Consistently declare timestamp variables as TimestampTz.

Twiddle the replication-related code so that its timestamp variables
are declared TimestampTz, rather than the uninformative "int64" that
was previously used for meant-to-be-always-integer timestamps.
This resolves the int64-vs-TimestampTz declaration inconsistencies
introduced by commit 7c030783a, though in the opposite direction to
what was originally suggested.

This required including datatype/timestamp.h in a couple more places
than before.  I decided it would be a good idea to slim down that
header by not having it pull in <float.h> etc, as those headers are
no longer at all relevant to its purpose.  Unsurprisingly, a small number
of .c files turn out to have been depending on those inclusions, so add
them back in the .c files as needed.

Discussion: https://postgr.es/m/26788.1487455319@sss.pgh.pa.us
Discussion: https://postgr.es/m/27694.1487456324@sss.pgh.pa.us

contrib/auth_delay/auth_delay.c

@@ -11,6 +11,8 @@
  */
 #include "postgres.h"
 
+#include <limits.h>
+
 #include "libpq/auth.h"
 #include "port.h"
 #include "utils/guc.h"

contrib/btree_gist/btree_ts.c

@@ -3,6 +3,8 @@
  */
 #include "postgres.h"
 
+#include <limits.h>
+
 #include "btree_gist.h"
 #include "btree_utils_num.h"
 #include "utils/builtins.h"

src/backend/access/common/reloptions.c

@@ -15,6 +15,8 @@
 
 #include "postgres.h"
 
+#include <float.h>
+
 #include "access/gist_private.h"
 #include "access/hash.h"
 #include "access/htup_details.h"

src/backend/access/transam/xlog.c

@@ -15,6 +15,7 @@
 #include "postgres.h"
 
 #include <ctype.h>
+#include <math.h>
 #include <time.h>
 #include <fcntl.h>
 #include <sys/stat.h>

src/backend/commands/prepare.c

@@ -16,6 +16,8 @@
  */
 #include "postgres.h"
 
+#include <limits.h>
+
 #include "access/xact.h"
 #include "catalog/pg_type.h"
 #include "commands/createas.h"

src/backend/executor/nodeBitmapHeapscan.c

@@ -35,6 +35,8 @@
  */
 #include "postgres.h"
 
+#include <math.h>
+
 #include "access/relscan.h"
 #include "access/transam.h"
 #include "executor/execdebug.h"

src/backend/replication/basebackup.c

@@ -92,10 +92,10 @@ static uint64 throttling_sample;
 static int64 throttling_counter;
 
 /* The minimum time required to transfer throttling_sample bytes. */
-static int64 elapsed_min_unit;
+static TimeOffset elapsed_min_unit;
 
 /* The last check of the transfer rate. */
-static int64 throttled_last;
+static TimestampTz throttled_last;
 
 /*
  * The contents of these directories are removed or recreated during server
@@ -254,7 +254,7 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
 			throttling_counter = 0;
 
 			/* The 'real data' starts now (header was ignored). */
-			throttled_last = GetCurrentIntegerTimestamp();
+			throttled_last = GetCurrentTimestamp();
 		}
 		else
 		{
@@ -1333,7 +1333,7 @@ _tarWriteDir(const char *pathbuf, int basepathlen, struct stat *statbuf,
 static void
 throttle(size_t increment)
 {
-	int64		elapsed,
+	TimeOffset	elapsed,
 				elapsed_min,
 				sleep;
 	int			wait_result;
@@ -1346,7 +1346,7 @@ throttle(size_t increment)
 		return;
 
 	/* Time elapsed since the last measurement (and possible wake up). */
-	elapsed = GetCurrentIntegerTimestamp() - throttled_last;
+	elapsed = GetCurrentTimestamp() - throttled_last;
 	/* How much should have elapsed at minimum? */
 	elapsed_min = elapsed_min_unit * (throttling_counter / throttling_sample);
 	sleep = elapsed_min - elapsed;
@@ -1381,5 +1381,5 @@ throttle(size_t increment)
 	 * Time interval for the remaining amount and possible next increments
 	 * starts now.
 	 */
-	throttled_last = GetCurrentIntegerTimestamp();
+	throttled_last = GetCurrentTimestamp();
 }

