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/*
* Copyright 2003-2016 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 "config.h"
#include "NfsInputPlugin.hxx"
#include "../AsyncInputStream.hxx"
#include "../InputPlugin.hxx"
#include "lib/nfs/Glue.hxx"
#include "lib/nfs/FileReader.hxx"
#include "util/StringCompare.hxx"
#include <string.h>
/**
* Do not buffer more than this number of bytes. It should be a
* reasonable limit that doesn't make low-end machines suffer too
* much, but doesn't cause stuttering on high-latency lines.
*/
static const size_t NFS_MAX_BUFFERED = 512 * 1024;
/**
* Resume the stream at this number of bytes after it has been paused.
*/
static const size_t NFS_RESUME_AT = 384 * 1024;
class NfsInputStream final : public AsyncInputStream, NfsFileReader {
uint64_t next_offset;
bool reconnect_on_resume, reconnecting;
public:
NfsInputStream(const char *_uri, Mutex &_mutex, Cond &_cond)
:AsyncInputStream(_uri, _mutex, _cond,
NFS_MAX_BUFFERED,
NFS_RESUME_AT),
reconnect_on_resume(false), reconnecting(false) {}
virtual ~NfsInputStream() {
DeferClose();
}
void Open() {
assert(!IsReady());
NfsFileReader::Open(GetURI());
}
private:
void DoRead();
protected:
/* virtual methods from AsyncInputStream */
virtual void DoResume() override;
virtual void DoSeek(offset_type new_offset) override;
private:
/* virtual methods from NfsFileReader */
void OnNfsFileOpen(uint64_t size) override;
void OnNfsFileRead(const void *data, size_t size) override;
void OnNfsFileError(std::exception_ptr &&e) override;
};
void
NfsInputStream::DoRead()
{
assert(NfsFileReader::IsIdle());
int64_t remaining = size - next_offset;
if (remaining <= 0)
return;
const size_t buffer_space = GetBufferSpace();
if (buffer_space == 0) {
Pause();
return;
}
size_t nbytes = std::min<size_t>(std::min<uint64_t>(remaining, 32768),
buffer_space);
try {
const ScopeUnlock unlock(mutex);
NfsFileReader::Read(next_offset, nbytes);
} catch (...) {
postponed_exception = std::current_exception();
cond.broadcast();
}
}
void
NfsInputStream::DoResume()
{
if (reconnect_on_resume) {
/* the NFS connection has died while this stream was
"paused" - attempt to reconnect */
reconnect_on_resume = false;
reconnecting = true;
ScopeUnlock unlock(mutex);
NfsFileReader::Close();
NfsFileReader::Open(GetURI());
return;
}
assert(NfsFileReader::IsIdle());
DoRead();
}
void
NfsInputStream::DoSeek(offset_type new_offset)
{
{
const ScopeUnlock unlock(mutex);
NfsFileReader::CancelRead();
}
next_offset = offset = new_offset;
SeekDone();
DoRead();
}
void
NfsInputStream::OnNfsFileOpen(uint64_t _size)
{
const std::lock_guard<Mutex> protect(mutex);
if (reconnecting) {
/* reconnect has succeeded */
reconnecting = false;
DoRead();
return;
}
size = _size;
seekable = true;
next_offset = 0;
SetReady();
DoRead();
}
void
NfsInputStream::OnNfsFileRead(const void *data, size_t data_size)
{
const std::lock_guard<Mutex> protect(mutex);
assert(!IsBufferFull());
assert(IsBufferFull() == (GetBufferSpace() == 0));
AppendToBuffer(data, data_size);
next_offset += data_size;
DoRead();
}
void
NfsInputStream::OnNfsFileError(std::exception_ptr &&e)
{
const std::lock_guard<Mutex> protect(mutex);
if (IsPaused()) {
/* while we're paused, don't report this error to the
client just yet (it might just be timeout, maybe
playback has been paused for quite some time) -
wait until the stream gets resumed and try to
reconnect, to give it another chance */
reconnect_on_resume = true;
return;
}
postponed_exception = std::move(e);
if (IsSeekPending())
SeekDone();
else if (!IsReady())
SetReady();
else
cond.broadcast();
}
/*
* InputPlugin methods
*
*/
static void
input_nfs_init(const ConfigBlock &)
{
nfs_init();
}
static void
input_nfs_finish()
{
nfs_finish();
}
static InputStream *
input_nfs_open(const char *uri,
Mutex &mutex, Cond &cond)
{
if (!StringStartsWith(uri, "nfs://"))
return nullptr;
NfsInputStream *is = new NfsInputStream(uri, mutex, cond);
try {
is->Open();
} catch (...) {
delete is;
throw;
}
return is;
}
const InputPlugin input_plugin_nfs = {
"nfs",
input_nfs_init,
input_nfs_finish,
input_nfs_open,
};
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