[thirdparty/squid.git] / src / HttpHdrCc.cc

/*
 * Copyright (C) 1996-2025 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */

/* DEBUG: section 65    HTTP Cache Control Header */

#include "squid.h"
#include "base/EnumIterator.h"
#include "base/LookupTable.h"
#include "HttpHdrCc.h"
#include "HttpHeader.h"
#include "HttpHeaderStat.h"
#include "HttpHeaderTools.h"
#include "sbuf/SBuf.h"
#include "SquidMath.h"
#include "StatHist.h"
#include "Store.h"
#include "StrList.h"
#include "util.h"

#include <map>
#include <vector>
#include <optional>
#include <ostream>

constexpr LookupTable<HttpHdrCcType>::Record attrsList[] = {
    {"public", HttpHdrCcType::CC_PUBLIC},
    {"private", HttpHdrCcType::CC_PRIVATE},
    {"no-cache", HttpHdrCcType::CC_NO_CACHE},
    {"no-store", HttpHdrCcType::CC_NO_STORE},
    {"no-transform", HttpHdrCcType::CC_NO_TRANSFORM},
    {"must-revalidate", HttpHdrCcType::CC_MUST_REVALIDATE},
    {"proxy-revalidate", HttpHdrCcType::CC_PROXY_REVALIDATE},
    {"max-age", HttpHdrCcType::CC_MAX_AGE},
    {"s-maxage", HttpHdrCcType::CC_S_MAXAGE},
    {"max-stale", HttpHdrCcType::CC_MAX_STALE},
    {"min-fresh", HttpHdrCcType::CC_MIN_FRESH},
    {"only-if-cached", HttpHdrCcType::CC_ONLY_IF_CACHED},
    {"stale-if-error", HttpHdrCcType::CC_STALE_IF_ERROR},
    {"immutable", HttpHdrCcType::CC_IMMUTABLE},
    {"Other,", HttpHdrCcType::CC_OTHER}, /* ',' will protect from matches */
    {nullptr, HttpHdrCcType::CC_ENUM_END}
};

constexpr const auto &
CcAttrs() {
    // TODO: Move these compile-time checks into LookupTable
    ConstexprForEnum<HttpHdrCcType::CC_PUBLIC, HttpHdrCcType::CC_ENUM_END>([](const auto ev) {
        const auto idx = static_cast<std::underlying_type<HttpHdrCcType>::type>(ev);
        // invariant: each row has a name except the last one
        static_assert(!attrsList[idx].name == (ev == HttpHdrCcType::CC_ENUM_END));
        // invariant: row[idx].id == idx
        static_assert(attrsList[idx].id == ev);
    });
    return attrsList;
}

static auto
ccTypeByName(const SBuf &name) {
    const static auto table = new LookupTable<HttpHdrCcType>(HttpHdrCcType::CC_OTHER, CcAttrs());
    return table->lookup(name);
}

/// Safely converts an integer into a Cache-Control directive name.
/// \returns std::nullopt if the given integer is not a valid index of a named attrsList entry
template <typename RawId>
static std::optional<const char *>
ccNameByType(const RawId rawId)
{
    // TODO: Store a by-ID index in (and move this functionality into) LookupTable.
    if (!Less(rawId, 0) && Less(rawId, int(HttpHdrCcType::CC_ENUM_END))) {
        const auto idx = static_cast<std::underlying_type<HttpHdrCcType>::type>(rawId);
        return CcAttrs()[idx].name;
    }
    return std::nullopt;
}