src/backend/replication/logical/worker.c

@@ -981,12 +981,11 @@ ApplyLoop(void)
 					{
 						XLogRecPtr	start_lsn;
 						XLogRecPtr	end_lsn;
-						TimestampTz	send_time;
+						TimestampTz send_time;
 
 						start_lsn = pq_getmsgint64(&s);
 						end_lsn = pq_getmsgint64(&s);
-						send_time =
-							IntegerTimestampToTimestampTz(pq_getmsgint64(&s));
+						send_time = pq_getmsgint64(&s);
 
 						if (last_received < start_lsn)
 							last_received = start_lsn;
@@ -1000,13 +999,12 @@ ApplyLoop(void)
 					}
 					else if (c == 'k')
 					{
-						XLogRecPtr endpos;
-						TimestampTz	timestamp;
-						bool reply_requested;
+						XLogRecPtr	endpos;
+						TimestampTz timestamp;
+						bool		reply_requested;
 
 						endpos = pq_getmsgint64(&s);
-						timestamp =
-							IntegerTimestampToTimestampTz(pq_getmsgint64(&s));
+						timestamp = pq_getmsgint64(&s);
 						reply_requested = pq_getmsgbyte(&s);
 
 						send_feedback(endpos, reply_requested, false);

src/backend/replication/walreceiver.c

@@ -892,8 +892,7 @@ XLogWalRcvProcessMsg(unsigned char type, char *buf, Size len)
 				/* read the fields */
 				dataStart = pq_getmsgint64(&incoming_message);
 				walEnd = pq_getmsgint64(&incoming_message);
-				sendTime = IntegerTimestampToTimestampTz(
-										  pq_getmsgint64(&incoming_message));
+				sendTime = pq_getmsgint64(&incoming_message);
 				ProcessWalSndrMessage(walEnd, sendTime);
 
 				buf += hdrlen;
@@ -913,8 +912,7 @@ XLogWalRcvProcessMsg(unsigned char type, char *buf, Size len)
 
 				/* read the fields */
 				walEnd = pq_getmsgint64(&incoming_message);
-				sendTime = IntegerTimestampToTimestampTz(
-										  pq_getmsgint64(&incoming_message));
+				sendTime = pq_getmsgint64(&incoming_message);
 				replyRequested = pq_getmsgbyte(&incoming_message);
 
 				ProcessWalSndrMessage(walEnd, sendTime);
@@ -1149,7 +1147,7 @@ XLogWalRcvSendReply(bool force, bool requestReply)
 	pq_sendint64(&reply_message, writePtr);
 	pq_sendint64(&reply_message, flushPtr);
 	pq_sendint64(&reply_message, applyPtr);
-	pq_sendint64(&reply_message, GetCurrentIntegerTimestamp());
+	pq_sendint64(&reply_message, GetCurrentTimestamp());
 	pq_sendbyte(&reply_message, requestReply ? 1 : 0);
 
 	/* Send it */
@@ -1241,7 +1239,7 @@ XLogWalRcvSendHSFeedback(bool immed)
 	/* Construct the message and send it. */
 	resetStringInfo(&reply_message);
 	pq_sendbyte(&reply_message, 'h');
-	pq_sendint64(&reply_message, GetCurrentIntegerTimestamp());
+	pq_sendint64(&reply_message, GetCurrentTimestamp());
 	pq_sendint(&reply_message, xmin, 4);
 	pq_sendint(&reply_message, nextEpoch, 4);
 	walrcv_send(wrconn, reply_message.data, reply_message.len);

src/backend/replication/walsender.c

@@ -823,12 +823,13 @@ CreateReplicationSlot(CreateReplicationSlotCmd *cmd)
 	dest = CreateDestReceiver(DestRemoteSimple);
 	MemSet(nulls, false, sizeof(nulls));
 
