refresh.cc File Reference

#include "squid.h"
#include "base/PackableStream.h"
#include "HttpHdrCc.h"
#include "HttpReply.h"
#include "HttpRequest.h"
#include "MemObject.h"
#include "mgr/Registration.h"
#include "refresh.h"
#include "RefreshPattern.h"
#include "SquidConfig.h"
#include "Store.h"
#include "util.h"

Include dependency graph for refresh.cc:

Go to the source code of this file.

Classes
struct	stale_flags
struct	RefreshCounts

Macros
#define	USE_POSIX_REGEX   /* put before includes; always use POSIX */

Enumerations
enum	refreshCountsEnum {   rcHTTP , rcICP , rcHTCP , rcCDigest ,   rcStore , rcCount }
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_MAX_STALE , STALE_DEFAULT = 299 }

Functions
static int	refreshStaleness (const StoreEntry *entry, time_t check_time, const time_t age, const RefreshPattern *R, stale_flags *sf)
const RefreshPattern *	refreshLimits (const char *url)
static const RefreshPattern *	refreshFirstDotRule ()
	the first explicit refresh_pattern rule that uses a "." regex (or nil)
static int	refreshCheck (const StoreEntry *entry, HttpRequest *request, time_t delta)
bool	refreshIsCachable (const StoreEntry *entry)
static bool	refreshIsStaleIfHit (const int reason)
	whether reply is stale if it is a hit
int	refreshCheckHTTP (const StoreEntry *entry, HttpRequest *request)
int	refreshCheckICP (const StoreEntry *entry, HttpRequest *request)
int	refreshCheckHTCP (const StoreEntry *entry, HttpRequest *request)
int	refreshCheckDigest (const StoreEntry *entry, time_t delta)
time_t	getMaxAge (const char *url)
static int	refreshCountsStatsEntry (StoreEntry *sentry, struct RefreshCounts &rc, int code, const char *desc)
static void	refreshCountsStats (StoreEntry *sentry, struct RefreshCounts &rc)
static void	refreshStats (StoreEntry *sentry)
static void	refreshRegisterWithCacheManager (void)
void	refreshInit (void)

Variables
static struct RefreshCounts	refreshCounts [rcCount]
static OBJH	refreshStats
static RefreshPattern	DefaultRefresh (nullptr)

Macro Definition Documentation

USE_POSIX_REGEX

#define USE_POSIX_REGEX   /* put before includes; always use POSIX */

Definition at line 12 of file refresh.cc.

Enumeration Type Documentation

anonymous enum

anonymous enum

Enumerator
FRESH_REQUEST_MAX_STALE_ALL
FRESH_REQUEST_MAX_STALE_VALUE
FRESH_EXPIRES
FRESH_LMFACTOR_RULE
FRESH_MIN_RULE
FRESH_OVERRIDE_EXPIRES
FRESH_OVERRIDE_LASTMOD
STALE_MUST_REVALIDATE
STALE_RELOAD_INTO_IMS
STALE_FORCED_RELOAD
STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE
STALE_EXPIRES
STALE_MAX_RULE
STALE_LMFACTOR_RULE
STALE_MAX_STALE
STALE_DEFAULT

Definition at line 57 of file refresh.cc.

refreshCountsEnum

enum refreshCountsEnum

Enumerator
rcHTTP
rcICP
rcHTCP
rcCDigest
rcStore
rcCount

Definition at line 28 of file refresh.cc.

Function Documentation

getMaxAge()

time_t getMaxAge

(

const char *

url

)

Get the configured maximum caching time for objects with this URL according to refresh_pattern.

Used by http.cc when generating a upstream requests to ensure that responses it is given are fresh enough to be worth caching.

Return values

pattern-max	if there is a refresh_pattern matching the URL configured.
REFRESH_DEFAULT_MAX	if there are no explicit limits configured

Definition at line 639 of file refresh.cc.

References debugs, RefreshPattern::max, REFRESH_DEFAULT_MAX, and refreshLimits().

