MemorySubscriptionManager.hpp

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#ifndef _MEMORYSUBSCRIPTIONMANAGER_H_
#define _MEMORYSUBSCRIPTIONMANAGER_H_

#include <ampsplusplus.hpp>
#include <Field.hpp>
#include <algorithm>
#include <list>
#include <map>
#include <memory>
#include <set>


namespace AMPS
{

class MemorySubscriptionManager : public SubscriptionManager
{
private:

 class SubscriptionInfo
 {
 public:
 SubscriptionInfo(MessageHandler messageHandler_,
 const Message& message_,
 unsigned requestedAckTypes_)
 : _handler(messageHandler_)
 , _m(message_)
 , _subId(message_.getSubscriptionId())
 , _requestedAckTypes(requestedAckTypes_)
 , _bookmark(!message_.getBookmark().empty())
 , _clearSubId(false)
 {
 std::string options = _m.getOptions();
 size_t replace = options.find("replace");
 // AMPS should be ok if options contains ,,
 static const size_t replaceLen = 7;
 if (replace != std::string::npos)
 {
 options.erase(replace, replaceLen);
 _m.setOptions(options);
 }
 _paused = (options.find("pause") != std::string::npos);
 }

 ~SubscriptionInfo()
 {
 if (_clearSubId)
 {
 _m.getSubscriptionId().clear();
 }
 }

 void resubscribe(Client& client_, int timeout_, void* userData_)
 {
 if(_bookmark)
 {
 if (_paused && !_recent.empty())
 _m.setBookmark(_recent);
 else
 _m.setBookmark(client_.getBookmarkStore().getMostRecent(_subId));
 }
 _m.newCommandId();
 _m.setAckTypeEnum(_requestedAckTypes);
 if (!userData_)
 {
 client_.send(_handler, _m, timeout_);
 }
 else
 {
 MessageHandler handler(_handler.function(), userData_);
 client_.send(handler, _m, timeout_);
 }
 }

 MessageHandler messageHandler() const
 {
 return _handler;
 }

 const Message::Field& subId() const
 {
 return _subId;
 }

 // Returns true if the last subId is removed, false otherwise
 bool removeSubId(const Message::Field& subId_)
 {
 size_t subIdLen = subId_.len();
 const char* subIdData = subId_.data();
 while (subIdLen && *subIdData == ',')
 {
 ++subIdData;
 --subIdLen;
 }
 while (subIdLen && subIdData[subIdLen-1] == ',')
 {
 --subIdLen;
 }
 if (subIdLen == 0 || subIdLen > _subId.len()) return _subId.empty();
 bool match = true;
 size_t matchStart = 0;
 size_t matchCount = 0;
 for (size_t i=0; i<_subId.len(); ++i)
 {
 if (_subId.data()[i] == ',')
 {
 if (matchCount == subIdLen) break;
 matchStart = i+1;
 matchCount = 0;
 match = true;
 }
 else if (match)
 {
 if (_subId.data()[i] == subIdData[matchCount])
 ++matchCount;
 else
 {
 matchCount = 0;
 match = false;
 }
 }
 }
 if (match && matchCount == subIdLen)
 {
 size_t newLen = _subId.len() - matchCount;
 if (newLen > 1) // More than just ,
 {
 while (matchStart + matchCount < _subId.len() &&
 _subId.data()[matchStart+matchCount] == ',')
 {
 ++matchCount;
 --newLen;
 }
 char* buffer = new char[newLen];
 // Match is not first
 if (matchStart > 0)
 {
 memcpy(buffer, _subId.data(), matchStart);
 }
 // Match is not last
 if (matchStart + matchCount < _subId.len())
 {
 memcpy(buffer+matchStart,
 _subId.data()+matchStart+matchCount,
 _subId.len()-matchStart-matchCount);
 }
 if (_clearSubId)
 {
 _m.getSubscriptionId().clear();
 }
 else
 {
 _clearSubId = true;
 }
 _m.assignSubscriptionId(buffer, newLen);
 _subId = _m.getSubscriptionId();
 return false;
 }
 else
 {
 if (_clearSubId)
 {
 _m.getSubscriptionId().clear();
 _clearSubId = false;
 }
 else
 {
 _m.getSubscriptionId().assign(NULL, 0);
 }
 _subId = _m.getSubscriptionId();
 return true;
 }
 }
 return _subId.empty();
 }