-	/*
+	/*----------
 	 * Need a tuple descriptor representing four columns:
 	 * - first field: the slot name
 	 * - second field: LSN at which we became consistent
 	 * - third field: exported snapshot's name
 	 * - fourth field: output plugin
+	 *----------
 	 */
 	tupdesc = CreateTemplateTupleDesc(4, false);
 	TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 1, "slot_name",
@@ -1014,7 +1015,7 @@ WalSndWriteData(LogicalDecodingContext *ctx, XLogRecPtr lsn, TransactionId xid,
 	 * several releases by streaming physical replication.
 	 */
 	resetStringInfo(&tmpbuf);
-	pq_sendint64(&tmpbuf, GetCurrentIntegerTimestamp());
+	pq_sendint64(&tmpbuf, GetCurrentTimestamp());
 	memcpy(&ctx->out->data[1 + sizeof(int64) + sizeof(int64)],
 		   tmpbuf.data, sizeof(int64));
 
@@ -2334,7 +2335,7 @@ XLogSendPhysical(void)
 	 * Fill the send timestamp last, so that it is taken as late as possible.
 	 */
 	resetStringInfo(&tmpbuf);
-	pq_sendint64(&tmpbuf, GetCurrentIntegerTimestamp());
+	pq_sendint64(&tmpbuf, GetCurrentTimestamp());
 	memcpy(&output_message.data[1 + sizeof(int64) + sizeof(int64)],
 		   tmpbuf.data, sizeof(int64));
 
@@ -2842,7 +2843,7 @@ WalSndKeepalive(bool requestReply)
 	resetStringInfo(&output_message);
 	pq_sendbyte(&output_message, 'k');
 	pq_sendint64(&output_message, sentPtr);
-	pq_sendint64(&output_message, GetCurrentIntegerTimestamp());
+	pq_sendint64(&output_message, GetCurrentTimestamp());
 	pq_sendbyte(&output_message, requestReply ? 1 : 0);
 
 	/* ... and send it wrapped in CopyData */

src/backend/tcop/pquery.c

@@ -15,6 +15,8 @@
 
 #include "postgres.h"
 
+#include <limits.h>
+
 #include "access/xact.h"
 #include "commands/prepare.h"
 #include "executor/tstoreReceiver.h"

src/backend/utils/adt/nabstime.c

@@ -19,6 +19,7 @@
 #include <ctype.h>
 #include <float.h>
 #include <limits.h>
+#include <math.h>
 #include <time.h>
 #include <sys/time.h>
 

src/backend/utils/cache/inval.c

@@ -95,6 +95,8 @@
  */
 #include "postgres.h"
 
+#include <limits.h>
+
 #include "access/htup_details.h"
 #include "access/xact.h"
 #include "catalog/catalog.h"

src/backend/utils/time/snapmgr.c

@@ -83,13 +83,13 @@ typedef struct OldSnapshotControlData
 	 * only allowed to move forward.
 	 */
 	slock_t		mutex_current;	/* protect current_timestamp */
-	int64		current_timestamp;		/* latest snapshot timestamp */
+	TimestampTz current_timestamp;		/* latest snapshot timestamp */
 	slock_t		mutex_latest_xmin;		/* protect latest_xmin and
 										 * next_map_update */
 	TransactionId latest_xmin;	/* latest snapshot xmin */
-	int64		next_map_update;	/* latest snapshot valid up to */
+	TimestampTz next_map_update;	/* latest snapshot valid up to */
 	slock_t		mutex_threshold;	/* protect threshold fields */
-	int64		threshold_timestamp;	/* earlier snapshot is old */
+	TimestampTz threshold_timestamp;	/* earlier snapshot is old */
 	TransactionId threshold_xid;	/* earlier xid may be gone */
 
 	/*
@@ -121,7 +121,7 @@ typedef struct OldSnapshotControlData
 	 * Persistence is not needed.
 	 */
 	int			head_offset;	/* subscript of oldest tracked time */
-	int64		head_timestamp; /* time corresponding to head xid */
+	TimestampTz head_timestamp; /* time corresponding to head xid */
 	int			count_used;		/* how many slots are in use */
 	TransactionId xid_by_minute[FLEXIBLE_ARRAY_MEMBER];
 } OldSnapshotControlData;
@@ -219,7 +219,7 @@ static Snapshot FirstXactSnapshot = NULL;
 static List *exportedSnapshots = NIL;
 
