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Fix RemoteStore::addToStore() latency

Browse source 
Since 6185d25e52, this was very
latency-bound since it required a round-trip for every 32 KiB. So for
example copying a 514 MiB closure over a virtual ethernet device with
a articial delay of just 1 ms took 343s. Now it takes 2.7s.

Fixes #3372.
This commit is contained in:
Eelco Dolstra 2020-07-29 00:48:39 +02:00
parent c159f48a39
commit 4c0077a07d
3 changed files with 154 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

81
src/libstore/remote-store.cc
View file

@ -503,9 +503,84 @@ void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
conn->to << info.registrationTime << info.narSize
<< info.ultimate << info.sigs << renderContentAddress(info.ca)
<< repair << !checkSigs;
bool tunnel = GET_PROTOCOL_MINOR(conn->daemonVersion) >= 21;
if (!tunnel) copyNAR(source, conn->to);
conn.processStderr(0, tunnel ? &source : nullptr);
if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 23) {
std::exception_ptr ex;
struct FramedSink : BufferedSink
{
ConnectionHandle & conn;
std::exception_ptr & ex;
FramedSink(ConnectionHandle & conn, std::exception_ptr & ex) : conn(conn), ex(ex)
{ }
~FramedSink()
{
try {
conn->to << 0;
conn->to.flush();
} catch (...) {
ignoreException();
}
}
void write(const unsigned char * data, size_t len) override
{
/* Don't send more data if the remote has
encountered an error. */
if (ex) {
auto ex2 = ex;
ex = nullptr;
std::rethrow_exception(ex2);
}
conn->to << len;
conn->to(data, len);
};
};
/* Handle log messages / exceptions from the remote on a
separate thread. */
std::thread stderrThread([&]()
{
try {
conn.processStderr(0, nullptr);
} catch (...) {
ex = std::current_exception();
}
});
Finally joinStderrThread([&]()
{
if (stderrThread.joinable()) {
stderrThread.join();
if (ex) {
try {
std::rethrow_exception(ex);
} catch (...) {
ignoreException();
}
}
}
});
{
FramedSink sink(conn, ex);
copyNAR(source, sink);
sink.flush();
}
stderrThread.join();
if (ex)
std::rethrow_exception(ex);
} else if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 21) {
conn.processStderr(0, &source);
} else {
copyNAR(source, conn->to);
conn.processStderr(0, nullptr);
}
}
}