/** * @file llavatarnamecache.cpp * @brief Provides lookup of avatar SLIDs ("bobsmith123") and display names * ("James Cook") from avatar UUIDs. * * $LicenseInfo:firstyear=2010&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2010, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ #include "linden_common.h" #include "llavatarnamecache.h" #include "llcachename.h" // we wrap this system #include "llframetimer.h" #include "llsd.h" #include "llsdserialize.h" #include "httpresponse.h" #include "llhttpsdhandler.h" #include <boost/tokenizer.hpp> #include "httpcommon.h" #include "httprequest.h" #include "httpheaders.h" #include "httpoptions.h" #include "llcoros.h" #include "lleventcoro.h" #include "llcorehttputil.h" #include "llexception.h" #include "stringize.h" #include "workqueue.h" #include <map> #include <set> // Time-to-live for a temp cache entry. const F64 TEMP_CACHE_ENTRY_LIFETIME = 60.0; // Maximum time an unrefreshed cache entry is allowed. const F64 MAX_UNREFRESHED_TIME = 20.0 * 60.0; // Send bulk lookup requests a few times a second at most. // Only need per-frame timing resolution. static LLFrameTimer sRequestTimer; // static to avoid unnessesary dependencies LLCore::HttpRequest::ptr_t sHttpRequest; LLCore::HttpHeaders::ptr_t sHttpHeaders; LLCore::HttpOptions::ptr_t sHttpOptions; LLCore::HttpRequest::policy_t sHttpPolicy; /* Sample response: <?xml version="1.0"?> <llsd> <map> <key>agents</key> <array> <map> <key>display_name_next_update</key> <date>2010-04-16T21:34:02+00:00Z</date> <key>display_name_expires</key> <date>2010-04-16T21:32:26.142178+00:00Z</date> <key>display_name</key> <string>MickBot390 LLQABot</string> <key>sl_id</key> <string>mickbot390.llqabot</string> <key>id</key> <string>0012809d-7d2d-4c24-9609-af1230a37715</string> <key>is_display_name_default</key> <boolean>false</boolean> </map> <map> <key>display_name_next_update</key> <date>2010-04-16T21:34:02+00:00Z</date> <key>display_name_expires</key> <date>2010-04-16T21:32:26.142178+00:00Z</date> <key>display_name</key> <string>Bjork Gudmundsdottir</string> <key>sl_id</key> <string>sardonyx.linden</string> <key>id</key> <string>3941037e-78ab-45f0-b421-bd6e77c1804d</string> <key>is_display_name_default</key> <boolean>true</boolean> </map> </array> </map> </llsd> */ // Coroutine for sending and processing avatar name cache requests. // Do not call directly. See documentation in lleventcoro.h and llcoro.h for // further explanation. LLAvatarNameCache::LLAvatarNameCache() { // Will be set to running later // For now fail immediate lookups and query async ones. mRunning = false; mUsePeopleAPI = true; sHttpRequest = LLCore::HttpRequest::ptr_t(new LLCore::HttpRequest()); sHttpHeaders = LLCore::HttpHeaders::ptr_t(new LLCore::HttpHeaders()); sHttpOptions = LLCore::HttpOptions::ptr_t(new LLCore::HttpOptions()); sHttpPolicy = LLCore::HttpRequest::DEFAULT_POLICY_ID; } LLAvatarNameCache::~LLAvatarNameCache() { sHttpRequest.reset(); sHttpHeaders.reset(); sHttpOptions.reset(); mCache.clear(); } void LLAvatarNameCache::requestAvatarNameCache_(std::string url, std::vector<LLUUID> agentIds) { LL_DEBUGS("AvNameCache") << "Entering coroutine " << LLCoros::getName() << " with url '" << url << "', requesting " << agentIds.size() << " Agent Ids" << LL_ENDL; // Check pointer that can be cleaned up by cleanupClass() if (!sHttpRequest || !sHttpOptions || !sHttpHeaders) { LL_WARNS("AvNameCache") << " Trying to request name cache when http pointers are not initialized." << LL_ENDL; return; } LLSD httpResults; bool success = true; try { LLCoreHttpUtil::HttpCoroutineAdapter httpAdapter("NameCache", sHttpPolicy); LLSD results = httpAdapter.getAndSuspend(sHttpRequest, url); LL_DEBUGS() << results << LL_ENDL; if (!results.isMap()) { LL_WARNS("AvNameCache") << " Invalid result returned from LLCoreHttpUtil::HttpCoroHandler." << LL_ENDL; success = false; } else { httpResults = results["http_result"]; if (!httpResults.isMap()) { success = false; LL_WARNS("AvNameCache") << " Invalid http_result returned from LLCoreHttpUtil::HttpCoroHandler." << LL_ENDL; } else { success = httpResults["success"].asBoolean(); if (!success) { LL_WARNS("AvNameCache") << "Error result from LLCoreHttpUtil::HttpCoroHandler. Code " << httpResults["status"] << ": '" << httpResults["message"] << "'" << LL_ENDL; } } } if (LLAvatarNameCache::instanceExists()) { // dispatch handler execution back to mainloop auto workqueue = LL::WorkQueue::getInstance("mainloop"); if (workqueue) { workqueue->post([=]() { if (!success) { // on any sort of failure add dummy records for any agent IDs // in this request that we do not have cached already for (const auto& agent_id : agentIds) { LLAvatarNameCache::getInstance()->handleAgentError(agent_id); } return; } LLAvatarNameCache::getInstance()->handleAvNameCacheSuccess(results, httpResults); }); } } } catch (const LLCoros::Stop&) { LL_DEBUGS("AvNameCache") << "Received a shutdown exception" << LL_ENDL; } catch (...) { LOG_UNHANDLED_EXCEPTION(STRINGIZE("coroutine " << LLCoros::getName() << "('" << url << "', " << agentIds.size() << "Agent Ids," << " http result: " << S32(success) << " has response: " << S32(httpResults.size()) << ")")); throw; } } void LLAvatarNameCache::handleAvNameCacheSuccess(const LLSD &data, const LLSD &httpResult) { LLSD headers = httpResult["headers"]; // Pull expiration out of headers if available F64 expires = LLAvatarNameCache::nameExpirationFromHeaders(headers); F64 now = LLFrameTimer::getTotalSeconds(); const LLSD& agents = data["agents"]; LLSD::array_const_iterator it = agents.beginArray(); for (; it != agents.endArray(); ++it) { const LLSD& row = *it; LLUUID agent_id = row["id"].asUUID(); LLAvatarName av_name; av_name.fromLLSD(row); // Use expiration time from header av_name.mExpires = expires; LL_DEBUGS("AvNameCache") << "LLAvatarNameResponder::result for " << agent_id << LL_ENDL; av_name.dump(); // cache it and fire signals LLAvatarNameCache::processName(agent_id, av_name); } // Same logic as error response case const LLSD& unresolved_agents = data["bad_ids"]; auto num_unresolved = unresolved_agents.size(); if (num_unresolved > 0) { LL_WARNS("AvNameCache") << "LLAvatarNameResponder::result " << num_unresolved << " unresolved ids; " << "expires in " << expires - now << " seconds" << LL_ENDL; it = unresolved_agents.beginArray(); for (; it != unresolved_agents.endArray(); ++it) { const LLUUID& agent_id = *it; // If cap fails, response can contain a lot of names, // don't spam too much LL_DEBUGS("AvNameCache") << "LLAvatarNameResponder::result " << "failed id " << agent_id << LL_ENDL; LLAvatarNameCache::handleAgentError(agent_id); } } LL_DEBUGS("AvNameCache") << "LLAvatarNameResponder::result " << LLAvatarNameCache::mCache.size() << " cached names" << LL_ENDL; } // Provide some fallback for agents that return errors void LLAvatarNameCache::handleAgentError(const LLUUID& agent_id) { std::map<LLUUID,LLAvatarName>::iterator existing = mCache.find(agent_id); if (existing == mCache.end()) { // there is no existing cache entry, so make a temporary name from legacy LL_DEBUGS("AvNameCache") << "LLAvatarNameCache get legacy for agent " << agent_id << LL_ENDL; gCacheName->get(agent_id, false, // legacy compatibility boost::bind(&LLAvatarNameCache::legacyNameFetch, _1, _2, _3)); } else { // we have a cached (but probably expired) entry - since that would have // been returned by the get method, there is no need to signal anyone // Clear this agent from the pending list LLAvatarNameCache::mPendingQueue.erase(agent_id); LLAvatarName& av_name = existing->second; LL_DEBUGS("AvNameCache") << "LLAvatarNameCache use cache for agent " << agent_id << LL_ENDL; av_name.dump(); // Reset expiry time so we don't constantly