remove file manager LRU cache from code.

This was a very clever attempt to fix a non-problem. If the platform doesn't have enough file descriptors available
then the platform is broken and we're not going to hack around trying to fix it.

8 files changed, 90 insertions, 133 deletions

diff --git a/libs/ardour/ardour/audiosource.h b/libs/ardour/ardour/audiosource.h
index 910e03170d..7d1878f286 100644
--- a/libs/ardour/ardour/audiosource.h
+++ b/libs/ardour/ardour/audiosource.h
@@ -32,7 +32,6 @@
 #include "ardour/source.h"
 #include "ardour/ardour.h"
 #include "ardour/readable.h"
-#include "pbd/file_manager.h"
 #include "pbd/stateful.h"
 #include "pbd/xml++.h"
 
@@ -160,7 +159,6 @@ class LIBARDOUR_API AudioSource : virtual public Source,
 	 */
         mutable Glib::Threads::Mutex _peaks_ready_lock;
 
-	PBD::FdFileDescriptor* _peakfile_descriptor;
 	int        _peakfile_fd;
 	framecnt_t peak_leftover_cnt;
 	framecnt_t peak_leftover_size;
diff --git a/libs/ardour/ardour/file_source.h b/libs/ardour/ardour/file_source.h
index 8cbbfed0d9..ac073d934c 100644
--- a/libs/ardour/ardour/file_source.h
+++ b/libs/ardour/ardour/file_source.h
@@ -110,8 +110,6 @@ protected:
 	uint16_t    _channel;
 	bool        _within_session;
 	std::string _origin;
-	bool        _open;
-
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/ardour/smf_source.h b/libs/ardour/ardour/smf_source.h
index 1c1f2bbcba..56b70b15bd 100644
--- a/libs/ardour/ardour/smf_source.h
+++ b/libs/ardour/ardour/smf_source.h
@@ -77,8 +77,16 @@ public:
 	void set_path (const std::string& newpath);
 
   private:
-	int open_for_write ();
+	bool _open;
+	Evoral::MusicalTime _last_ev_time_beats;
+	framepos_t          _last_ev_time_frames;
+	/** end time (start + duration) of last call to read_unlocked */
+	mutable framepos_t _smf_last_read_end;
+	/** time (in SMF ticks, 1 tick per _ppqn) of the last event read by read_unlocked */
+	mutable framepos_t _smf_last_read_time;
 
+	int open_for_write ();
+	
 	framecnt_t read_unlocked (Evoral::EventSink<framepos_t>& dst,
 	                          framepos_t                     position,
 	                          framepos_t                     start,
@@ -89,12 +97,6 @@ public:
 	                           framepos_t                  position,
 	                           framecnt_t                  cnt);
 
-	Evoral::MusicalTime _last_ev_time_beats;
-	framepos_t          _last_ev_time_frames;
-	/** end time (start + duration) of last call to read_unlocked */
-	mutable framepos_t _smf_last_read_end;
-	/** time (in SMF ticks, 1 tick per _ppqn) of the last event read by read_unlocked */
-	mutable framepos_t _smf_last_read_time;
 };
 
 }; /* namespace ARDOUR */
diff --git a/libs/ardour/ardour/sndfilesource.h b/libs/ardour/ardour/sndfilesource.h
index 7f5e538f4a..11ec6fe33c 100644
--- a/libs/ardour/ardour/sndfilesource.h
+++ b/libs/ardour/ardour/sndfilesource.h
@@ -24,7 +24,6 @@
 
 #include "ardour/audiofilesource.h"
 #include "ardour/broadcast_info.h"
-#include "pbd/sndfile_manager.h"
 
 namespace ARDOUR {
 
@@ -75,8 +74,6 @@ class LIBARDOUR_API SndFileSource : public AudioFileSource {
 
 	static int get_soundfile_info (const std::string& path, SoundFileInfo& _info, std::string& error_msg);
 
-	void release_descriptor ();
-
   protected:
 	void set_path (const std::string& p);
 	void set_header_timeline_position ();
@@ -86,7 +83,7 @@ class LIBARDOUR_API SndFileSource : public AudioFileSource {
 	framecnt_t write_float (Sample* data, framepos_t pos, framecnt_t cnt);
 
   private:
-	PBD::SndFileDescriptor* _descriptor;
+	SNDFILE* _sndfile;
 	SF_INFO _info;
 	BroadcastInfo *_broadcast_info;
 
