(Config.onoff.surrogate_is_remote
&& sctusable->noStoreRemote())) {
surrogateNoStore = true;
- entry->makePrivate();
+ // Be conservative for now and make it non-shareable because
+ // there is no enough information here to make the decision.
+ entry->makePrivate(false);
}
/* The HttpHeader logic cannot tell if the header it's parsing is a reply to an
}
}
-int
-HttpStateData::cacheableReply()
+HttpStateData::ReuseDecision::Answers
+HttpStateData::reusableReply(HttpStateData::ReuseDecision &decision)
{
HttpReply const *rep = finalReply();
HttpHeader const *hdr = &rep->header;
const char *v;
+
#if USE_HTTP_VIOLATIONS
const RefreshPattern *R = NULL;
#define REFRESH_OVERRIDE(flag) 0
#endif
- if (EBIT_TEST(entry->flags, RELEASE_REQUEST)) {
- debugs(22, 3, "NO because " << *entry << " has been released.");
- return 0;
- }
+ if (EBIT_TEST(entry->flags, RELEASE_REQUEST))
+ return decision.make(ReuseDecision::reuseNot, "the entry has been released");
// RFC 7234 section 4: a cache MUST use the most recent response
// (as determined by the Date header field)
- if (sawDateGoBack) {
- debugs(22, 3, "NO because " << *entry << " has an older date header.");
- return 0;
- }
+ // TODO: whether such responses could be shareable?
+ if (sawDateGoBack)
+ return decision.make(ReuseDecision::reuseNot, "the response has an older date header");
// Check for Surrogate/1.0 protocol conditions
// NP: reverse-proxy traffic our parent server has instructed us never to cache
- if (surrogateNoStore) {
- debugs(22, 3, HERE << "NO because Surrogate-Control:no-store");
- return 0;
- }
+ if (surrogateNoStore)
+ return decision.make(ReuseDecision::reuseNot, "Surrogate-Control:no-store");
// RFC 2616: HTTP/1.1 Cache-Control conditions
if (!ignoreCacheControl) {
// for now we are not reliably doing that so we waste CPU re-checking request CC
// RFC 2616 section 14.9.2 - MUST NOT cache any response with request CC:no-store
- if (request && request->cache_control && request->cache_control->noStore() &&
- !REFRESH_OVERRIDE(ignore_no_store)) {
- debugs(22, 3, HERE << "NO because client request Cache-Control:no-store");
- return 0;
- }
+ if (request && request->cache_control && request->cache_control->hasNoStore() &&
+ !REFRESH_OVERRIDE(ignore_no_store))
+ return decision.make(ReuseDecision::reuseNot,
+ "client request Cache-Control:no-store");
// NP: request CC:no-cache only means cache READ is forbidden. STORE is permitted.
if (rep->cache_control && rep->cache_control->hasNoCache() && rep->cache_control->noCache().size() > 0) {
* successfully (ie, must revalidate AND these headers are prohibited on stale replies).
* That is a bit tricky for squid right now so we avoid caching entirely.
*/
- debugs(22, 3, HERE << "NO because server reply Cache-Control:no-cache has parameters");
- return 0;
+ return decision.make(ReuseDecision::reuseNot,
+ "server reply Cache-Control:no-cache has parameters");
}
// NP: request CC:private is undefined. We ignore.
// NP: other request CC flags are limiters on HIT/MISS. We don't care about here.
// RFC 2616 section 14.9.2 - MUST NOT cache any response with CC:no-store
- if (rep->cache_control && rep->cache_control->noStore() &&
- !REFRESH_OVERRIDE(ignore_no_store)) {
- debugs(22, 3, HERE << "NO because server reply Cache-Control:no-store");
- return 0;
- }
+ if (rep->cache_control && rep->cache_control->hasNoStore() &&
+ !REFRESH_OVERRIDE(ignore_no_store))
+ return decision.make(ReuseDecision::reuseNot,
+ "server reply Cache-Control:no-store");
// RFC 2616 section 14.9.1 - MUST NOT cache any response with CC:private in a shared cache like Squid.