 bool paused() const
 {
 return _paused;
 }

 void pause()
 {
 if (_paused) return;
 std::string opts(Message::Options::Pause());
 opts.append(_m.getOptions());
 _m.setOptions(opts);
 _paused = true;
 }

 std::string getMostRecent(Client& client_)
 {
 if (!_recent.empty()) return _recent;
 std::map<amps_uint64_t, amps_uint64_t> publishers;
 const char* start = _subId.data();
 const char* end = _subId.data() + _subId.len();
 while (start < end)
 {
 const char* comma = (const char*)memchr(start, ',',
 (size_t)(end-start));
 // No more commas found, just use start->end
 if(!comma) comma = end;
 if(comma == start)
 {
 start = comma + 1;
 continue;
 }
 Message::Field sid(start, (size_t)(comma-start));
 Message::Field sidRecent = client_.getBookmarkStore().getMostRecent(sid);
 const char* sidRecentStart = sidRecent.data();
 const char* sidRecentEnd = sidRecent.data() + sidRecent.len();
 while (sidRecentStart < sidRecentEnd)
 {
 const char* sidRecentComma = (const char*)
 memchr(sidRecentStart, ',',
 (size_t)(sidRecentEnd-sidRecentStart));
 // No more commas found, just use start->end
 if(!sidRecentComma) sidRecentComma = sidRecentEnd;
 if(sidRecentComma == sidRecentStart)
 {
 sidRecentStart = sidRecentComma + 1;
 continue;
 }
 Message::Field bookmark(sidRecentStart,
 (size_t)(sidRecentComma-sidRecentStart));
 amps_uint64_t publisher = (amps_uint64_t)0;
 amps_uint64_t seq = (amps_uint64_t)0;
 Field::parseBookmark(bookmark, publisher, seq);
 if (publishers.count(publisher) == 0
 || publishers[publisher] > seq)
 {
 publishers[publisher] = seq;
 }
 // Move past comma
 sidRecentStart = sidRecentComma + 1;
 }
 // Move past comma
 start = comma + 1;
 }
 std::ostringstream os;
 for(std::map<amps_uint64_t, amps_uint64_t>::iterator i = publishers.begin();
 i != publishers.end();
 ++i)
 {
 if (i->first == 0 && i->second == 0) continue;
 if (os.tellp() > 0) os << ',';
 os << i->first << '|' << i->second << "|";
 }
 _recent = os.str();
 return _recent;
 }

 void setMostRecent(const std::string& recent_)
 {
 _recent = recent_;
 }

 private:
 std::string _recent;
 MessageHandler _handler;
 Message _m;
 Message::Field _subId;
 unsigned _requestedAckTypes;
 bool _bookmark;
 bool _paused;
 bool _clearSubId;

 };//class SubscriptionInfo

 class Resubscriber
 {
 Client& _client;
 int _timeout;
 public:
 Resubscriber(Client& client_, int timeout_)
 : _client(client_)
 , _timeout(timeout_)
 { }
 void operator()(std::pair<Message::Field, SubscriptionInfo*> iter_)
 {
 void* data = amps_invoke_copy_route_function(iter_.second->messageHandler().userData());
 iter_.second->resubscribe(_client, _timeout, data);
 }
 void operator()(SubscriptionInfo* iter_)
 {
 void* data = amps_invoke_copy_route_function(iter_->messageHandler().userData());
 iter_->resubscribe(_client, _timeout, data);
 }
 };

 class Deleter
 {
 bool _clearSubId;
 public:
 Deleter(bool clearSubId_ = false)
 : _clearSubId(clearSubId_)
 { }
 void operator()(std::pair<Message::Field, SubscriptionInfo*> iter_)
 {
 if (_clearSubId)
 {
 iter_.first.clear();
 }
 else
 {
 amps_invoke_remove_route_function(iter_.second->messageHandler().userData());
 delete iter_.second;
 }
 }
 void operator()(SubscriptionInfo* iter_)
 {
 delete iter_;
 }
 };

public:
 typedef std::map<Message::Field, SubscriptionInfo*, Message::Field::FieldHash> SubscriptionMap;

 MemorySubscriptionManager()
 : _resubscribing(0)
 , _resubscriptionTimeout(getDefaultResubscriptionTimeout())
 { ; }