@@ -113,7 +110,6 @@ class LIBARDOUR_API SndFileSource : public AudioFileSource {
 	framecnt_t nondestructive_write_unlocked (Sample *dst, framecnt_t cnt);
 	void handle_header_position_change ();
 	PBD::ScopedConnection header_position_connection;
-	PBD::ScopedConnection file_manager_connection;
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/audiosource.cc b/libs/ardour/audiosource.cc
index fd20c3afdb..a032aa1f63 100644
--- a/libs/ardour/audiosource.cc
+++ b/libs/ardour/audiosource.cc
@@ -71,27 +71,25 @@ bool AudioSource::_build_peakfiles = false;
 AudioSource::AudioSource (Session& s, string name)
 	: Source (s, DataType::AUDIO, name)
 	, _length (0)
+	, _peak_byte_max (0)
+	, _peaks_built (false)
+	, _peakfile_fd (-1)
+	, peak_leftover_cnt (0)
+	, peak_leftover_size (0)
+	, peak_leftovers (0)
 {
-	_peaks_built = false;
-	_peak_byte_max = 0;
-	_peakfile_descriptor = 0;
-	peak_leftover_cnt = 0;
-	peak_leftover_size = 0;
-	peak_leftovers = 0;
 }
 
 AudioSource::AudioSource (Session& s, const XMLNode& node)
 	: Source (s, node)
 	, _length (0)
+	, _peak_byte_max (0)
+	, _peaks_built (false)
+	, _peakfile_fd (-1)
+	, peak_leftover_cnt (0)
+	, peak_leftover_size (0)
+	, peak_leftovers (0)
 {
-
-	_peaks_built = false;
-	_peak_byte_max = 0;
-	_peakfile_descriptor = 0;
-	peak_leftover_cnt = 0;
-	peak_leftover_size = 0;
-	peak_leftovers = 0;
-
 	if (set_state (node, Stateful::loading_state_version)) {
 		throw failed_constructor();
 	}
@@ -105,7 +103,9 @@ AudioSource::~AudioSource ()
 		cerr << "AudioSource destroyed with leftover peak data pending" << endl;
 	}
 
-	delete _peakfile_descriptor;
+	close (_peakfile_fd);
+	_peakfile_fd = -1;
+
 	delete [] peak_leftovers;
 }
 
@@ -318,6 +318,13 @@ AudioSource::read_peaks (PeakData *peaks, framecnt_t npeaks, framepos_t start, f
  *  @param npeaks Number of peaks to write.
  */
 
+struct ScopedFileDescriptor {
+	ScopedFileDescriptor (int fd) : _fd (fd) {}
+	~ScopedFileDescriptor() { close (_fd); }
+	operator int() { return _fd; }
+	int _fd;
+};
+
 int
 AudioSource::read_peaks_with_fpp (PeakData *peaks, framecnt_t npeaks, framepos_t start, framecnt_t cnt,
 				  double samples_per_visual_peak, framecnt_t samples_per_file_peak) const
@@ -331,9 +338,13 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, framecnt_t npeaks, framepos_t
 	ssize_t nread;
 	framecnt_t zero_fill = 0;
 
-	boost::scoped_ptr<FdFileDescriptor> peakfile_descriptor(new FdFileDescriptor (peakpath, false, 0664));
-	int peakfile_fd = -1;
+	ScopedFileDescriptor sfd (::open (peakpath.c_str(), O_RDONLY));
 
+	if (sfd < 0) {
+		error << string_compose (_("Cannot open peakfile @ %1 for reading (%2)"), peakpath, strerror (errno)) << endmsg;
+		return -1;
+	}
+				  
 	expected_peaks = (cnt / (double) samples_per_file_peak);
 	scale = npeaks/expected_peaks;
 
@@ -382,21 +393,16 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, framecnt_t npeaks, framepos_t
 		ssize_t bytes_to_read = sizeof (PeakData)* npeaks;
 		/* open, read, close */
 
