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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#include <svl/broadcast.hxx>
#include <svl/listener.hxx>
#include <svl/hint.hxx>
#include <o3tl/safeint.hxx>
#include <cassert>
#include <algorithm>
static void sortListeners(std::vector<SvtListener*>& listeners, size_t firstUnsorted)
{
// Add() only appends new values, so often the container will be sorted expect for one
// or few last items. For larger containers it is much more efficient to just handle
// the unsorted part.
auto sortedEnd = firstUnsorted == 0
? std::is_sorted_until(listeners.begin(),listeners.end())
: listeners.begin() + firstUnsorted;
if( listeners.end() - sortedEnd == 1 )
{ // Just one item, insert it in the right place.
SvtListener* item = listeners.back();
listeners.pop_back();
listeners.insert( std::upper_bound( listeners.begin(), listeners.end(), item ), item );
}
else if( o3tl::make_unsigned( sortedEnd - listeners.begin()) > listeners.size() * 3 / 4 )
{ // Sort the unsorted part and then merge.
std::sort( sortedEnd, listeners.end());
std::inplace_merge( listeners.begin(), sortedEnd, listeners.end());
}
else
{
std::sort(listeners.begin(), listeners.end());
}
}
void SvtBroadcaster::Normalize() const
{
if (mnListenersFirstUnsorted != maListeners.size())
{
sortListeners(maListeners, mnListenersFirstUnsorted);
mnListenersFirstUnsorted = maListeners.size();
}
if (!mbDestNormalized)
{
sortListeners(maDestructedListeners, 0);
mbDestNormalized = true;
}
}
void SvtBroadcaster::Add( SvtListener* p )
{
assert(!mbDisposing && "called inside my own destructor?");
assert(!mbAboutToDie && "called after PrepareForDestruction()?");
if (mbDisposing || mbAboutToDie)
return;
// Avoid normalizing if the item appended keeps the container sorted.
if (maListeners.empty() || (mnListenersFirstUnsorted == maListeners.size() && maListeners.back() < p))
++mnListenersFirstUnsorted;
maListeners.push_back(p);
}
void SvtBroadcaster::Remove( SvtListener* p )
{
if (mbDisposing)
return;
if (mbAboutToDie)
{
// only reset mbDestNormalized if we are going to become unsorted
if (!maDestructedListeners.empty() && maDestructedListeners.back() > p)
mbDestNormalized = false;
maDestructedListeners.push_back(p);
return;
}
Normalize();
auto it = std::lower_bound(maListeners.begin(), maListeners.end(), p);
assert (it != maListeners.end() && *it == p);
if (it != maListeners.end() && *it == p)
{
maListeners.erase(it);
--mnListenersFirstUnsorted;
}
if (maListeners.empty())
ListenersGone();
}
SvtBroadcaster::SvtBroadcaster()
: mbAboutToDie(false)
, mbDisposing(false)
, mbDestNormalized(true)
, mnListenersFirstUnsorted(0)
{}
SvtBroadcaster::SvtBroadcaster( const SvtBroadcaster &rBC ) :
mbAboutToDie(false), mbDisposing(false),
mbDestNormalized(true), mnListenersFirstUnsorted(0)
{
assert(!rBC.mbAboutToDie && "copying an object marked with PrepareForDestruction()?");
assert(!rBC.mbDisposing && "copying an object that is in its destructor?");
rBC.Normalize(); // so that insert into ourself is in-order, and therefore we do not need to Normalize()
maListeners.reserve(rBC.maListeners.size());
for (SvtListener* p : rBC.maListeners)
p->StartListening(*this); // this will call back into this->Add()
}
SvtBroadcaster::~SvtBroadcaster()
{
mbDisposing = true;
Broadcast( SfxHint(SfxHintId::Dying) );
Normalize();
// now when both lists are sorted, we can linearly unregister all
// listeners, with the exception of those that already asked to be removed
// during their own destruction
ListenersType::const_iterator dest(maDestructedListeners.begin());
for (auto& rpListener : maListeners)
{
// skip the destructed ones
while (dest != maDestructedListeners.end() && (*dest < rpListener))
++dest;
if (dest == maDestructedListeners.end() || *dest != rpListener)
rpListener->BroadcasterDying(*this);
}
}
void SvtBroadcaster::Broadcast( const SfxHint &rHint )
{
Normalize();
ListenersType::const_iterator dest(maDestructedListeners.begin());
ListenersType aListeners(maListeners); // this copy is important to avoid erasing entries while iterating
for (auto& rpListener : aListeners)
{
// skip the destructed ones
while (dest != maDestructedListeners.end() && (*dest < rpListener))
++dest;
if (dest == maDestructedListeners.end() || *dest != rpListener)
rpListener->Notify(rHint);
}
}
void SvtBroadcaster::ListenersGone() {}
SvtBroadcaster::ListenersType& SvtBroadcaster::GetAllListeners()
{
Normalize();
return maListeners;
}
const SvtBroadcaster::ListenersType& SvtBroadcaster::GetAllListeners() const
{
Normalize();
return maListeners;
}
bool SvtBroadcaster::HasListeners() const
{
return !maListeners.empty();
}
void SvtBroadcaster::PrepareForDestruction()
{
mbAboutToDie = true;
// the reserve() serves two purpose (1) performance (2) makes sure our iterators do not become invalid
maDestructedListeners.reserve(maListeners.size());
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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