invlib.c

tvapp用于播放tv程序

		entryptr = (ENTRY *)intptr + imid;
		i = strncmp(searchterm, invcntl->logblk->chrblk + entryptr->offset,
		    (int) entryptr->size );
		if (i == 0)
			i = strlen(searchterm) - entryptr->size;
		if (i < 0)
			ihigh = imid - 1;
		else if (i > 0)
			ilow = ++imid;
		else {
			num = entryptr->post;
			break;
		}
	}
	/* be careful about case where searchterm is after last in this block  */
	if (imid >= invcntl->logblk->invblk[0]) {
		invcntl->keypnt = invcntl->logblk->invblk[0];
		invstep(invcntl);
		/* note if this happens the term could be in extended block */
		if (invcntl->param.startbyte < invcntl->numblk * invcntl->param.sizeblk)
			goto srch_ext;
	} else
		invcntl->keypnt = imid;
	return(num);
}

#if DEBUG

/** invdump dumps the block the term parameter is in **/
void
invdump(INVCONTROL *invcntl, char *term)
{
	long	i, j, n, *longptr;
	ENTRY * entryptr;
	char	temp[512], *ptr;

	/* dump superindex if term is "-"  */
	if (*term == '-') {
		j = atoi(term + 1);
		longptr = (long *)invcntl->iindex;
		n = *longptr++;
		(void) printf("Superindex dump, num blocks=%ld\n", n);
		longptr += j;
		while ((longptr <= ((long *)invcntl->iindex) + n) && invbreak == 0) {
			(void) printf("%2ld  %6ld %s\n", j++, *longptr, invcntl->iindex + *longptr);
			longptr++;
		}
		return;
	} else if (*term == '#') {
		j = atoi(term + 1);
		/* fetch the appropriate logical block */
		invcntl->numblk = j;
		(void) fseek(invcntl->invfile, (j * invcntl->param.sizeblk) + invcntl->param.cntlsize, 0);
		(void) fread(invcntl->logblk, (int) invcntl->param.sizeblk, 1, invcntl->invfile);
	} else
		i = abs((int) invfind(invcntl, term));
	longptr = invcntl->logblk->invblk;
	n = *longptr++;
	(void) printf("Entry term to invdump=%s, postings=%ld, forwrd ptr=%ld, back ptr=%ld\n"
	    , term, i, *(longptr), *(longptr + 1));
	/* FIXME HBB: magic number alert! (3) */
	entryptr = (ENTRY *) (invcntl->logblk->invblk + 3);
	(void) printf("%ld terms in this block, block=%ld\n", n, invcntl->numblk);
	(void) printf("\tterm\t\t\tposts\tsize\toffset\tspace\t1st word\n");
	for (j = 0; j < n && invbreak == 0; j++) {
		ptr = invcntl->logblk->chrblk + entryptr->offset;
		(void) strncpy(temp, ptr, (int) entryptr->size);
		temp[entryptr->size] = '\0';
		ptr += (sizeof(long) * (long)((entryptr->size + (sizeof(long) - 1)) / sizeof(long)));
		(void) printf("%2ld  %-24s\t%5ld\t%3d\t%d\t%d\t%ld\n", j, temp, entryptr->post,
		    entryptr->size, entryptr->offset, entryptr->space,
		    *(long *)ptr);
		entryptr++;
	}
}
#endif

static int
boolready(void)
{
	numitems = 0;
	if (item1 != NULL) 
		free(item1);
	setsize1 = SETINC;
	if ((item1 = malloc(SETINC * sizeof(POSTING))) == NULL) {
		invcannotalloc(SETINC);
		return(-1);
	}
	if (item2 != NULL) 
		free(item2);
	setsize2 = SETINC;
	if ((item2 = malloc(SETINC * sizeof(POSTING))) == NULL) {
		invcannotalloc(SETINC);
		return(-1);
	}
	item = item1;
	enditem = item;
	return(0);
}

void
boolclear(void)
{
	numitems = 0;
	item = item1;
	enditem = item;
}

POSTING *
boolfile(INVCONTROL *invcntl, long *num, int boolarg)
{
	ENTRY	*entryptr;
	FILE	*file;
	void	*ptr;
	unsigned long	*ptr2;
	POSTING	*newitem = NULL; /* initialize, to avoid warning */
	POSTING	posting;
	unsigned u;
	POSTING *newsetp = NULL, *set1p;
	long	newsetc, set1c, set2c;

	/* FIXME HBB: magic number alert! (3) */
	entryptr = (ENTRY *) (invcntl->logblk->invblk + 3) + invcntl->keypnt;
	ptr = invcntl->logblk->chrblk + entryptr->offset;
	ptr2 = ((unsigned long *) ptr) + (entryptr->size + (sizeof(long) - 1)) / sizeof(long);
	*num = entryptr->post;
	switch (boolarg) {
	case BOOL_OR:
	case NOT:
		if (*num == 0) {
			*num = numitems;
			return(item);
		}
	}
	/* make room for the new set */
	u = 0;
	switch (boolarg) {
	case AND:
	case NOT:
		newsetp = set1p = item;
		break;

