Ticket #12: diablo-hashfeed.patch

doc/pod/newsfeeds.pod

@@ -382 +382 @@
 new process will run with.  This flag can be used to raise the priority to
 normal if you're using the I<nicekids> parameter in F<inn.conf>.
 
+=item B<Q> I<hashfeed>
+
+The hashfeed value for this site. The message-id of the article is
+hashed using a quick (and dirty) hash method (31-bits sum of the value
+of all characters). The hashfeed value must be given as value/mod
+or as start-end/mod. If the message-id hash modulus "mod" plus one
+equals "number" or is between "start" and "end", the article will be
+fed to the site.
+
+Example:
+
+    Q1/2     Feeds about 50% of the messages to this site
+    Q2/2     Feeds the other 50% of the messages
+
+    Q1-3/10  Feeds about 30% of the messages
+    Q4-5/10  Feeds about 30% of the messages
+    Q6/10    Feeds about 50% of the messages
+
+If this flag is specified multiple times the contents will be
+logically ORed together (just one match needed).
+
+The algorithm is compatible with the one used by Diablo.
+
 =item B<S> I<size>
 
 If the amount of data queued for the site gets to be larger than I<size>

innd/art.c

@@ -1547 +1547 @@
 }
 
 /*
+**  Return true if an element of the QHASHLIST matches the
+**  quickhash of the message-id.
+*/
+static bool
+QHashMatch(QHASHLIST *qh, char *MessageID)
+{
+  unsigned char *p = (unsigned char *)MessageID;
+  int h = 0;
+
+  while (*p)
+    h += *p++;
+
+  while (qh) {
+    if ((h % qh->mod + 1) >= qh->begin &&
+        (h % qh->mod + 1) <= qh->end)
+          return true;
+    qh = qh->next;
+  }
+
+  return false;
+}
+
+/*
 **  Propagate an article to the sites have "expressed an interest."
 */
 static void
@@ -1619 +1642 @@
        * cross-posting. */
       continue;
 
+    if (sp->QHashList && !QHashMatch(sp->QHashList, HDR(HDR__MESSAGE_ID)))
+      /* quickhash doesn't match */
+      continue;
+
     if (list && *list != NULL && sp->Distributions &&
       !DISTwantany(sp->Distributions, list))
       /* Not in the site's desired list of distributions. */

innd/innd.h

@@ -407 +407 @@
 
 
 /*
+**  Diablo-style hashed feeds or hashfeeds.
+*/
+typedef struct _QHASHLIST {
+  int                   begin;
+  int                   end;
+  int                   mod;
+  struct _QHASHLIST     *next;
+} QHASHLIST;
+
+
+/*
 **  A site may reject something in its subscription list if it has
 **  too many hops, or a bad distribution.
 */
@@ -458 +469 @@
   struct buffer   Buffer;
   bool            Buffered;
   char        **  Originator;
+  QHASHLIST    *  QHashList;
   int             Next;
   int             Prev;
 } SITE;

innd/newsfeeds.c

@@ -448 +448 @@
     int                 isp;
     SITE                *nsp;
     struct buffer       b;
+    QHASHLIST           *qh;
 
     b = sp->Buffer;
     *sp = SITEnull;
@@ -467 +468 @@
     sp->NeedOverviewCreation = false;
     sp->FeedwithoutOriginator = false;
     sp->DropFiltered = false;
+    sp->QHashList = NULL;
 
     /* Nip off the first field, the site name. */
     if ((f2 = strchr(Entry, NF_FIELD_SEP)) == NULL)
@@ -603 +605 @@
             if (*++p && CTYPE(isdigit, *p))
                 sp->Nice = atoi(p);
             break;
+        case 'Q':
+            qh = xmalloc(sizeof(QHASHLIST));
+            p++;
+            if (sscanf(p, "%d/%d", &qh->begin, &qh->mod) == 2) {
+                qh->end = qh->begin;
+            } else if (sscanf(p, "%d-%d/%d", &qh->begin, &qh->end, &qh->mod) != 3) {
+                free(qh);
+                return "hash not in x/z or x-y/z format";
+            }
+            qh->next = sp->QHashList;
+            sp->QHashList = qh;
+            break;
         case 'S':
             if (*++p && CTYPE(isdigit, *p))
                 sp->StartSpooling = atol(p);

innd/site.c

@@ -997 +997 @@
 SITEfree(SITE *sp)
 {
     SITE                *s;
+    QHASHLIST           *qh, *qn;
     int                 new;
     int                 i;
     
@@ -1051 +1052 @@
         sp->FNLnames.data = NULL;
         sp->FNLnames.size = 0;
     }
+    if (sp->QHashList) {
+        for (qh = sp->QHashList; qh; qh = qn) {
+            qn = qh->next;
+            free(qh);
+        }
+        sp->QHashList = NULL;
+    }
 
     /* If this site was a master, find a new one. */
     if (sp->IsMaster) {