1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
/*-------------------------------------------------------------------------
*
* walreceiver.h
* Exports from replication/walreceiverfuncs.c.
*
* Portions Copyright (c) 2010-2012, PostgreSQL Global Development Group
*
* src/include/replication/walreceiver.h
*
*-------------------------------------------------------------------------
*/
#ifndef _WALRECEIVER_H
#define _WALRECEIVER_H
#include "access/xlog.h"
#include "access/xlogdefs.h"
#include "storage/spin.h"
#include "pgtime.h"
/* user-settable parameters */
extern int wal_receiver_status_interval;
extern int wal_receiver_timeout;
extern bool hot_standby_feedback;
/*
* MAXCONNINFO: maximum size of a connection string.
*
* XXX: Should this move to pg_config_manual.h?
*/
#define MAXCONNINFO 1024
/* Can we allow the standby to accept replication connection from another standby? */
#define AllowCascadeReplication() (EnableHotStandby && max_wal_senders > 0)
/*
* Values for WalRcv->walRcvState.
*/
typedef enum
{
WALRCV_STOPPED, /* stopped and mustn't start up again */
WALRCV_STARTING, /* launched, but the process hasn't
* initialized yet */
WALRCV_RUNNING, /* walreceiver is running */
WALRCV_STOPPING /* requested to stop, but still running */
} WalRcvState;
/* Shared memory area for management of walreceiver process */
typedef struct
{
/*
* PID of currently active walreceiver process, its current state and
* start time (actually, the time at which it was requested to be
* started).
*/
pid_t pid;
WalRcvState walRcvState;
pg_time_t startTime;
/*
* receiveStart is the first byte position that will be received. When
* startup process starts the walreceiver, it sets receiveStart to the
* point where it wants the streaming to begin.
*/
XLogRecPtr receiveStart;
/*
* receivedUpto-1 is the last byte position that has already been
* received. At the first startup of walreceiver, receivedUpto is set to
* receiveStart. After that, walreceiver updates this whenever it flushes
* the received WAL to disk.
*/
XLogRecPtr receivedUpto;
/*
* latestChunkStart is the starting byte position of the current "batch"
* of received WAL. It's actually the same as the previous value of
* receivedUpto before the last flush to disk. Startup process can use
* this to detect whether it's keeping up or not.
*/
XLogRecPtr latestChunkStart;
/*
* Time of send and receive of any message received.
*/
TimestampTz lastMsgSendTime;
TimestampTz lastMsgReceiptTime;
/*
* Latest reported end of WAL on the sender
*/
XLogRecPtr latestWalEnd;
TimestampTz latestWalEndTime;
/*
* connection string; is used for walreceiver to connect with the primary.
*/
char conninfo[MAXCONNINFO];
slock_t mutex; /* locks shared variables shown above */
} WalRcvData;
extern WalRcvData *WalRcv;
/* libpqwalreceiver hooks */
typedef bool (*walrcv_connect_type) (char *conninfo, XLogRecPtr startpoint);
extern PGDLLIMPORT walrcv_connect_type walrcv_connect;
typedef bool (*walrcv_receive_type) (int timeout, unsigned char *type,
char **buffer, int *len);
extern PGDLLIMPORT walrcv_receive_type walrcv_receive;
typedef void (*walrcv_send_type) (const char *buffer, int nbytes);
extern PGDLLIMPORT walrcv_send_type walrcv_send;
typedef void (*walrcv_disconnect_type) (void);
extern PGDLLIMPORT walrcv_disconnect_type walrcv_disconnect;
/* prototypes for functions in walreceiver.c */
extern void WalReceiverMain(void) __attribute__((noreturn));
/* prototypes for functions in walreceiverfuncs.c */
extern Size WalRcvShmemSize(void);
extern void WalRcvShmemInit(void);
extern void ShutdownWalRcv(void);
extern bool WalRcvInProgress(void);
extern void RequestXLogStreaming(XLogRecPtr recptr, const char *conninfo);
extern XLogRecPtr GetWalRcvWriteRecPtr(XLogRecPtr *latestChunkStart);
extern int GetReplicationApplyDelay(void);
extern int GetReplicationTransferLatency(void);
#endif /* _WALRECEIVER_H */
|
