/*
- * $Id: refresh.cc,v 1.52 2000/06/06 19:34:31 hno Exp $
+ * $Id: refresh.cc,v 1.53 2000/11/09 18:21:27 wessels Exp $
*
* DEBUG: section 22 Refresh Calculation
* AUTHOR: Harvest Derived
#include "squid.h"
typedef enum {
- rcHTTP, rcICP, rcHTCP, rcCDigest, rcStore, rcCount
+ rcHTTP,
+ rcICP,
+#if USE_HTCP
+ rcHTCP,
+#endif
+#if USE_CACHE_DIGESTS
+ rcCDigest,
+#endif
+ rcStore,
+ rcCount
} refreshCountsEnum;
+typedef struct {
+ unsigned int expires:1;
+ unsigned int min:1;
+ unsigned int lmfactor:1;
+ unsigned int max;
+} stale_flags;
+
+/*
+ * This enumerated list assigns specific values, ala HTTP/FTP status
+ * codes. All Fresh codes are in the range 100-199 and all stale
+ * codes are 200-299. We might want to use these codes in logging,
+ * so best to keep them consistent over time.
+ */
+enum {
+ FRESH_REQUEST_MAX_STALE_ALL = 100,
+ FRESH_REQUEST_MAX_STALE_VALUE,
+ FRESH_EXPIRES,
+ FRESH_LMFACTOR_RULE,
+ FRESH_MIN_RULE,
+ FRESH_OVERRIDE_EXPIRES,
+ FRESH_OVERRIDE_LASTMOD,
+ STALE_MUST_REVALIDATE = 200,
+ STALE_RELOAD_INTO_IMS,
+ STALE_FORCED_RELOAD,
+ STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE,
+ STALE_EXPIRES,
+ STALE_MAX_RULE,
+ STALE_LMFACTOR_RULE,
+ STALE_DEFAULT = 299
+};
+
static struct RefreshCounts {
const char *proto;
int total;
- int revalidate_stale;
- int request_max_age_stale;
- int request_reload2ims_stale;
- int request_reload_stale;
- int negative_age_stale;
- int min_age_override_exp_fresh;
- int min_age_override_lmt_fresh;
- int response_expires_stale;
- int response_expires_fresh;
- int conf_max_age_stale;
- int last_modified_factor_fresh;
- int last_modified_factor_stale;
- int response_lmt_now_stale;
- int conf_min_age_fresh;
- int default_stale;
- /* maybe-counters -- intermediate decisions that may affect the result */
- int request_reload_ignore_maybe;
- int response_lmt_future_maybe;
+ int status[STALE_DEFAULT + 1];
} refreshCounts[rcCount];
/*
static const refresh_t *refreshLimits(const char *);
static const refresh_t *refreshUncompiledPattern(const char *);
static OBJH refreshStats;
+static int refreshStaleness(const StoreEntry *, time_t, time_t, const refresh_t *, stale_flags *);
+
+static refresh_t DefaultRefresh;
static const refresh_t *
refreshLimits(const char *url)
return NULL;
}
+/*
+ * Calculate how stale the response is (or will be at the check_time).
+ * Staleness calculation is based on the following: (1) response
+ * expiration time, (2) age greater than configured maximum, (3)
+ * last-modified factor, and (4) age less than configured minimum.
+ *
+ * If the response is fresh, return -1. Otherwise return its
+ * staleness. NOTE return value of 0 means the response is stale.
+ *
+ * The 'stale_flags' structure is used to tell the calling function
+ * _why_ this response is fresh or stale. Its used, for example,
+ * when the admin wants to override expiration and last-modified
+ * times.
+ */
+static int
+refreshStaleness(const StoreEntry * entry, time_t check_time, time_t age, const refresh_t * R, stale_flags * sf)
+{
+ /*
+ * Check for an explicit expiration time.
+ */
+ if (entry->expires > -1) {
+ sf->expires = 1;
+ if (entry->expires > check_time) {
+ debug(22, 3) ("FRESH: expires %d >= check_time %d \n",
+ (int) entry->expires, (int) check_time);
+ return -1;
+ } else {
+ debug(22, 3) ("STALE: expires %d < check_time %d \n",
+ (int) entry->expires, (int) check_time);
+ return (check_time - entry->expires);
+ }
+ }
+ assert(age >= 0);
+ /*
+ * Use local heuristics to determine staleness. Start with the
+ * max age from the refresh_pattern rule.
