(remove_loc_no): New static function.

(read_ranges_precondition): New static function.
(read_ranges_postcondition): New static function.
(mark_as_read): Extracted debug code to read_ranges_precondition
	and read_ranges_postcondition.
(mark_as_unread): New function.
(check_range_list): New static function.
(set_read_ranges): New function.

src/server/membership.c

 /*
- * $Id: membership.c,v 0.79 2002/11/13 00:41:15 ceder Exp $
+ * $Id: membership.c,v 0.80 2002/11/15 17:15:12 ceder Exp $
  * Copyright (C) 1991-2002  Lysator Academic Computer Association.
  *
  * This file is part of the LysKOM server.
@@ -553,8 +553,7 @@ adjust_read(Membership *m,
 }
 
 /*
- * insert TEXT in the list of read texts in M. The texts are sorted.
- * m->no_of_read is updated.
+ * insert TEXT in the set of read texts in M.
  *
  * Returns FAILURE if the text is already read.
  *
@@ -632,6 +631,90 @@ insert_loc_no(Local_text_no   text,
     return OK;
 }
 
+static void
+remove_loc_no(Local_text_no   text,
+	      Membership    * m)
+{
+    struct read_range *lo;
+    struct read_range *hi;
+    struct read_range *mid;
+    struct read_range *begin;
+    struct read_range *end;
+    ptrdiff_t save;
+    struct read_range *gap;
+    struct read_range *move;
+
+    if (m->no_of_read_ranges == 0)
+	return;
+
+    begin = lo = &m->read_ranges[0];
+    end = hi = lo + m->no_of_read_ranges;
+
+    while (hi - lo > 1)
+    {
+	mid = lo + (hi - lo) / 2;
+	if (text < mid->first_read - 1)
+	    hi = mid;
+	else if (text > mid->last_read + 1)
+	    lo = mid;
+	else
+	{
+	    lo = mid;
+	    hi = mid + 1;
+	}
+    }
+
+    if (text < lo->first_read || text > lo->last_read)
+	return;			/* This text was already unread. */
+    
+    if (text == lo->first_read)
+    {
+	if (lo->first_read != lo->last_read)
+	{
+	    /* Remove the first text of this range. */
+	    lo->first_read++;
+	    return;
+	}
+
+	/* This range contains a single text.  Remove the entire range.  */
+	for (move = lo; move < (end-1); move++)
+	    *move = *(move+1);
+	m->no_of_read_ranges--;
+	return;
+    }
+
+    if (text == lo->last_read)
+    {
+	assert(text != lo->first_read);
+
+	/* Remove the last text of this range.  */
+	lo->last_read--;
+	return;
+    }
+
+    assert(lo->first_read < text && text < lo->last_read);
+
+    /* We have to split this block. */
+    save = lo - begin;
+    m->read_ranges = srealloc(
+	m->read_ranges,
+	++(m->no_of_read_ranges) * sizeof(m->read_ranges[0]));
+    begin = &m->read_ranges[0];
+    gap = begin + save;
+    end = begin + m->no_of_read_ranges;
+    for (move = end - 1; move > gap; move--)
+	*move = *(move - 1);
+
+    assert(gap->first_read == (gap+1)->first_read);
+    assert(gap->last_read == (gap+1)->last_read);
+    assert(text > gap->first_read);
+    assert(text < gap->last_read);
+
+    gap->last_read = text - 1;
+    (gap+1)->first_read = text + 1;
+    return;
+}
+
 
 /*
  * Send a new-membership message to the affected person
@@ -1319,8 +1402,60 @@ check_membership(Pers_no pno,
 
     return errors;
 }
+
+static void
+read_ranges_precondition(Membership *m,
+			 Membership *save,
+			 const Conference *conf_c,
+			 const char *func)
+{
+    if (check_membership(ACTPERS, conf_c, m) > 0)
+	kom_log("%s(): the above error was detected on entry to me.\n", func);
+
+    if (m->read_ranges == NULL && m->no_of_read_ranges != 0)
+    {
+	kom_log("%s(): m->read_ranges == NULL && "
+		"m->no_of_read_ranges == %lu (corrected).\n",
+		func,
+		(unsigned long)m->no_of_read_ranges);
+	m->no_of_read_ranges = 0;
+    }
+    
+    *save = *m;
+    save->read_ranges = smalloc(m->no_of_read_ranges
+				* sizeof(save->read_ranges[0]));
+    memcpy(save->read_ranges, m->read_ranges,
+	   m->no_of_read_ranges * sizeof(save->read_ranges[0]));
+}
+
+static int
+read_ranges_postcondition(Membership *m,
+			  Membership *save,
+			  const Conference *conf_c,
+			  const char *func)
+{
+    static int log_no = 0;
+    int ret = 0;
+
+    /* Check that the membership is correct. Otherwise log all info. */
+    if (check_membership(ACTPERS, conf_c, m) > 0 && log_no < 40)
+    {
+	kom_log("%s(): (%d) Person %lu has a corrupt membership:\n",
+		func, ++log_no, (unsigned long)ACTPERS);
+	kom_log("Dump of data follows: <original membership>"
+		"<updated membership>\n");
+	foutput_membership(stderr, save);
+	putc('\n', stderr);
+	foutput_membership(stderr, m);
+	ret = -1;
+    }
+
+    sfree(save->read_ranges);
+    return ret;
+}
 #endif
 