rerequest. av_name.setExpires(TEMP_CACHE_ENTRY_LIFETIME); } } void LLAvatarNameCache::processName(const LLUUID& agent_id, const LLAvatarName& av_name) { if (agent_id.isNull()) { return; } bool updated_account = true; // assume obsolete value for new arrivals by default std::map<LLUUID, LLAvatarName>::iterator it = mCache.find(agent_id); if (it != mCache.end() && (*it).second.getAccountName() == av_name.getAccountName()) { updated_account = false; } // Add to the cache mCache[agent_id] = av_name; // Suppress request from the queue mPendingQueue.erase(agent_id); // notify mute list about changes if (updated_account && mAccountNameChangedCallback) { mAccountNameChangedCallback(agent_id, av_name); } // Signal everyone waiting on this name signal_map_t::iterator sig_it = mSignalMap.find(agent_id); if (sig_it != mSignalMap.end()) { callback_signal_t* signal = sig_it->second; (*signal)(agent_id, av_name); mSignalMap.erase(agent_id); delete signal; signal = NULL; } } void LLAvatarNameCache::requestNamesViaCapability() { F64 now = LLFrameTimer::getTotalSeconds(); // URL format is like: // http://pdp60.lindenlab.com:8000/agents/?ids=3941037e-78ab-45f0-b421-bd6e77c1804d&ids=0012809d-7d2d-4c24-9609-af1230a37715&ids=0019aaba-24af-4f0a-aa72-6457953cf7f0 // // Apache can handle URLs of 4096 chars, but let's be conservative static const U32 NAME_URL_MAX = 4096; static const U32 NAME_URL_SEND_THRESHOLD = 3500; std::string url; url.reserve(NAME_URL_MAX); std::vector<LLUUID> agent_ids; agent_ids.reserve(128); U32 ids = 0; ask_queue_t::const_iterator it; while(!mAskQueue.empty()) { it = mAskQueue.begin(); LLUUID agent_id = *it; mAskQueue.erase(it); if (url.empty()) { // ...starting new request url += mNameLookupURL; url += "?ids="; ids = 1; } else { // ...continuing existing request url += "&ids="; ids++; } url += agent_id.asString(); agent_ids.push_back(agent_id); // mark request as pending mPendingQueue[agent_id] = now; if (url.size() > NAME_URL_SEND_THRESHOLD) { break; } } if (!url.empty()) { LL_DEBUGS("AvNameCache") << "requested " << ids << " ids" << LL_ENDL; std::string coroname = LLCoros::instance().launch("LLAvatarNameCache::requestAvatarNameCache_", boost::bind(&LLAvatarNameCache::requestAvatarNameCache_, url, agent_ids)); LL_DEBUGS("AvNameCache") << coroname << " with url '" << url << "', agent_ids.size()=" << agent_ids.size() << LL_ENDL; } } void LLAvatarNameCache::legacyNameCallback(const LLUUID& agent_id, const std::string& full_name, bool is_group) { // Put the received data in the cache legacyNameFetch(agent_id, full_name, is_group); // Retrieve the name and set it to never (or almost never...) expire: when we are using the legacy // protocol, we do not get an expiration date for each name and there's no reason to ask the // data again and again so we set the expiration time to the largest value admissible. std::map<LLUUID,LLAvatarName>::iterator av_record = LLAvatarNameCache::getInstance()->mCache.find(agent_id); LLAvatarName& av_name = av_record->second; av_name.setExpires(MAX_UNREFRESHED_TIME); } void LLAvatarNameCache::legacyNameFetch(const LLUUID& agent_id, const std::string& full_name, bool is_group) { LL_DEBUGS("AvNameCache") << "LLAvatarNameCache agent " << agent_id << " " << "full name '" << full_name << "'" << ( is_group ? " [group]" : "" ) << LL_ENDL; // Construct an av_name record from this name. LLAvatarName av_name; av_name.fromString(full_name); // Add to cache: we're still using the new cache even if we're using the old (legacy) protocol. LLAvatarNameCache::getInstance()->processName(agent_id, av_name); } void LLAvatarNameCache::requestNamesViaLegacy() { static const S32 MAX_REQUESTS = 100; F64 now = LLFrameTimer::getTotalSeconds(); std::string full_name; ask_queue_t::const_iterator it; for (S32 requests = 0; !mAskQueue.empty() && requests < MAX_REQUESTS; ++requests) { it = mAskQueue.begin(); LLUUID agent_id = *it; mAskQueue.erase(it); // Mark as pending first, just in case the callback is immediately // invoked below. This should never happen in practice. mPendingQueue[agent_id] = now; LL_DEBUGS("AvNameCache") << "agent " << agent_id << LL_ENDL; gCacheName->get(agent_id, false, // legacy compatibility boost::bind(&LLAvatarNameCache::legacyNameCallback, _1, _2, _3)); } } bool LLAvatarNameCache::importFile(std::istream& istr) { LLSD data; if (LLSDParser::PARSE_FAILURE == LLSDSerialize::fromXMLDocument(data, istr)) { LL_WARNS("AvNameCache") << "avatar name cache data xml parse failed" << LL_ENDL; return false; } // by convention LLSD storage is a map // we only store one entry in the map LLSD agents = data["agents"]; LLUUID agent_id; LLAvatarName av_name; LLSD::map_const_iterator it = agents.beginMap(); for ( ; it != agents.endMap(); ++it) { agent_id.set(it->first); av_name.fromLLSD( it->second ); mCache[agent_id] = av_name; } LL_INFOS("AvNameCache") << "LLAvatarNameCache loaded " << mCache.size() << LL_ENDL; // Some entries may have expired since the cache was stored, // but they will be flushed in the first call to eraseUnrefreshed // from LLAvatarNameResponder::idle return true; } void LLAvatarNameCache::exportFile(std::ostream& ostr) { LLSD agents; F64 max_unrefreshed = LLFrameTimer::getTotalSeconds() - MAX_UNREFRESHED_TIME; LL_INFOS("AvNameCache") << "LLAvatarNameCache at exit cache has " << mCache.size() << LL_ENDL; cache_t::const_iterator it = mCache.begin(); for ( ; it != mCache.end(); ++it) { const LLUUID& agent_id = it->first; const LLAvatarName& av_name = it->second; // Do not write temporary or expired entries to the stored cache if (av_name.isValidName(max_unrefreshed)) { // key must be a string agents[agent_id.asString()] = av_name.asLLSD(); } } LL_INFOS("AvNameCache") << "LLAvatarNameCache returning " << agents.size() << LL_ENDL; LLSD data; data["agents"] = agents; LLSDSerialize::toPrettyXML(data, ostr); } void LLAvatarNameCache::setNameLookupURL(const std::string& name_lookup_url) { mNameLookupURL = name_lookup_url; } bool LLAvatarNameCache::hasNameLookupURL() { return !mNameLookupURL.empty(); } void LLAvatarNameCache::setUsePeopleAPI(bool use_api) { mUsePeopleAPI = use_api; } bool LLAvatarNameCache::usePeopleAPI() { return hasNameLookupURL() && mUsePeopleAPI; } void LLAvatarNameCache::idle() { // By convention, start running at first idle() call mRunning = true; // *TODO: Possibly re-enabled this based on People API load measurements // 100 ms is the threshold for "user speed" operations, so we can // stall for about that long to batch up requests. const F32 SECS_BETWEEN_REQUESTS = 0.1f; if (!sRequestTimer.hasExpired()) { return; } if (!mAskQueue.empty()) { if (usePeopleAPI()) { requestNamesViaCapability(); } else { LL_WARNS_ONCE("AvNameCache") << "LLAvatarNameCache still using legacy api" << LL_ENDL; requestNamesViaLegacy(); } } if (mAskQueue.empty()) { // cleared the list, reset the request timer. sRequestTimer.resetWithExpiry(SECS_BETWEEN_REQUESTS); } // erase anything that has not been refreshed for more than MAX_UNREFRESHED_TIME eraseUnrefreshed(); } bool LLAvatarNameCache::isRequestPending(const LLUUID& agent_id) { bool isPending = false; const F64 PENDING_TIMEOUT_SECS = 5.0 * 60.0; pending_queue_t::const_iterator it = mPendingQueue.find(agent_id); if (it != mPendingQueue.end()) { // in the list of requests in flight, retry if too old F64 expire_time = LLFrameTimer::getTotalSeconds() - PENDING_TIMEOUT_SECS; isPending = (it->second > expire_time); } return isPending; } void LLAvatarNameCache::eraseUnrefreshed() { F64 now = LLFrameTimer::getTotalSeconds(); F64 max_unrefreshed = now - MAX_UNREFRESHED_TIME; if (!mLastExpireCheck || mLastExpireCheck < max_unrefreshed) { mLastExpireCheck = now; S32 expired = 0; for (cache_t::iterator it = mCache.begin(); it != mCache.end();) { const LLAvatarName& av_name = it->second; if (av_name.mExpires < max_unrefreshed) { LL_DEBUGS("AvNameCacheExpired") << "LLAvatarNameCache " << it->first << " user '" << av_name.getAccountName() << "' " << "expired " << now - av_name.mExpires << " secs ago" << LL_ENDL; mCache.erase(it++); expired++; } else { ++it; } } LL_INFOS("AvNameCache") << "LLAvatarNameCache expired " << expired << " cached avatar names, " << mCache.size() << " remaining" << LL_ENDL; } } //static, wrapper bool LLAvatarNameCache::get(const LLUUID& agent_id, LLAvatarName *av_name) { return LLAvatarNameCache::getInstance()->getName(agent_id, av_name); } // fills in av_name if it has it in the cache, even if expired (can check expiry time) // returns bool specifying if av_name was filled, false otherwise bool LLAvatarNameCache::getName(const LLUUID& agent_id, LLAvatarName *av_name) { if (mRunning) { // ...only do immediate lookups when cache is running std::map<LLUUID,LLAvatarName>::iterator it = mCache.find(agent_id); if (it != mCache.end()) { *av_name = it->second; // re-request name if entry is expired if (av_name->mExpires < LLFrameTimer::getTotalSeconds()) { if (!isRequestPending(agent_id)) { LL_DEBUGS("AvNameCache") << "LLAvatarNameCache refresh agent " << agent_id << LL_ENDL; mAskQueue.insert(agent_id); } } return true; } } if (!isRequestPending(agent_id)) { LL_DEBUGS("AvNameCache") << "LLAvatarNameCache queue request for agent " << agent_id << LL_ENDL; mAskQueue.insert(agent_id); } return false; } void LLAvatarNameCache::fireSignal(const LLUUID& agent_id, const callback_slot_t& slot, const LLAvatarName& av_name) { callback_signal_t signal; signal.connect(slot); signal(agent_id, av_name); } // static, wrapper LLAvatarNameCache::callback_connection_t LLAvatarNameCache::get(const LLUUID& agent_id, callback_slot_t slot) { return LLAvatarNameCache::getInstance()->getNameCallback(agent_id, slot); } LLAvatarNameCache::callback_connection_t LLAvatarNameCache::getNameCallback(const LLUUID& agent_id, callback_slot_t slot) { callback_connection_t connection; if (mRunning) { // ...only do immediate lookups when cache is running std::map<LLUUID,LLAvatarName>::iterator it = mCache.find(agent_id); if (it != mCache.end()) { const LLAvatarName& av_name = it->second; if (av_name.mExpires > LLFrameTimer::getTotalSeconds()) { // ...name already exists in cache, fire callback now fireSignal(agent_id, slot, av_name); return connection; } } } // schedule a request if (!isRequestPending(agent_id)) { mAskQueue.insert(agent_id); } // always store additional callback, even if request is pending signal_map_t::iterator sig_it = mSignalMap.find(agent_id); if (sig_it == mSignalMap.end()) { // ...new callback for this id callback_signal_t* signal = new callback_signal_t(); connection = signal->connect(slot); mSignalMap[agent_id] = signal; } else { // ...existing callback, bind additional slot callback_signal_t* signal = sig_it->second; connection = signal->connect(slot); } return connection; } void LLAvatarNameCache::setUseDisplayNames(bool use) { if (use != LLAvatarName::useDisplayNames()) { LLAvatarName::setUseDisplayNames(use); mUseDisplayNamesSignal(); } } void LLAvatarNameCache::setUseUsernames(bool use) { if (use != LLAvatarName::useUsernames()) { LLAvatarName::setUseUsernames(use); mUseDisplayNamesSignal(); } } void LLAvatarNameCache::erase(const LLUUID& agent_id) { mCache.erase(agent_id); } void LLAvatarNameCache::insert(const LLUUID& agent_id, const LLAvatarName& av_name) { // *TODO: update timestamp if zero? mCache[agent_id] = av_name; } LLUUID LLAvatarNameCache::findIdByName(const std::string& name) { std::map<LLUUID, LLAvatarName>::iterator it; std::map<LLUUID, LLAvatarName>::iterator end = mCache.end(); for (it = mCache.begin(); it != end; ++it) { if (it->second.getUserName() == name) { return it->first; } } // Legacy method LLUUID id; if (gCacheName && gCacheName->getUUID(name, id)) { return