/// used to walk a table of http_header_cc_type structs
static HttpHdrCcType &
operator++ (HttpHdrCcType &aHeader)
{
    int tmp = (int)aHeader;
    aHeader = (HttpHdrCcType)(++tmp);
    return aHeader;
}

void
HttpHdrCc::clear()
{
    *this=HttpHdrCc();
}

/// set a data member to a new value, and set the corresponding mask-bit.
/// if setting is false, then the mask-bit is cleared.
void
HttpHdrCc::setValue(int32_t &value, int32_t new_value, HttpHdrCcType hdr, bool setting)
{
    if (setting) {
        if (new_value < 0) {
            debugs(65, 3, "rejecting negative-value Cache-Control directive " << hdr
                   << " value " << new_value);
            return;
        }
    } else {
        new_value = -1; //rely on the convention that "unknown" is -1
    }

    value = new_value;
    setMask(hdr,setting);
}

bool
HttpHdrCc::parse(const String & str)
{
    const char *item;
    const char *p;      /* '=' parameter */
    const char *pos = nullptr;
    int ilen;
    int nlen;

    /* iterate through comma separated list */

    while (strListGetItem(&str, ',', &item, &ilen, &pos)) {
        /* isolate directive name */

        if ((p = (const char *)memchr(item, '=', ilen)) && (p - item < ilen)) {
            nlen = p - item;
            ++p;
        } else {
            nlen = ilen;
        }

        /* find type */
        const auto type = ccTypeByName(SBuf(item, nlen));

        // ignore known duplicate directives
        if (isSet(type)) {
            if (type != HttpHdrCcType::CC_OTHER) {
                debugs(65, 2, "hdr cc: ignoring duplicate cache-directive: near '" << item << "' in '" << str << "'");
                continue;
            }
        }

        /* special-case-parsing and attribute-setting */
        switch (type) {

        case HttpHdrCcType::CC_MAX_AGE:
            if (!p || !httpHeaderParseInt(p, &max_age) || max_age < 0) {
                debugs(65, 2, "cc: invalid max-age specs near '" << item << "'");
                clearMaxAge();
            } else {
                setMask(type,true);
            }
            break;

        case HttpHdrCcType::CC_S_MAXAGE:
            if (!p || !httpHeaderParseInt(p, &s_maxage) || s_maxage < 0) {
                debugs(65, 2, "cc: invalid s-maxage specs near '" << item << "'");
                clearSMaxAge();
            } else {
                setMask(type,true);
            }
            break;

        case HttpHdrCcType::CC_MAX_STALE:
            if (!p || !httpHeaderParseInt(p, &max_stale) || max_stale < 0) {
                debugs(65, 2, "cc: max-stale directive is valid without value");
                maxStale(MAX_STALE_ANY);
            } else {
                setMask(type,true);
            }
            break;

        case HttpHdrCcType::CC_MIN_FRESH:
            if (!p || !httpHeaderParseInt(p, &min_fresh) || min_fresh < 0) {
                debugs(65, 2, "cc: invalid min-fresh specs near '" << item << "'");
                clearMinFresh();
            } else {
                setMask(type,true);
            }
            break;

        case HttpHdrCcType::CC_STALE_IF_ERROR:
            if (!p || !httpHeaderParseInt(p, &stale_if_error) || stale_if_error < 0) {
                debugs(65, 2, "cc: invalid stale-if-error specs near '" << item << "'");
                clearStaleIfError();
            } else {
                setMask(type,true);
            }
            break;

        case HttpHdrCcType::CC_PRIVATE: {
            String temp;
            if (!p)  {
                // Value parameter is optional.
                private_.clean();
            }            else if (/* p &&*/ httpHeaderParseQuotedString(p, (ilen-nlen-1), &temp)) {
                private_.append(temp);
            }            else {
                debugs(65, 2, "cc: invalid private= specs near '" << item << "'");
            }
            // to be safe we ignore broken parameters, but always remember the 'private' part.
            setMask(type,true);
        }
        break;

        case HttpHdrCcType::CC_NO_CACHE: {
            String temp;
            if (!p) {
                // On Requests, missing value parameter is expected syntax.
                // On Responses, value parameter is optional.
                setMask(type,true);
                no_cache.clean();
            } else if (/* p &&*/ httpHeaderParseQuotedString(p, (ilen-nlen-1), &temp)) {
                // On Requests, a value parameter is invalid syntax.
                // XXX: identify when parsing request header and dump err message here.
                setMask(type,true);
                no_cache.append(temp);
            } else {
                debugs(65, 2, "cc: invalid no-cache= specs near '" << item << "'");
            }
        }
        break;