Referenced by HttpStateData::httpBuildRequestHeader().

refreshCheck()

static int refreshCheck ( const StoreEntry *  entry, HttpRequest *  request, time_t  delta  )

static

Checks whether a store entry is fresh or stale, and why.

This is where all aspects of request, response and squid configuration meet to decide whether a response is cacheable or not:

1. Client request headers that affect cacheability, e.g.
   • Cache-Control: no-cache
   • Cache-Control: max-age=N
   • Cache-Control: max-stale[=N]
   • Pragma: no-cache
2. Server response headers that affect cacheability, e.g.
   • Age:
   • Cache-Control: proxy-revalidate
   • Cache-Control: must-revalidate
   • Cache-Control: no-cache
   • Cache-Control: max-age=N
   • Cache-Control: s-maxage=N
   • Date:
   • Expires:
   • Last-Modified:
3. Configuration options, e.g.
   • reload-into-ims (refresh_pattern)
   • ignore-reload (refresh_pattern)
   • refresh-ims (refresh_pattern)
   • override-lastmod (refresh_pattern)
   • override-expire (refresh_pattern)
   • reload_into_ims (global option)
   • refresh_all_ims (global option)

Returns

a status code (from enum above):

• FRESH_REQUEST_MAX_STALE_ALL
• FRESH_REQUEST_MAX_STALE_VALUE
• FRESH_EXPIRES
• FRESH_LMFACTOR_RULE
• FRESH_MIN_RULE
• FRESH_OVERRIDE_EXPIRES
• FRESH_OVERRIDE_LASTMOD
• STALE_MUST_REVALIDATE
• STALE_RELOAD_INTO_IMS
• STALE_FORCED_RELOAD
• STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE
• STALE_EXPIRES
• STALE_MAX_RULE
• STALE_LMFACTOR_RULE
• STALE_MAX_STALE
• STALE_DEFAULT

Note

request may be NULL (e.g. for cache digests build)

the store entry being examined is not necessarily cached (e.g. if this response is being evaluated for the first time)

Definition at line 253 of file refresh.cc.

References assert, SBuf::c_str(), Http::Message::cache_control, Config, debugs, DefaultRefresh, EBIT_TEST, HttpRequest::effectiveRequestUri(), ENTRY_REVALIDATE_ALWAYS, ENTRY_REVALIDATE_STALE, stale_flags::expires, RequestFlags::failOnValidationError, HttpRequest::flags, RefreshPattern::flags, StoreEntry::flags, Time::FormatRfc1123(), FRESH_EXPIRES, FRESH_LMFACTOR_RULE, FRESH_MIN_RULE, FRESH_OVERRIDE_EXPIRES, FRESH_OVERRIDE_LASTMOD, FRESH_REQUEST_MAX_STALE_ALL, FRESH_REQUEST_MAX_STALE_VALUE, StoreEntry::hasFreshestReply(), HttpHdrCc::hasMaxAge(), HttpHdrCc::hasMaxStale(), HttpHdrCc::hasMinFresh(), HttpHdrCc::hasStaleIfError(), RefreshPattern::ignore_reload, RequestFlags::ignoreCc, RequestFlags::ims, stale_flags::lmfactor, stale_flags::max, RefreshPattern::max_stale, HttpHdrCc::MAX_STALE_ANY, SquidConfig::maxStale, StoreEntry::mem_obj, min(), stale_flags::min, RequestFlags::noCache, RequestFlags::noCacheHack(), SquidConfig::onoff, RefreshPattern::override_expire, RefreshPattern::override_lastmod, SquidConfig::refresh_all_ims, RefreshPattern::refresh_ims, refreshFirstDotRule(), refreshLimits(), refreshStaleness(), RefreshPattern::reload_into_ims, SquidConfig::reload_into_ims, squid_curtime, STALE_DEFAULT, STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE, STALE_EXPIRES, STALE_FORCED_RELOAD, STALE_LMFACTOR_RULE, STALE_MAX_RULE, STALE_MAX_STALE, STALE_MUST_REVALIDATE, STALE_RELOAD_INTO_IMS, MemObject::storeId(), and StoreEntry::timestamp.

