/***************************************************************************
* *
* Squish Developers Kit Source, Version 2.00 *
* Copyright 1989-1994 by SCI Communications. All rights reserved. *
* *
* USE OF THIS FILE IS SUBJECT TO THE RESTRICTIONS CONTAINED IN THE *
* SQUISH DEVELOPERS KIT LICENSING AGREEMENT IN SQDEV.PRN. IF YOU DO NOT *
* FIND THE TEXT OF THIS AGREEMENT IN THE AFOREMENTIONED FILE, OR IF YOU *
* DO NOT HAVE THIS FILE, YOU SHOULD IMMEDIATELY CONTACT THE AUTHOR AT *
* ONE OF THE ADDRESSES LISTED BELOW. IN NO EVENT SHOULD YOU PROCEED TO *
* USE THIS FILE WITHOUT HAVING ACCEPTED THE TERMS OF THE SQUISH *
* DEVELOPERS KIT LICENSING AGREEMENT, OR SUCH OTHER AGREEMENT AS YOU ARE *
* ABLE TO REACH WITH THE AUTHOR. *
* *
* You can contact the author at one of the address listed below: *
* *
* Scott Dudley FidoNet 1:249/106 *
* 777 Downing St. Internet sjd@f106.n249.z1.fidonet.org *
* Kingston, Ont. CompuServe >INTERNET:sjd@f106.n249.z1.fidonet.org *
* Canada K7M 5N3 BBS 1-613-634-3058, V.32bis *
* *
***************************************************************************/
/* $Id: api_sq.h,v 1.6 2002/06/10 12:59:18 mche Exp $ */
#ifndef __API_SQ_H_DEFINED
#define __API_SQ_H_DEFINED
#include "compiler.h"
struct _sqhdr;
struct _sqidx;
typedef struct _sqidx SQIDX;
typedef struct _sqhdr SQHDR;
typedef long FOFS;
/* Try to access a locked Squish base up to five times */
#define SQUISH_LOCK_RETRY 5
/* Expand the Squish index by 64 records at a time */
#define SQUIQSH_IDX_EXPAND 64
/* No frame offset */
#define NULL_FRAME ((FOFS)0L)
/* Frame types for sqhdr.frame_type */
#define FRAME_NORMAL 0x00 /* Normal text frame */
#define FRAME_FREE 0x01 /* Part of the free chain */
#define FRAME_LZSS 0x02 /* Not implemented */
#define FRAME_UPDATE 0x03 /* Frame is being updated by another task */
/* BItmask for sqidx.hash to indicate that the msg was received */
#define IDXE_MSGREAD 0x80000000Lu
/* Macros for accessing the hidden parts of data structures */
#define Sqd ((SQDATA *)(ha->apidata))
#define HSqd ((SQDATA *)(((struct _msgh *)hmsg)->ha->apidata))
/* Squish frame header. This comes before each and every message in a *
* Squish message base. */
struct _sqhdr
{
#define SQHDRID 0xafae4453L
dword id; /* sqhdr.id must always equal SQHDRID */
FOFS next_frame; /* Next frame in the linked list */
FOFS prev_frame; /* Prior frame in the linked list */
dword frame_length; /* Length of this frame */
dword msg_length; /* Length used in this frame by XMSG, ctrl and text */
dword clen; /* Length used in this frame by ctrl info only */
word frame_type; /* Type of frame -- see above FRAME_XXXX */
word rsvd; /* Reserved for future use */
};
/* An individual index entry in <area>.SQI */
struct _sqidx
{
FOFS ofs; /* Offset of the frame relating to this msg */
UMSGID umsgid; /* Unique message identifier of this msg */
dword hash; /* SquishHash of msg.to for this msg */
};
/* Header block at offset 0 of <area>.SQD */
typedef struct _sqbase
{
word len; /* LENGTH OF THIS STRUCTURE! */ /* 0 */
word rsvd1; /* reserved */ /* 2 */
dword num_msg; /* Number of messages in area */ /* 4 */
dword high_msg; /* Highest msg in area. Same as num_msg*/ /* 8 */
dword skip_msg; /* Skip killing first x msgs in area */ /* 12 */
dword high_water; /* Msg# (not umsgid) of HWM */ /* 16 */
dword uid; /* Number of the next UMSGID to use */ /* 20 */
byte base[80]; /* Base name of SquishFile */ /* 24 */
FOFS begin_frame; /* Offset of first frame in file */ /* 104 */
FOFS last_frame; /* Offset to last frame in file */ /* 108 */
FOFS free_frame; /* Offset of first FREE frame in file */ /* 112 */
FOFS last_free_frame; /* Offset of last free frame in file */ /* 116 */
FOFS end_frame; /* Pointer to end of file */ /* 120 */
dword max_msg; /* Max # of msgs to keep in area */ /* 124 */
word keep_days; /* Max age of msgs in area (SQPack) */ /* 128 */
word sz_sqhdr; /* sizeof(SQHDR) */ /* 130 */
byte rsvd2[124]; /* Reserved by Squish for future use*/ /* 132 */
/* total: 256 */
} SQBASE;
typedef struct
{
dword dwUsed; /* Number of entries used in this seg */
dword dwMax; /* Number of entries allocated in this seg */
SQIDX far *psqi; /* Pointer to index entries for this segment */
} SQIDXSEG;
