transmission/libtransmission/torrents.h

119 lines
3.0 KiB
C++

// This file Copyright © 2022 Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0), GPLv3 (SPDX: GPL-3.0),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#pragma once
#ifndef __TRANSMISSION__
#error only libtransmission should #include this header.
#endif
#include <ctime>
#include <map>
#include <set>
#include <string_view>
#include <vector>
#include "transmission.h"
#include "torrent-metainfo.h"
struct tr_torrent;
struct tr_torrent_metainfo;
// A helper class to manage tracking sets of tr_torrent objects.
class tr_torrents
{
public:
tr_torrents();
// returns a fast lookup id for `tor`
[[nodiscard]] int add(tr_torrent* tor);
void remove(tr_torrent const* tor, time_t current_time);
// O(1)
[[nodiscard]] tr_torrent* get(int id);
[[nodiscard]] tr_torrent const* get(int id) const;
// O(log n)
[[nodiscard]] tr_torrent const* get(tr_sha1_digest_t const& hash) const;
[[nodiscard]] tr_torrent* get(tr_sha1_digest_t const& hash);
[[nodiscard]] tr_torrent const* get(tr_torrent_metainfo const& metainfo) const
{
return get(metainfo.infoHash());
}
[[nodiscard]] tr_torrent* get(tr_torrent_metainfo const& metainfo)
{
return get(metainfo.infoHash());
}
// These convenience functions use get(tr_sha1_digest_t const&)
// after parsing the magnet link to get the info hash. If you have
// the info hash already, use get() instead to avoid excess parsing.
[[nodiscard]] tr_torrent const* get(std::string_view magnet_link) const;
[[nodiscard]] tr_torrent* get(std::string_view magnet_link);
template<typename T>
[[nodiscard]] bool contains(T const& key) const
{
return get(key) != nullptr;
}
[[nodiscard]] std::set<int> removedSince(time_t) const;
[[nodiscard]] auto cbegin() const
{
return std::cbegin(by_hash_);
}
[[nodiscard]] auto begin() const
{
return cbegin();
}
[[nodiscard]] auto begin()
{
return std::begin(by_hash_);
}
[[nodiscard]] auto cend() const
{
return std::cend(by_hash_);
}
[[nodiscard]] auto end() const
{
return cend();
}
[[nodiscard]] auto end()
{
return std::end(by_hash_);
}
[[nodiscard]] auto size() const
{
return std::size(by_hash_);
}
[[nodiscard]] auto empty() const
{
return std::empty(by_hash_);
}
private:
std::vector<tr_torrent*> by_hash_;
// This is a lookup table where by_id_[id]->uniqueId == id.
// There is a small tradeoff here -- lookup is O(1) at the cost
// of a wasted slot in the lookup table whenever a torrent is
// removed. This improves speed for all use cases at the cost of
// wasting a small amount of memory in uncommon use cases, e.g. a
// long-lived session where thousands of torrents are removed
std::vector<tr_torrent*> by_id_;
std::map<int, time_t> removed_;
};