 /* Prototypes for local functions */
-static int64 AlignTimestampToMinuteBoundary(int64 ts);
+static TimestampTz AlignTimestampToMinuteBoundary(TimestampTz ts);
 static Snapshot CopySnapshot(Snapshot snapshot);
 static void FreeSnapshot(Snapshot snapshot);
 static void SnapshotResetXmin(void);
@@ -239,7 +239,7 @@ typedef struct SerializedSnapshotData
 	bool		suboverflowed;
 	bool		takenDuringRecovery;
 	CommandId	curcid;
-	int64		whenTaken;
+	TimestampTz whenTaken;
 	XLogRecPtr	lsn;
 } SerializedSnapshotData;
 
@@ -1611,26 +1611,29 @@ ThereAreNoPriorRegisteredSnapshots(void)
 
 
 /*
- * Return an int64 timestamp which is exactly on a minute boundary.
+ * Return a timestamp that is exactly on a minute boundary.
  *
  * If the argument is already aligned, return that value, otherwise move to
  * the next minute boundary following the given time.
  */
-static int64
-AlignTimestampToMinuteBoundary(int64 ts)
+static TimestampTz
+AlignTimestampToMinuteBoundary(TimestampTz ts)
 {
-	int64		retval = ts + (USECS_PER_MINUTE - 1);
+	TimestampTz retval = ts + (USECS_PER_MINUTE - 1);
 
 	return retval - (retval % USECS_PER_MINUTE);
 }
 
 /*
- * Get current timestamp for snapshots as int64 that never moves backward.
+ * Get current timestamp for snapshots
+ *
+ * This is basically GetCurrentTimestamp(), but with a guarantee that
+ * the result never moves backward.
  */
-int64
+TimestampTz
 GetSnapshotCurrentTimestamp(void)
 {
-	int64		now = GetCurrentIntegerTimestamp();
+	TimestampTz now = GetCurrentTimestamp();
 
 	/*
 	 * Don't let time move backward; if it hasn't advanced, use the old value.
@@ -1652,10 +1655,10 @@ GetSnapshotCurrentTimestamp(void)
  * XXX: So far, we never trust that a 64-bit value can be read atomically; if
  * that ever changes, we could get rid of the spinlock here.
  */
-int64
+TimestampTz
 GetOldSnapshotThresholdTimestamp(void)
 {
-	int64		threshold_timestamp;
+	TimestampTz threshold_timestamp;
 
 	SpinLockAcquire(&oldSnapshotControl->mutex_threshold);
 	threshold_timestamp = oldSnapshotControl->threshold_timestamp;
@@ -1665,7 +1668,7 @@ GetOldSnapshotThresholdTimestamp(void)
 }
 
 static void
-SetOldSnapshotThresholdTimestamp(int64 ts, TransactionId xlimit)
+SetOldSnapshotThresholdTimestamp(TimestampTz ts, TransactionId xlimit)
 {
 	SpinLockAcquire(&oldSnapshotControl->mutex_threshold);
 	oldSnapshotControl->threshold_timestamp = ts;
@@ -1690,10 +1693,10 @@ TransactionIdLimitedForOldSnapshots(TransactionId recentXmin,
 		&& old_snapshot_threshold >= 0
 		&& RelationAllowsEarlyPruning(relation))
 	{
-		int64		ts = GetSnapshotCurrentTimestamp();
+		TimestampTz ts = GetSnapshotCurrentTimestamp();
 		TransactionId xlimit = recentXmin;
 		TransactionId latest_xmin;
-		int64		update_ts;
+		TimestampTz update_ts;
 		bool		same_ts_as_threshold = false;
 
 		SpinLockAcquire(&oldSnapshotControl->mutex_latest_xmin);
@@ -1790,11 +1793,11 @@ TransactionIdLimitedForOldSnapshots(TransactionId recentXmin,
  * Take care of the circular buffer that maps time to xid.
  */
 void
-MaintainOldSnapshotTimeMapping(int64 whenTaken, TransactionId xmin)
+MaintainOldSnapshotTimeMapping(TimestampTz whenTaken, TransactionId xmin)
 {
-	int64		ts;
+	TimestampTz ts;
 	TransactionId latest_xmin;
-	int64		update_ts;
+	TimestampTz update_ts;
 	bool		map_update_required = false;
 
