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author | sfan5 <sfan5@live.de> | 2022-05-05 22:03:49 +0200 |
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committer | sfan5 <sfan5@live.de> | 2022-05-08 19:12:10 +0200 |
commit | 1fa4f58080b068920d7611291709377072d0cd00 (patch) | |
tree | f036bfc98dfb8cbf96dc860ced9ae6e4b4dac33d /src | |
parent | 7fff9da71d2de352e0afea7482fc2e26534a51a4 (diff) | |
download | minetest-1fa4f58080b068920d7611291709377072d0cd00.tar.gz minetest-1fa4f58080b068920d7611291709377072d0cd00.tar.bz2 minetest-1fa4f58080b068920d7611291709377072d0cd00.zip |
Cache serialized mapblocks during sending
This reduces the
(absolute) time spent in Server::SendBlocks() from 700ms to 300ms
(relative) share of MapBlock::serialize() from 80% to 60%
in a test setup with 10 players and many block changes
Diffstat (limited to 'src')
-rw-r--r-- | src/server.cpp | 44 | ||||
-rw-r--r-- | src/server.h | 14 |
2 files changed, 45 insertions, 13 deletions
diff --git a/src/server.cpp b/src/server.cpp index 6a4349ba5..d85a2e95a 100644 --- a/src/server.cpp +++ b/src/server.cpp @@ -2326,22 +2326,34 @@ void Server::sendMetadataChanged(const std::list<v3s16> &meta_updates, float far } void Server::SendBlockNoLock(session_t peer_id, MapBlock *block, u8 ver, - u16 net_proto_version) + u16 net_proto_version, SerializedBlockCache *cache) { - /* - Create a packet with the block in the right format - */ thread_local const int net_compression_level = rangelim(g_settings->getS16("map_compression_level_net"), -1, 9); - std::ostringstream os(std::ios_base::binary); - block->serialize(os, ver, false, net_compression_level); - block->serializeNetworkSpecific(os); - std::string s = os.str(); + std::string s, *sptr = nullptr; - NetworkPacket pkt(TOCLIENT_BLOCKDATA, 2 + 2 + 2 + s.size(), peer_id); + if (cache) { + auto it = cache->find({block->getPos(), ver}); + if (it != cache->end()) + sptr = &it->second; + } + // Serialize the block in the right format + if (!sptr) { + std::ostringstream os(std::ios_base::binary); + block->serialize(os, ver, false, net_compression_level); + block->serializeNetworkSpecific(os); + s = os.str(); + sptr = &s; + } + + NetworkPacket pkt(TOCLIENT_BLOCKDATA, 2 + 2 + 2 + sptr->size(), peer_id); pkt << block->getPos(); - pkt.putRawString(s.c_str(), s.size()); + pkt.putRawString(*sptr); Send(&pkt); + + // Store away in cache + if (cache && sptr == &s) + (*cache)[{block->getPos(), ver}] = std::move(s); } void Server::SendBlocks(float dtime) @@ -2351,7 +2363,7 @@ void Server::SendBlocks(float dtime) std::vector<PrioritySortedBlockTransfer> queue; - u32 total_sending = 0; + u32 total_sending = 0, unique_clients = 0; { ScopeProfiler sp2(g_profiler, "Server::SendBlocks(): Collect list"); @@ -2366,7 +2378,9 @@ void Server::SendBlocks(float dtime) continue; total_sending += client->getSendingCount(); + const auto old_count = queue.size(); client->GetNextBlocks(m_env,m_emerge, dtime, queue); + unique_clients += queue.size() > old_count ? 1 : 0; } } @@ -2385,6 +2399,12 @@ void Server::SendBlocks(float dtime) ScopeProfiler sp(g_profiler, "Server::SendBlocks(): Send to clients"); Map &map = m_env->getMap(); + SerializedBlockCache cache, *cache_ptr = nullptr; + if (unique_clients > 1) { + // caching is pointless with a single client + cache_ptr = &cache; + } + for (const PrioritySortedBlockTransfer &block_to_send : queue) { if (total_sending >= max_blocks_to_send) break; @@ -2399,7 +2419,7 @@ void Server::SendBlocks(float dtime) continue; SendBlockNoLock(block_to_send.peer_id, block, client->serialization_version, - client->net_proto_version); + client->net_proto_version, cache_ptr); client->SentBlock(block_to_send.pos); total_sending++; diff --git a/src/server.h b/src/server.h index 5090a3579..b1b9675d9 100644 --- a/src/server.h +++ b/src/server.h @@ -424,6 +424,16 @@ private: std::unordered_set<session_t> waiting_players; }; + // the standard library does not implement std::hash for pairs so we have this: + struct SBCHash { + size_t operator() (const std::pair<v3s16, u16> &p) const { + return (((size_t) p.first.X) << 48) | (((size_t) p.first.Y) << 32) | + (((size_t) p.first.Z) << 16) | ((size_t) p.second); + } + }; + + typedef std::unordered_map<std::pair<v3s16, u16>, std::string, SBCHash> SerializedBlockCache; + void init(); void SendMovement(session_t peer_id); @@ -484,7 +494,9 @@ private: float far_d_nodes = 100); // Environment and Connection must be locked when called - void SendBlockNoLock(session_t peer_id, MapBlock *block, u8 ver, u16 net_proto_version); + // `cache` may only be very short lived! (invalidation not handeled) + void SendBlockNoLock(session_t peer_id, MapBlock *block, u8 ver, + u16 net_proto_version, SerializedBlockCache *cache = nullptr); // Sends blocks to clients (locks env and con on its own) void SendBlocks(float dtime); |