+
 /*
  * mark_as_read() is used to tell LysKOM which texts you have read.
  * You can mark several texts in one chunk, but the chunk should not
@@ -1361,35 +1496,25 @@ mark_as_read (Conf_no		     conference,
 #ifdef DEBUG_MARK_AS_READ
     Membership   original;
     int		 loop;
-    static int   log_no = 0;
 #endif
 
-    
     CHK_CONNECTION(FAILURE);
     CHK_LOGIN(FAILURE);
     GET_C_STAT(conf_c, conference, FAILURE);
 
     if ( (m = locate_membership( conference, ACT_P)) == NULL)
     {
+#if 1
         err_stat = conference;
 	kom_errno = KOM_NOT_MEMBER;
+#else  /* FIXME: (bug 48): Write test case, then do like below.  */
+	set_conf_errno(active_connection, conference, KOM_NOT_MEMBER);
+#endif
 	return FAILURE;
     }
 
 #ifdef DEBUG_MARK_AS_READ
-    if ( m->read_ranges == NULL && m->no_of_read_ranges != 0 )
-    {
-	kom_log("mark_as_read(): m->read_ranges == NULL && "
-		"m->no_of_read_ranges == %lu (corrected).\n",
-		(unsigned long)m->no_of_read_ranges);
-	m->no_of_read_ranges = 0;
-    }
-    
-    original = *m;
-    original.read_ranges = smalloc(m->no_of_read_ranges
-				   * sizeof(original.read_ranges[0]));
-    memcpy(original.read_ranges, m->read_ranges,
-	   m->no_of_read_ranges * sizeof(original.read_ranges[0]));
+    read_ranges_precondition(m, &original, conf_c, "mark_as_read");
 #endif
     
     for( i = no_of_texts; i > 0; i--, text_arr++ )
@@ -1430,6 +1555,7 @@ mark_as_read (Conf_no		     conference,
 	}
     
 	adjust_read(m, conf_c);
+	/* FIXME (bug 877): shouldn't this be mark_person_as_changed? */
 	mark_conference_as_changed(conference);
 
 	if (active_connection->cwc == conference)
@@ -1437,29 +1563,187 @@ mark_as_read (Conf_no		     conference,
     }
 
 #ifdef DEBUG_MARK_AS_READ
-    /* Check that the membership is correct. Otherwise log all info. */
-    if (check_membership(ACTPERS, conf_c, m) > 0 && log_no < 40)
+    if (read_ranges_postcondition(m, &original, conf_c, "mark_as_read") < 0)
     {
-	kom_log("mark_as_read(): (%d) Person %lu has a corrupt membership:\n",
-		++log_no, (unsigned long)ACTPERS);
-	kom_log("Dump of data follows: <original membership>"
-		"<updated membership> <texts to mark>\n");
-	foutput_membership(stderr, &original);
-	putc('\n', stderr);
-	foutput_membership(stderr, m);
+	kom_log("this was triggered by an attempt to mark this as read\n");
 	fprintf(stderr, "\n%lu { ", (unsigned long)no_of_texts);
-	for ( loop = 0; loop < no_of_texts; loop++ )
-	{
+	for (loop = 0; loop < no_of_texts; loop++)
 	    fprintf(stderr, "\n%lu ", (unsigned long)text_arr_start[loop]);
-	}
 	fprintf(stderr, "}\n");
     }
+#endif
+    return retval;
+}
+
+
+extern Success
+mark_as_unread(Conf_no        conference,
+	       Local_text_no  lno)
+{
+    Membership * m;
+    Conference * conf_c;
+    Success	 retval = OK;
+#ifdef DEBUG_MARK_AS_READ
+    Membership   original;
+#endif
+
+    CHK_CONNECTION(FAILURE);
+    CHK_LOGIN(FAILURE);
+    GET_C_STAT(conf_c, conference, FAILURE);
+
+    if ((m = locate_membership(conference, ACT_P)) == NULL)
+    {
+	set_conf_errno(active_connection, conference, KOM_NOT_MEMBER);
+	return FAILURE;
+    }
+
+#ifdef DEBUG_MARK_AS_READ
+    read_ranges_precondition(m, &original, conf_c, "unmark_as_read");
+#endif
+
+    if (lno == 0)
+    {
+	kom_errno = KOM_LOCAL_TEXT_ZERO;
+	err_stat = 0;
+	retval = FAILURE;
+    }
+    else if (lno >= l2g_first_appendable_key(&conf_c->texts))
+    {
+	kom_errno = KOM_NO_SUCH_LOCAL_TEXT;
+	err_stat = lno;
+	retval = FAILURE;
+    }
+    else
+    {
+	remove_loc_no(lno, m);
+	adjust_read(m, conf_c);
+	/* FIXME (bug 877): mark_as_read uses mark_conference_as_changed
+	   instead.  If that is proper, then this line is wrong.  */
+	mark_person_as_changed(ACTPERS);
+    }
 