 	/* Never call this function when old snapshot checking is disabled. */

src/bin/pg_basebackup/pg_recvlogical.c

@@ -57,7 +57,7 @@ static int	outfd = -1;
 static volatile sig_atomic_t time_to_abort = false;
 static volatile sig_atomic_t output_reopen = false;
 static bool output_isfile;
-static int64 output_last_fsync = -1;
+static TimestampTz output_last_fsync = -1;
 static bool output_needs_fsync = false;
 static XLogRecPtr output_written_lsn = InvalidXLogRecPtr;
 static XLogRecPtr output_fsync_lsn = InvalidXLogRecPtr;
@@ -112,7 +112,7 @@ usage(void)
  * Send a Standby Status Update message to server.
  */
 static bool
-sendFeedback(PGconn *conn, int64 now, bool force, bool replyRequested)
+sendFeedback(PGconn *conn, TimestampTz now, bool force, bool replyRequested)
 {
 	static XLogRecPtr last_written_lsn = InvalidXLogRecPtr;
 	static XLogRecPtr last_fsync_lsn = InvalidXLogRecPtr;
@@ -175,7 +175,7 @@ disconnect_and_exit(int code)
 }
 
 static bool
-OutputFsync(int64 now)
+OutputFsync(TimestampTz now)
 {
 	output_last_fsync = now;
 
@@ -212,7 +212,7 @@ StreamLogicalLog(void)
 {
 	PGresult   *res;
 	char	   *copybuf = NULL;
-	int64		last_status = -1;
+	TimestampTz last_status = -1;
 	int			i;
 	PQExpBuffer query;
 
@@ -285,7 +285,7 @@ StreamLogicalLog(void)
 		int			r;
 		int			bytes_left;
 		int			bytes_written;
-		int64		now;
+		TimestampTz now;
 		int			hdr_len;
 		XLogRecPtr	cur_record_lsn = InvalidXLogRecPtr;
 
@@ -365,8 +365,8 @@ StreamLogicalLog(void)
 			 * response back to the client.
 			 */
 			fd_set		input_mask;
-			int64		message_target = 0;
-			int64		fsync_target = 0;
+			TimestampTz message_target = 0;
+			TimestampTz fsync_target = 0;
 			struct timeval timeout;
 			struct timeval *timeoutptr = NULL;
 
@@ -394,7 +394,7 @@ StreamLogicalLog(void)
 			/* Now compute when to wakeup. */
 			if (message_target > 0 || fsync_target > 0)
 			{
-				int64		targettime;
+				TimestampTz targettime;
 				long		secs;
 				int			usecs;
 
@@ -622,7 +622,7 @@ StreamLogicalLog(void)
 
 	if (outfd != -1 && strcmp(outfile, "-") != 0)
 	{
-		int64		t = feGetCurrentTimestamp();
+		TimestampTz t = feGetCurrentTimestamp();
 
 		/* no need to jump to error on failure here, we're finishing anyway */
 		OutputFsync(t);

src/bin/pg_basebackup/receivelog.c

@@ -42,15 +42,15 @@ static PGresult *HandleCopyStream(PGconn *conn, StreamCtl *stream,
 static int	CopyStreamPoll(PGconn *conn, long timeout_ms);
 static int	CopyStreamReceive(PGconn *conn, long timeout, char **buffer);
 static bool ProcessKeepaliveMsg(PGconn *conn, StreamCtl *stream, char *copybuf,
-					int len, XLogRecPtr blockpos, int64 *last_status);
+					int len, XLogRecPtr blockpos, TimestampTz *last_status);
 static bool ProcessXLogDataMsg(PGconn *conn, StreamCtl *stream, char *copybuf, int len,
 				   XLogRecPtr *blockpos);
 static PGresult *HandleEndOfCopyStream(PGconn *conn, StreamCtl *stream, char *copybuf,
 					  XLogRecPtr blockpos, XLogRecPtr *stoppos);
 static bool CheckCopyStreamStop(PGconn *conn, StreamCtl *stream, XLogRecPtr blockpos,
 					XLogRecPtr *stoppos);
-static long CalculateCopyStreamSleeptime(int64 now, int standby_message_timeout,
-							 int64 last_status);
+static long CalculateCopyStreamSleeptime(TimestampTz now, int standby_message_timeout,
+							 TimestampTz last_status);
 