-		if ((peakfile_fd = peakfile_descriptor->allocate ()) < 0) {
-			error << string_compose(_("AudioSource: cannot open peakpath (a) \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
-			return -1;
-		}
-
 		DEBUG_TRACE (DEBUG::Peaks, "DIRECT PEAKS\n");
 
-		offset = lseek (peakfile_fd, first_peak_byte, SEEK_SET);
+		offset = lseek (sfd, first_peak_byte, SEEK_SET);
 
 		if (offset != first_peak_byte) {
 			error << string_compose(_("AudioSource: could not seek to correct location in peak file \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
 			return -1;
 		}
 
-		nread = ::read (peakfile_fd, peaks, bytes_to_read);
+		nread = ::read (sfd, peaks, bytes_to_read);
 
 		if (nread != bytes_to_read) {
 			DEBUG_TRACE (DEBUG::Peaks,  string_compose ("[%1]: Cannot read peaks from peakfile! (read only %2 not %3 at sample %4 = byte %5 )\n"
@@ -449,11 +455,6 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, framecnt_t npeaks, framepos_t
 
 		/* open ... close during out: handling */
 
-		if ((peakfile_fd = peakfile_descriptor->allocate ()) < 0) {
-			error << string_compose(_("AudioSource: cannot open peakpath (b) \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
-			return 0;
-		}
-
 		while (nvisual_peaks < npeaks) {
 
 			if (i == stored_peaks_read) {
@@ -467,16 +468,16 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, framecnt_t npeaks, framepos_t
 						, bytes_to_read, start_byte));
 
 
-				off_t offset = lseek (peakfile_fd, start_byte, SEEK_SET);
+				off_t offset = lseek (sfd, start_byte, SEEK_SET);
 
 				if (offset != start_byte) {
 					error << string_compose(_("AudioSource: could not seek to correct location in peak file \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
 					return -1;
 				}
 
-				if ((nread = ::read (peakfile_fd, staging.get(), bytes_to_read)) != bytes_to_read) {
+				if ((nread = ::read (sfd, staging.get(), bytes_to_read)) != bytes_to_read) {
 
-					off_t fend = lseek (peakfile_fd, 0, SEEK_END);
+					off_t fend = lseek (sfd, 0, SEEK_END);
 
 					DEBUG_TRACE (DEBUG::Peaks, string_compose ("[%1]: cannot read peak data from peakfile (%2 peaks instead of %3) (%4) at start_byte = %5 _length = %6 versus len = %7 expected maxpeaks = %8 npeaks was %9"
 					     , _name, (nread / sizeof(PeakData)), to_read, g_strerror (errno), start_byte, _length, fend, ((_length - current_frame)/samples_per_file_peak), npeaks));
@@ -667,8 +668,7 @@ AudioSource::build_peaks_from_scratch ()
 int
 AudioSource::prepare_for_peakfile_writes ()
 {
-	_peakfile_descriptor = new FdFileDescriptor (peakpath, true, 0664);
-	if ((_peakfile_fd = _peakfile_descriptor->allocate()) < 0) {
+	if ((_peakfile_fd = open (peakpath.c_str(), O_CREAT|O_RDWR, 0664)) < 0) {
 		error << string_compose(_("AudioSource: cannot open peakpath (c) \"%1\" (%2)"), peakpath, strerror (errno)) << endmsg;
 		return -1;
 	}
@@ -688,8 +688,8 @@ AudioSource::done_with_peakfile_writes (bool done)
 		PeaksReady (); /* EMIT SIGNAL */
 	}
 
-	delete _peakfile_descriptor;
-	_peakfile_descriptor = 0;
+	close (_peakfile_fd);
+	_peakfile_fd = -1;
 }
 
 /** @param first_frame Offset from the source start of the first frame to process */
@@ -712,8 +712,10 @@ AudioSource::compute_and_write_peaks (Sample* buf, framecnt_t first_frame, frame
 	off_t first_peak_byte;
 	boost::scoped_array<Sample> buf2;
 
