/* wblock.c -- Copyright 1991, 1993, 1994, 1996 Liam R. E. Quin.
* All Rights Reserved.
* This code is NOT in the public domain.
* See the file COPYRIGHT for full details.
*/
/* The low-level physical Word Database for lq-text.
*
* $Id: wblock.c,v 1.9 1996/05/14 16:36:03 lee Exp $
*/
#include "error.h"
#include "globals.h" /* defines and declarations for database filenames */
#include <stdio.h> /* stderr, also for fileinfo.h */
#include <sys/types.h>
#ifdef HAVE_FCNTL_H
# ifdef HAVE_SYSV_FCNTL_H
# include <sys/stat.h>
# endif
# include <fcntl.h>
#endif
#include "fileinfo.h" /* for wordinfo.h */
#include "wordinfo.h"
#include "pblock.h"
#include "numbers.h"
#include "wordrules.h"
#include "putbyte.h"
#include "blkheader.h"
#include "liblqtext.h"
/** C library functions that need to be declared: **/
/** lqtext library functions that need to be declared: **/
/** Functions within this file that need to be declared: **/
/** **/
/* <Function>
* <Class>Database/Physical
* <Name>LQT_FlushBlock
* <Purpose>
* Writes out the given block to the cache. This is really the
* same as LQT_WriteBlock, except that it is used for the last
* block in each chain of matches.
* </Function>
*/
API void
LQT_FlushBlock(db, Block, ByteCount, NextOffset, LastStart, WID)
t_LQTEXT_Database *db;
unsigned char *Block;
int ByteCount;
unsigned long *NextOffset, *LastStart;
t_WID WID;
{
if (*LastStart && Block) {
/*NOSTRICT*/
t_BlockHeader *BH = (t_BlockHeader *) Block;
register unsigned char *p;
int BlocksToWrite = (ByteCount + BLOCKSIZE - 1) / BLOCKSIZE;
/* round up! */
BH->NextOffset = 0L;
#ifdef WIDINBLOCK
BH->WID = WID;
#endif
/* pad with -1 for future compatibility */
for (
p = &Block[BLOCKSIZE*BlocksToWrite - 1];
p >= &Block[ByteCount];
p--
) {
*p = (unsigned char) 0xFF;
}
LQT_SetLastBlockInChain(db, WID, LastStart, &Block[ByteCount], Block);
LQT_WriteBlock(db, *LastStart, Block, BlocksToWrite, WID);
}
if (*NextOffset) {
/* We allocated it in case we needed it, and we didn't need it */
LQT_SetBlockStatus(db, *NextOffset, SET_BLOCK_AS_FREE);
}
*LastStart = *NextOffset = 0L;
}
/* This is simply to help keep the source lines getting too long! */
typedef unsigned char *UCP;
LIBRARY int
LQTp__PutByte(
db,
Byte,
WID,
sp,
Blockp,
BlockLength,
LastStart,
NextBlock,
NextLength
)
t_LQTEXT_Database *db;
unsigned int Byte;
t_WID WID;
unsigned char **sp;
unsigned char **Blockp;
unsigned int *BlockLength;
unsigned long *NextBlock;
unsigned long *NextLength;
unsigned long *LastStart; /* for writing the linked list */
{
t_BlockHeader *BH;
if (*sp - (*Blockp) >= (*BlockLength)) {
int NumberOfBlocks;
if (!*NextBlock && !*LastStart) {
return -1; /* only do the 1st block */
}
NumberOfBlocks = (*BlockLength + BLOCKSIZE - 1) / BLOCKSIZE;
if (*NextBlock == (unsigned long) 0) {
*NextBlock = LQT_FindFreeBlock(db, WID, BlockLength, 0);
} else {
if (NextLength && *NextLength) {
*BlockLength = (*NextLength);
*NextLength = 0;
} else {
Error(E_BUG,
"LQTp__PutByte: NextLength is %s",
NextLength ? "zero" : "a null pointer"
);
}
}
/* Complete the information in the previous block, if required */
if (*LastStart) {
BH = (t_BlockHeader *) (*Blockp);
#ifdef WIDINBLOCK
BH->WID = WID;
#endif
BH->NextOffset = (*NextBlock);
/* Write the old block */
LQT_WriteBlock(db, *LastStart, *Blockp, NumberOfBlocks, WID);
*LastStart = 0L;
}
*LastStart = (*NextBlock);
(*NextBlock) = 0L;
*Blockp = LQT_ReadBlock(db, *LastStart, (t_WID) 0);
/*NOSTRICT*/
BH = (t_BlockHeader *) (*Blockp);
BH->NumberOfBlocks = (*BlockLength/BLOCKSIZE); /*exact*/
(*sp) = (UCP) BH->Data;
}
**sp = Byte;
(*sp)++;
return 0;
}
/* PutLong -- write a long number in compressed/abbreviated form into a
* string. If this moves the string pointer beyond the block, write out
* the block and start a new one. In that case, the number written may well
* span the gap between the blocks. We use an overflow buffer to copy
* the bytes (if any) that overflowed into it.