+ */
+ if (age > R->max) {
+ debug(22, 3) ("STALE: age %d > max %d \n", (int) age, (int) R->max);
+ sf->max = 1;
+ return (age - R->max);
+ }
+ /*
+ * Try the last-modified factor algorithm.
+ */
+ if (entry->lastmod > -1 && entry->timestamp > entry->lastmod) {
+ /*
+ * stale_age is the Age of the response when it became/becomes
+ * stale according to the last-modified factor algorithm.
+ */
+ time_t stale_age = (entry->timestamp - entry->lastmod) * R->pct;
+ sf->lmfactor = 1;
+ if (age >= stale_age) {
+ debug(22, 3) ("STALE: age %d > stale_age %d\n",
+ (int) age, (int) stale_age);
+ return (age - stale_age);
+ } else {
+ debug(22, 3) ("FRESH: age %d <= stale_age %d\n",
+ (int) age, (int) stale_age);
+ return -1;
+ }
+ }
+ /*
+ * If we are here, staleness is determined by the refresh_pattern
+ * configured minimum age.
+ */
+ if (age <= R->min) {
+ debug(22, 3) ("FRESH: age %d <= min %d\n", (int) age, (int) R->min);
+ sf->min = 1;
+ return -1;
+ }
+ debug(22, 3) ("STALE: age %d > min %d\n", (int) age, (int) R->min);
+ return (age - R->min);
+}
+
/* return 1 if the entry must be revalidated within delta seconds
* 0 otherwise
*
* note: request maybe null (e.g. for cache digests build)
*/
static int
-refreshCheck(const StoreEntry * entry, request_t * request, time_t delta, struct RefreshCounts *rc)
+refreshCheck(const StoreEntry * entry, request_t * request, time_t delta)
{
const refresh_t *R;
const char *uri = NULL;
- time_t min = REFRESH_DEFAULT_MIN;
- double pct = REFRESH_DEFAULT_PCT;
- time_t max = REFRESH_DEFAULT_MAX;
-#if HTTP_VIOLATIONS
- int override_expire = 0;
- int override_lastmod = 0;
- int reload_into_ims = 0;
- int ignore_reload = 0;
-#endif
- const char *pattern = "<none>";
- time_t age;
- double factor;
+ time_t age = 0;
time_t check_time = squid_curtime + delta;
+ int staleness;
+ stale_flags sf;
if (entry->mem_obj)
uri = entry->mem_obj->url;
else if (request)
uri = urlCanonical(request);
- debug(22, 3) ("refreshCheck(%s): '%s'\n", rc->proto, uri ? uri : "<none>");
- rc->total++;
- if (EBIT_TEST(entry->flags, ENTRY_REVALIDATE)) {
- debug(22, 3) ("refreshCheck: YES: Required Authorization\n");
- rc->revalidate_stale++;
- return 1;
- }
- if ((R = uri ? refreshLimits(uri) : refreshUncompiledPattern("."))) {
- min = R->min;
- pct = R->pct;
- max = R->max;
- pattern = R->pattern;
-#if HTTP_VIOLATIONS
- override_expire = R->flags.override_expire;
- override_lastmod = R->flags.override_lastmod;
- reload_into_ims = R->flags.reload_into_ims;
- ignore_reload = R->flags.ignore_reload;
-#endif
- }
-#if HTTP_VIOLATIONS
- if (!reload_into_ims)
- reload_into_ims = Config.onoff.reload_into_ims;
-#endif
+ debug(22, 3) ("refreshCheck: '%s'\n", uri ? uri : "<none>");
+
+ if (check_time > entry->timestamp)
+ age = check_time - entry->timestamp;
+ R = uri ? refreshLimits(uri) : refreshUncompiledPattern(".");
+ if (NULL == R)
+ R = &DefaultRefresh;
+ memset(&sf, '\0', sizeof(sf));
+ staleness = refreshStaleness(entry, check_time, age, R, &sf);
+ debug(22, 3) ("Staleness = %d\n", staleness);
+
debug(22, 3) ("refreshCheck: Matched '%s %d %d%% %d'\n",
- pattern, (int) min, (int) (100.0 * pct), (int) max);
- age = check_time - entry->timestamp;
+ R->pattern, (int) R->min, (int) (100.0 * R->pct), (int) R->max);
debug(22, 3) ("refreshCheck: age = %d\n", (int) age);