-	if (_peakfile_descriptor == 0) {
-		prepare_for_peakfile_writes ();
+	if (_peakfile_fd < 0) {
+		if (prepare_for_peakfile_writes ()) {
+			return -1;
+		}
 	}
 
   restart:
@@ -887,7 +889,7 @@ AudioSource::compute_and_write_peaks (Sample* buf, framecnt_t first_frame, frame
 void
 AudioSource::truncate_peakfile ()
 {
-	if (_peakfile_descriptor == 0) {
+	if (_peakfile_fd < 0) {
 		error << string_compose (_("programming error: %1"), "AudioSource::truncate_peakfile() called without open peakfile descriptor")
 		      << endmsg;
 		return;
diff --git a/libs/ardour/file_source.cc b/libs/ardour/file_source.cc
index 06867e688e..0aec49e6bd 100644
--- a/libs/ardour/file_source.cc
+++ b/libs/ardour/file_source.cc
@@ -59,7 +59,6 @@ FileSource::FileSource (Session& session, DataType type, const string& path, con
 	, _file_is_new (!origin.empty()) // if origin is left unspecified (empty string) then file must exist
 	, _channel (0)
         , _origin (origin)
-        , _open (false)
 {
 	set_within_session_from_path (path);
 }
@@ -68,7 +67,6 @@ FileSource::FileSource (Session& session, const XMLNode& node, bool /*must_exist
 	: Source (session, node)
 	, _file_is_new (false)
 	, _channel (0)
-	, _open (false)
 {
 	/* this setting of _path is temporary - we expect derived classes
 	   to call ::init() which will actually locate the file
diff --git a/libs/ardour/smf_source.cc b/libs/ardour/smf_source.cc
index e4cfede179..b25977fe8d 100644
--- a/libs/ardour/smf_source.cc
+++ b/libs/ardour/smf_source.cc
@@ -59,6 +59,7 @@ SMFSource::SMFSource (Session& s, const string& path, Source::Flag flags)
 	, MidiSource(s, path, flags)
 	, FileSource(s, DataType::MIDI, path, string(), flags)
 	, Evoral::SMF()
+	, _open (false)
 	, _last_ev_time_beats(0.0)
 	, _last_ev_time_frames(0)
 	, _smf_last_read_end (0)
@@ -94,6 +95,7 @@ SMFSource::SMFSource (Session& s, const string& path)
 	, MidiSource(s, path, Source::Flag (0))
 	, FileSource(s, DataType::MIDI, path, string(), Source::Flag (0))
 	, Evoral::SMF()
+	, _open (false)
 	, _last_ev_time_beats(0.0)
 	, _last_ev_time_frames(0)
 	, _smf_last_read_end (0)
@@ -125,6 +127,7 @@ SMFSource::SMFSource (Session& s, const XMLNode& node, bool must_exist)
 	: Source(s, node)
 	, MidiSource(s, node)
 	, FileSource(s, node, must_exist)
+	, _open (false)
 	, _last_ev_time_beats(0.0)
 	, _last_ev_time_frames(0)
 	, _smf_last_read_end (0)
@@ -174,7 +177,7 @@ SMFSource::SMFSource (Session& s, const XMLNode& node, bool must_exist)
 		return;
 	}
 
