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Fix RemoteStore::addToStore() latency

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

View file

@ -86,7 +86,7 @@ struct TunnelLogger : public Logger
}
/* startWork() means that we're starting an operation for which we
want to send out stderr to the client. */
want to send out stderr to the client. */
void startWork()
{
auto state(state_.lock());
@ -703,24 +703,84 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
if (!trusted)
info.ultimate = false;
std::unique_ptr<Source> source;
if (GET_PROTOCOL_MINOR(clientVersion) >= 21)
source = std::make_unique<TunnelSource>(from, to);
else {
StringSink saved;
TeeSource tee { from, saved };
ParseSink ether;
parseDump(ether, tee);
source = std::make_unique<StringSource>(std::move(*saved.s));
if (GET_PROTOCOL_MINOR(clientVersion) >= 23) {
struct FramedSource : Source
{
Source & from;
bool eof = false;
std::vector<unsigned char> pending;
size_t pos = 0;
FramedSource(Source & from) : from(from)
{ }
~FramedSource()
{
if (!eof) {
while (true) {
auto n = readInt(from);
if (!n) break;
std::vector<unsigned char> data(n);
from(data.data(), n);
}
}
}
size_t read(unsigned char * data, size_t len) override
{
if (eof) throw EndOfFile("reached end of FramedSource");
if (pos >= pending.size()) {
size_t len = readInt(from);
if (!len) {
eof = true;
return 0;
}
pending = std::vector<unsigned char>(len);
pos = 0;
from(pending.data(), len);
}
auto n = std::min(len, pending.size() - pos);
memcpy(data, pending.data() + pos, n);
pos += n;
return n;
}
};
logger->startWork();
{
FramedSource source(from);
store->addToStore(info, source, (RepairFlag) repair,
dontCheckSigs ? NoCheckSigs : CheckSigs);
}
logger->stopWork();
}
logger->startWork();
else {
std::unique_ptr<Source> source;
if (GET_PROTOCOL_MINOR(clientVersion) >= 21)
source = std::make_unique<TunnelSource>(from, to);
else {
StringSink saved;
TeeSource tee { from, saved };
ParseSink ether;
parseDump(ether, tee);
source = std::make_unique<StringSource>(std::move(*saved.s));
}
// FIXME: race if addToStore doesn't read source?
store->addToStore(info, *source, (RepairFlag) repair,
dontCheckSigs ? NoCheckSigs : CheckSigs);
logger->startWork();
// FIXME: race if addToStore doesn't read source?
store->addToStore(info, *source, (RepairFlag) repair,
dontCheckSigs ? NoCheckSigs : CheckSigs);
logger->stopWork();
}
logger->stopWork();
break;
}