transmission/libtransmission/peer-mgr-wishlist.h

50 lines
1.6 KiB
C++

// This file Copyright © Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#pragma once
#ifndef LIBTRANSMISSION_PEER_MODULE
#error only the libtransmission peer module should #include this header.
#endif
#include <cstddef> // size_t
#include <vector>
#include "libtransmission/transmission.h"
/**
* Figures out what blocks we want to request next.
*/
class Wishlist
{
public:
static auto constexpr EndgameMaxPeers = size_t{ 2U };
struct Mediator
{
[[nodiscard]] virtual bool clientCanRequestBlock(tr_block_index_t block) const = 0;
[[nodiscard]] virtual bool clientCanRequestPiece(tr_piece_index_t piece) const = 0;
[[nodiscard]] virtual bool isEndgame() const = 0;
[[nodiscard]] virtual bool isSequentialDownload() const = 0;
[[nodiscard]] virtual size_t countActiveRequests(tr_block_index_t block) const = 0;
[[nodiscard]] virtual size_t countMissingBlocks(tr_piece_index_t piece) const = 0;
[[nodiscard]] virtual tr_block_span_t blockSpan(tr_piece_index_t) const = 0;
[[nodiscard]] virtual tr_piece_index_t countAllPieces() const = 0;
[[nodiscard]] virtual tr_priority_t priority(tr_piece_index_t) const = 0;
virtual ~Mediator() = default;
};
constexpr explicit Wishlist(Mediator const& mediator)
: mediator_{ mediator }
{
}
// the next blocks that we should request from a peer
[[nodiscard]] std::vector<tr_block_span_t> next(size_t n_wanted_blocks);
private:
Mediator const& mediator_;
};