-	if (open(_path)) {
+	if (open (_path)) {
 		throw failed_constructor ();
 	}
 
diff --git a/libs/ardour/sndfilesource.cc b/libs/ardour/sndfilesource.cc
index 9af2b56056..27c91c8c27 100644
--- a/libs/ardour/sndfilesource.cc
+++ b/libs/ardour/sndfilesource.cc
@@ -58,7 +58,7 @@ const Source::Flag SndFileSource::default_writable_flags = Source::Flag (
 SndFileSource::SndFileSource (Session& s, const XMLNode& node)
 	: Source(s, node)
 	, AudioFileSource (s, node)
-	, _descriptor (0)
+	, _sndfile (0)
 	, _broadcast_info (0)
 	, _capture_start (false)
 	, _capture_end (false)
@@ -82,7 +82,7 @@ SndFileSource::SndFileSource (Session& s, const string& path, int chn, Flag flag
 	: Source(s, DataType::AUDIO, path, flags)
           /* note that the origin of an external file is itself */
 	, AudioFileSource (s, path, Flag (flags & ~(Writable|Removable|RemovableIfEmpty|RemoveAtDestroy)))
-	, _descriptor (0)
+	, _sndfile (0)
 	, _broadcast_info (0)
 	, _capture_start (false)
 	, _capture_end (false)
@@ -108,7 +108,7 @@ SndFileSource::SndFileSource (Session& s, const string& path, const string& orig
                               SampleFormat sfmt, HeaderFormat hf, framecnt_t rate, Flag flags)
 	: Source(s, DataType::AUDIO, path, flags)
 	, AudioFileSource (s, path, origin, flags, sfmt, hf)
-	, _descriptor (0)
+	, _sndfile (0)
 	, _broadcast_info (0)
 	, _capture_start (false)
 	, _capture_end (false)
@@ -194,7 +194,7 @@ SndFileSource::SndFileSource (Session& s, const string& path, int chn)
 	: Source (s, DataType::AUDIO, path, Flag (0))
 	  /* the final boolean argument is not used, its value is irrelevant. see audiofilesource.h for explanation */
 	, AudioFileSource (s, path, Flag (0))
-	, _descriptor (0)
+	, _sndfile (0)
 	, _broadcast_info (0)
 	, _capture_start (false)
 	, _capture_end (false)
@@ -235,17 +235,19 @@ SndFileSource::open ()
 {
 	string path_to_open;
 
+	if (_sndfile) {
+		return 0;
+	}
+	
 #ifdef PLATFORM_WINDOWS
 	path_to_open = Glib::locale_from_utf8(_path);
 #else
 	path_to_open = _path;
 #endif
 
-	_descriptor = new SndFileDescriptor (path_to_open.c_str(), writable(), &_info);
-	_descriptor->Closed.connect_same_thread (file_manager_connection, boost::bind (&SndFileSource::file_closed, this));
-	SNDFILE* sf = _descriptor->allocate ();
+	_sndfile = sf_open (path_to_open.c_str(), writable() ? SFM_RDWR : SFM_READ, &_info);
 
-	if (sf == 0) {
+	if (_sndfile == 0) {
 		char errbuf[1024];
 		sf_error_str (0, errbuf, sizeof (errbuf) - 1);
 #ifndef HAVE_COREAUDIO
@@ -265,8 +267,8 @@ SndFileSource::open ()
 #ifndef HAVE_COREAUDIO
 		error << string_compose(_("SndFileSource: file only contains %1 channels; %2 is invalid as a channel number"), _info.channels, _channel) << endmsg;
 #endif
-		delete _descriptor;
-		_descriptor = 0;
+		sf_close (_sndfile);
+		_sndfile = 0;
 		return -1;
 	}
 
@@ -276,7 +278,7 @@ SndFileSource::open ()
 		_broadcast_info = new BroadcastInfo;
 	}
 
-	bool bwf_info_exists = _broadcast_info->load_from_file (sf);
+	bool bwf_info_exists = _broadcast_info->load_from_file (_sndfile);
 
 	if (_file_is_new && _length == 0 && writable() && !bwf_info_exists) {
 		/* newly created files will not have a BWF header at this point in time.
@@ -305,7 +307,7 @@ SndFileSource::open ()
 	}
 
 	if (writable()) {
-		sf_command (sf, SFC_SET_UPDATE_HEADER_AUTO, 0, SF_FALSE);
+		sf_command (_sndfile, SFC_SET_UPDATE_HEADER_AUTO, 0, SF_FALSE);
 
                 if (_flags & Broadcast) {
 
@@ -316,7 +318,7 @@ SndFileSource::open ()
                         _broadcast_info->set_from_session (_session, header_position_offset);
                         _broadcast_info->set_description (string_compose ("BWF %1", _name));
 
-                        if (!_broadcast_info->write_to_file (sf)) {
+                        if (!_broadcast_info->write_to_file (_sndfile)) {
                                 error << string_compose (_("cannot set broadcast info for audio file %1 (%2); dropping broadcast info for this file"),
                                                          path_to_open, _broadcast_info->get_error())
                                       << endmsg;
@@ -326,15 +328,16 @@ SndFileSource::open ()
                         }
                 }
         }
-
-        _descriptor->release ();
-        _open = true;
+	
 	return 0;
 }
 
