From: wessels <>
Date: Tue, 21 Jul 1998 09:16:04 +0000 (+0000)
Subject: New refresh algorithm.  No longer set entry->lastmod == entry->timestamp
X-Git-Tag: SQUID_3_0_PRE1~3028
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1c3e77cd17c0d0727042c796860ac27e21019e09;p=thirdparty%2Fsquid.git

New refresh algorithm.  No longer set entry->lastmod == entry->timestamp
when the Last-Modified header is absent.  Also, don't do ISM validations
without a Last-Modified timestamp.
---

diff --git a/src/client_side.cc b/src/client_side.cc
index 94ef3f24f0..c4ad34ca7e 100644
--- a/src/client_side.cc
+++ b/src/client_side.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: client_side.cc,v 1.359 1998/07/20 20:37:38 wessels Exp $
+ * $Id: client_side.cc,v 1.360 1998/07/21 03:16:04 wessels Exp $
  *
  * DEBUG: section 33    Client-side Routines
  * AUTHOR: Duane Wessels
@@ -234,6 +234,7 @@ clientProcessExpired(void *data)
     char *url = http->uri;
     StoreEntry *entry = NULL;
     debug(33, 3) ("clientProcessExpired: '%s'\n", http->uri);
+    assert(entry->lastmod >= 0);
     /*
      * check if we are allowed to contact other servers
      * @?@: Instead of a 504 (Gateway Timeout) reply, we may want to return 
@@ -253,8 +254,7 @@ clientProcessExpired(void *data)
     storeClientListAdd(entry, http);
     storeClientListAdd(http->old_entry, http);
     entry->lastmod = http->old_entry->lastmod;
-    debug(33, 5) ("clientProcessExpired: setting lmt = %d\n",
-	(int) entry->lastmod);
+    debug(33, 5) ("clientProcessExpired: lastmod %d\n", (int) entry->lastmod);
     entry->refcount++;		/* EXPIRED CASE */
     http->entry = entry;
     http->out.offset = 0;
@@ -405,17 +405,21 @@ modifiedSince(StoreEntry * entry, request_t * request)
 {
     int object_length;
     MemObject *mem = entry->mem_obj;
+    time_t mod_time = entry->lastmod;
     debug(33, 3) ("modifiedSince: '%s'\n", storeUrl(entry));
-    if (entry->lastmod < 0)
+    if (mod_time < 0)
+	mod_time = entry->timestamp;
+    debug(33,3)("modifiedSince: mod_time = %d\n", (int) mod_time);
+    if (mod_time < 0)
 	return 1;
     /* Find size of the object */
     object_length = mem->reply->content_length;
     if (object_length < 0)
 	object_length = contentLen(entry);
-    if (entry->lastmod > request->ims) {
+    if (mod_time > request->ims) {
 	debug(33, 3) ("--> YES: entry newer than client\n");
 	return 1;
-    } else if (entry->lastmod < request->ims) {
+    } else if (mod_time < request->ims) {
 	debug(33, 3) ("-->  NO: entry older than client\n");
 	return 0;
     } else if (request->imslen < 0) {
@@ -884,7 +888,9 @@ isTcpHit(log_type code)
     return 0;
 }
 
