---------------------
PatchSet 3348 
Date: 2001/11/20 22:55:51
Author: jkay
Branch: push
Tag: (none) 
Log:

update forwarding support.

Members: 
	src/dist.c:1.1->1.1.2.1 

--- /dev/null	Wed Feb 14 00:55:47 2007
+++ squid/src/dist.c	Wed Feb 14 00:56:33 2007
@@ -0,0 +1,157 @@
+/*
+ * $Id: dist.c,v 1.1.2.1 2001/11/20 22:55:51 jkay Exp $
+ *
+ * Distribution network algorithm.
+ *
+ * AUTHOR: Jon Kay, 1997
+ *
+ * SQUID Internet Object Cache  http://squid.nlanr.net/Squid/
+ * --------------------------------------------------------
+ *
+ *  Squid is the result of efforts by numerous individuals from the
+ *  Internet community.  Development is led by Duane Wessels of the
+ *  National Laboratory for Applied Network Research and funded by
+ *  the National Science Foundation.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *  
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *  
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *  
+ */
+
+#include "squid.h"
+
+static void distUpdate(Updatee *u);
+
+static char urlbuf[MAX_URL + 48];
+
+
+/* Updatee management */
+
+/* Create new updatee ds & add to object's updatee list */
+Updatee *
+distNewUpdatee(StoreEntry *entry, struct in_addr host, int dport)
+{
+    Updatee *u;
+    
+    /* Don't add a client if it isn't interested in updates */
+    if (dport == 0)
+	return(NULL);
+    
+    /* Make sure new guy isn't already on list */
+    for (u = entry->updatees; u; u = u->next) {
+	if (u->saddr.sin_addr.s_addr == host.s_addr
+	    && u->saddr.sin_port == dport)
+	    return(u);
+    }
+
+    /* Need new updatee, alloc and add to list */
+    u = xcalloc(sizeof(*u), 1);
+    u->next = entry->updatees;
+    u->entry = entry;
+    u->saddr.sin_family = AF_INET;
+    u->saddr.sin_addr = host;
+    u->saddr.sin_port = dport;
+    u->lastmod = entry->lastmod;
+    entry->updatees = u;
+    return(u);
+}
+
+void
+distDelUpdatee(StoreEntry *entry, struct sockaddr_in *sin)
+{
+    Updatee *i, **optr;
+
+    optr = &entry->updatees;
+    for (i = entry->updatees; i; i = i->next) {
+	if (i->saddr.sin_addr.s_addr == sin->sin_addr.s_addr
+	    && i->saddr.sin_port == sin->sin_port) {
+	    (*optr) = i->next;
+	    xfree(i);
+	}
+	optr = &i->next;
+    }
+}
+
+void
+distDelUpdatees(Updatee *u)
+{
+    Updatee *nu;
+
+    for ( ; u; u = nu) {
+	nu = u->next;
+	xfree(u);
+    }
+}
+
+
+/* Code to distribute contents of entry to updatees */
+
+static void
+distUpdate(Updatee *u)
+{
+    if (u->lastmod >= u->entry->lastmod)
+	/* Already has this version */
+	return;
+    u->lastmod = u->entry->lastmod;  /* Mark version being xferred */
+    ++statCounter.push.dists;
+
+    u->p = putSend(u->entry, &u->saddr, (PF *) 0, 0, 1 /* dodist */);
+}
+
+/* Distribute entry contents to anybody interested */
+void
+distEntryUpdate(StoreEntry *entry, request_t *req, struct sockaddr_in *peer)
+{
+    struct sockaddr_in *me = &Config.Sockaddr.http->s;
+    Updatee *u;
+    
+    /* Open distribution socket to everybody interested */
+    for (u = entry->updatees; u; u = u->next) {
+	if (!req || !req->dport || req->dport != u->saddr.sin_port
+	        || peer->sin_addr.s_addr != me->sin_addr.s_addr)
+	    /* Send if got a dist and it isn't to where we got this update */
+	    distUpdate(u);
+    }
+}
+
+
+/* Best-case object consistency support */
+
+/* Change url from http: to httpdist1234: */
+/* Note: returns pointer to static buffer - contents change on next call. */
+char *
+distifyUrl(char *url)
+{
+    char distbuf[20];  /* dist string holder */
+    int plen, poff;
+    char *eop;
+
+    /* Find the end of the protocol field */
+    if ((eop = strchr(url, ':')) == NULL)
+	/* Give up if not of form http://... */
+	return(url);
+    poff = eop - url;
+
+    snprintf(distbuf, sizeof(distbuf), "dist%d",
+	     ntohs(Config.Sockaddr.http->s.sin_port));
+    plen = strlen(distbuf);
+
+    /* Assemble the new URL */
+    xmemcpy(urlbuf, url, poff);
+    xmemcpy(urlbuf + poff, distbuf, plen);
+    xstrncpy(urlbuf + poff + plen, url + poff, MAX_URL);
+    
+    return(urlbuf);
+}
+