        case HttpHdrCcType::CC_PUBLIC:
            Public(true);
            break;
        case HttpHdrCcType::CC_NO_STORE:
            noStore(true);
            break;
        case HttpHdrCcType::CC_NO_TRANSFORM:
            noTransform(true);
            break;
        case HttpHdrCcType::CC_MUST_REVALIDATE:
            mustRevalidate(true);
            break;
        case HttpHdrCcType::CC_PROXY_REVALIDATE:
            proxyRevalidate(true);
            break;
        case HttpHdrCcType::CC_ONLY_IF_CACHED:
            onlyIfCached(true);
            break;
        case HttpHdrCcType::CC_IMMUTABLE:
            Immutable(true);
            break;

        case HttpHdrCcType::CC_OTHER:
            if (other.size())
                other.append(", ");

            other.append(item, ilen);
            break;

        default:
            /* note that we ignore most of '=' specs (RFCVIOLATION) */
            break;
        }
    }

    return (mask != 0);
}

void
HttpHdrCc::packInto(Packable * p) const
{
    // optimization: if the mask is empty do nothing
    if (mask==0)
        return;

    HttpHdrCcType flag;
    int pcount = 0;
    assert(p);

    for (flag = HttpHdrCcType::CC_PUBLIC; flag < HttpHdrCcType::CC_ENUM_END; ++flag) {
        if (isSet(flag) && flag != HttpHdrCcType::CC_OTHER) {

            /* print option name for all options */
            p->appendf((pcount ? ", %s": "%s"), *ccNameByType(flag));

            /* for all options having values, "=value" after the name */
            switch (flag) {
            case HttpHdrCcType::CC_PUBLIC:
                break;
            case HttpHdrCcType::CC_PRIVATE:
                if (private_.size())
                    p->appendf("=\"" SQUIDSTRINGPH "\"", SQUIDSTRINGPRINT(private_));
                break;

            case HttpHdrCcType::CC_NO_CACHE:
                if (no_cache.size())
                    p->appendf("=\"" SQUIDSTRINGPH "\"", SQUIDSTRINGPRINT(no_cache));
                break;
            case HttpHdrCcType::CC_NO_STORE:
                break;
            case HttpHdrCcType::CC_NO_TRANSFORM:
                break;
            case HttpHdrCcType::CC_MUST_REVALIDATE:
                break;
            case HttpHdrCcType::CC_PROXY_REVALIDATE:
                break;
            case HttpHdrCcType::CC_MAX_AGE:
                p->appendf("=%d", max_age);
                break;
            case HttpHdrCcType::CC_S_MAXAGE:
                p->appendf("=%d", s_maxage);
                break;
            case HttpHdrCcType::CC_MAX_STALE:
                /* max-stale's value is optional.
                  If we didn't receive it, don't send it */
                if (max_stale != MAX_STALE_ANY)
                    p->appendf("=%d", max_stale);
                break;
            case HttpHdrCcType::CC_MIN_FRESH:
                p->appendf("=%d", min_fresh);
                break;
            case HttpHdrCcType::CC_ONLY_IF_CACHED:
                break;
            case HttpHdrCcType::CC_STALE_IF_ERROR:
                p->appendf("=%d", stale_if_error);
                break;
            case HttpHdrCcType::CC_IMMUTABLE:
                break;
            case HttpHdrCcType::CC_OTHER:
            case HttpHdrCcType::CC_ENUM_END:
                // done below after the loop
                break;
            }