 SndFileSource::~SndFileSource ()
 {
-	delete _descriptor;
+	if (_sndfile) {
+		sf_close (_sndfile);
+		_sndfile = 0;
+	}
 	delete _broadcast_info;
 	delete [] xfade_buf;
 }
@@ -355,15 +358,13 @@ SndFileSource::read_unlocked (Sample *dst, framepos_t start, framecnt_t cnt) con
 	uint32_t real_cnt;
 	framepos_t file_cnt;
 
-        if (writable() && !_open) {
+        if (writable() && !_sndfile) {
                 /* file has not been opened yet - nothing written to it */
                 memset (dst, 0, sizeof (Sample) * cnt);
                 return cnt;
         }
 
-	SNDFILE* sf = _descriptor->allocate ();
-
-	if (sf == 0) {
+	if (_sndfile == 0) {
 		error << string_compose (_("could not allocate file %1 for reading."), _path) << endmsg;
 		return 0;
 	}
@@ -396,22 +397,20 @@ SndFileSource::read_unlocked (Sample *dst, framepos_t start, framecnt_t cnt) con
 
 	if (file_cnt) {
 
-		if (sf_seek (sf, (sf_count_t) start, SEEK_SET|SFM_READ) != (sf_count_t) start) {
+		if (sf_seek (_sndfile, (sf_count_t) start, SEEK_SET|SFM_READ) != (sf_count_t) start) {
 			char errbuf[256];
 			sf_error_str (0, errbuf, sizeof (errbuf) - 1);
 			error << string_compose(_("SndFileSource: could not seek to frame %1 within %2 (%3)"), start, _name.val().substr (1), errbuf) << endmsg;
-			_descriptor->release ();
 			return 0;
 		}
 
 		if (_info.channels == 1) {
-			framecnt_t ret = sf_read_float (sf, dst, file_cnt);
+			framecnt_t ret = sf_read_float (_sndfile, dst, file_cnt);
 			if (ret != file_cnt) {
 				char errbuf[256];
 				sf_error_str (0, errbuf, sizeof (errbuf) - 1);
 				error << string_compose(_("SndFileSource: @ %1 could not read %2 within %3 (%4) (len = %5, ret was %6)"), start, file_cnt, _name.val().substr (1), errbuf, _length, ret) << endl;
 			}
-			_descriptor->release ();
 			return ret;
 		}
 	}
@@ -420,7 +419,7 @@ SndFileSource::read_unlocked (Sample *dst, framepos_t start, framecnt_t cnt) con
 
 	Sample* interleave_buf = get_interleave_buffer (real_cnt);
 
-	nread = sf_read_float (sf, interleave_buf, real_cnt);
+	nread = sf_read_float (_sndfile, interleave_buf, real_cnt);
 	ptr = interleave_buf + _channel;
 	nread /= _info.channels;
 
@@ -431,14 +430,13 @@ SndFileSource::read_unlocked (Sample *dst, framepos_t start, framecnt_t cnt) con
 		ptr += _info.channels;
 	}
 
-	_descriptor->release ();
 	return nread;
 }
 
 framecnt_t
 SndFileSource::write_unlocked (Sample *data, framecnt_t cnt)
 {
-        if (!_open && open()) {
+        if (open()) {
                 return 0; // failure
         }
 
@@ -589,19 +587,12 @@ SndFileSource::flush_header ()
 		return -1;
 	}
 
-        if (!_open) {
-		warning << string_compose (_("attempt to flush an un-opened audio file source (%1)"), _path) << endmsg;
-		return -1;
-        }
-
-	SNDFILE* sf = _descriptor->allocate ();
-	if (sf == 0) {
+	if (_sndfile == 0) {
 		error << string_compose (_("could not allocate file %1 to write header"), _path) << endmsg;
 		return -1;
 	}
 
-	int const r = sf_command (sf, SFC_UPDATE_HEADER_NOW, 0, 0) != SF_TRUE;
-	_descriptor->release ();
+	int const r = sf_command (_sndfile, SFC_UPDATE_HEADER_NOW, 0, 0) != SF_TRUE;
 
 	return r;
 }
@@ -609,25 +600,18 @@ SndFileSource::flush_header ()
 void
 SndFileSource::flush ()
 {
-	if (!_open) {
-		warning << string_compose (_("attempt to flush an un-opened audio file source (%1)"), _path) << endmsg;
-		return;
-	}
-
 	if (!writable()) {
 		warning << string_compose (_("attempt to flush a non-writable audio file source (%1)"), _path) << endmsg;
 		return;
 	}
 