-/* returns true if If-Range specs match reply, false otherwise */
+/*
+ * returns true if If-Range specs match reply, false otherwise
+ */
 static int
 clientIfRangeMatch(clientHttpRequest * http, HttpReply * rep)
 {
@@ -1159,7 +1165,14 @@ clientCacheHit(void *data, char *buf, ssize_t size)
 	/*
 	 * We hold a stale copy; it needs to be validated
 	 */
-	if (r->protocol == PROTO_HTTP) {
+        if (e->lastmod < 0) {
+ 	    /*
+	     * Previous reply didn't have a Last-Modified header,
+	     * we cannot revalidate it.
+	     */
+	    http->log_type = LOG_TCP_MISS;
+	    clientProcessMiss(http);
+	} else if (r->protocol == PROTO_HTTP) {
 	    http->log_type = LOG_TCP_REFRESH_MISS;
 	    clientProcessExpired(http);
 	} else {
diff --git a/src/main.cc b/src/main.cc
index 0080ab55dc..c46092e7e6 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: main.cc,v 1.255 1998/07/20 17:19:51 wessels Exp $
+ * $Id: main.cc,v 1.256 1998/07/21 03:16:05 wessels Exp $
  *
  * DEBUG: section 1     Startup and Main Loop
  * AUTHOR: Harvest Derived
@@ -499,6 +499,7 @@ mainInitialize(void)
 	mimeInit(Config.mimeTablePathname);
 	pconnInit();
 	eventInit();
+	refreshInit();
     }
     serverConnectionsOpen();
     if (theOutIcpConnection >= 0 && (!Config2.Accel.on || Config.onoff.accel_with_proxy))
diff --git a/src/protos.h b/src/protos.h
index 1499a09fa5..e31dc8a81b 100644
--- a/src/protos.h
+++ b/src/protos.h
@@ -609,6 +609,7 @@ extern void refreshAddToList(const char *, int, time_t, int, time_t);
 extern int refreshCheck(const StoreEntry *, request_t *, time_t delta);
 extern time_t refreshWhen(const StoreEntry * entry);
 extern time_t getMaxAge(const char *url);
+extern void refreshInit(void);
 
 extern void serverConnectionsClose(void);
 extern void shut_down(int);
diff --git a/src/refresh.cc b/src/refresh.cc
index a8ff2d71ad..329421b92b 100644
--- a/src/refresh.cc
+++ b/src/refresh.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: refresh.cc,v 1.25 1998/07/20 17:20:03 wessels Exp $
+ * $Id: refresh.cc,v 1.26 1998/07/21 03:16:07 wessels Exp $
  *
  * DEBUG: section 22    Refresh Calculation
  * AUTHOR: Harvest Derived
@@ -35,6 +35,19 @@
 
 #include "squid.h"
 
+struct {
+    int total;
+    int revalidate_stale;
+    int request_max_age_stale;
+    int response_expires_stale;
+    int response_expires_fresh;
+    int conf_max_age_stale;
+    int last_modified_factor_fresh;
+    int last_modified_factor_stale;
+    int conf_min_age_fresh;
+    int default_stale;
+} refreshCounts;
+
 /*
  * Defaults:
  *      MIN     NONE
@@ -47,6 +60,7 @@
 
 static const refresh_t * refreshLimits(const char *);
 static const refresh_t *refreshUncompiledPattern(const char *);
+static OBJH refreshStats;
 
 static const refresh_t *
 refreshLimits(const char *url)
@@ -91,8 +105,10 @@ refreshCheck(const StoreEntry * entry, request_t * request, time_t delta)
     else
 	uri = urlCanonical(request);
     debug(22, 3) ("refreshCheck: '%s'\n", uri);
+    refreshCounts.total++;
     if (EBIT_TEST(entry->flag, ENTRY_REVALIDATE)) {
 	debug(22, 3) ("refreshCheck: YES: Required Authorization\n");
+	refreshCounts.revalidate_stale++;
 	return 1;
     }
     if ((R = refreshLimits(uri))) {
@@ -110,41 +126,45 @@ refreshCheck(const StoreEntry * entry, request_t * request, time_t delta)
     if (request->max_age > -1) {
 	if (age > request->max_age) {
 	    debug(22, 3) ("refreshCheck: YES: age > client-max-age\n");
+	    refreshCounts.request_max_age_stale++;
 	    return 1;
 	}
     }
-    if (age <= min) {
-	debug(22, 3) ("refreshCheck: NO: age < min\n");
-	return 0;
-    }
-    if (-1 < entry->expires) {
+    if (entry->expires > -1) {
 	if (entry->expires <= check_time) {
 	    debug(22, 3) ("refreshCheck: YES: expires <= curtime\n");
+	    refreshCounts.response_expires_stale++;
 	    return 1;
 	} else {
 	    debug(22, 3) ("refreshCheck: NO: expires > curtime\n");
+	    refreshCounts.response_expires_fresh++;
 	    return 0;
 	}
     }
     if (age > max) {
 	debug(22, 3) ("refreshCheck: YES: age > max\n");
+	refreshCounts.conf_max_age_stale++;
 	return 1;
     }
-    if (entry->timestamp <= entry->lastmod) {
-	if (request->protocol != PROTO_HTTP) {
-	    debug(22, 3) ("refreshCheck: NO: non-HTTP request\n");
+    if (entry->lastmod > -1 && entry->timestamp > entry->lastmod) {
+	factor = (double) age / (double) (entry->timestamp - entry->lastmod);
+	debug(22, 3) ("refreshCheck: factor = %f\n", factor);
+	if (factor < pct) {
+	    debug(22, 3) ("refreshCheck: NO: factor < pct\n");
+	    refreshCounts.last_modified_factor_fresh++;
 	    return 0;
+	} else {
+	    debug(22, 3) ("refreshCheck: YES: factor >= pct\n");
+	    refreshCounts.last_modified_factor_stale++;
+	    return 1;
 	}
-	debug(22, 3) ("refreshCheck: YES: lastvalid <= lastmod (%d <= %d)\n",
-	    (int) entry->timestamp, (int) entry->lastmod);
-	return 1;
     }
-    factor = (double) age / (double) (entry->timestamp - entry->lastmod);
-    debug(22, 3) ("refreshCheck: factor = %f\n", factor);
-    if (factor < pct) {
-	debug(22, 3) ("refreshCheck: NO: factor < pct\n");
+    if (age <= min) {
+	debug(22, 3) ("refreshCheck: NO: age < min\n");
+	refreshCounts.conf_min_age_fresh++;
 	return 0;
     }
+    refreshCounts.default_stale++;
     return 1;
 }
 
