1 /*-------------------------------------------------------------------------
4 * Exports from postmaster/syslogger.c.
6 * Copyright (c) 2004-2012, PostgreSQL Global Development Group
8 * src/include/postmaster/syslogger.h
10 *-------------------------------------------------------------------------
15 #include <limits.h> /* for PIPE_BUF */
19 * Primitive protocol structure for writing to syslogger pipe(s). The idea
20 * here is to divide long messages into chunks that are not more than
21 * PIPE_BUF bytes long, which according to POSIX spec must be written into
22 * the pipe atomically. The pipe reader then uses the protocol headers to
23 * reassemble the parts of a message into a single string. The reader can
24 * also cope with non-protocol data coming down the pipe, though we cannot
25 * guarantee long strings won't get split apart.
27 * We use non-nul bytes in is_last to make the protocol a tiny bit
28 * more robust against finding a false double nul byte prologue. But
29 * we still might find it in the len and/or pid bytes unless we're careful.
33 /* Are there any systems with PIPE_BUF > 64K? Unlikely, but ... */
35 #define PIPE_CHUNK_SIZE 65536
37 #define PIPE_CHUNK_SIZE ((int) PIPE_BUF)
39 #else /* not defined */
40 /* POSIX says the value of PIPE_BUF must be at least 512, so use that */
41 #define PIPE_CHUNK_SIZE 512
46 char nuls[2]; /* always \0\0 */
47 uint16 len; /* size of this chunk (counts data only) */
48 int32 pid; /* writer's pid */
49 char is_last; /* last chunk of message? 't' or 'f' ('T' or
50 * 'F' for CSV case) */
51 char data[1]; /* data payload starts here */
56 PipeProtoHeader proto;
57 char filler[PIPE_CHUNK_SIZE];
60 #define PIPE_HEADER_SIZE offsetof(PipeProtoHeader, data)
61 #define PIPE_MAX_PAYLOAD ((int) (PIPE_CHUNK_SIZE - PIPE_HEADER_SIZE))
65 extern bool Logging_collector;
66 extern int Log_RotationAge;
67 extern int Log_RotationSize;
68 extern PGDLLIMPORT char *Log_directory;
69 extern PGDLLIMPORT char *Log_filename;
70 extern bool Log_truncate_on_rotation;
71 extern int Log_file_mode;
73 extern bool am_syslogger;
76 extern int syslogPipe[2];
78 extern HANDLE syslogPipe[2];
82 extern int SysLogger_Start(void);
84 extern void write_syslogger_file(const char *buffer, int count, int dest);
87 extern void SysLoggerMain(int argc, char *argv[]);
90 #endif /* _SYSLOGGER_H */