// CC:private overrides CC:public when both are present in a response.
* successfully (ie, must revalidate AND these headers are prohibited on stale replies).
* That is a bit tricky for squid right now so we avoid caching entirely.
*/
- debugs(22, 3, HERE << "NO because server reply Cache-Control:private");
- return 0;
+ return decision.make(ReuseDecision::reuseNot,
+ "server reply Cache-Control:private");
}
}
// RFC 2068, sec 14.9.4 - MUST NOT cache any response with Authentication UNLESS certain CC controls are present
// allow HTTP violations to IGNORE those controls (ie re-block caching Auth)
if (request && (request->flags.auth || request->flags.authSent) && !REFRESH_OVERRIDE(ignore_auth)) {
- if (!rep->cache_control) {
- debugs(22, 3, HERE << "NO because Authenticated and server reply missing Cache-Control");
- return 0;
- }
+ if (!rep->cache_control)
+ return decision.make(ReuseDecision::reuseNot,
+ "authenticated and server reply missing Cache-Control");
- if (ignoreCacheControl) {
- debugs(22, 3, HERE << "NO because Authenticated and ignoring Cache-Control");
- return 0;
- }
+ if (ignoreCacheControl)
+ return decision.make(ReuseDecision::reuseNot,
+ "authenticated and ignoring Cache-Control");
bool mayStore = false;
// HTTPbis pt6 section 3.2: a response CC:public is present
- if (rep->cache_control->Public()) {
+ if (rep->cache_control->hasPublic()) {
debugs(22, 3, HERE << "Authenticated but server reply Cache-Control:public");
mayStore = true;
#endif
// HTTPbis pt6 section 3.2: a response CC:s-maxage is present
- } else if (rep->cache_control->sMaxAge()) {
+ } else if (rep->cache_control->hasSMaxAge()) {
debugs(22, 3, HERE << "Authenticated but server reply Cache-Control:s-maxage");
mayStore = true;
}
- if (!mayStore) {
- debugs(22, 3, HERE << "NO because Authenticated transaction");
- return 0;
- }
+ if (!mayStore)
+ return decision.make(ReuseDecision::reuseNot, "authenticated transaction");
// NP: response CC:no-cache is equivalent to CC:must-revalidate,max-age=0. We MAY cache, and do so.
// NP: other request CC flags are limiters on HIT/MISS/REFRESH. We don't care about here.
* probably should not be cachable
*/
if ((v = hdr->getStr(HDR_CONTENT_TYPE)))
- if (!strncasecmp(v, "multipart/x-mixed-replace", 25)) {
- debugs(22, 3, HERE << "NO because Content-Type:multipart/x-mixed-replace");
- return 0;
- }
+ if (!strncasecmp(v, "multipart/x-mixed-replace", 25))
+ return decision.make(ReuseDecision::reuseNot, "Content-Type:multipart/x-mixed-replace");
+
+ // TODO: if possible, provide more specific message for each status code
+ static const char *shareableError = "shareable error status code";
+ static const char *nonShareableError = "non-shareable error status code";
+ ReuseDecision::Answers statusAnswer = ReuseDecision::reuseNot;
+ const char *statusReason = nonShareableError;
switch (rep->sline.status()) {
+
+ /* There are several situations when a non-cacheable response may be
+ * still shareable (e.g., among collapsed clients). We assume that these
+ * are 3xx and 5xx responses, indicating server problems and some of
+ * 4xx responses, common for all clients with a given cache key (e.g.,
+ * 404 Not Found or 414 URI Too Long). On the other hand, we should not
+ * share non-cacheable client-specific errors, such as 400 Bad Request
+ * or 406 Not Acceptable.
+ */
+
/* Responses that are cacheable */
case Http::scOkay:
* Don't cache objects that need to be refreshed on next request,
* unless we know how to refresh it.