	case BOOL_OR:
		u = enditem - item;
		/* FALLTHROUGH */
	case REVERSENOT:
		u += *num;
		if (item == item2) {
			if (u > setsize1) {
				u += SETINC;
				if ((item1 = realloc(
				    item1, u * sizeof(POSTING))) == NULL) {
					goto cannotalloc;
				}
				setsize1 = u;
			}
			newitem = item1;
		}
		else {
			if (u > setsize2) {
				u += SETINC;
				if ((item2 = realloc( 
				    item2, u * sizeof(POSTING))) == NULL) {
				cannotalloc:
					invcannotalloc(u * sizeof(POSTING));
					(void) boolready();
					*num = -1;
					return(NULL);
				}
				setsize2 = u;
			}
			newitem = item2;
		}
		set1p = item;
		newsetp = newitem;
	}
	file = invcntl->postfile;
	(void) fseek(file, (long) *ptr2, 0);
	(void) fread(&posting, (int) sizeof(posting), 1, file);
	newsetc = 0;
	switch (boolarg) {
	case BOOL_OR:
		/* while something in both sets */
		set1p = item;
		newsetp = newitem;
		for (set1c = 0, set2c = 0;
		    set1c < numitems && set2c < *num; newsetc++) {
			if (set1p->lineoffset < posting.lineoffset) {
				*newsetp++ = *set1p++;
				set1c++;
			}
			else if (set1p->lineoffset > posting.lineoffset) {
				*newsetp++ = posting;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
			else if (set1p->type < posting.type) {
				*newsetp++ = *set1p++;
				set1c++;
			}
			else if (set1p->type > posting.type) {
				*newsetp++ = posting;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
			else {	/* identical postings */
				*newsetp++ = *set1p++;
				set1c++;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
		}
		/* find out what ran out and move the rest in */
		if (set1c < numitems) {
			newsetc += numitems - set1c;
			while (set1c++ < numitems) {
				*newsetp++ = *set1p++;
			}
		} else {
			while (set2c++ < *num) {
				*newsetp++ = posting;
				newsetc++;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
			}
		}
		item = newitem;
		break; /* end of BOOL_OR */
#if 0
	case AND:
		for (set1c = 0, set2c = 0; set1c < numitems && set2c < *num; ) {
			if (set1p->lineoffset < posting.lineoffset) {
				set1p++;
				set1c++;
			}
			else if (set1p->lineoffset > posting.lineoffset) {
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
			else if (set1p->type < posting.type)  {
				*set1p++;
				set1c++;
			}
			else if (set1p->type > posting.type) {
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
			else {	/* identical postings */
				*newsetp++ = *set1p++;
				newsetc++;
				set1c++;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
		}
		break; /* end of AND */

	case NOT:
		for (set1c = 0, set2c = 0; set1c < numitems && set2c < *num; ) {
			if (set1p->lineoffset < posting.lineoffset) {
				*newsetp++ = *set1p++;
				newsetc++;
				set1c++;
			}
			else if (set1p->lineoffset > posting.lineoffset) {
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
			else if (set1p->type < posting.type) {
				*newsetp++ = *set1p++;
				newsetc++;
				set1c++;
			}
			else if (set1p->type > posting.type) {
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
			else {	/* identical postings */
				set1c++;
				set1p++;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
		}
		newsetc += numitems - set1c;
		while (set1c++ < numitems) {
			*newsetp++ = *set1p++;
		}
		break; /* end of NOT */

	case REVERSENOT:  /* core NOT incoming set */
		for (set1c = 0, set2c = 0; set1c < numitems && set2c < *num; ) {
			if (set1p->lineoffset < posting.lineoffset) {
				set1p++;
				set1c++;
			}
			else if (set1p->lineoffset > posting.lineoffset) {
				*newsetp++ = posting;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
			else if (set1p->type < posting.type) {
				set1p++;
				set1c++;
			}
			else if (set1p->type > posting.type) {
				*newsetp++ = posting;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
			else {	/* identical postings */
				set1c++;
				set1p++;
				(void) fread(&posting, (int) sizeof(posting), 1, file);
				set2c++;
			}
		}
		while (set2c++ < *num) {
			*newsetp++ = posting;
			newsetc++;
			(void) fread(&posting, (int) sizeof(posting), 1, file);
		}
		item = newitem;
		break; /* end of REVERSENOT  */
#endif
	}
	numitems = newsetc;
	*num = newsetc;
	enditem = (POSTING *) newsetp;
	return((POSTING *) item);
}

#if 0
POSTING *
boolsave(int clear)		/* flag about whether to clear core  */
{
	int	i;
	POSTING	*ptr;
	POSTING	*oldstuff, *newstuff;

	if (numitems == 0) {
		if (clear) 
			boolclear();
		return(NULL);
	}
	/* if clear then give them what we have and use (void) boolready to realloc  */
	if (clear) {
		ptr = item;
		/* free up the space we didn't give them */
		if (item == item1)
			item1 = NULL;
		else
			item2 = NULL;
		(void) boolready();
		return(ptr);
	}
	i = (enditem - item) * sizeof(POSTING) + 100;
	if ((ptr = malloc(i))r == NULL) {
		invcannotalloc(i);
		return(ptr);
	}
	/* move present set into place  */
	oldstuff = item;
	newstuff = ptr;
	while (oldstuff < enditem)
		*newstuff++ = *oldstuff++;
	return(ptr);
}
#endif

static void
invcannotalloc(unsigned n)
{
	(void) fprintf(stderr, "%s: cannot allocate %u bytes\n", argv0, n);
}

static void
invcannotopen(char *file)
{
	(void) fprintf(stderr, "%s: cannot open file %s\n", argv0, file);
}

static void
invcannotwrite(char *file)
{
	perror(argv0);	/* must be first to preserve errno */
	(void) fprintf(stderr, "%s: write to file %s failed\n", argv0, file);
}