            ++pcount;
        }
    }

    if (other.size() != 0)
        p->appendf((pcount ? ", " SQUIDSTRINGPH : SQUIDSTRINGPH), SQUIDSTRINGPRINT(other));
}

void
httpHdrCcUpdateStats(const HttpHdrCc * cc, StatHist * hist)
{
    assert(cc);

    for (HttpHdrCcType c = HttpHdrCcType::CC_PUBLIC; c < HttpHdrCcType::CC_ENUM_END; ++c)
        if (cc->isSet(c))
            hist->count(c);
}

void
httpHdrCcStatDumper(StoreEntry * sentry, int, double val, double, int count)
{
    extern const HttpHeaderStat *dump_stat; /* argh! */
    const int id = static_cast<int>(val);
    const auto name = ccNameByType(id);
    if (count || name)
        storeAppendPrintf(sentry, "%2d\t %-20s\t %5d\t %6.2f\n",
                          id, name.value_or("INVALID"), count, xdiv(count, dump_stat->ccParsedCount));
}

std::ostream &
operator<< (std::ostream &s, HttpHdrCcType c)
{
    s << ccNameByType(c).value_or("INVALID") << '[' << static_cast<int>(c) << ']';
    return s;
}
Commit	Line	Data
	1	/*
	2	* Copyright (C) 1996-2025 The Squid Software Foundation and contributors
	3	*
	4	* Squid software is distributed under GPLv2+ license and includes
	5	* contributions from numerous individuals and organizations.
	6	* Please see the COPYING and CONTRIBUTORS files for details.
	7	*/
	8
	9	/* DEBUG: section 65 HTTP Cache Control Header */
	10
	11	#include "squid.h"
	12	#include "base/EnumIterator.h"
	13	#include "base/LookupTable.h"
	14	#include "HttpHdrCc.h"
	15	#include "HttpHeader.h"
	16	#include "HttpHeaderStat.h"
	17	#include "HttpHeaderTools.h"
	18	#include "sbuf/SBuf.h"
	19	#include "SquidMath.h"
	20	#include "StatHist.h"
	21	#include "Store.h"
	22	#include "StrList.h"
	23	#include "util.h"
	24
	25	#include <map>
	26	#include <vector>
	27	#include <optional>
	28	#include <ostream>
	29
	30	constexpr LookupTable<HttpHdrCcType>::Record attrsList[] = {
	31	{"public", HttpHdrCcType::CC_PUBLIC},
	32	{"private", HttpHdrCcType::CC_PRIVATE},
	33	{"no-cache", HttpHdrCcType::CC_NO_CACHE},
	34	{"no-store", HttpHdrCcType::CC_NO_STORE},
	35	{"no-transform", HttpHdrCcType::CC_NO_TRANSFORM},
	36	{"must-revalidate", HttpHdrCcType::CC_MUST_REVALIDATE},
	37	{"proxy-revalidate", HttpHdrCcType::CC_PROXY_REVALIDATE},
	38	{"max-age", HttpHdrCcType::CC_MAX_AGE},
	39	{"s-maxage", HttpHdrCcType::CC_S_MAXAGE},
	40	{"max-stale", HttpHdrCcType::CC_MAX_STALE},
	41	{"min-fresh", HttpHdrCcType::CC_MIN_FRESH},
	42	{"only-if-cached", HttpHdrCcType::CC_ONLY_IF_CACHED},
	43	{"stale-if-error", HttpHdrCcType::CC_STALE_IF_ERROR},
	44	{"immutable", HttpHdrCcType::CC_IMMUTABLE},
	45	{"Other,", HttpHdrCcType::CC_OTHER}, /* ',' will protect from matches */
	46	{nullptr, HttpHdrCcType::CC_ENUM_END}
	47	};
	48
	49	constexpr const auto &
	50	CcAttrs() {
	51	// TODO: Move these compile-time checks into LookupTable
	52	ConstexprForEnum<HttpHdrCcType::CC_PUBLIC, HttpHdrCcType::CC_ENUM_END>([](const auto ev) {
	53	const auto idx = static_cast<std::underlying_type<HttpHdrCcType>::type>(ev);
	54	// invariant: each row has a name except the last one
