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Diffstat (limited to '')
-rw-r--r-- | src/input/plugins/NfsInputPlugin.cxx | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/src/input/plugins/NfsInputPlugin.cxx b/src/input/plugins/NfsInputPlugin.cxx new file mode 100644 index 000000000..baa707738 --- /dev/null +++ b/src/input/plugins/NfsInputPlugin.cxx @@ -0,0 +1,221 @@ +/* + * Copyright (C) 2003-2014 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/Domain.hxx" +#include "lib/nfs/Glue.hxx" +#include "lib/nfs/FileReader.hxx" +#include "util/HugeAllocator.hxx" +#include "util/StringUtil.hxx" +#include "util/Error.hxx" + +extern "C" { +#include <nfsc/libnfs.h> +} + +#include <string.h> +#include <sys/stat.h> +#include <fcntl.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; + +public: + NfsInputStream(const char *_uri, + Mutex &_mutex, Cond &_cond, + void *_buffer) + :AsyncInputStream(_uri, _mutex, _cond, + _buffer, NFS_MAX_BUFFERED, + NFS_RESUME_AT) {} + + virtual ~NfsInputStream() { + DeferClose(); + } + + bool Open(Error &error) { + assert(!IsReady()); + + return NfsFileReader::Open(GetURI(), error); + } + +private: + bool 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(Error &&error) override; +}; + +bool +NfsInputStream::DoRead() +{ + assert(NfsFileReader::IsIdle()); + + int64_t remaining = size - next_offset; + if (remaining <= 0) + return true; + + const size_t buffer_space = GetBufferSpace(); + if (buffer_space == 0) { + Pause(); + return true; + } + + size_t nbytes = std::min<size_t>(std::min<uint64_t>(remaining, 32768), + buffer_space); + + mutex.unlock(); + Error error; + bool success = NfsFileReader::Read(next_offset, nbytes, error); + mutex.lock(); + + if (!success) { + PostponeError(std::move(error)); + return false; + } + + return true; +} + +void +NfsInputStream::DoResume() +{ + assert(NfsFileReader::IsIdle()); + + DoRead(); +} + +void +NfsInputStream::DoSeek(offset_type new_offset) +{ + mutex.unlock(); + NfsFileReader::CancelRead(); + mutex.lock(); + + next_offset = offset = new_offset; + SeekDone(); + DoRead(); +} + +void +NfsInputStream::OnNfsFileOpen(uint64_t _size) +{ + const ScopeLock protect(mutex); + + size = _size; + seekable = true; + next_offset = 0; + SetReady(); + DoRead(); +} + +void +NfsInputStream::OnNfsFileRead(const void *data, size_t data_size) +{ + const ScopeLock protect(mutex); + assert(!IsBufferFull()); + assert(IsBufferFull() == (GetBufferSpace() == 0)); + AppendToBuffer(data, data_size); + + next_offset += data_size; + + DoRead(); +} + +void +NfsInputStream::OnNfsFileError(Error &&error) +{ + const ScopeLock protect(mutex); + postponed_error = std::move(error); + + if (IsSeekPending()) + SeekDone(); + else if (!IsReady()) + SetReady(); +} + +/* + * InputPlugin methods + * + */ + +static InputPlugin::InitResult +input_nfs_init(const config_param &, Error &) +{ + nfs_init(); + return InputPlugin::InitResult::SUCCESS; +} + +static void +input_nfs_finish() +{ + nfs_finish(); +} + +static InputStream * +input_nfs_open(const char *uri, + Mutex &mutex, Cond &cond, + Error &error) +{ + if (!StringStartsWith(uri, "nfs://")) + return nullptr; + + void *buffer = HugeAllocate(NFS_MAX_BUFFERED); + if (buffer == nullptr) { + error.Set(nfs_domain, "Out of memory"); + return nullptr; + } + + NfsInputStream *is = new NfsInputStream(uri, mutex, cond, buffer); + if (!is->Open(error)) { + delete is; + return nullptr; + } + + return is; +} + +const InputPlugin input_plugin_nfs = { + "nfs", + input_nfs_init, + input_nfs_finish, + input_nfs_open, +}; |