transmission/tests/libtransmission/peer-mgr-wishlist-test.cc

346 lines
11 KiB
C++

// This file Copyright (C) 2021-2022 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.
#include <algorithm>
#include <map>
#include <type_traits>
#define LIBTRANSMISSION_PEER_MODULE
#include "transmission.h"
#include "peer-mgr-wishlist.h"
#include "gtest/gtest.h"
class PeerMgrWishlistTest : public ::testing::Test
{
protected:
struct MockMediator : public Wishlist::Mediator
{
mutable std::map<tr_block_index_t, size_t> active_request_count_;
mutable std::map<tr_piece_index_t, size_t> missing_block_count_;
mutable std::map<tr_piece_index_t, tr_block_span_t> block_span_;
mutable std::map<tr_piece_index_t, tr_priority_t> piece_priority_;
mutable std::set<tr_block_index_t> can_request_block_;
mutable std::set<tr_piece_index_t> can_request_piece_;
tr_piece_index_t piece_count_ = 0;
bool is_endgame_ = false;
[[nodiscard]] bool clientCanRequestBlock(tr_block_index_t block) const final
{
return can_request_block_.count(block) != 0;
}
[[nodiscard]] bool clientCanRequestPiece(tr_piece_index_t piece) const final
{
return can_request_piece_.count(piece) != 0;
}
[[nodiscard]] bool isEndgame() const final
{
return is_endgame_;
}
[[nodiscard]] size_t countActiveRequests(tr_block_index_t block) const final
{
return active_request_count_[block];
}
[[nodiscard]] size_t countMissingBlocks(tr_piece_index_t piece) const final
{
return missing_block_count_[piece];
}
[[nodiscard]] tr_block_span_t blockSpan(tr_piece_index_t piece) const final
{
return block_span_[piece];
}
[[nodiscard]] tr_piece_index_t countAllPieces() const final
{
return piece_count_;
}
[[nodiscard]] tr_priority_t priority(tr_piece_index_t piece) const final
{
return piece_priority_[piece];
}
};
};
TEST_F(PeerMgrWishlistTest, doesNotRequestPiecesThatCannotBeRequested)
{
auto mediator = MockMediator{};
// setup: three pieces, all missing
mediator.piece_count_ = 3;
mediator.missing_block_count_[0] = 100;
mediator.missing_block_count_[1] = 100;
mediator.missing_block_count_[2] = 50;
mediator.block_span_[0] = { 0, 100 };
mediator.block_span_[1] = { 100, 200 };
mediator.block_span_[2] = { 200, 251 };
// but we only want the first piece
mediator.can_request_piece_.insert(0);
for (tr_block_index_t i = mediator.block_span_[0].begin; i < mediator.block_span_[0].end; ++i)
{
mediator.can_request_block_.insert(i);
}
// we should only get the first piece back
auto spans = Wishlist::next(mediator, 1000);
ASSERT_EQ(1U, std::size(spans));
EXPECT_EQ(mediator.block_span_[0].begin, spans[0].begin);
EXPECT_EQ(mediator.block_span_[0].end, spans[0].end);
}
TEST_F(PeerMgrWishlistTest, doesNotRequestBlocksThatCannotBeRequested)
{
auto mediator = MockMediator{};
// setup: three pieces, all missing
mediator.piece_count_ = 3;
mediator.missing_block_count_[0] = 100;
mediator.missing_block_count_[1] = 100;
mediator.missing_block_count_[2] = 50;
mediator.block_span_[0] = { 0, 100 };
mediator.block_span_[1] = { 100, 200 };
mediator.block_span_[2] = { 200, 251 };
// and we want all three pieces
mediator.can_request_piece_.insert(0);
mediator.can_request_piece_.insert(1);
mediator.can_request_piece_.insert(2);
// but we've already requested blocks [0..10) from someone else,
// so we don't want to send repeat requests
for (tr_block_index_t i = 10; i < 250; ++i)
{
mediator.can_request_block_.insert(i);
}
// even if we ask wishlist for more blocks than exist,
// it should omit blocks 1-10 from the return set
auto spans = Wishlist::next(mediator, 1000);
auto requested = tr_bitfield(250);
for (auto const& span : spans)
{
requested.setSpan(span.begin, span.end);
}
EXPECT_EQ(240U, requested.count());
EXPECT_EQ(0U, requested.count(0, 10));
EXPECT_EQ(240U, requested.count(10, 250));
}
TEST_F(PeerMgrWishlistTest, doesNotRequestTooManyBlocks)
{
auto mediator = MockMediator{};
// setup: three pieces, all missing
mediator.piece_count_ = 3;
mediator.missing_block_count_[0] = 100;
mediator.missing_block_count_[1] = 100;
mediator.missing_block_count_[2] = 50;
mediator.block_span_[0] = { 0, 100 };
mediator.block_span_[1] = { 100, 200 };
mediator.block_span_[2] = { 200, 251 };
// and we want everything
for (tr_piece_index_t i = 0; i < 3; ++i)
{
mediator.can_request_piece_.insert(i);
}
for (tr_block_index_t i = 0; i < 250; ++i)
{
mediator.can_request_block_.insert(i);
}
// but we only ask for 10 blocks,
// so that's how many we should get back
auto const n_wanted = 10U;
auto const spans = Wishlist::next(mediator, n_wanted);
auto n_got = size_t{};
for (auto const& span : spans)
{
n_got += span.end - span.begin;
}
EXPECT_EQ(n_wanted, n_got);
}
TEST_F(PeerMgrWishlistTest, prefersHighPriorityPieces)
{
auto mediator = MockMediator{};
// setup: three pieces, all missing
mediator.piece_count_ = 3;
mediator.missing_block_count_[0] = 100;
mediator.missing_block_count_[1] = 100;
mediator.missing_block_count_[2] = 100;
mediator.block_span_[0] = { 0, 100 };
mediator.block_span_[1] = { 100, 200 };
mediator.block_span_[2] = { 200, 300 };
// and we want everything
for (tr_piece_index_t i = 0; i < 3; ++i)
{
mediator.can_request_piece_.insert(i);
}
for (tr_block_index_t i = 0; i < 299; ++i)
{
mediator.can_request_block_.insert(i);
}
// and the second piece is high priority
mediator.piece_priority_[1] = TR_PRI_HIGH;
// wishlist should pick the high priority piece's blocks first.