*/
+ if (refreshIsCachable(entry) || REFRESH_OVERRIDE(store_stale))
+ decision.make(ReuseDecision::cachePositively, "refresh check returned cacheable");
+ else
+ decision.make(ReuseDecision::doNotCacheButShare, "refresh check returned non-cacheable");
- if (!refreshIsCachable(entry) && !REFRESH_OVERRIDE(store_stale)) {
- debugs(22, 3, "NO because refreshIsCachable() returned non-cacheable..");
- return 0;
- } else {
- debugs(22, 3, HERE << "YES because HTTP status " << rep->sline.status());
- return 1;
- }
- /* NOTREACHED */
break;
/* Responses that only are cacheable if the server says so */
case Http::scFound:
case Http::scTemporaryRedirect:
- if (rep->date <= 0) {
- debugs(22, 3, HERE << "NO because HTTP status " << rep->sline.status() << " and Date missing/invalid");
- return 0;
- }
- if (rep->expires > rep->date) {
- debugs(22, 3, HERE << "YES because HTTP status " << rep->sline.status() << " and Expires > Date");
- return 1;
- } else {
- debugs(22, 3, HERE << "NO because HTTP status " << rep->sline.status() << " and Expires <= Date");
- return 0;
- }
- /* NOTREACHED */
- break;
- /* Errors can be negatively cached */
+ if (rep->date <= 0)
+ decision.make(ReuseDecision::doNotCacheButShare, "Date is missing/invalid");
+ else if (rep->expires > rep->date)
+ decision.make(ReuseDecision::cachePositively, "Expires > Date");
+ else
+ decision.make(ReuseDecision::doNotCacheButShare, "Expires <= Date");
+ break;
+ /* These responses can be negatively cached. Most can also be shared. */
case Http::scNoContent:
-
case Http::scUseProxy:
-
- case Http::scBadRequest:
-
case Http::scForbidden:
-
case Http::scNotFound:
-
case Http::scMethodNotAllowed:
-
case Http::scUriTooLong:
-
case Http::scInternalServerError:
-
case Http::scNotImplemented:
-
case Http::scBadGateway:
-
case Http::scServiceUnavailable:
-
case Http::scGatewayTimeout:
case Http::scMisdirectedRequest:
+ statusAnswer = ReuseDecision::doNotCacheButShare;
+ statusReason = shareableError;
+ // fall through to the actual decision making below
- debugs(22, 3, "MAYBE because HTTP status " << rep->sline.status());
- return -1;
+ case Http::scBadRequest: // no sharing; perhaps the server did not like something specific to this request
- /* NOTREACHED */
+#if USE_HTTP_VIOLATIONS
+ if (Config.negativeTtl > 0)
+ decision.make(ReuseDecision::cacheNegatively, "Config.negativeTtl > 0");
+ else
+#endif
+ decision.make(statusAnswer, statusReason);
break;
- /* Some responses can never be cached */
-
- case Http::scPartialContent: /* Not yet supported */
-
+ /* these responses can never be cached, some
+ of them can be shared though */
case Http::scSeeOther:
-
case Http::scNotModified:
-
case Http::scUnauthorized:
-
case Http::scProxyAuthenticationRequired:
-
- case Http::scInvalidHeader: /* Squid header parsing error */
-
- case Http::scHeaderTooLarge:
-
case Http::scPaymentRequired:
+ case Http::scInsufficientStorage:
+ // TODO: use more specific reason for non-error status codes
+ decision.make(ReuseDecision::doNotCacheButShare, shareableError);
+ break;
+
+ case Http::scPartialContent: /* Not yet supported. TODO: make shareable for suitable ranges */
case Http::scNotAcceptable:
- case Http::scRequestTimeout:
- case Http::scConflict:
+ case Http::scRequestTimeout: // TODO: is this shareable?