debug(22, 3) ("\tcheck_time:\t%s\n", mkrfc1123(check_time));
debug(22, 3) ("\tentry->timestamp:\t%s\n", mkrfc1123(entry->timestamp));
+
+ if (EBIT_TEST(entry->flags, ENTRY_REVALIDATE) && staleness > -1) {
+ debug(22, 3) ("refreshCheck: YES: Must revalidate stale response\n");
+ return STALE_MUST_REVALIDATE;
+ }
/* request-specific checks */
if (request) {
+ HttpHdrCc *cc = request->cache_control;
#if HTTP_VIOLATIONS
- if (request->flags.nocache_hack) {
- if (ignore_reload) {
- /* The clients no-cache header is ignored */
- debug(22, 3) ("refreshCheck: MAYBE: ignore-reload\n");
- rc->request_reload_ignore_maybe++;
- } else if (reload_into_ims) {
- /* The clients no-cache header is changed into a IMS query */
- debug(22, 3) ("refreshCheck: YES: reload-into-ims\n");
- rc->request_reload2ims_stale++;
- return 1;
- } else {
- /* The clients no-cache header is not overridden on this request */
- debug(22, 3) ("refreshCheck: YES: client reload\n");
- request->flags.nocache = 1;
- rc->request_reload_stale++;
- return 1;
- }
+ if (!request->flags.nocache_hack) {
+ (void) 0;
+ } else if (R->flags.ignore_reload) {
+ /* The clients no-cache header is ignored */
+ debug(22, 3) ("refreshCheck: MAYBE: ignore-reload\n");
+ } else if (R->flags.reload_into_ims || Config.onoff.reload_into_ims) {
+ /* The clients no-cache header is changed into a IMS query */
+ debug(22, 3) ("refreshCheck: YES: reload-into-ims\n");
+ return STALE_RELOAD_INTO_IMS;
+ } else {
+ /* The clients no-cache header is not overridden on this request */
+ debug(22, 3) ("refreshCheck: YES: client reload\n");
+ request->flags.nocache = 1;
+ return STALE_FORCED_RELOAD;
}
#endif
- if (age < 0) {
- debug(22, 3) ("refreshCheck: YES: age < 0\n");
- rc->negative_age_stale++;
- return 1;
- }
- if (request->cache_control && request->cache_control->max_age > -1) {
- if (age > request->cache_control->max_age) {
- debug(22, 3) ("refreshCheck: YES: age > client-max-age\n");
- rc->request_max_age_stale++;
- return 1;
+ if (NULL != cc) {
+ if (cc->max_age > -1) {
+ if (age > cc->max_age) {
+ debug(22, 3) ("refreshCheck: YES: age > client-max-age\n");
+ return STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE;
+ }
+ }
+ if (EBIT_TEST(cc->mask, CC_MAX_STALE) && staleness > -1) {
+ if (cc->max_stale < 0) {
+ /* max-stale directive without a value */
+ debug(22, 3) ("refreshCheck: NO: max-stale wildcard\n");
+ return FRESH_REQUEST_MAX_STALE_ALL;
+ } else if (staleness < cc->max_stale) {
+ debug(22, 3) ("refreshCheck: NO: staleness < max-stale\n");
+ return FRESH_REQUEST_MAX_STALE_VALUE;
+ }
}
}
}
-#if HTTP_VIOLATIONS
- if (override_expire && age <= min) {
- debug(22, 3) ("refreshCheck: NO: age < min && override_expire\n");
- rc->min_age_override_exp_fresh++;
- return 0;
+ if (-1 == staleness) {
+ if (sf.expires)
+ return FRESH_EXPIRES;
+ assert(!sf.max);
+ if (sf.lmfactor)
+ return FRESH_LMFACTOR_RULE;
+ assert(sf.min);
+ return FRESH_MIN_RULE;
}
-#endif
- if (entry->expires > -1) {
- if (entry->expires <= check_time) {
- debug(22, 3) ("refreshCheck: YES: expires <= curtime\n");
- rc->response_expires_stale++;
- return 1;
- } else {
- debug(22, 3) ("refreshCheck: NO: expires > curtime\n");
- rc->response_expires_fresh++;
- return 0;
+ /*
+ * At this point the response is stale, unless one of
+ * the override optios kicks in.
