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/*
* Copyright (c) 2000 Silicon Graphics, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* Further, this software is distributed without any warranty that it is
* free of the rightful claim of any third person regarding infringement
* or the like. Any license provided herein, whether implied or
* otherwise, applies only to this software file. Patent licenses, if
* any, provided herein do not apply to combinations of this program with
* other software, or any other product whatsoever.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
* Mountain View, CA 94043, or:
*
* http://www.sgi.com
*
* For further information regarding this notice, see:
*
* http://oss.sgi.com/projects/GenInfo/NoticeExplan/
*/
#ifndef _WRITE_LOG_H_
#define _WRITE_LOG_H_
/*
* Constants defining the max size of various wlog_rec fields. ANY SIZE
* CHANGES HERE MUST BE REFLECTED IN THE WLOG_REC_DISK STRUCTURE DEFINED
* BELOW.
*/
#define WLOG_MAX_PATH 128
#define WLOG_MAX_PATTERN 64
#define WLOG_MAX_HOST 8
#define WLOG_REC_MAX_SIZE (sizeof(struct wlog_rec)+WLOG_MAX_PATH+WLOG_MAX_PATTERN+WLOG_MAX_HOST+2)
/*
* User view of a write log record. Note that this is not necessiliary
* how the data is formatted on disk (signifigant compression occurrs), so
* don't expect to od the write log file and see things formatted this way.
*/
struct wlog_rec {
int w_pid; /* pid doing the write */
int w_offset; /* file offset */
int w_nbytes; /* # bytes written */
int w_oflags; /* low-order open() flags */
int w_done; /* 1 if io confirmed done */
int w_async; /* 1 if async write (writea) */
char w_host[WLOG_MAX_HOST+1]; /* host doing write - */
/* null terminated */
int w_hostlen; /* host name length */
char w_path[WLOG_MAX_PATH+1]; /* file written to - */
/* null terminated */
int w_pathlen; /* file name length */
char w_pattern[WLOG_MAX_PATTERN+1]; /* pattern written - */
/* null terminated */
int w_patternlen; /* pattern length */
};
#ifndef uint
#define uint unsigned int
#endif
/*
* On-disk structure of a wlog_rec. Actually, the record consists of
* 3 parts: [wlog_rec_disk structure][variable length data][length]
* where length is a 2 byte field containing the total record length
* (including the 2 bytes). It is used for scanning the logfile in reverse
* order.
*
* The variable length data includes the path, host, and pattern (in that
* order). The lengths of these pieces of data are held in the
* wlog_rec_disk structure. Thus, the actual on-disk record looks like
* this (top is lower byte offset):
*
* struct wlog_rec_disk
* path (w_pathlen bytes - not null terminated)
* host (w_hostlen bytes - not null terminated)
* pattern (w_patternlen bytes - not null terminated)
* 2-byte record length
*
* Another way of looking at it is:
*
* <struct wlog_rec_disk><path (wpathlen bytes)>-->
* --><host (w_hostlen bytes)><pattern (w_patternlen bytes)><length (2 bytes)>
*
* The maximum length of this record is defined by the WLOG_REC_MAX_SIZE
* record. Note that the 2-byte record length forces this to be
* <= 64k bytes.
*
* Note that there is lots of bit-masking done here. The w_pathlen,
* w_hostlen, and w_patternlen fields MUST have enough bits to hold
* WLOG_MAX_PATH, WLOG_MAX_HOST, and WLOG_MAX_PATTERN bytes respectivly.
*/
struct wlog_rec_disk {
#ifdef CRAY
uint w_offset : 44; /* file offset */
uint w_extra0 : 20; /* EXTRA BITS IN WORD 0 */
#else
/* NB: sgi is pissy about fields > 32 bit, even cc -mips3 */
uint w_offset : 32; /* file offset */
uint w_extra0 : 32; /* EXTRA BITS IN WORD 0 */
#endif
uint w_nbytes : 32; /* # bytes written */
uint w_oflags : 32; /* low-order open() flags */
uint w_pid : 17; /* pid doing the write */
uint w_pathlen : 7; /* length of file path */
uint w_patternlen: 6; /* length of pattern */
uint w_hostlen : 4; /* length of host */
uint w_done : 1; /* 1 if io confirmed done */
uint w_async : 1; /* 1 if async write (writea) */
uint w_extra2 : 28; /* EXTRA BITS IN WORD 2 */
};
/*
* write log file datatype. wlog_open() initializes this structure
* which is then passed around to the various wlog_xxx routines.
*/
struct wlog_file {
int w_afd; /* append fd */
int w_rfd; /* random-access fd */
char w_file[1024]; /* name of the write_log */
};
/*
* return value defines for the user-supplied function to
* wlog_scan_backward().
*/
#define WLOG_STOP_SCAN 0
#define WLOG_CONTINUE_SCAN 1
/*
* wlog prototypes
*/
#if __STDC__
extern int wlog_open(struct wlog_file *wfile, int trunc, int mode);
extern int wlog_close(struct wlog_file *wfile);
extern int wlog_record_write(struct wlog_file *wfile,
struct wlog_rec *wrec, long offset);
extern int wlog_scan_backward(struct wlog_file *wfile, int nrecs,
int (*func)(struct wlog_rec *rec),
long data);
#else
int wlog_open();
int wlog_close();
int wlog_record_write();
int wlog_scan_backward();
#endif
extern char Wlog_Error_String[];
#endif /* _WRITE_LOG_H_ */
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