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