rt-mt.c

早期freebsd实现

    if (num < 0 || num >= total.author) {
	/*error("invalid author in thread file: %d [%ld]\n", num, art_num);*/
	invalid_data = TRUE;
	return Nullch;
    }
    return savestr(author_array[num]);
}

/* Our parent/sibling information is a relative offset in the article array.
** zero for none.  Child values are always found in the very next array
** element if child_cnt is non-zero.
*/
static ARTICLE *
the_article(relative_offset, num)
WORD relative_offset;
int num;
{
    union { ARTICLE *ap; int num; } uni;

    if (!relative_offset)
	return Nullart;
    num += relative_offset;
    if (num < 0 || num >= total.article) {
	/*error("invalid article offset in thread file.\n");*/
	invalid_data = TRUE;
	return Nullart;
    }
    uni.num = num+1;
    return uni.ap;		/* slip them an offset in disguise */
}

/* Read the articles into their trees.  Point everything everywhere. */
static int
read_articles()
{
    register int count;
    register ARTICLE *article, **art_ptr;
    int ret;

    /* Build an array to interpret interlinkages of articles. */
    article_array = (ARTICLE**)safemalloc(total.article * sizeof (ARTICLE*));
    art_ptr = article_array;

    invalid_data = FALSE;
    for (count = 0; count < total.article; count++) {
#ifdef USE_XTHREAD
	ret = nntp_read((char*)&p_article, (long)sizeof (PACKED_ARTICLE));
#else
	ret = fread((char*)&p_article, 1, sizeof (PACKED_ARTICLE), fp);
#endif
	if (ret != sizeof (PACKED_ARTICLE)) {
	    /*error("failed article read -- %d bytes instead of %d.\n",
		ret, sizeof (PACKED_ARTICLE));*/
	    return 0;
	}
	lp_bmap(&p_article.num, 2);
	wp_bmap(&p_article.subject, 8);

	article = *art_ptr++ = allocate_article(p_article.num);
	article->date = p_article.date;
#ifndef DBM_XREFS
	if (olden_days < 2 && !(p_article.flags & HAS_XREFS))
	    article->xrefs = nullstr;
#endif
	article->from = the_author(p_article.author);
	article->parent = the_article(p_article.parent, count);
	article->child1 = the_article(p_article.child_cnt ? 1 : 0, count);
	article->sibling = the_article(p_article.sibling, count);
	article->subj = the_subject(p_article.subject);
	if (invalid_data) {
	    /* (Error already logged.) */
	    return 0;
	}
	/* This is ok because parent articles precede their children */
	if (article->parent) {
	    union { ARTICLE *ap; int num; } uni;
	    uni.ap = article->parent;
	    article->parent = article_array[uni.num-1];
	}
	if (article->subj) {
	    if (!(article->flags & AF_MISSING)) {
		article->flags |= AF_FROMTRUNCED | AF_THREADED
		    | ((p_article.flags & ROOT_ARTICLE)? 0 : AF_HAS_RE);
	    }
	    /* Give this subject to any faked parent articles */
	    while (article->parent && !article->parent->subj) {
		article->parent->subj = article->subj;
		article = article->parent;
	    }
	} else
	    article->flags |= AF_FAKE;
    }

    /* We're done with most of the pointer arrays at this point. */
    safefree((char**)&subject_array);
    safefree((char**)&author_array);
    safefree(&strings);

    return 1;
}

/* Read the message-id strings and attach them to each article.  The data
** format consists of the mushed-together null-terminated strings (a domain
** name followed by all its unique-id prefixes) and then the article offsets
** to which they belong.  The first domain name was omitted, as it is a null
** domain for those truly weird message-id's without '@'s.
*/
static int
read_ids()
{
    register ARTICLE *article;
    register char *string_ptr;
    register int i, count, len, len2;

    if (!read_item(&strings, (MEM_SIZE)total.string2)
     || !read_item((char**)&ids,
		(MEM_SIZE)(total.article+total.domain+1) * sizeof (WORD))) {
	return 0;
    }
    wp_bmap(ids, total.article + total.domain + 1);

    string_ptr = strings;
    string_end = string_ptr + total.string2;

    if (string_end[-1] != '\0') {
	/*error("second string table is invalid.\n");*/
	return 0;
    }

    for (i = 0, count = total.domain + 1; count--; i++) {
	if (i) {
	    if (string_ptr >= string_end) {
		/*error("error unpacking domain strings.\n");*/
		return 0;
	    }
	    sprintf(buf, "@%s", string_ptr);
	    len = strlen(string_ptr) + 1;
	    string_ptr += len;
	} else {
	    *buf = '\0';
	    len = 0;
	}
	if (ids[i] != -1) {
	    if (ids[i] < 0 || ids[i] >= total.article) {
		/*error("error in id array.\n");*/
		return 0;
	    }
	    article = article_array[ids[i]];
	    for (;;) {
		if (string_ptr >= string_end) {
		    /*error("error unpacking domain strings.\n");*/
		    return 0;
		}
		len2 = strlen(string_ptr);
		article->msgid = safemalloc(len2 + len + 2 + 1);
		sprintf(article->msgid, "<%s%s>", string_ptr, buf);
		string_ptr += len2 + 1;
		if (msgid_hash)
		{
		    HASHDATUM data;
		    if ((article->flags & AF_TMPMEM) == AF_TMPMEM) {
			data.dat_ptr = (char*)article;
			data.dat_len = 0;
		    } else {
			data.dat_ptr = Nullch;
			data.dat_len = article_num(article);
		    }
		    hashstore(msgid_hash, article->msgid, len2+len+2, data);
		}
		if (++i >= total.article + total.domain + !count) {
		    /*error("overran id array unpacking domains.\n");*/
		    return 0;
		}
		if (ids[i] != -1) {
		    if (ids[i] < 0 || ids[i] >= total.article)
			return 0;
		    article = article_array[ids[i]];
		} else
		    break;
	    }
	}
    }
    safefree((char**)&ids);
    safefree(&strings);