-	SNDFILE* sf = _descriptor->allocate ();
-	if (sf == 0) {
+	if (_sndfile == 0) {
 		error << string_compose (_("could not allocate file %1 to flush contents"), _path) << endmsg;
 		return;
 	}
 
 	// Hopefully everything OK
-	sf_write_sync (sf);
-	_descriptor->release ();
+	sf_write_sync (_sndfile);
 }
 
 int
@@ -638,7 +622,7 @@ SndFileSource::setup_broadcast_info (framepos_t /*when*/, struct tm& now, time_t
 		return -1;
 	}
 
-        if (!_open) {
+        if (!_sndfile) {
 		warning << string_compose (_("attempt to set BWF info for an un-opened audio file source (%1)"), _path) << endmsg;
 		return -1;
         }
@@ -654,9 +638,7 @@ SndFileSource::setup_broadcast_info (framepos_t /*when*/, struct tm& now, time_t
 
 	set_header_timeline_position ();
 
-	SNDFILE* sf = _descriptor->allocate ();
-
-	if (sf == 0 || !_broadcast_info->write_to_file (sf)) {
+	if (!_broadcast_info->write_to_file (_sndfile)) {
 		error << string_compose (_("cannot set broadcast info for audio file %1 (%2); dropping broadcast info for this file"),
 		                           _path, _broadcast_info->get_error())
 		      << endmsg;
@@ -665,7 +647,6 @@ SndFileSource::setup_broadcast_info (framepos_t /*when*/, struct tm& now, time_t
 		_broadcast_info = 0;
 	}
 
-	_descriptor->release ();
 	return 0;
 }
 
@@ -678,9 +659,7 @@ SndFileSource::set_header_timeline_position ()
 
 	_broadcast_info->set_time_reference (_timeline_position);
 
-	SNDFILE* sf = _descriptor->allocate ();
-	
-	if (sf == 0 || !_broadcast_info->write_to_file (sf)) {
+	if (_sndfile == 0 || !_broadcast_info->write_to_file (_sndfile)) {
 		error << string_compose (_("cannot set broadcast info for audio file %1 (%2); dropping broadcast info for this file"),
 		                           _path, _broadcast_info->get_error())
 		      << endmsg;
@@ -688,29 +667,22 @@ SndFileSource::set_header_timeline_position ()
 		delete _broadcast_info;
 		_broadcast_info = 0;
 	}
-
-	_descriptor->release ();
 }
 
 framecnt_t
 SndFileSource::write_float (Sample* data, framepos_t frame_pos, framecnt_t cnt)
 {
-	SNDFILE* sf = _descriptor->allocate ();
-
-	if (sf == 0 || sf_seek (sf, frame_pos, SEEK_SET|SFM_WRITE) < 0) {
+	if (_sndfile == 0 || sf_seek (_sndfile, frame_pos, SEEK_SET|SFM_WRITE) < 0) {
 		char errbuf[256];
 		sf_error_str (0, errbuf, sizeof (errbuf) - 1);
 		error << string_compose (_("%1: cannot seek to %2 (libsndfile error: %3)"), _path, frame_pos, errbuf) << endmsg;
-		_descriptor->release ();
 		return 0;
 	}
 
-	if (sf_writef_float (sf, data, cnt) != (ssize_t) cnt) {
-		_descriptor->release ();
+	if (sf_writef_float (_sndfile, data, cnt) != (ssize_t) cnt) {
 		return 0;
 	}
 
-	_descriptor->release ();
 	return cnt;
 }
 
@@ -1011,17 +983,5 @@ void
 SndFileSource::set_path (const string& p)
 {
         FileSource::set_path (p);
-
-        if (_descriptor) {
-                _descriptor->set_path (_path);
-        }
 }
 
-void
-SndFileSource::release_descriptor ()
-{
-	if (_descriptor) {
-		_descriptor->release ();
-		_descriptor = 0;
-	}
-}