//
// NB: when all other things are equal in the wishlist, pieces are
// picked at random so this test -could- pass even if there's a bug.
// So test several times to shake out any randomness
auto const num_runs = 1000;
for (int run = 0; run < num_runs; ++run)
{
auto const n_wanted = 10U;
auto spans = Wishlist::next(mediator, n_wanted);
auto n_got = size_t{};
for (auto const& span : spans)
{
for (auto block = span.begin; block < span.end; ++block)
{
EXPECT_LE(mediator.block_span_[1].begin, block);
EXPECT_LT(block, mediator.block_span_[1].end);
}
n_got += span.end - span.begin;
}
EXPECT_EQ(n_wanted, n_got);
}
}
TEST_F(PeerMgrWishlistTest, onlyRequestsDupesDuringEndgame)
{
auto mediator = MockMediator{};
// setup: three pieces, all missing
mediator.piece_count_ = 3;
mediator.missing_block_count_[0] = 100;
mediator.missing_block_count_[1] = 100;
mediator.missing_block_count_[2] = 100;
mediator.block_span_[0] = { 0, 100 };
mediator.block_span_[1] = { 100, 200 };
mediator.block_span_[2] = { 200, 300 };
// and we want everything
for (tr_piece_index_t i = 0; i < 3; ++i)
{
mediator.can_request_piece_.insert(i);
}
for (tr_block_index_t i = 0; i < 300; ++i)
{
mediator.can_request_block_.insert(i);
}
// and we've already requested blocks [0-150)
for (tr_block_index_t i = 0; i < 150; ++i)
{
mediator.active_request_count_[i] = 1;
}
// even if we ask wishlist to list more blocks than exist,
// those first 150 should be omitted from the return list
auto spans = Wishlist::next(mediator, 1000);
auto requested = tr_bitfield(300);
for (auto const& span : spans)
{
requested.setSpan(span.begin, span.end);
}
EXPECT_EQ(150U, requested.count());
EXPECT_EQ(0U, requested.count(0, 150));
EXPECT_EQ(150U, requested.count(150, 300));
// BUT during endgame it's OK to request dupes,
// so then we _should_ see the first 150 in the list
mediator.is_endgame_ = true;
spans = Wishlist::next(mediator, 1000);
requested = tr_bitfield(300);
for (auto const& span : spans)
{
requested.setSpan(span.begin, span.end);
}
EXPECT_EQ(300U, requested.count());
EXPECT_EQ(150U, requested.count(0, 150));
EXPECT_EQ(150U, requested.count(150, 300));
}
TEST_F(PeerMgrWishlistTest, prefersNearlyCompletePieces)
{
auto mediator = MockMediator{};
// setup: three pieces, same size
mediator.piece_count_ = 3;
mediator.block_span_[0] = { 0, 100 };
mediator.block_span_[1] = { 100, 200 };
mediator.block_span_[2] = { 200, 300 };
// and we want everything
for (tr_piece_index_t i = 0; i < 3; ++i)
{
mediator.can_request_piece_.insert(i);
}
// but some pieces are closer to completion than others
mediator.missing_block_count_[0] = 10;
mediator.missing_block_count_[1] = 20;
mediator.missing_block_count_[2] = 100;
for (tr_piece_index_t piece = 0; piece < 3; ++piece)
{
auto const& span = mediator.block_span_[piece];
auto const& n_missing = mediator.missing_block_count_[piece];
for (size_t i = 0; i < n_missing; ++i)
{
mediator.can_request_block_.insert(span.begin + i);
}
}
// wishlist prefers to get pieces completed ASAP, so it
// should pick the ones with the fewest missing blocks first.
// NB: when all other things are equal in the wishlist, pieces are
// picked at random so this test -could- pass even if there's a bug.
// So test several times to shake out any randomness
auto const num_runs = 1000;
for (int run = 0; run < num_runs; ++run)
{
auto const ranges = Wishlist::next(mediator, 10);
auto requested = tr_bitfield(300);
for (auto const& range : ranges)
{
requested.setSpan(range.begin, range.end);
}
EXPECT_EQ(10U, requested.count());
EXPECT_EQ(10U, requested.count(0, 100));
EXPECT_EQ(0U, requested.count(100, 300));
}
// Same premise as previous test, but ask for more blocks.
// Since the second piece is also the second-closest to completion,
// those blocks should be next in line.
for (int run = 0; run < num_runs; ++run)
{
auto const ranges = Wishlist::next(mediator, 20);
auto requested = tr_bitfield(300);
for (auto const& range : ranges)
{
requested.setSpan(range.begin, range.end);
}
EXPECT_EQ(20U, requested.count());
EXPECT_EQ(10U, requested.count(0, 100));
EXPECT_EQ(10U, requested.count(100, 200));
EXPECT_EQ(0U, requested.count(200, 300));
}
}