    return 1;
}

/* And finally, turn all the links into real pointers and mark missing
** articles as read.
*/
static void
tweak_data()
{
    register int count;
    register ARTICLE *ap, **art_ptr;
    register SUBJECT *sp;
    register ART_NUM i;
    union { ARTICLE *ap; int num; } uni;

    for (sp = first_subject; sp; sp = sp->next) {
	uni.ap = sp->thread;
	sp->thread = article_array[uni.num];
	sp->thread->subj->flags |= SF_THREAD;
    }
    art_ptr = article_array;
    for (count = total.article; count--; ) {
	ap = *art_ptr++;
	if (ap->child1) {
	    uni.ap = ap->child1;
	    ap->child1 = article_array[uni.num-1];
	}
	if (ap->sibling) {
	    uni.ap = ap->sibling;
	    ap->sibling = article_array[uni.num-1];
	}
	if (!(ap->flags & AF_MISSING))
	    cache_article(ap);
    }

    /* Mark any missing articles as read */
    for (i = absfirst, ap = article_ptr(i); i <= total.last; i++, ap++) {
	if ((ap->flags & (AF_CACHED|AF_MISSING)) == AF_CACHED)
	    check_poster(ap);
	else
	    onemissing(ap);
    }
    safefree((char**)&article_array);
}

/* A shorthand for reading a chunk of the file into a malloc'ed array.
*/
static int
read_item(dest, len)
char **dest;
MEM_SIZE len;
{
    long ret;

    *dest = safemalloc(len);
#ifdef USE_XTHREAD
    ret = nntp_read(*dest, (long)len);
#else
    ret = fread(*dest, 1, (int)len, fp);
#endif
    if (ret != len) {
	free(*dest);
	*dest = Nullch;
	return 0;
    }
    putchar('.'), fflush(stdout);
    return 1;
}

/* Free some memory if it hasn't already been freed.
*/
static void
safefree(pp)
char **pp;
{
    if (*pp) {
	free(*pp);
	*pp = Nullch;
    }
}

/* Determine this machine's byte map for WORDs and LONGs.  A byte map is an
** array of BYTEs (sizeof (WORD) or sizeof (LONG) of them) with the 0th BYTE
** being the byte number of the high-order byte in my <type>, and so forth.
*/
static void
mybytemap(map)
BMAP *map;
{
    union {
	BYTE b[sizeof (LONG)];
	WORD w;
	LONG l;
    } u;
    register BYTE *mp;
    register int i, j;

    mp = &map->w[sizeof (WORD)];
    u.w = 1;
    for (i = sizeof (WORD); i > 0; i--) {
	for (j = 0; j < sizeof (WORD); j++) {
	    if (u.b[j] != 0)
		break;
	}
	if (j == sizeof (WORD))
	    goto bad_news;
	*--mp = j;
	while (u.b[j] != 0 && u.w)
	    u.w <<= 1;
    }

    mp = &map->l[sizeof (LONG)];
    u.l = 1;
    for (i = sizeof (LONG); i > 0; i--) {
	for (j = 0; j < sizeof (LONG); j++) {
	    if (u.b[j] != 0)
		break;
	}
	if (j == sizeof (LONG)) {
	  bad_news:
	    /* trouble -- set both to *something* consistent */
	    for (j = 0; j < sizeof (WORD); j++)
		map->w[j] = j;
	    for (j = 0; j < sizeof (LONG); j++)
		map->l[j] = j;
	    return;
	}
	*--mp = j;
	while (u.b[j] != 0 && u.l)
	    u.l <<= 1;
    }
}

/* Transform each WORD's byte-ordering in a buffer of the designated length.
*/
static void
wp_bmap(buf, len)
WORD *buf;
int len;
{
    union {
	BYTE b[sizeof (WORD)];
	WORD w;
    } in, out;
    register int i;

    if (word_same)
	return;

    while (len--) {
	in.w = *buf;
	for (i = 0; i < sizeof (WORD); i++)
	    out.b[my_bmap.w[i]] = in.b[mt_bmap.w[i]];
	*buf++ = out.w;
    }
}

/* Transform each LONG's byte-ordering in a buffer of the designated length.
*/
static void
lp_bmap(buf, len)
LONG *buf;
int len;
{
    union {
	BYTE b[sizeof (LONG)];
	LONG l;
    } in, out;
    register int i;

    if (long_same)
	return;

    while (len--) {
	in.l = *buf;
	for (i = 0; i < sizeof (LONG); i++)
	    out.b[my_bmap.l[i]] = in.b[mt_bmap.l[i]];
	*buf++ = out.l;
    }
}

#endif /* USE_MT */