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/*
* Copyright 2003-2021 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "ThreadInputStream.hxx"
#include "CondHandler.hxx"
#include "thread/Name.hxx"
#include <cassert>
#include <string.h>
ThreadInputStream::ThreadInputStream(const char *_plugin,
const char *_uri,
Mutex &_mutex,
size_t _buffer_size) noexcept
:InputStream(_uri, _mutex),
plugin(_plugin),
thread(BIND_THIS_METHOD(ThreadFunc)),
allocation(_buffer_size),
buffer(&allocation.front(), allocation.size())
{
allocation.ForkCow(false);
}
void
ThreadInputStream::Stop() noexcept
{
if (!thread.IsDefined())
return;
{
const std::scoped_lock<Mutex> lock(mutex);
close = true;
wake_cond.notify_one();
}
Cancel();
thread.Join();
buffer.Clear();
}
void
ThreadInputStream::Start()
{
thread.Start();
}
inline void
ThreadInputStream::ThreadFunc() noexcept
{
FormatThreadName("input:%s", plugin);
std::unique_lock<Mutex> lock(mutex);
try {
Open();
} catch (...) {
postponed_exception = std::current_exception();
SetReady();
return;
}
/* we're ready, tell it to our client */
SetReady();
while (!close) {
assert(!postponed_exception);
auto w = buffer.Write();
if (w.empty()) {
wake_cond.wait(lock);
} else {
size_t nbytes;
try {
const ScopeUnlock unlock(mutex);
nbytes = ThreadRead(w.data, w.size);
} catch (...) {
postponed_exception = std::current_exception();
InvokeOnAvailable();
break;
}
InvokeOnAvailable();
if (nbytes == 0) {
eof = true;
break;
}
buffer.Append(nbytes);
}
}
Close();
}
void
ThreadInputStream::Check()
{
assert(!thread.IsInside());
if (postponed_exception)
std::rethrow_exception(postponed_exception);
}
bool
ThreadInputStream::IsAvailable() const noexcept
{
assert(!thread.IsInside());
return !buffer.empty() || eof || postponed_exception;
}
inline size_t
ThreadInputStream::Read(std::unique_lock<Mutex> &lock,
void *ptr, size_t read_size)
{
assert(!thread.IsInside());
CondInputStreamHandler cond_handler;
while (true) {
if (postponed_exception)
std::rethrow_exception(postponed_exception);
auto r = buffer.Read();
if (!r.empty()) {
size_t nbytes = std::min(read_size, r.size);
memcpy(ptr, r.data, nbytes);
buffer.Consume(nbytes);
wake_cond.notify_all();
offset += nbytes;
return nbytes;
}
if (eof)
return 0;
const ScopeExchangeInputStreamHandler h(*this, &cond_handler);
cond_handler.cond.wait(lock);
}
}
bool
ThreadInputStream::IsEOF() const noexcept
{
assert(!thread.IsInside());
return eof;
}