 static bool ReadEndOfStreamingResult(PGresult *res, XLogRecPtr *startpos,
 						 uint32 *timeline);
@@ -319,7 +319,7 @@ writeTimeLineHistoryFile(StreamCtl *stream, char *filename, char *content)
  * Send a Standby Status Update message to server.
  */
 static bool
-sendFeedback(PGconn *conn, XLogRecPtr blockpos, int64 now, bool replyRequested)
+sendFeedback(PGconn *conn, XLogRecPtr blockpos, TimestampTz now, bool replyRequested)
 {
 	char		replybuf[1 + 8 + 8 + 8 + 8 + 1];
 	int			len = 0;
@@ -761,7 +761,7 @@ HandleCopyStream(PGconn *conn, StreamCtl *stream,
 				 XLogRecPtr *stoppos)
 {
 	char	   *copybuf = NULL;
-	int64		last_status = -1;
+	TimestampTz last_status = -1;
 	XLogRecPtr	blockpos = stream->startpos;
 
 	still_sending = true;
@@ -769,7 +769,7 @@ HandleCopyStream(PGconn *conn, StreamCtl *stream,
 	while (1)
 	{
 		int			r;
-		int64		now;
+		TimestampTz now;
 		long		sleeptime;
 
 		/*
@@ -994,11 +994,11 @@ CopyStreamReceive(PGconn *conn, long timeout, char **buffer)
  */
 static bool
 ProcessKeepaliveMsg(PGconn *conn, StreamCtl *stream, char *copybuf, int len,
-					XLogRecPtr blockpos, int64 *last_status)
+					XLogRecPtr blockpos, TimestampTz *last_status)
 {
 	int			pos;
 	bool		replyRequested;
-	int64		now;
+	TimestampTz now;
 
 	/*
 	 * Parse the keepalive message, enclosed in the CopyData message. We just
@@ -1253,10 +1253,10 @@ CheckCopyStreamStop(PGconn *conn, StreamCtl *stream, XLogRecPtr blockpos,
  * Calculate how long send/receive loops should sleep
  */
 static long
-CalculateCopyStreamSleeptime(int64 now, int standby_message_timeout,
-							 int64 last_status)
+CalculateCopyStreamSleeptime(TimestampTz now, int standby_message_timeout,
+							 TimestampTz last_status)
 {
-	int64		status_targettime = 0;
+	TimestampTz status_targettime = 0;
 	long		sleeptime;
 
 	if (standby_message_timeout && still_sending)

src/bin/pg_basebackup/streamutil.c

@@ -433,20 +433,18 @@ DropReplicationSlot(PGconn *conn, const char *slot_name)
 
 /*
  * Frontend version of GetCurrentTimestamp(), since we are not linked with
- * backend code. The replication protocol always uses integer timestamps,
- * regardless of the server setting.
+ * backend code.
  */
-int64
+TimestampTz
 feGetCurrentTimestamp(void)
 {
-	int64		result;
+	TimestampTz result;
 	struct timeval tp;
 
 	gettimeofday(&tp, NULL);
 
-	result = (int64) tp.tv_sec -
+	result = (TimestampTz) tp.tv_sec -
 		((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY);
-
 	result = (result * USECS_PER_SEC) + tp.tv_usec;
 
 	return result;
@@ -457,10 +455,10 @@ feGetCurrentTimestamp(void)
  * backend code.
  */
 void
-feTimestampDifference(int64 start_time, int64 stop_time,
+feTimestampDifference(TimestampTz start_time, TimestampTz stop_time,
 					  long *secs, int *microsecs)
 {
-	int64		diff = stop_time - start_time;
+	TimestampTz diff = stop_time - start_time;
 
 	if (diff <= 0)
 	{
@@ -479,11 +477,11 @@ feTimestampDifference(int64 start_time, int64 stop_time,
  * linked with backend code.
  */
 bool
-feTimestampDifferenceExceeds(int64 start_time,
-							 int64 stop_time,
+feTimestampDifferenceExceeds(TimestampTz start_time,
+							 TimestampTz stop_time,
 							 int msec)
 {
-	int64		diff = stop_time - start_time;
+	TimestampTz diff = stop_time - start_time;
 
 	return (diff >= msec * INT64CONST(1000));
 }

src/bin/pg_basebackup/streamutil.h

@@ -15,6 +15,7 @@
 #include "libpq-fe.h"
 