@@ -213,3 +233,38 @@ getMaxAge(const char *url)
     else
 	return REFRESH_DEFAULT_MAX;
 }
+
+static void
+refreshStats(StoreEntry * sentry)
+{
+    storeAppendPrintf(sentry, "refreshCounts.total\t%d\n",
+	refreshCounts.total);
+    storeAppendPrintf(sentry, "refreshCounts.revalidate_stale\t%d\n",
+	refreshCounts.revalidate_stale);
+    storeAppendPrintf(sentry, "refreshCounts.request_max_age_stale\t%d\n",
+	refreshCounts.request_max_age_stale);
+    storeAppendPrintf(sentry, "refreshCounts.response_expires_stale\t%d\n",
+	refreshCounts.response_expires_stale);
+    storeAppendPrintf(sentry, "refreshCounts.response_expires_fresh\t%d\n",
+	refreshCounts.response_expires_fresh);
+    storeAppendPrintf(sentry, "refreshCounts.conf_max_age_stale\t%d\n",
+	refreshCounts.conf_max_age_stale);
+    storeAppendPrintf(sentry, "refreshCounts.last_modified_factor_fresh\t%d\n",
+	refreshCounts.last_modified_factor_fresh);
+    storeAppendPrintf(sentry, "refreshCounts.last_modified_factor_stale\t%d\n",
+	refreshCounts.last_modified_factor_stale);
+    storeAppendPrintf(sentry, "refreshCounts.conf_min_age_fresh\t%d\n",
+	refreshCounts.conf_min_age_fresh);
+    storeAppendPrintf(sentry, "refreshCounts.default_stale\t%d\n",
+	refreshCounts.default_stale);
+}
+
+void
+refreshInit(void)
+{
+    cachemgrRegister("refresh",
+	"Refresh Algorithm Statistics",
+	refreshStats,
+	0,
+	1);
+}
diff --git a/src/store.cc b/src/store.cc
index 9f49c4fb08..33e89e764a 100644
--- a/src/store.cc
+++ b/src/store.cc
@@ -1,6 +1,6 @@
 
 /*
- * $Id: store.cc,v 1.429 1998/07/20 20:21:11 wessels Exp $
+ * $Id: store.cc,v 1.430 1998/07/21 03:16:08 wessels Exp $
  *
  * DEBUG: section 20    Storage Manager
  * AUTHOR: Harvest Derived
@@ -983,10 +983,7 @@ storeTimestampsSet(StoreEntry * entry)
     if (served_date < 0)
 	served_date = squid_curtime;
     entry->expires = reply->expires;
-    if (reply->last_modified > -1)
-	entry->lastmod = reply->last_modified;
-    if (entry->lastmod < 0)
-	entry->lastmod = served_date;
+    entry->lastmod = reply->last_modified;
     entry->timestamp = served_date;
 }