home *** CD-ROM | disk | FTP | other *** search
- /* -*-c++-*- */
-
- #ifndef __msgcath
-
-
- /***********************************************************
- Copyright 1990, by Alfalfa Software Incorporated, Cambridge, Massachusetts.
-
- All Rights Reserved
-
- Permission to use, copy, modify, and distribute this software and its
- documentation for any purpose and without fee is hereby granted,
- provided that the above copyright notice appear in all copies and that
- both that copyright notice and this permission notice appear in
- supporting documentation, and that Alfalfa's name not be used in
- advertising or publicity pertaining to distribution of the software
- without specific, written prior permission.
-
- ALPHALPHA DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
- ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
- ALPHALPHA BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
- ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
- WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
- ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
- SOFTWARE.
-
- If you make any modifications, bugfixes or other changes to this software
- we'd appreciate it if you could send a copy to us so we can keep things
- up-to-date. Many thanks.
- Kee Hinckley
- Alfalfa Software, Inc.
- 267 Allston St., #3
- Cambridge, MA 02139 USA
- nazgul@alfalfa.com
-
- ******************************************************************/
-
-
- #include <sys/types.h>
-
- /*
- * On disk data structures
- */
-
- /* Edit History
-
- 02/25/91 2 nazgul Byte order flags, upped the version number
- 11/03/90 1 hamilton Alphalpha->Alfalfa & OmegaMail->Poste
- 08/13/90 1 schulert move from ua to omu
- */
-
- /* For or'd constants */
- #define MCMakeId(s,m) (unsigned long) ( ((unsigned short)s << (sizeof(short)*8)) \
- | (unsigned short)m )
- #define MCSetId(id) (unsigned int) ( id >> (sizeof(short) * 8) )
- #define MCMsgId(id) (unsigned int) ( (id << (sizeof(short) * 8)) \
- >> (sizeof(short) * 8) )
- #undef S
- #undef UI
- #undef UL
-
- #define MCMagicLen 8
- #define MCMagic "*nazgul*"
- #define MCLastMsg 0
- #define MCLastSet 0
-
- #define MCMajorVer 1
- #define MCMinorVer 0
-
- /*
- * Critical note here. Sets and Messages *MUST* be stored in ascending
- * order. There are stored that way (by specification) in the original
- * data file, however in the process of merging in new stuff you might
- * mix that up. Don't! The catget stuff does a binary search and will
- * totally lose it if these aren't in order (not contiguous mind you, just
- * in order. If this turns out to be a major problem this could be enhanced
- * by adding a 'sorted' flag to the db, and sorting msgs and sets at load
- * time if things aren't sorted, but I'd like not to have to do that.
- */
-
- /*
- * I have tried here to define data structures which can be used
- * while the catalog is on disk, and at runtime.
- * This is rather dangerous of course, but I think it can be done without
- * overly increasing the memory usage, and it makes loading and storing
- * somewhat simpler and less prone to accidents. I have also tried to
- * define on disk data structures which can be updated in place, so that
- * with a very large catalog (e.g. all system errors) you don't have to
- * load everything in memory in order to add or update one set. With
- * this in mind there are "invalid" flags which allow items to be
- * invalidated and thus not loaded at runtime. Note however that although
- * I pay attention to these when I load the DB, I do not currently use
- * them in gencat (it just reads everything into memory), so there is
- * no guarantee that this will all work.
- */
-
- /* These should be publicly available */
-
- #define MCLoadBySet 0 /* Load entire sets as they are used */
- #define MCLoadAll 1 /* Load entire DB on catopen */
-
- extern char *MCAppPath; /* Additional search path for strings (appended) */
-
- /*
- * MCOffsetT - Union to handle both disk and runtime pointers
- */
- typedef union {
- off_t off;
- char *str;
- void *ptr;
- struct _MCMsgT *msg;
- struct _MCSetT *set;
- } MCOffsetT;
-
- /*
- * MCMsgT - Message structure (disk and runtime)
- */
- typedef struct _MCMsgT {
- long msgId; /* Id of this message */
- MCOffsetT msg; /* Relative offset on disk or pointer in memory */
- long invalid; /* Valid on disk, loaded in memory */
- } MCMsgT;
-
- /*
- * MCSetT - Set structure (disk and runtime)
- */
- typedef struct _MCSetT {
- long setId; /* Id of this set */
- off_t nextSet; /* Offset of next set on disk */
- union {
- off_t firstMsg; /* Offset to first Msg (while on disk) */
- MCMsgT *msgs; /* Pointer to array of msgs (in mem, loaded) */
- } u;
- MCOffsetT data; /* Offset to data, or pointer to data */
- long dataLen; /* Length of data area on disk */
- long numMsgs; /* Number of messages */
- long invalid; /* Valid on disk, loaded in memory */
- } MCSetT;
-
- /*
- * MCCatT - Runtime catalog pointer
- */
- typedef struct {
- long loadType; /* How to load the messages (see MSLoadType) */
- #ifdef HAVE_MMAP
- union {
- #endif
- int fd; /* File descriptor of catalog (if load-on-demand) */
- #ifdef HAVE_MMAP
- caddr_t addr; /* Mmaped() address */
- } u;
- off_t size; /* File size */
- #endif
- long numSets; /* Number of sets */
- MCSetT *sets; /* Pointer to the sets */
- off_t firstSet; /* Offset of first set on disk */
- } MCCatT;
-
- /*
- * MCHeaderT - Disk file header
- */
- typedef struct {
- char magic[MCMagicLen]; /* Magic cookie "*nazgul*" */
- long majorVer; /* ++ on incompatible changes */
- long minorVer; /* ++ on compatible changes */
- long flags; /* Informational flags */
- long numSets; /* Number of valid Sets */
- off_t firstSet; /* Offset of first set on disk */
- } MCHeaderT;
-
- /* Some flags */
- #define MC68KByteOrder 0x01
- #define MCn86ByteOrder 0x02
-
-
-
-
- #endif
-