 #include "access/xlogdefs.h"
+#include "datatype/timestamp.h"
 
 extern const char *progname;
 extern char *connection_string;
@@ -38,11 +39,11 @@ extern bool RunIdentifySystem(PGconn *conn, char **sysid,
 				  TimeLineID *starttli,
 				  XLogRecPtr *startpos,
 				  char **db_name);
-extern int64 feGetCurrentTimestamp(void);
-extern void feTimestampDifference(int64 start_time, int64 stop_time,
+extern TimestampTz feGetCurrentTimestamp(void);
+extern void feTimestampDifference(TimestampTz start_time, TimestampTz stop_time,
 					  long *secs, int *microsecs);
 
-extern bool feTimestampDifferenceExceeds(int64 start_time, int64 stop_time,
+extern bool feTimestampDifferenceExceeds(TimestampTz start_time, TimestampTz stop_time,
 							 int msec);
 extern void fe_sendint64(int64 i, char *buf);
 extern int64 fe_recvint64(char *buf);

src/include/datatype/timestamp.h

@@ -15,10 +15,6 @@
 #ifndef DATATYPE_TIMESTAMP_H
 #define DATATYPE_TIMESTAMP_H
 
-#include <math.h>
-#include <limits.h>
-#include <float.h>
-
 /*
  * Timestamp represents absolute time.
  *

src/include/utils/snapmgr.h

@@ -51,8 +51,8 @@ extern PGDLLIMPORT int old_snapshot_threshold;
 
 extern Size SnapMgrShmemSize(void);
 extern void SnapMgrInit(void);
-extern int64 GetSnapshotCurrentTimestamp(void);
-extern int64 GetOldSnapshotThresholdTimestamp(void);
+extern TimestampTz GetSnapshotCurrentTimestamp(void);
+extern TimestampTz GetOldSnapshotThresholdTimestamp(void);
 
 extern bool FirstSnapshotSet;
 
@@ -93,7 +93,8 @@ extern void DeleteAllExportedSnapshotFiles(void);
 extern bool ThereAreNoPriorRegisteredSnapshots(void);
 extern TransactionId TransactionIdLimitedForOldSnapshots(TransactionId recentXmin,
 									Relation relation);
-extern void MaintainOldSnapshotTimeMapping(int64 whenTaken, TransactionId xmin);
+extern void MaintainOldSnapshotTimeMapping(TimestampTz whenTaken,
+							   TransactionId xmin);
 
 extern char *ExportSnapshot(Snapshot snapshot);
 

src/include/utils/snapshot.h

@@ -15,6 +15,7 @@
 
 #include "access/htup.h"
 #include "access/xlogdefs.h"
+#include "datatype/timestamp.h"
 #include "lib/pairingheap.h"
 #include "storage/buf.h"
 
@@ -107,7 +108,7 @@ typedef struct SnapshotData
 	uint32		regd_count;		/* refcount on RegisteredSnapshots */
 	pairingheap_node ph_node;	/* link in the RegisteredSnapshots heap */
 
-	int64		whenTaken;		/* timestamp when snapshot was taken */
+	TimestampTz whenTaken;		/* timestamp when snapshot was taken */
 	XLogRecPtr	lsn;			/* position in the WAL stream when taken */
 } SnapshotData;
 

src/include/utils/timestamp.h

@@ -76,13 +76,6 @@ extern bool TimestampDifferenceExceeds(TimestampTz start_time,
 						   TimestampTz stop_time,
 						   int msec);
 
-/*
- * Prototypes for functions to deal with integer timestamps, when the native
- * format is float timestamps.
- */
-#define GetCurrentIntegerTimestamp()	GetCurrentTimestamp()
-#define IntegerTimestampToTimestampTz(timestamp) (timestamp)
-
 extern TimestampTz time_t_to_timestamptz(pg_time_t tm);
 extern pg_time_t timestamptz_to_time_t(TimestampTz t);