+ */
+ if (sf.expires) {
+#if HTTP_VIOLATIONS
+ if (R->flags.override_expire && age < R->min) {
+ debug(22, 3) ("refreshCheck: NO: age < min && override-expire\n");
+ return FRESH_OVERRIDE_EXPIRES;
}
+#endif
+ return STALE_EXPIRES;
}
- if (age > max) {
- debug(22, 3) ("refreshCheck: YES: age > max\n");
- rc->conf_max_age_stale++;
- return 1;
- }
+ if (sf.max)
+ return STALE_MAX_RULE;
+ if (sf.lmfactor) {
#if HTTP_VIOLATIONS
- if (override_lastmod && age <= min) {
- debug(22, 3) ("refreshCheck: NO: age < min && override_lastmod\n");
- rc->min_age_override_lmt_fresh++;
- return 0;
- }
-#endif
- 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");
- rc->last_modified_factor_fresh++;
- return 0;
- } else {
- debug(22, 3) ("refreshCheck: YES: factor >= pct\n");
- rc->last_modified_factor_stale++;
- return 1;
+ if (R->flags.override_lastmod && age < R->min) {
+ debug(22, 3) ("refreshCheck: NO: age < min && override-lastmod\n");
+ return FRESH_OVERRIDE_LASTMOD;
}
- } else if (entry->lastmod > -1 && entry->timestamp == entry->lastmod) {
- debug(22, 3) ("refreshCheck: YES: last-modified 'now'\n");
- rc->response_lmt_now_stale++;
- return 1;
- } else if (entry->lastmod > -1 && entry->timestamp < entry->lastmod) {
- debug(22, 3) ("refreshCheck: MAYBE: last-modified in the future\n");
- rc->response_lmt_future_maybe++;
- }
- if (age <= min) {
- debug(22, 3) ("refreshCheck: NO: age <= min\n");
- rc->conf_min_age_fresh++;
- return 0;
+#endif
+ return STALE_LMFACTOR_RULE;
}
- debug(22, 3) ("refreshCheck: YES: default stale\n");
- rc->default_stale++;
- return 1;
+ return STALE_DEFAULT;
}
int
* 60 seconds delta, to avoid objects which expire almost
* immediately, and which can't be refreshed.
*/
- if (!refreshCheck(entry, NULL, 60, &refreshCounts[rcStore]))
+ int reason = refreshCheck(entry, NULL, 60);
+ refreshCounts[rcStore].total++;
+ refreshCounts[rcStore].status[reason]++;
+ if (reason < 200)
/* Does not need refresh. This is certainly cachable */
return 1;
if (entry->lastmod < 0)
int
refreshCheckHTTP(const StoreEntry * entry, request_t * request)
{
- return refreshCheck(entry, request, 0, &refreshCounts[rcHTTP]);
+ int reason = refreshCheck(entry, request, 0);
+ refreshCounts[rcHTTP].total++;
+ refreshCounts[rcHTTP].status[reason]++;
+ return (reason < 200) ? 0 : 1;
}
int
refreshCheckICP(const StoreEntry * entry, request_t * request)
{
- return refreshCheck(entry, request, 30, &refreshCounts[rcICP]);
+ int reason = refreshCheck(entry, request, 30);
+ refreshCounts[rcICP].total++;
+ refreshCounts[rcICP].status[reason]++;
+ return (reason < 200) ? 0 : 1;
}
+#if USE_HTCP
int
refreshCheckHTCP(const StoreEntry * entry, request_t * request)
{
- return refreshCheck(entry, request, 10, &refreshCounts[rcHTCP]);
+ int reason = refreshCheck(entry, request, 10);
+ refreshCounts[rcHTCP].total++;
+ refreshCounts[rcHTCP].status[reason]++;
+ return (reason < 200) ? 0 : 1;
}
+#endif
+#if USE_CACHE_DIGESTS
int
refreshCheckDigest(const StoreEntry * entry, time_t delta)
{
- return refreshCheck(entry,
+ int reason = refreshCheck(entry,
entry->mem_obj ? entry->mem_obj->request : NULL,
- delta,
- &refreshCounts[rcCDigest]);
+ delta);
+ refreshCounts[rcCDigest].total++;
+ refreshCounts[rcCDigest].status[reason]++;
+ return (reason < 200) ? 0 : 1;
}
+#endif
time_t
getMaxAge(const char *url)
int tot = rc->total;
storeAppendPrintf(sentry, "\n\n%s histogram:\n", rc->proto);
- storeAppendPrintf(sentry, "Category\tCount\t%%Total\n");
+ storeAppendPrintf(sentry, "Count\t%%Total\tCategory\n");