id; } return LLUUID::null; } #if 0 F64 LLAvatarNameCache::nameExpirationFromHeaders(LLCore::HttpHeaders *headers) { F64 expires = 0.0; if (expirationFromCacheControl(headers, &expires)) { return expires; } else { // With no expiration info, default to an hour const F64 DEFAULT_EXPIRES = 60.0 * 60.0; F64 now = LLFrameTimer::getTotalSeconds(); return now + DEFAULT_EXPIRES; } } bool LLAvatarNameCache::expirationFromCacheControl(LLCore::HttpHeaders *headers, F64 *expires) { bool fromCacheControl = false; F64 now = LLFrameTimer::getTotalSeconds(); // Allow the header to override the default const std::string *cache_control; cache_control = headers->find(HTTP_IN_HEADER_CACHE_CONTROL); if (cache_control && !cache_control->empty()) { S32 max_age = 0; if (max_age_from_cache_control(*cache_control, &max_age)) { *expires = now + (F64)max_age; fromCacheControl = true; } } LL_DEBUGS("AvNameCache") << ( fromCacheControl ? "expires based on cache control " : "default expiration " ) << "in " << *expires - now << " seconds" << LL_ENDL; return fromCacheControl; } #else F64 LLAvatarNameCache::nameExpirationFromHeaders(const LLSD& headers) { F64 expires = 0.0; if (expirationFromCacheControl(headers, &expires)) { return expires; } else { // With no expiration info, default to an hour const F64 DEFAULT_EXPIRES = 60.0 * 60.0; F64 now = LLFrameTimer::getTotalSeconds(); return now + DEFAULT_EXPIRES; } } bool LLAvatarNameCache::expirationFromCacheControl(const LLSD& headers, F64 *expires) { bool fromCacheControl = false; F64 now = LLFrameTimer::getTotalSeconds(); // Allow the header to override the default std::string cache_control; if (headers.has(HTTP_IN_HEADER_CACHE_CONTROL)) { cache_control = headers[HTTP_IN_HEADER_CACHE_CONTROL].asString(); } if (!cache_control.empty()) { S32 max_age = 0; if (max_age_from_cache_control(cache_control, &max_age)) { *expires = now + (F64)max_age; fromCacheControl = true; } } LL_DEBUGS("AvNameCache") << "LLAvatarNameCache " << ( fromCacheControl ? "expires based on cache control " : "default expiration " ) << "in " << *expires - now << " seconds" << LL_ENDL; return fromCacheControl; } #endif void LLAvatarNameCache::addUseDisplayNamesCallback(const use_display_name_signal_t::slot_type& cb) { mUseDisplayNamesSignal.connect(cb); } static const std::string MAX_AGE("max-age"); static const boost::char_separator<char> EQUALS_SEPARATOR("="); static const boost::char_separator<char> COMMA_SEPARATOR(","); bool max_age_from_cache_control(const std::string& cache_control, S32 *max_age) { // Split the string on "," to get a list of directives typedef boost::tokenizer<boost::char_separator<char> > tokenizer; tokenizer directives(cache_control, COMMA_SEPARATOR); tokenizer::iterator token_it = directives.begin(); for ( ; token_it != directives.end(); ++token_it) { // Tokens may have leading or trailing whitespace std::string token = *token_it; LLStringUtil::trim(token); if (token.compare(0, MAX_AGE.size(), MAX_AGE) == 0) { // ...this token starts with max-age, so let's chop it up by "=" tokenizer subtokens(token, EQUALS_SEPARATOR); tokenizer::iterator subtoken_it = subtokens.begin(); // Must have a token if (subtoken_it == subtokens.end()) return false; std::string subtoken = *subtoken_it; // Must exactly equal "max-age" LLStringUtil::trim(subtoken); if (subtoken != MAX_AGE) return false; // Must have another token ++subtoken_it; if (subtoken_it == subtokens.end()) return false; subtoken = *subtoken_it; // Must be a valid integer // *NOTE: atoi() returns 0 for invalid values, so we have to // check the string first. // *TODO: Do servers ever send "0000" for zero? We don't handle it LLStringUtil::trim(subtoken); if (subtoken == "0") { *max_age = 0; return true; } S32 val = atoi( subtoken.c_str() ); if (val > 0 && val < S32_MAX) { *max_age = val; return true; } return false; } } return false; }