/
if (opt->includewal && fi->xlogdir)
{
Assert(lnext(lc) == NULL);
}
else
pq_putemptymessage('c'); /* CopyDone */
}
}
/* ----------------
* printtup_internal_20 --- print a binary tuple in protocol 2.0
*
* We use a different message type, i.e. 'B' instead of 'D' to
* indicate a tuple in internal (binary) form.
*
* This is largely same as printtup_20, except we use binary formatting.
* ----------------
*/
static void
printtup_internal_20(TupleTableSlot *slot, DestReceiver *self)
{
TupleDesc typeinfo = slot->tts_tupleDescriptor;
DR_printtup *myState = (DR_printtup *) self;
StringInfoData buf;
int natts = typeinfo->natts;
int i,
j,
k;
/* Set or update my derived attribute info, if needed */
if (myState->attrinfo != typeinfo || myState->nattrs != natts)
printtup_prepare_info(myState, typeinfo, natts);
/* Make sure the tuple is fully deconstructed */
slot_getallattrs(slot);
/*
* tell the frontend to expect new tuple data (in binary style)
*/
pq_beginmessage(&buf, 'B');
/*
* send a bitmap of which attributes are not null
*/
j = 0;
k = 1 << 7;
for (i = 0; i < natts; ++i)
{
if (!slot->tts_isnull[i])
j |= k; /* set bit if not null */
k >>= 1;
if (k == 0) /* end of byte? */
{
pq_sendint(&buf, j, 1);
j = 0;
k = 1 << 7;
}
}
if (k != (1 << 7)) /* flush last partial byte */
pq_sendint(&buf, j, 1);
/*
* send the attributes of this tuple
*/
for (i = 0; i < natts; ++i)
{
PrinttupAttrInfo *thisState = myState->myinfo + i;
Datum origattr = slot->tts_values[i],
attr;
bytea *outputbytes;
if (slot->tts_isnull[i])
continue;
Assert(thisState->format == 1);
/*
* If we have a toasted datum, forcibly detoast it here to avoid
* memory leakage inside the type's output routine.
*/
if (thisState->typisvarlena)
attr = PointerGetDatum(PG_DETOAST_DATUM(origattr));
else
attr = origattr;
outputbytes = SendFunctionCall(&thisState->finfo, attr);
/* We assume the result will not have been toasted */
pq_sendint(&buf, VARSIZE(outputbytes) - VARHDRSZ, 4);
pq_sendbytes(&buf, VARDATA(outputbytes),
VARSIZE(outputbytes) - VARHDRSZ);
pfree(outputbytes);
/* Clean up detoasted copy, if any */
if (DatumGetPointer(attr) != DatumGetPointer(origattr))
pfree(DatumGetPointer(attr));
}
pq_endmessage(&buf);
}