	55	static_assert(!attrsList[idx].name == (ev == HttpHdrCcType::CC_ENUM_END));
	56	// invariant: row[idx].id == idx
	57	static_assert(attrsList[idx].id == ev);
	58	});
	59	return attrsList;
	60	}
	61
	62	static auto
	63	ccTypeByName(const SBuf &name) {
	64	const static auto table = new LookupTable<HttpHdrCcType>(HttpHdrCcType::CC_OTHER, CcAttrs());
	65	return table->lookup(name);
	66	}
	67
	68	/// Safely converts an integer into a Cache-Control directive name.
	69	/// \returns std::nullopt if the given integer is not a valid index of a named attrsList entry
	70	template <typename RawId>
	71	static std::optional<const char *>
	72	ccNameByType(const RawId rawId)
	73	{
	74	// TODO: Store a by-ID index in (and move this functionality into) LookupTable.
	75	if (!Less(rawId, 0) && Less(rawId, int(HttpHdrCcType::CC_ENUM_END))) {
	76	const auto idx = static_cast<std::underlying_type<HttpHdrCcType>::type>(rawId);
	77	return CcAttrs()[idx].name;
	78	}
	79	return std::nullopt;
	80	}
	81
	82	/// used to walk a table of http_header_cc_type structs
	83	static HttpHdrCcType &
	84	operator++ (HttpHdrCcType &aHeader)
	85	{
	86	int tmp = (int)aHeader;
	87	aHeader = (HttpHdrCcType)(++tmp);
	88	return aHeader;
	89	}
	90
	91	void
	92	HttpHdrCc::clear()
	93	{
	94	*this=HttpHdrCc();
	95	}
	96
	97	/// set a data member to a new value, and set the corresponding mask-bit.
	98	/// if setting is false, then the mask-bit is cleared.
	99	void
	100	HttpHdrCc::setValue(int32_t &value, int32_t new_value, HttpHdrCcType hdr, bool setting)
	101	{
	102	if (setting) {
	103	if (new_value < 0) {
	104	debugs(65, 3, "rejecting negative-value Cache-Control directive " << hdr
	105	<< " value " << new_value);
	106	return;
	107	}
	108	} else {
	109	new_value = -1; //rely on the convention that "unknown" is -1
	110	}
	111
	112	value = new_value;
	113	setMask(hdr,setting);
	114	}
	115
	116	bool
	117	HttpHdrCc::parse(const String & str)
	118	{
	119	const char *item;
	120	const char p; / '=' parameter */
	121	const char *pos = nullptr;
	122	int ilen;
	123	int nlen;
	124
	125	/* iterate through comma separated list */
	126
	127	while (strListGetItem(&str, ',', &item, &ilen, &pos)) {
	128	/* isolate directive name */
	129
	130	if ((p = (const char *)memchr(item, '=', ilen)) && (p - item < ilen)) {
	131	nlen = p - item;
	132	++p;
	133	} else {
	134	nlen = ilen;
	135	}
	136
	137	/* find type */
	138	const auto type = ccTypeByName(SBuf(item, nlen));
	139
	140	// ignore known duplicate directives
	141	if (isSet(type)) {
	142	if (type != HttpHdrCcType::CC_OTHER) {
	143	debugs(65, 2, "hdr cc: ignoring duplicate cache-directive: near '" << item << "' in '" << str << "'");
	144	continue;
	145	}
	146	}
	147
	148	/* special-case-parsing and attribute-setting */
	149	switch (type) {
	150
	151	case HttpHdrCcType::CC_MAX_AGE:
	152	if (!p \|\| !httpHeaderParseInt(p, &max_age) \|\| max_age < 0) {
	153	debugs(65, 2, "cc: invalid max-age specs near '" << item << "'");
	154	clearMaxAge();
	155	} else {