* Then we write them at the start of the next block.
*
* This routine returns -1 and writes a partial number (no allocated block)
* if *LastBlock and *NextBlock are zero. This allows PutwOrdPlaces to be
* called to put the WordPlaces into the WIDFILE block without writing out
* an entire chain.
*/
LIBRARY int
LQTp__PutLong(
db,
Long,
WID,
sp,
Blockp,
BlockLength,
LastStart,
NextBlock,
NextLength
)
t_LQTEXT_Database *db;
unsigned long Long;
t_WID WID;
unsigned char **sp;
unsigned char **Blockp;
unsigned int *BlockLength;
unsigned long *NextBlock;
unsigned long *NextLength;
unsigned long *LastStart; /* for writing the linked list */
{
unsigned char *Start = (*sp);
if (LQT_sWriteNumber(
(unsigned char **) sp,
Long,
*Blockp,
*BlockLength
) < 0) {
unsigned int BytesWritten;
int NumberOfBlocks;
t_BlockHeader *BH;
if (!*NextBlock && !*LastStart) {
/* We were being tentative, seeing if the data would fit
* or not, and it didn't.
*/
return -1;
}
NumberOfBlocks = (*BlockLength + BLOCKSIZE - 1) / BLOCKSIZE;
BytesWritten = (*BlockLength - (Start - (*Blockp)));
if (*NextBlock == (unsigned long) 0) {
*NextBlock = LQT_FindFreeBlock(db, WID, BlockLength, 0);
} else {
if (NextLength && *NextLength) {
*BlockLength = (*NextLength);
*NextLength = 0;
} else {
Error(E_BUG,
"LQTp__PutLong: NextLength is %s",
NextLength ? "zero" : "a null pointer"
);
}
}
/* Complete the information in the previous block, if required */
if (*LastStart) {
BH = (t_BlockHeader *) (*Blockp);
BH->NextOffset = *NextBlock;
#ifdef WIDINBLOCK
BH->WID = WID;
#endif
/* Write the old block */
LQT_WriteBlock(db, *LastStart, *Blockp, NumberOfBlocks, WID);
}
/* If both LastStart and NextBlock are set, it is because
* we allocated a block before calling LQT_WriteWordPlaces.
* In that case, we will use that block next, and then after
* that NextBlock will always be zero.
*/
*LastStart = (*NextBlock);
(*NextBlock) = 0L;
*Blockp = LQT_ReadBlock(db, *LastStart, (t_WID) 0);
BH = (t_BlockHeader *) (*Blockp);
(*sp) = (UCP) BH->Data;
BH->NumberOfBlocks = *BlockLength / BLOCKSIZE; /* always exact */
/* now write the rest of the number out */
{
unsigned char Buffer[sizeof(unsigned long) * 8 / 7 + 1];
unsigned char *Bufp = Buffer;
register unsigned char *p;
(void) LQT_sWriteNumber(
&Bufp, Long, Buffer, sizeof Buffer
);
for (p = &Buffer[BytesWritten]; p < Bufp; p++) {
*((*sp)++) = (*p);
}
}
}
return 0;
}