Referenced by refreshCheckDigest(), refreshCheckHTCP(), refreshCheckHTTP(), refreshCheckICP(), and refreshIsCachable().

refreshCheckDigest()

int refreshCheckDigest	(	const StoreEntry *	entry,
		time_t	delta
	)

See also

int refreshCheckHTTP(const StoreEntry * entry, HttpRequest * request)

Definition at line 617 of file refresh.cc.

References RefCount< C >::getRaw(), StoreEntry::mem_obj, rcCDigest, refreshCheck(), refreshCounts, MemObject::request, RefreshCounts::status, and RefreshCounts::total.

Referenced by storeDigestAddable().

refreshCheckHTCP()

int refreshCheckHTCP	(	const StoreEntry *	entry,
		HttpRequest *	request
	)

See also

int refreshCheckHTTP(const StoreEntry * entry, HttpRequest * request)

Definition at line 604 of file refresh.cc.

References rcHTCP, refreshCheck(), refreshCounts, RefreshCounts::status, and RefreshCounts::total.

Referenced by htcpSpecifier::checkHit().

refreshCheckHTTP()

int refreshCheckHTTP	(	const StoreEntry *	entry,
		HttpRequest *	request
	)

Protocol-specific wrapper around refreshCheck() function.

Note the reason for STALE/FRESH then return true/false respectively.

Return values

1	if STALE
0	if FRESH

Do not call this when StoreClient::didCollapse is true. XXX: Callers should not have to remember to check didCollapse. TODO: Refactor by adding something like pure virtual StoreClient::refreshCheck() with protocol specializations?

Definition at line 582 of file refresh.cc.

References Config, HttpRequest::flags, SquidConfig::offline, SquidConfig::onoff, rcHTTP, refreshCheck(), refreshCounts, refreshIsStaleIfHit(), RequestFlags::staleIfHit, RefreshCounts::status, and RefreshCounts::total.

Referenced by clientReplyContext::cacheHit().

refreshCheckICP()

int refreshCheckICP	(	const StoreEntry *	entry,
		HttpRequest *	request
	)

See also

int refreshCheckHTTP(const StoreEntry * entry, HttpRequest * request)

Definition at line 593 of file refresh.cc.

References rcICP, refreshCheck(), refreshCounts, RefreshCounts::status, and RefreshCounts::total.

Referenced by ICPState::confirmAndPrepHit().

refreshCountsStats()

static void refreshCountsStats ( StoreEntry *  sentry, struct RefreshCounts &  rc  )

static

Definition at line 658 of file refresh.cc.

References FRESH_EXPIRES, FRESH_LMFACTOR_RULE, FRESH_MIN_RULE, FRESH_OVERRIDE_EXPIRES, FRESH_OVERRIDE_LASTMOD, FRESH_REQUEST_MAX_STALE_ALL, FRESH_REQUEST_MAX_STALE_VALUE, RefreshCounts::proto, refreshCountsStatsEntry(), STALE_DEFAULT, STALE_EXCEEDS_REQUEST_MAX_AGE_VALUE, STALE_EXPIRES, STALE_FORCED_RELOAD, STALE_LMFACTOR_RULE, STALE_MAX_RULE, STALE_MUST_REVALIDATE, STALE_RELOAD_INTO_IMS, storeAppendPrintf(), and RefreshCounts::total.

Referenced by refreshStats().

refreshCountsStatsEntry()

static int refreshCountsStatsEntry ( StoreEntry *  sentry, struct RefreshCounts &  rc, int  code, const char *  desc  )

static

Definition at line 651 of file refresh.cc.

References RefreshCounts::status, storeAppendPrintf(), RefreshCounts::total, and xpercent().

Referenced by refreshCountsStats().

refreshFirstDotRule()

static const RefreshPattern * refreshFirstDotRule ( )

static

Definition at line 107 of file refresh.cc.

References Config, and SquidConfig::Refresh.