-    sfree(original.read_ranges);
+#ifdef DEBUG_MARK_AS_READ
+    if (read_ranges_postcondition(m, &original, conf_c, "unmark_as_read") < 0)
+    {
+	kom_log("this was triggered by an attempt to mark %lu as not read\n",
+		(unsigned long)lno);
+    }
 #endif
     return retval;
 }
 
+static Success
+check_range_list(const struct read_range_list *read_ranges)
+{
+    Local_text_no last = 0;
+    unsigned short i;
+
+    if (read_ranges->length > param.max_read_ranges)
+    {
+	kom_errno = KOM_LONG_ARRAY;
+	err_stat = param.max_read_ranges;
+	return FAILURE;
+    }
+
+    for (i = 0; i < read_ranges->length; i++)
+    {
+	if (read_ranges->ranges[i].first_read >
+	    read_ranges->ranges[i].last_read)
+	{
+	    kom_errno = KOM_INVALID_RANGE;
+	    err_stat = i;
+	    return FAILURE;
+	}
+
+	if (read_ranges->ranges[i].first_read <= last)
+	{
+	    if (read_ranges->ranges[i].first_read == 0)
+		kom_errno = KOM_LOCAL_TEXT_ZERO;
+	    else
+		kom_errno = KOM_INVALID_RANGE_LIST;
+	    err_stat = i;
+	    return FAILURE;
+	}
+
+	last = read_ranges->ranges[i].last_read;
+    }
+
+    return OK;
+}
+
+
+Success
+set_read_ranges(Conf_no conference,
+		const struct read_range_list *read_ranges)
+{
+    Membership * m;
+    Conference * conf_c;
+    Success	 retval = OK;
+#ifdef DEBUG_MARK_AS_READ
+    Membership   original;
+#endif
+
+    if (check_range_list(read_ranges) == FAILURE)
+	return FAILURE;
+
+    CHK_CONNECTION(FAILURE);
+    CHK_LOGIN(FAILURE);
+    GET_C_STAT(conf_c, conference, FAILURE);
+
+    if ((m = locate_membership(conference, ACT_P)) == NULL)
+    {
+	set_conf_errno(active_connection, conference, KOM_NOT_MEMBER);
+	return FAILURE;
+    }
+
+#ifdef DEBUG_MARK_AS_READ
+    read_ranges_precondition(m, &original, conf_c, "set_read_ranges");
+#endif
+
+    if (read_ranges->length == 0)
+    {
+	if (m->no_of_read_ranges != 0)
+	{
+	    sfree(m->read_ranges);
+	    m->read_ranges = NULL;
+	    m->no_of_read_ranges = 0;
+	    /* FIXME (bug 877): mark_as_read uses mark_conference_as_changed
+	       instead.  If that is proper, then this line is wrong.  */
+	    mark_person_as_changed(ACTPERS);
+	}
+    }
+    else if (read_ranges->ranges[read_ranges->length-1].last_read
+	     >= l2g_first_appendable_key(&conf_c->texts))
+    {
+	kom_errno = KOM_NO_SUCH_LOCAL_TEXT;
+	err_stat = read_ranges->ranges[read_ranges->length-1].last_read;
+	retval = FAILURE;
+    }
+    else
+    {
+	if (m->no_of_read_ranges != read_ranges->length)
+	{
+	    m->no_of_read_ranges = read_ranges->length;
+	    m->read_ranges = srealloc(
+		m->read_ranges,
+		m->no_of_read_ranges * sizeof(m->read_ranges[0]));
+	}
+	memcpy(m->read_ranges, read_ranges->ranges,
+	       m->no_of_read_ranges * sizeof(m->read_ranges[0]));
+	adjust_read(m, conf_c);
+	/* FIXME (bug 877): mark_as_read uses mark_conference_as_changed
+	   instead.  If that is proper, then this line is wrong.  */
+	mark_person_as_changed(ACTPERS);
+    }
+
+#ifdef DEBUG_MARK_AS_READ
+    read_ranges_postcondition(m, &original, conf_c, "set_read_ranges");
+#endif
+    return retval;
+}
+
+
+
 /*
  * Ask what conferences a person is a member of.
  */