/* Handle to a Squish index file */
typedef struct
{
#define ID_HIDX 0x9fee
word id; /* Must be ID_HIDX */
HAREA ha; /* Area to which this index belongs */
long lAllocatedRecords; /* Space allocated in idx file */
long lDeltaLo; /* Low # of changed msg */
long lDeltaHi; /* High # of changed msg */
int fBuffer; /* Use index buffer? */
int cSeg; /* Number of segments used */
SQIDXSEG *pss; /* Segments containing messages */
} *HIDX;
/* Private data in handle passed among API functions which handle message *
* areas. */
typedef struct _sqdata
{
word cbSqbase; /* Length of the .SQD file header */
word cbSqhdr; /* Length of a .SQD frame header */
dword dwMaxMsg; /* Max number of msgs in area */
word wMaxDays; /* Max age (in days) of msgs in area */
word wSkipMsg; /* Number of msgs to skip before keeping wMaxMsg */
dword dwHighWater; /* High water message NUMBER */
UMSGID uidNext; /* Next UMSGID to assign */
FOFS foFirst; /* Offset of first frame in file */
FOFS foLast; /* Offset to last frame in file */
FOFS foFree; /* Offset of first FREE frame in file */
FOFS foLastFree; /* Offset of last free frame in file */
FOFS foEnd; /* Pointer to end of file */
FOFS foNext; /* Next frame in the linked list */
FOFS foPrev; /* Prior frame in the linked list */
FOFS foCur; /* Current frame position */
word fHaveExclusive; /* Are we currently updating the base header? */
word fLocked; /* Do we have byte 0 locked? */
word fLockFunc; /* Number of times we have called Lock w/o Unlock */
int sfd; /* SquishFile handle */
int ifd; /* SquishIndex handle */
SQBASE sqbDelta; /* Last _sqbase read from .SQD file */
/* Linked lists indicating open resources */
HAREA haNext; /* Next area in the list of open areas */
HMSG hmsgOpen; /* List of open messages */
HIDX hix; /* Index handle for current base */
} SQDATA;
/* Message handle. This is passed back and forth between all of the *
* API functions that handle specific messages. */
struct _msgh
{
HAREA ha; /* Area to which this message belongs */
dword id; /* Must always equal MSGH_ID */
dword bytes_written; /* Bytes written to this msg so far */
dword cur_pos; /* Current read posn within msg */
/* Squish-specific information starts here */
dword dwMsg; /* This message number */
/* Frame offset of this message, IF we are reading a message. *
* *
* However, if we are writing a message, this may hold one of *
* several things, depending on the value of wMode: *
* *
* *
* wMode==MOPEN_CREATE: If we are writing a completely new message, *
* this field is zero. Otherwise, if we are *
* creating a message on top of an existing *
* message, this will hold the frame offset of *
* the old message. *
* wMode==MOPEN_RW This holds the offset of the message that *
* or MOPEN_WRITE we are rewriting (same as foWrite) */
FOFS foRead;
/* SQHDR used when reading. *
* *
* If writing, this will hold the frame header of the message that we *
* replaced. (We only replaced a message if foRead != NULL_FRAME) */
SQHDR sqhRead;
/* If we are writing a message, this holds the offset of the current *
* frame header. If no frame header has been allocated for the message *
* yet, this field will be NULL_FRAME. */
FOFS foWrite;
/* If we are writing a message, this holds the frame that we wrote. This *
* SQHDR is only valid when foWrite != NULL_FRAME. */
SQHDR sqhWrite;
/* If we know the UMSGID for this message, uidUs is non-zero */
UMSGID uidUs;
dword dwWritePos; /* Current write position */
word wMode; /* MOPEN_READ, MOPEN_WRITE, or MOPEN_RW */
word fDiskErr; /* Has a disk error occurred? */
word fWritten; /* Have we already written to this message? */
HMSG hmsgNext; /* Next msg in the list of open msgs */
};
#define SQHDR_SIZE 28
#define SQIDX_SIZE 12
#define SQBASE_SIZE 256
SMAPI_EXT int read_xmsg(int handle, XMSG *pxmsg);
SMAPI_EXT int write_xmsg(int handle, XMSG *pxmsg);
SMAPI_EXT int read_sqhdr(int, SQHDR *);
SMAPI_EXT int write_sqhdr(int, SQHDR *);
SMAPI_EXT int read_sqidx(int, SQIDX *, dword);
SMAPI_EXT int write_sqidx(int, SQIDX *, dword);
SMAPI_EXT int read_sqbase(int handle, struct _sqbase *psqbase);
SMAPI_EXT int write_sqbase(int handle, struct _sqbase *psqbase);
#endif /* __API_SQ_H_DEFINED */
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