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/*
This file is part of cpp-ethereum.
cpp-ethereum is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
cpp-ethereum 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file DownloadMan.h
* @author Gav Wood <i@gavwood.com>
* @date 2014
*/
#pragma once
#include <vector>
#include <unordered_set>
#include <unordered_map>
#include <libdevcore/Guards.h>
#include <libdevcore/Worker.h>
#include <libdevcore/RangeMask.h>
#include <libdevcore/FixedHash.h>
namespace dev
{
namespace eth
{
class DownloadMan;
class DownloadSub
{
friend class DownloadMan;
public:
DownloadSub(DownloadMan& _man);
~DownloadSub();
/// Finished last fetch - grab the next bunch of block hashes to download.
h256Hash nextFetch(unsigned _n);
/// Note that we've received a particular block. @returns true if we had asked for it but haven't received it yet.
bool noteBlock(h256 _hash);
/// Nothing doing here.
void doneFetch() { resetFetch(); }
bool askedContains(unsigned _i) const { Guard l(m_fetch); return m_asked.contains(_i); }
RangeMask<unsigned> const& asked() const { return m_asked; }
RangeMask<unsigned> const& attemped() const { return m_attempted; }
private:
void resetFetch() // Called by DownloadMan when we need to reset the download.
{
Guard l(m_fetch);
m_remaining.clear();
m_indices.clear();
m_asked.reset();
m_attempted.reset();
}
DownloadMan* m_man = nullptr;
mutable Mutex m_fetch;
h256Hash m_remaining;
std::unordered_map<h256, unsigned> m_indices;
RangeMask<unsigned> m_asked;
RangeMask<unsigned> m_attempted;
};
class DownloadMan
{
friend class DownloadSub;
public:
struct Overview
{
size_t total;
size_t firstIncomplete;
size_t lastComplete;
size_t lastStarted;
};
~DownloadMan()
{
for (auto i: m_subs)
i->m_man = nullptr;
}
void appendToChain(h256s const& _hashes)
{
WriteGuard l(m_lock);
m_chain.insert(m_chain.end(), _hashes.cbegin(), _hashes.cend());
m_blocksGot = RangeMask<unsigned>(0, m_chain.size());
}
void resetToChain(h256s const& _chain)
{
DEV_READ_GUARDED(x_subs)
for (auto i: m_subs)
i->resetFetch();
WriteGuard l(m_lock);
m_chain.clear();
m_chain.reserve(_chain.size());
for (auto i = _chain.rbegin(); i != _chain.rend(); ++i)
m_chain.push_back(*i);
m_blocksGot = RangeMask<unsigned>(0, m_chain.size());
}
void reset()
{
DEV_READ_GUARDED(x_subs)
for (auto i: m_subs)
i->resetFetch();
WriteGuard l(m_lock);
m_chain.clear();
m_blocksGot.reset();
}
RangeMask<unsigned> taken(bool _desperate = false) const
{
ReadGuard l(m_lock);
auto ret = m_blocksGot;
if (!_desperate)
DEV_READ_GUARDED(x_subs)
for (auto i: m_subs)
ret += i->m_asked;
return ret;
}
bool isComplete() const
{
ReadGuard l(m_lock);
return m_blocksGot.full();
}
h256s remaining() const
{
h256s ret;
DEV_READ_GUARDED(m_lock)
for (auto i: m_blocksGot.inverted())
ret.push_back(m_chain[i]);
return ret;
}
h256 firstBlock() const { return m_chain.empty() ? h256() : m_chain[0]; }
Overview overview() const;
size_t chainSize() const { ReadGuard l(m_lock); return m_chain.size(); }
size_t chainEmpty() const { ReadGuard l(m_lock); return m_chain.empty(); }
void foreachSub(std::function<void(DownloadSub const&)> const& _f) const { ReadGuard l(x_subs); for(auto i: m_subs) _f(*i); }
unsigned subCount() const { ReadGuard l(x_subs); return m_subs.size(); }
RangeMask<unsigned> blocksGot() const { ReadGuard l(m_lock); return m_blocksGot; }
private:
mutable SharedMutex m_lock;
h256s m_chain;
RangeMask<unsigned> m_blocksGot;
mutable SharedMutex x_subs;
std::unordered_set<DownloadSub*> m_subs;
};
}
}