Referenced by refreshCheck().

refreshInit()

void refreshInit

(

void

)

Definition at line 760 of file refresh.cc.

References RefreshCounts::proto, rcCDigest, rcHTCP, rcHTTP, rcICP, rcStore, refreshCounts, and refreshRegisterWithCacheManager().

Referenced by mainInitialize().

refreshIsCachable()

bool refreshIsCachable

(

const StoreEntry *

entry

)

This is called by http.cc once it has received and parsed the origin server's response headers. It uses the result as part of its algorithm to decide whether a response should be cached.

Return values

true	if the entry is cacheable, regardless of whether FRESH or STALE
false	if the entry is not cacheable

TODO: this algorithm seems a bit odd and might not be quite right. Verify against HTTPbis.

Definition at line 518 of file refresh.cc.

References MemObject::baseReply(), Config, Http::Message::content_length, StoreEntry::lastModified(), StoreEntry::mem_obj, SquidConfig::minimum_expiry_time, rcStore, refreshCheck(), refreshCounts, STALE_MUST_REVALIDATE, RefreshCounts::status, and RefreshCounts::total.

Referenced by HttpStateData::reusableReply().

refreshIsStaleIfHit()

static bool refreshIsStaleIfHit ( const int  reason )

static

Definition at line 557 of file refresh.cc.

References FRESH_EXPIRES, FRESH_LMFACTOR_RULE, and FRESH_MIN_RULE.

Referenced by refreshCheckHTTP().

refreshLimits()

const RefreshPattern * refreshLimits

(

const char *

url

)

Locate the first refresh_pattern rule that matches the given URL by regex.

Returns

A pointer to the refresh_pattern parameters to use, or nullptr if there is no match.

Definition at line 92 of file refresh.cc.

References Config, and SquidConfig::Refresh.

Referenced by getMaxAge(), and refreshCheck().

refreshRegisterWithCacheManager()

static void refreshRegisterWithCacheManager ( void  )

static

Definition at line 754 of file refresh.cc.

References refreshStats, and Mgr::RegisterAction().

Referenced by refreshInit().

refreshStaleness()

static int refreshStaleness ( const StoreEntry *  entry, time_t  check_time, const time_t  age, const RefreshPattern *  R, stale_flags *  sf  )

static

Calculate how stale the response is (or will be at the check_time).

We try the following ways until one gives a result:

1. response expiration time, if one was set
2. age greater than configured maximum
3. last-modified factor algorithm
4. age less than configured minimum
5. default (stale)

Parameters

entry	the StoreEntry being examined
check_time	the time (maybe future) at which we want to know whether $
age	the age of the entry at check_time
R	the refresh_pattern rule that matched this entry
sf	small struct to indicate reason for stale/fresh decision

Return values

-1	If the response is fresh.
>0	The amount of staleness.
0	NOTE return value of 0 means the response is stale.

Definition at line 139 of file refresh.cc.

References debugs, stale_flags::expires, StoreEntry::expires, StoreEntry::lastModified(), stale_flags::lmfactor, stale_flags::max, RefreshPattern::max, min(), stale_flags::min, RefreshPattern::min, RefreshPattern::pct, and StoreEntry::timestamp.

Referenced by refreshCheck().

refreshStats()

static void refreshStats ( StoreEntry *  sentry )

static

Definition at line 685 of file refresh.cc.

References Config, PRIu64, rcCount, SquidConfig::Refresh, refreshCounts, refreshCountsStats(), storeAppendPrintf(), and xpercent().

Variable Documentation

DefaultRefresh

RefreshPattern DefaultRefresh(nullptr) ( nullptr  )

static

Referenced by refreshCheck().

refreshCounts

struct RefreshCounts refreshCounts[rcCount]

static

Referenced by refreshCheckDigest(), refreshCheckHTCP(), refreshCheckHTTP(), refreshCheckICP(), refreshInit(), refreshIsCachable(), and refreshStats().

refreshStats

OBJH refreshStats

static

Definition at line 82 of file refresh.cc.

Referenced by refreshRegisterWithCacheManager().