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// **********************************************************************
//
// Copyright (c) 2003-2012 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************
#include <EvictorBase.h>
EvictorBase::EvictorBase(Ice::Int size) :
_size(size)
{
if (_size < 0)
{
_size = 1000;
}
}
Ice::ObjectPtr
EvictorBase::locate(const Ice::Current& c, Ice::LocalObjectPtr& cookie)
{
IceUtil::Mutex::Lock lock(_mutex);
//
// Check if we have a servant in the map already.
//
EvictorEntryPtr entry;
EvictorMap::iterator i = _map.find(c.id);
if(i != _map.end())
{
//
// Got an entry already, dequeue the entry from its current position.
//
entry = i->second;
_queue.erase(entry->queuePos);
}
else
{
//
// We do not have an entry. Ask the derived class to
// instantiate a servant and add a new entry to the map.
//
entry = new EvictorEntry;
entry->servant = add(c, entry->userCookie); // Down-call
if(!entry->servant)
{
return 0;
}
entry->useCount = 0;
i = _map.insert(std::make_pair(c.id, entry)).first;
}
//
// Increment the use count of the servant and enqueue
// the entry at the front, so we get LRU order.
//
++(entry->useCount);
entry->queuePos = _queue.insert(_queue.begin(), i);
cookie = entry;
return entry->servant;
}
void
EvictorBase::finished(const Ice::Current&, const Ice::ObjectPtr&, const Ice::LocalObjectPtr& cookie)
{
IceUtil::Mutex::Lock lock(_mutex);
EvictorEntryPtr entry = EvictorEntryPtr::dynamicCast(cookie);
//
// Decrement use count and check if there is something to evict.
//
--(entry->useCount);
evictServants();
}
void
EvictorBase::deactivate(const std::string& /*category*/)
{
IceUtil::Mutex::Lock lock(_mutex);
_size = 0;
evictServants();
}
void
EvictorBase::evictServants()
{
//
// If the evictor queue has grown larger than the limit,
// look at the excess elements to see whether any of them
// can be evicted.
//
EvictorQueue::reverse_iterator p = _queue.rbegin();
int excessEntries = static_cast<int>(_map.size() - _size);
for(int i = 0; i < excessEntries; ++i)
{
EvictorMap::iterator mapPos = *p;
if(mapPos->second->useCount == 0)
{
evict(mapPos->second->servant, mapPos->second->userCookie); // Down-call
p = EvictorQueue::reverse_iterator(_queue.erase(mapPos->second->queuePos));
_map.erase(mapPos);
}
else
{
++p;
}
}
}
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