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/*
* (c) Copyright 1990, Kim Fabricius Storm. All rights reserved.
*
* Article sorting.
*/
#include "config.h"
#include "articles.h"
#ifdef BAD_ORDER_SUBJ_DATE
/* If one article's subject is identical to the first part of another
article, the two subjects will still be considered identical if the
length of the shorter subject is at least the limit set by this variable. */
export int subject_match_limit = 20; /* "strncmp" limit for subjects */
#else
/* Subjects are considered identical if their first s-m-l characters match */
export int subject_match_limit = 256; /* "strncmp" limit for subjects */
#endif
export int match_skip_prefix = 0; /* skip first N bytes in matches */
export int match_parts_equal = 0; /* match digits as equal */
export int sort_mode = 1; /* default sort mode */
/*
* String matching macroes.
*
* MATCH_DROP(t, a) and MATCH_DROP(t, b) must both be proven false
* before MATCH_???(t, a, b) is used.
*/
#define MATCH_DROP(table, c) ( c & 0200 || table[c] == 0 )
#define MATCH_EQ(table, a, b) ( a == b || table[a] == table[b] )
#define MATCH_LS_EQ(table, a, b) ( a <= b || table[a] <= table[b] )
#define MATCH_LS(table, a, b) ( a < b || table[a] < table[b] )
#define MATCH_CMP(table, a, b) (table[a] - table[b])
static char match_subject[128] = {
/* NUL SOH STX ETX EOT ENQ ACK BEL BS TAB NL VT FF CR SO SI */
00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00,
/* DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US */
00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00,
/* SP ! " # $ % & ' ( ) * + , - . / */
00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 99, 00, 00, 00, 00,
/* ^^ */
/* 0 1 2 3 4 5 6 7 8 9 : ; < = > ? */
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 00, 00, 00, 00, 00, 00,
/* @ A B C D E F G H I J K L M N O */
00, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
/* P Q R S T U V W X Y Z [ \ ] ^ _ */
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 00, 00,
/* ` a b c d e f g h i j k l m n o */
00, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
/* p q r s t u v w x y z { | } ~ DEL */
26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 00, 00
};
static order_subj_date(ah1, ah2)
article_header **ah1, **ah2;
{
register char *a = (**ah1).subject, *b = (**ah2).subject;
register char ca, cb;
register int p, len;
if (match_skip_prefix) {
if ((**ah1).subj_length > match_skip_prefix) {
if ((**ah2).subj_length > match_skip_prefix) {
a += match_skip_prefix;
b += match_skip_prefix;
} else
return 1;
} else {
if ((**ah2).subj_length > match_skip_prefix) {
return -1;
}
}
}
#ifdef BAD_ORDER_SUBJ_DATE
for (len = 0; ; len++, a++, b++) {
#else
for (len = subject_match_limit; --len >= 0; a++, b++) {
#endif
while ((ca = *a) && MATCH_DROP(match_subject, ca)) a++;
while ((cb = *b) && MATCH_DROP(match_subject, cb)) b++;
if (ca == NUL) {
if (cb == NUL) break;
#ifdef BAD_ORDER_SUBJ_DATE
if (len >= subject_match_limit) break;
#endif
return -1;
}
if (cb == NUL) {
#ifdef BAD_ORDER_SUBJ_DATE
if (len >= subject_match_limit) break;
#endif
return 1;
}
if (p = MATCH_CMP(match_subject, ca, cb)) return p;
}
if ((**ah1).t_stamp > (**ah2).t_stamp) return 1;
if ((**ah1).t_stamp < (**ah2).t_stamp) return -1;
return order_arrival(ah1, ah2);
}
/* data_subj_date can only be used after root_t_stamp is set */
static order_date_subj_date(ah1, ah2)
article_header **ah1, **ah2;
{
register time_stamp t1 = (**ah1).root_t_stamp;
register time_stamp t2 = (**ah2).root_t_stamp;
if (t1 > t2) return 1;
if (t1 < t2) return -1;
return order_subj_date(ah1, ah2); /* get original order */
}
static order_arrival(a, b)
article_header **a, **b;
{
register long i;
if ((i = (int)((*a)->a_number - (*b)->a_number)) == 0)
i = (*a)->fpos - (*b)->fpos;
return (i > 0) ? 1 : (i < 0) ? -1 : 0;
}
static order_date(ah1, ah2)
register article_header **ah1, **ah2;
{
if ((**ah1).t_stamp > (**ah2).t_stamp) return 1;
if ((**ah1).t_stamp < (**ah2).t_stamp) return -1;
return order_arrival(ah1, ah2);
}
static order_from_date(ah1, ah2)
register article_header **ah1, **ah2;