	156	setMask(type,true);
	157	}
	158	break;
	159
	160	case HttpHdrCcType::CC_S_MAXAGE:
	161	if (!p \|\| !httpHeaderParseInt(p, &s_maxage) \|\| s_maxage < 0) {
	162	debugs(65, 2, "cc: invalid s-maxage specs near '" << item << "'");
	163	clearSMaxAge();
	164	} else {
	165	setMask(type,true);
	166	}
	167	break;
	168
	169	case HttpHdrCcType::CC_MAX_STALE:
	170	if (!p \|\| !httpHeaderParseInt(p, &max_stale) \|\| max_stale < 0) {
	171	debugs(65, 2, "cc: max-stale directive is valid without value");
	172	maxStale(MAX_STALE_ANY);
	173	} else {
	174	setMask(type,true);
	175	}
	176	break;
	177
	178	case HttpHdrCcType::CC_MIN_FRESH:
	179	if (!p \|\| !httpHeaderParseInt(p, &min_fresh) \|\| min_fresh < 0) {
	180	debugs(65, 2, "cc: invalid min-fresh specs near '" << item << "'");
	181	clearMinFresh();
	182	} else {
	183	setMask(type,true);
	184	}
	185	break;
	186
	187	case HttpHdrCcType::CC_STALE_IF_ERROR:
	188	if (!p \|\| !httpHeaderParseInt(p, &stale_if_error) \|\| stale_if_error < 0) {
	189	debugs(65, 2, "cc: invalid stale-if-error specs near '" << item << "'");
	190	clearStaleIfError();
	191	} else {
	192	setMask(type,true);
	193	}
	194	break;
	195
	196	case HttpHdrCcType::CC_PRIVATE: {
	197	String temp;
	198	if (!p) {
	199	// Value parameter is optional.
	200	private_.clean();
	201	} else if (/* p &&*/ httpHeaderParseQuotedString(p, (ilen-nlen-1), &temp)) {
	202	private_.append(temp);
	203	} else {
	204	debugs(65, 2, "cc: invalid private= specs near '" << item << "'");
	205	}
	206	// to be safe we ignore broken parameters, but always remember the 'private' part.
	207	setMask(type,true);
	208	}
	209	break;
	210
	211	case HttpHdrCcType::CC_NO_CACHE: {
	212	String temp;
	213	if (!p) {
	214	// On Requests, missing value parameter is expected syntax.
	215	// On Responses, value parameter is optional.
	216	setMask(type,true);
	217	no_cache.clean();
	218	} else if (/* p &&*/ httpHeaderParseQuotedString(p, (ilen-nlen-1), &temp)) {
	219	// On Requests, a value parameter is invalid syntax.
	220	// XXX: identify when parsing request header and dump err message here.
	221	setMask(type,true);
	222	no_cache.append(temp);
	223	} else {
	224	debugs(65, 2, "cc: invalid no-cache= specs near '" << item << "'");
	225	}
	226	}
	227	break;
	228
	229	case HttpHdrCcType::CC_PUBLIC:
	230	Public(true);
	231	break;
	232	case HttpHdrCcType::CC_NO_STORE:
	233	noStore(true);
	234	break;
	235	case HttpHdrCcType::CC_NO_TRANSFORM:
	236	noTransform(true);
	237	break;
	238	case HttpHdrCcType::CC_MUST_REVALIDATE:
	239	mustRevalidate(true);
	240	break;
	241	case HttpHdrCcType::CC_PROXY_REVALIDATE:
	242	proxyRevalidate(true);
	243	break;
	244	case HttpHdrCcType::CC_ONLY_IF_CACHED:
	245	onlyIfCached(true);
	246	break;
	247	case HttpHdrCcType::CC_IMMUTABLE:
	248	Immutable(true);
	249	break;
	250
	251	case HttpHdrCcType::CC_OTHER:
	252	if (other.size())
	253	other.append(", ");
	254
	255	other.append(item, ilen);
	256	break;
	257
	258	default:
	259	/* note that we ignore most of '=' specs (RFCVIOLATION) */
	260	break;