 ~MemorySubscriptionManager()
 {
 _clear();
 }

 void subscribe(MessageHandler messageHandler_,
 const Message& message_, unsigned requestedAckTypes_)
 {
 const Message::Field& subId = message_.getSubscriptionId();
 if(!subId.empty())
 {
 Lock<Mutex> l(_lock);
 while(_resubscribing != 0) _lock.wait(10);
 std::string options = message_.getOptions();
 if (options.find("resume") != std::string::npos)
 {
 // For a resume, we store each sub id with a single Subscription
 SubscriptionInfo* subInfo = new SubscriptionInfo(MessageHandler(),
 message_,
 requestedAckTypes_);
 bool saved = false;
 Field fullSubId = subInfo->subId();
 const char* start = fullSubId.data();
 const char* end = fullSubId.data() + fullSubId.len();
 while (start < end)
 {
 const char* comma = (const char*)memchr(start, ',',
 (size_t)(end-start));
 // No more commas found, just use start->end
 if(!comma) comma = end;
 if(comma == start)
 {
 start = comma + 1;
 continue;
 }
 Message::Field sid = Message::Field(start,
 (size_t)(comma-start));
 // Calling resume on something already resumed is ignored,
 // so don't update anything that exists.
 if (_resumed.find(sid) == _resumed.end())
 {
 _resumed[sid.deepCopy()] = subInfo;
 saved = true;
 }
 // Move past comma
 start = comma + 1;
 }
 if (saved) _resumedSet.insert(subInfo);
 else delete subInfo;
 }
 else if (options.find("pause") != std::string::npos)
 {
 const char* start = subId.data();
 const char* end = subId.data() + subId.len();
 while (start < end)
 {
 MessageHandler messageHandler = messageHandler_;
 const char* comma = (const char*)memchr(start, ',',
 (size_t)(end-start));
 // No more commas found, just use start->end
 if(!comma) comma = end;
 if(comma == start)
 {
 start = comma + 1;
 continue;
 }
 Message::Field sid = Message::Field(start,
 (size_t)(comma-start));
 SubscriptionMap::iterator resume = _resumed.find(sid);
 if (resume != _resumed.end())
 {
 SubscriptionInfo* subPtr = resume->second;
 Message::Field subField(resume->first);
 _resumed.erase(resume); // Remove mapping for sid
 subField.clear();
 // If last subId, remove completely
 if (subPtr->removeSubId(sid))
 {
 _resumedSet.erase(subPtr);
 delete subPtr;
 }
 }
 // Move past comma
 start = comma + 1;
 SubscriptionMap::iterator item = _active.find(sid);
 if(item != _active.end())
 {
 if (options.find("replace") != std::string::npos)
 {
 messageHandler = item->second->messageHandler();
 delete item->second;
 _active.erase(item);
 }
 else
 {
 item->second->pause();
 continue; // Leave current one
 }
 }
 else
 {
 Unlock<Mutex> u(_lock);
 void* data = amps_invoke_copy_route_function(messageHandler_
 .userData());
 if (data)
 {
 messageHandler = MessageHandler(messageHandler_.function(), data);
 }
 }
 Message m = message_.deepCopy();
 m.setSubscriptionId(sid.data(), sid.len());
 SubscriptionInfo* s = new SubscriptionInfo(messageHandler, m,
 requestedAckTypes_);
 // Insert using the subId from s, which is deep copy of original
 _active[s->subId()] = s;
 }
 }
 else // Not a pause or resume
 {
 MessageHandler messageHandler = messageHandler_;
 SubscriptionMap::iterator item = _active.find(subId);
 if(item != _active.end())
 {
 messageHandler = item->second->messageHandler();
 delete item->second;
 _active.erase(item);
 }
 else
 {
 Unlock<Mutex> u(_lock);
 void* data = amps_invoke_copy_route_function(messageHandler_
 .userData());
 if (data)
 {
 messageHandler = MessageHandler(messageHandler_.function(), data);
 }
 }
 SubscriptionInfo* s = new SubscriptionInfo(messageHandler,
 message_,
 requestedAckTypes_);
 // Insert using the subId from s, which is deep copy of original
 _active[s->subId()] = s;
 }
 }
 }