{
register int i;
if (i = strcmp((**ah1).sender, (**ah2).sender)) return i;
return order_date(ah1, ah2);
}
static flag_type article_equal(ah1, ah2) /* ah1.hdr == ah2.hdr */
article_header **ah1, **ah2;
{
register char *a = (**ah1).subject, *b = (**ah2).subject;
register int len;
if (match_skip_prefix) {
if ((**ah1).subj_length > match_skip_prefix) {
if ((**ah2).subj_length > match_skip_prefix) {
a += match_skip_prefix;
b += match_skip_prefix;
}
}
}
for (len = 0;; len++, a++, b++) {
while (*a && MATCH_DROP(match_subject, *a)) a++;
while (*b && MATCH_DROP(match_subject, *b)) b++;
if (*a == NUL) {
if (*b == NUL) break;
if (len >= subject_match_limit) return A_ALMOST_SAME;
return 0;
}
if (*b == NUL) {
if (len >= subject_match_limit) return A_ALMOST_SAME;
return 0;
}
if (!MATCH_EQ(match_subject, *a, *b)) {
if (len >= subject_match_limit)
return A_ALMOST_SAME;
if (match_parts_equal && isdigit(*a) && isdigit(*b))
return A_ALMOST_SAME;
return 0;
}
}
return A_SAME;
}
sort_articles(mode)
int mode;
{
register article_header **app;
register long n;
register flag_type same;
fct_type cmp;
extern int bypass_consolidation;
if (n_articles <= 0) return;
for (n = n_articles; --n >= 0;)
articles[n]->flag &= ~(A_SAME|A_ALMOST_SAME|A_NEXT_SAME|A_ROOT_ART);
if (n_articles == 1) {
articles[0]->flag |= A_ROOT_ART;
return;
}
if (mode == -1) mode = sort_mode;
switch (mode) {
case -2: /* restore original ordering for update */
cmp = order_arrival;
break;
default:
case 0: /* arrival (no sort) */
cmp = order_arrival;
bypass_consolidation = 1;
break;
case 1: /* date-subject-date */
case 2: /* subject-date */
cmp = order_subj_date;
break;
case 3: /* date only */
cmp = order_date;
bypass_consolidation = 1;
break;
case 4: /* sender-date */
cmp = order_from_date;
bypass_consolidation = 1;
break;
}
quicksort(articles, n_articles, article_header *, cmp);
articles[0]->root_t_stamp = articles[0]->t_stamp;
articles[0]->flag |= A_ROOT_ART;
for (n = n_articles - 1, app = articles + 1; --n >= 0; app++) {
if (same = article_equal(app, app - 1)) {
app[0]->root_t_stamp = app[-1]->root_t_stamp;
app[0]->flag |= same;
app[-1]->flag |= A_NEXT_SAME;
} else {
app[0]->root_t_stamp = app[0]->t_stamp;
app[0]->flag |= A_ROOT_ART;
}
}
if (mode == 1)
quicksort(articles, n_articles, article_header *, order_date_subj_date);
}
/*
* If articles are not sorted via sort_articles, they must still be
* marked with proper attributes (e.g. A_ROOT_ART) via no_sort_articles.
*/
no_sort_articles()
{
register article_number n;
register article_header *ah;
extern int bypass_consolidation;
for (n = n_articles; --n >= 0;) {
ah = articles[n];
ah->flag &= ~(A_SAME|A_ALMOST_SAME|A_NEXT_SAME|A_ROOT_ART);
ah->flag |= A_ROOT_ART;
}
bypass_consolidation = 1;
}
/*
* Eliminate articles with the A_KILL flag set preserving the present ordering.
* This will only release the last entries in the articles array.
* Neither strings nor articles headers are released.
*/
elim_articles(list, list_lgt)
register article_number *list;
int list_lgt;
{
register article_header **srca, **desta;
register article_number n, count;
register flag_type same;
int changed, llen;
count = 0;
changed = 0, llen = 0;
for (n = 0, srca = desta = articles; n < n_articles; n++, srca++) {
if ((*srca)->attr == A_KILL) {
if (list_lgt > 0) {
if (n < *list) {
if (llen) changed = 1;
} else
if (n == *list) {
if (llen) {
llen++;
list_lgt--;
*list++ = -1;
} else
++(*list);
changed = 1;
}
}
continue;
}
if (list_lgt > 0 && n == *list) {
*list++ = count;
list_lgt--;
llen++;
}
count++;
*desta++ = *srca;
}
if (list_lgt > 0) {
if (!llen) *list = 0;
changed = 1;
}
n_articles = count;
if (changed && n_articles > 0) {
srca = articles;
srca[0]->flag &= ~(A_SAME|A_ALMOST_SAME|A_NEXT_SAME);
srca[0]->flag |= A_ROOT_ART;
for (n = n_articles - 1, srca++; --n >= 0; srca++) {
srca[0]->flag &= ~(A_SAME|A_ALMOST_SAME|A_NEXT_SAME|A_ROOT_ART);
if (same = article_equal(srca, srca - 1)) {
srca[0]->flag |= same;
srca[-1]->flag |= A_NEXT_SAME;
} else
srca[0]->flag |= A_ROOT_ART;
}
}
return changed;
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.