	261	}
	262	}
	263
	264	return (mask != 0);
	265	}
	266
	267	void
	268	HttpHdrCc::packInto(Packable * p) const
	269	{
	270	// optimization: if the mask is empty do nothing
	271	if (mask==0)
	272	return;
	273
	274	HttpHdrCcType flag;
	275	int pcount = 0;
	276	assert(p);
	277
	278	for (flag = HttpHdrCcType::CC_PUBLIC; flag < HttpHdrCcType::CC_ENUM_END; ++flag) {
	279	if (isSet(flag) && flag != HttpHdrCcType::CC_OTHER) {
	280
	281	/* print option name for all options */
	282	p->appendf((pcount ? ", %s": "%s"), *ccNameByType(flag));
	283
	284	/* for all options having values, "=value" after the name */
	285	switch (flag) {
	286	case HttpHdrCcType::CC_PUBLIC:
	287	break;
	288	case HttpHdrCcType::CC_PRIVATE:
	289	if (private_.size())
	290	p->appendf("=\"" SQUIDSTRINGPH "\"", SQUIDSTRINGPRINT(private_));
	291	break;
	292
	293	case HttpHdrCcType::CC_NO_CACHE:
	294	if (no_cache.size())
	295	p->appendf("=\"" SQUIDSTRINGPH "\"", SQUIDSTRINGPRINT(no_cache));
	296	break;
	297	case HttpHdrCcType::CC_NO_STORE:
	298	break;
	299	case HttpHdrCcType::CC_NO_TRANSFORM:
	300	break;
	301	case HttpHdrCcType::CC_MUST_REVALIDATE:
	302	break;
	303	case HttpHdrCcType::CC_PROXY_REVALIDATE:
	304	break;
	305	case HttpHdrCcType::CC_MAX_AGE:
	306	p->appendf("=%d", max_age);
	307	break;
	308	case HttpHdrCcType::CC_S_MAXAGE:
	309	p->appendf("=%d", s_maxage);
	310	break;
	311	case HttpHdrCcType::CC_MAX_STALE:
	312	/* max-stale's value is optional.
	313	If we didn't receive it, don't send it */
	314	if (max_stale != MAX_STALE_ANY)
	315	p->appendf("=%d", max_stale);
	316	break;
	317	case HttpHdrCcType::CC_MIN_FRESH:
	318	p->appendf("=%d", min_fresh);
	319	break;
	320	case HttpHdrCcType::CC_ONLY_IF_CACHED:
	321	break;
	322	case HttpHdrCcType::CC_STALE_IF_ERROR:
	323	p->appendf("=%d", stale_if_error);
	324	break;
	325	case HttpHdrCcType::CC_IMMUTABLE:
	326	break;
	327	case HttpHdrCcType::CC_OTHER:
	328	case HttpHdrCcType::CC_ENUM_END:
	329	// done below after the loop
	330	break;
	331	}
	332
	333	++pcount;
	334	}
	335	}
	336
	337	if (other.size() != 0)
	338	p->appendf((pcount ? ", " SQUIDSTRINGPH : SQUIDSTRINGPH), SQUIDSTRINGPRINT(other));
	339	}
	340
	341	void
	342	httpHdrCcUpdateStats(const HttpHdrCc * cc, StatHist * hist)
	343	{
	344	assert(cc);
	345
	346	for (HttpHdrCcType c = HttpHdrCcType::CC_PUBLIC; c < HttpHdrCcType::CC_ENUM_END; ++c)
	347	if (cc->isSet(c))
	348	hist->count(c);
	349	}
	350
	351	void
	352	httpHdrCcStatDumper(StoreEntry * sentry, int, double val, double, int count)
	353	{
	354	extern const HttpHeaderStat dump_stat; / argh! */
	355	const int id = static_cast<int>(val);
	356	const auto name = ccNameByType(id);
	357	if (count \|\| name)
	358	storeAppendPrintf(sentry, "%2d\t %-20s\t %5d\t %6.2f\n",
	359	id, name.value_or("INVALID"), count, xdiv(count, dump_stat->ccParsedCount));
	360	}
	361
	362	std::ostream &
	363	operator<< (std::ostream &s, HttpHdrCcType c)
	364	{
	365	s << ccNameByType(c).value_or("INVALID") << '[' << static_cast<int>(c) << ']';
	366	return s;
	367	}
	368