-#define refreshCountsStatsEntry(name) { \
- storeAppendPrintf(sentry, "%s\t%6d\t%6.2f\n", \
- #name, rc->name, xpercent(rc->name, tot)); \
- sum += rc->name; \
+#define refreshCountsStatsEntry(code,desc) { \
+ storeAppendPrintf(sentry, "%6d\t%6.2f\t%s\n", \
+ rc->status[code], xpercent(rc->status[code], tot), desc); \
+ sum += rc->status[code]; \
}
- refreshCountsStatsEntry(revalidate_stale);
- refreshCountsStatsEntry(request_reload2ims_stale);
- refreshCountsStatsEntry(request_reload_stale);
- refreshCountsStatsEntry(request_max_age_stale);
- refreshCountsStatsEntry(min_age_override_exp_fresh);
- refreshCountsStatsEntry(response_expires_stale);
- refreshCountsStatsEntry(response_expires_fresh);
- refreshCountsStatsEntry(conf_max_age_stale);
- refreshCountsStatsEntry(min_age_override_lmt_fresh);
- refreshCountsStatsEntry(last_modified_factor_fresh);
- refreshCountsStatsEntry(last_modified_factor_stale);
- refreshCountsStatsEntry(response_lmt_now_stale);
- refreshCountsStatsEntry(conf_min_age_fresh);
- refreshCountsStatsEntry(default_stale);
+
+ refreshCountsStatsEntry(FRESH_REQUEST_MAX_STALE_ALL,
+ "Fresh: request max-stale wildcard");
+ refreshCountsStatsEntry(FRESH_REQUEST_MAX_STALE_VALUE,
+ "Fresh: request max-stale value");
+ refreshCountsStatsEntry(FRESH_EXPIRES,
+ "Fresh: expires time not reached");
+ refreshCountsStatsEntry(FRESH_LMFACTOR_RULE,
+ "Fresh: refresh_pattern last-mod factor percentage");
+ refreshCountsStatsEntry(FRESH_MIN_RULE,
+ "Fresh: refresh_pattern min value");
+ refreshCountsStatsEntry(FRESH_OVERRIDE_EXPIRES,
+ "Fresh: refresh_pattern override expires");
+ refreshCountsStatsEntry(FRESH_OVERRIDE_LASTMOD,
+ "Fresh: refresh_pattern override lastmod");
+ refreshCountsStatsEntry(STALE_MUST_REVALIDATE,
+ "Stale: response has must-revalidate");
+ refreshCountsStatsEntry(STALE_RELOAD_INTO_IMS,
+ "Stale: changed reload into IMS");
+ refreshCountsStatsEntry(STALE_FORCED_RELOAD,
+ "Stale: request has no-cache directive");
+ refreshCountsStatsEntry(STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE,
+ "Stale: age exceeds request max-age value");
+ refreshCountsStatsEntry(STALE_EXPIRES,
+ "Stale: expires time reached");
+ refreshCountsStatsEntry(STALE_MAX_RULE,
+ "Stale: refresh_pattern max age rule");
+ refreshCountsStatsEntry(STALE_LMFACTOR_RULE,
+ "Stale: refresh_pattern last-mod factor percentage");
+ refreshCountsStatsEntry(STALE_DEFAULT,
+ "Stale: by default");
+
tot = sum; /* paranoid: "total" line shows 100% if we forgot nothing */
- refreshCountsStatsEntry(total);
- /* maybe counters */
- storeAppendPrintf(sentry, "\n");
- refreshCountsStatsEntry(request_reload_ignore_maybe);
- refreshCountsStatsEntry(response_lmt_future_maybe);
+ storeAppendPrintf(sentry, "%6d\t%6.2f\tTOTAL\n",
+ rc->total, xpercent(rc->total, tot));
+ \
+ storeAppendPrintf(sentry, "\n");
}
static void
memset(refreshCounts, 0, sizeof(refreshCounts));
refreshCounts[rcHTTP].proto = "HTTP";
refreshCounts[rcICP].proto = "ICP";
+#if USE_HTCP
refreshCounts[rcHTCP].proto = "HTCP";
+#endif
refreshCounts[rcStore].proto = "On Store";
+#if USE_CACHE_DIGESTS
refreshCounts[rcCDigest].proto = "Cache Digests";
-
+#endif
cachemgrRegister("refresh",
"Refresh Algorithm Statistics",
refreshStats,
0,
1);
+ memset(&DefaultRefresh, '\0', sizeof(DefaultRefresh));
+ DefaultRefresh.pattern = "<none>";
+ DefaultRefresh.min = REFRESH_DEFAULT_MIN;
+ DefaultRefresh.pct = REFRESH_DEFAULT_PCT;
+ DefaultRefresh.max = REFRESH_DEFAULT_MAX;
}
projects / thirdparty / squid.git / commitdiff