+ case Http::scConflict: // TODO: is this shareable?
case Http::scLengthRequired:
case Http::scPreconditionFailed:
case Http::scPayloadTooLarge:
case Http::scUnsupportedMediaType:
case Http::scUnprocessableEntity:
- case Http::scLocked:
+ case Http::scLocked: // TODO: is this shareable?
case Http::scFailedDependency:
- case Http::scInsufficientStorage:
case Http::scRequestedRangeNotSatisfied:
case Http::scExpectationFailed:
-
- debugs(22, 3, HERE << "NO because HTTP status " << rep->sline.status());
- return 0;
-
+ case Http::scInvalidHeader: /* Squid header parsing error */
+ case Http::scHeaderTooLarge:
+ decision.make(ReuseDecision::reuseNot, nonShareableError);
+ break;
default:
/* RFC 2616 section 6.1.1: an unrecognized response MUST NOT be cached. */
- debugs (11, 3, HERE << "NO because unknown HTTP status code " << rep->sline.status());
- return 0;
- /* NOTREACHED */
+ decision.make(ReuseDecision::reuseNot, "unknown status code");
break;
}
- /* NOTREACHED */
+ return decision.answer;
}
/// assemble a variant key (vary-mark) from the given Vary header and HTTP request
Ctx ctx = ctx_enter(entry->mem_obj->urlXXX());
HttpReply *rep = finalReply();
+ const Http::StatusCode statusCode = rep->sline.status();
entry->timestampsSet();
/* Check if object is cacheable or not based on reply code */
- debugs(11, 3, "HTTP CODE: " << rep->sline.status());
+ debugs(11, 3, "HTTP CODE: " << statusCode);
if (const StoreEntry *oldEntry = findPreviouslyCachedEntry(entry))
sawDateGoBack = rep->olderThan(oldEntry->getReply());
const SBuf vary(httpMakeVaryMark(request, rep));
if (vary.isEmpty()) {
- entry->makePrivate();
+ // TODO: check whether such responses are shareable.
+ // Do not share for now.
+ entry->makePrivate(false);
if (!fwd->reforwardableStatus(rep->sline.status()))
EBIT_CLR(entry->flags, ENTRY_FWD_HDR_WAIT);
varyFailure = true;
if (!fwd->reforwardableStatus(rep->sline.status()))
EBIT_CLR(entry->flags, ENTRY_FWD_HDR_WAIT);
- switch (cacheableReply()) {
+ ReuseDecision decision(entry, statusCode);
- case 1:
- entry->makePublic();
+ switch (reusableReply(decision)) {
+
+ case ReuseDecision::reuseNot:
+ entry->makePrivate(false);
break;
- case 0:
- entry->makePrivate();
+ case ReuseDecision::cachePositively:
+ entry->makePublic();
break;
- case -1:
+ case ReuseDecision::cacheNegatively:
+ entry->cacheNegatively();
+ break;
-#if USE_HTTP_VIOLATIONS
- if (Config.negativeTtl > 0)
- entry->cacheNegatively();
- else
-#endif
- entry->makePrivate();
+ case ReuseDecision::doNotCacheButShare:
+ entry->makePrivate(true);
break;
default:
assert(0);
break;
}
+ debugs(11, 3, "decided: " << decision);
}
if (!ignoreCacheControl) {
mustStop(reason);
}
+HttpStateData::ReuseDecision::ReuseDecision(const StoreEntry *e, const Http::StatusCode code)
+ : answer(HttpStateData::ReuseDecision::reuseNot), reason(nullptr), entry(e), statusCode(code) {}
+
+HttpStateData::ReuseDecision::Answers
+HttpStateData::ReuseDecision::make(const HttpStateData::ReuseDecision::Answers ans, const char *why)
+{
+ answer = ans;
+ reason = why;
+ return answer;
+}
+
+std::ostream &operator <<(std::ostream &os, const HttpStateData::ReuseDecision &d)
+{
+ static const char *ReuseMessages[] = {
+ "do not cache and do not share", // reuseNot
+ "cache positively and share", // cachePositively
+ "cache negatively and share", // cacheNegatively
+ "do not cache but share" // doNotCacheButShare
+ };
+
+ assert(d.answer >= HttpStateData::ReuseDecision::reuseNot &&
+ d.answer <= HttpStateData::ReuseDecision::doNotCacheButShare);
+ return os << ReuseMessages[d.answer] << " because " << d.reason <<
+ "; HTTP status " << d.statusCode << " " << *(d.entry);
+}
+
}
void
-StoreEntry::makePrivate()
+StoreEntry::makePrivate(const bool shareable)
{
/* This object should never be cached at all */
expireNow();
- releaseRequest(); /* delete object when not used */
+ releaseRequest(shareable); /* delete object when not used */
+}
+
+void
+StoreEntry::clearPrivate()
+{
+ EBIT_CLR(flags, KEY_PRIVATE);
+ shareableWhenPrivate = false;
}
void
ping_status(PING_NONE),
store_status(STORE_PENDING),
swap_status(SWAPOUT_NONE),
- lock_count(0)
+ lock_count(0),
+ shareableWhenPrivate(false)
{
debugs(20, 5, "StoreEntry constructed, this=" << this);
}
}
void
-StoreEntry::releaseRequest()
+StoreEntry::releaseRequest(const bool shareable)
{
if (EBIT_TEST(flags, RELEASE_REQUEST))
return;
setReleaseFlag(); // makes validToSend() false, preventing future hits
- setPrivateKey();
+ setPrivateKey(shareable);
}
int
* concept'.