 void unsubscribe(const Message::Field& subId_)
 {
 Lock<Mutex> l(_lock);
 SubscriptionMap::iterator item = _active.find(subId_);
 if(item != _active.end())
 {
 SubscriptionInfo* subPtr = item->second;
 _active.erase(item);
 while(_resubscribing != 0) _lock.wait(10);
 Unlock<Mutex> u(_lock);
 amps_invoke_remove_route_function(subPtr->messageHandler().userData());
 delete subPtr;
 }
 item = _resumed.find(subId_);
 if(item != _resumed.end())
 {
 SubscriptionInfo* subPtr = item->second;
 Message::Field subField(item->first);
 _resumed.erase(item);
 subField.clear();
 // If last subId, remove completely
 if (subPtr->removeSubId(subId_))
 {
 _resumedSet.erase(subPtr);
 while(_resubscribing != 0) _lock.wait(10);
 delete subPtr;
 }
 }
 }

 void clear()
 {
 _clear();
 }

 void _clear()
 {
 Lock<Mutex> l(_lock);
 while(_resubscribing != 0) _lock.wait(10);
 // Settting _resubscribing keeps other threads from touching data
 // even if lock isn't held. Don't want to hold lock when
 // amps_invoke_remove_route_function is called.
 AtomicFlagFlip resubFlip(&_resubscribing);
 {
 Unlock<Mutex> u(_lock);
 std::for_each(_active.begin(), _active.end(), Deleter());
 std::for_each(_resumedSet.begin(), _resumedSet.end(), Deleter());
 std::for_each(_resumed.begin(), _resumed.end(), Deleter(true));
 }
 _active.clear();
 _resumed.clear();
 _resumedSet.clear();
 }

 void resubscribe(Client& client_)
 {
 // At this point, it's better to throw an exception back to disconnect
 // handling than to attempt a reconnect in send, so turn off retry.
 bool retry = client_.getRetryOnDisconnect();
 client_.setRetryOnDisconnect(false);
 std::list<SubscriptionInfo*> subscriptions;
 try
 {
 AtomicFlagFlip resubFlip(&_resubscribing);
 {
 Lock<Mutex> l(_lock);
 subscriptions.assign(_resumedSet.begin(), _resumedSet.end());
 for (SubscriptionMap::iterator iter = _active.begin();
 iter != _active.end(); ++iter)
 {
 SubscriptionInfo* sub = iter->second;
 if (sub->paused())
 {
 SubscriptionMap::iterator resIter = _resumed.find(sub->subId());
 // All pause subs resuming together should be sent with
 // bookmark as list of the resumes' most recents
 if (resIter != _resumed.end())
 {
 sub->setMostRecent(resIter->second->getMostRecent(client_));
 }
 }
 subscriptions.push_front(iter->second);
 }
 }
 Resubscriber resubscriber(client_, _resubscriptionTimeout);
 std::for_each(subscriptions.begin(), subscriptions.end(),
 resubscriber);
 client_.setRetryOnDisconnect(retry);
 }
 catch(const AMPSException& e)
 {
 client_.setRetryOnDisconnect(retry);
 throw e;
 }
 catch(const std::exception& e)
 {
 client_.setRetryOnDisconnect(retry);
 throw e;
 }
 }

 void setResubscriptionTimeout(int timeout_)
 {
 if (timeout_ >= 0)
 {
 _resubscriptionTimeout = timeout_;
 }
 }

 int getResubscriptionTimeout(void)
 {
 return _resubscriptionTimeout;
 }

 static int setDefaultResubscriptionTimeout(int timeout_)
 {
 static int _defaultResubscriptionTimeout =
 AMPS_SUBSCRIPTION_MANAGER_DEFAULT_TIMEOUT;
 if (timeout_ >= 0)
 {
 _defaultResubscriptionTimeout = timeout_;
 }
 return _defaultResubscriptionTimeout;
 }

 static int getDefaultResubscriptionTimeout(void)
 {
 return setDefaultResubscriptionTimeout(-1);
 }

private:

 SubscriptionMap _active;
 SubscriptionMap _resumed;
 std::set<SubscriptionInfo*> _resumedSet;
 Mutex _lock;
 ATOMIC_TYPE_8 _resubscribing;
 int _resubscriptionTimeout;
}; //class MemorySubscriptionManager

} // namespace AMPS

#endif //_MEMORYSUBSCRIPTIONMANAGER_H_