*/
void
-StoreEntry::setPrivateKey()
+StoreEntry::setPrivateKey(const bool shareable)
{
const cache_key *newkey;
- if (key && EBIT_TEST(flags, KEY_PRIVATE))
- return; /* is already private */
+ if (key && EBIT_TEST(flags, KEY_PRIVATE)) {
+ // The entry is already private, but it may be still shareable.
+ if (!shareable)
+ shareableWhenPrivate = false;
+ return;
+ }
if (key) {
setReleaseFlag(); // will markForUnlink(); all caches/workers will know
assert(hash_lookup(store_table, newkey) == NULL);
EBIT_SET(flags, KEY_PRIVATE);
+ shareableWhenPrivate = shareable;
hashInsert(newkey);
}
if (StoreEntry *e2 = (StoreEntry *)hash_lookup(store_table, newkey)) {
assert(e2 != this);
debugs(20, 3, "Making old " << *e2 << " private.");
- e2->setPrivateKey();
- e2->release();
+
+ // TODO: check whether there is any sense in keeping old entry
+ // shareable here. Leaving it non-shareable for now.
+ e2->setPrivateKey(false);
+ e2->release(false);
}
if (key)
hashDelete();
- EBIT_CLR(flags, KEY_PRIVATE);
+ clearPrivate();
hashInsert(newkey);
e->lock("storeCreateEntry");
if (neighbors_do_private_keys || !flags.hierarchical)
- e->setPrivateKey();
+ e->setPrivateKey(false);
else
e->setPublicKey();
/* release an object from a cache */
void
-StoreEntry::release()
+StoreEntry::release(const bool shareable)
{
PROF_start(storeRelease);
debugs(20, 3, "releasing " << *this << ' ' << getMD5Text());
if (locked()) {
expireNow();
debugs(20, 3, "storeRelease: Only setting RELEASE_REQUEST bit");
- releaseRequest();
+ releaseRequest(shareable);
PROF_stop(storeRelease);
return;
}
Store::Root().memoryUnlink(*this);
if (StoreController::store_dirs_rebuilding && swap_filen > -1) {
- setPrivateKey();
+ setPrivateKey(shareable);
if (swap_filen > -1) {
// lock the entry until rebuilding is done
if (EBIT_TEST(e.flags, REFRESH_REQUEST)) os << 'F';
if (EBIT_TEST(e.flags, ENTRY_REVALIDATE_STALE)) os << 'E';
if (EBIT_TEST(e.flags, ENTRY_DISPATCHED)) os << 'D';
- if (EBIT_TEST(e.flags, KEY_PRIVATE)) os << 'I';
+ if (EBIT_TEST(e.flags, KEY_PRIVATE)) {
+ os << 'I';
+ if (e.shareableWhenPrivate)
+ os << 'H';
+ }
if (EBIT_TEST(e.flags, ENTRY_FWD_HDR_WAIT)) os << 'W';
if (EBIT_TEST(e.flags, ENTRY_NEGCACHED)) os << 'N';
if (EBIT_TEST(e.flags, ENTRY_VALIDATED)) os << 'V';
projects / thirdparty / squid.git / commitdiff
