#include <LocalCacheFile.h>

Inheritance diagram for LocalCacheFile:

Public Member Functions
virtual void	close (void)

virtual void	flush (void)

	LocalCacheFile (Storage *base, const std::string &tmpdir="")

virtual IOOffset	position (IOOffset offset, Relative whence=SET)

virtual bool	prefetch (const IOPosBuffer *what, IOSize n)

virtual IOSize	read (void *into, IOSize n)

virtual IOSize	read (void *into, IOSize n, IOOffset pos)

virtual IOSize	readv (IOBuffer *into, IOSize n)

virtual IOSize	readv (IOPosBuffer *into, IOSize n)

virtual void	resize (IOOffset size)

virtual IOSize	write (const void *from, IOSize n)

virtual IOSize	write (const void *from, IOSize n, IOOffset pos)

virtual IOSize	writev (const IOBuffer *from, IOSize n)

virtual IOSize	writev (const IOPosBuffer *from, IOSize n)

	~LocalCacheFile (void)

Public Member Functions inherited from Storage
virtual bool	eof (void) const

virtual IOOffset	position (void) const

IOSize	read (IOBuffer into, IOOffset pos)

virtual void	rewind (void)

virtual IOOffset	size (void) const

	Storage (void)

IOSize	write (IOBuffer from, IOOffset pos)

virtual	~Storage (void)

Public Member Functions inherited from IOInput
int	read (void)

IOSize	read (IOBuffer into)

IOSize	xread (IOBuffer into)

IOSize	xread (void *into, IOSize n)

IOSize	xreadv (IOBuffer *into, IOSize buffers)

virtual	~IOInput (void)
	Destruct the stream. A no-op. More...

Public Member Functions inherited from IOOutput
IOSize	write (unsigned char byte)

IOSize	write (IOBuffer from)

IOSize	xwrite (const void *from, IOSize n)

IOSize	xwrite (IOBuffer from)

IOSize	xwritev (const IOBuffer *from, IOSize buffers)

virtual	~IOOutput (void)
	Destruct the stream. A no-op. More...

Private Member Functions
void	cache (IOOffset start, IOOffset end)

Private Attributes
unsigned int	cacheCount_

unsigned int	cacheTotal_

bool	closedFile_

File *	file_

IOOffset	image_

std::vector< char >	present_

Storage *	storage_

Additional Inherited Members
Public Types inherited from Storage
enum	Relative { SET, CURRENT, END }

Detailed Description

Proxy class to copy a file locally in large chunks.

Definition at line 10 of file LocalCacheFile.h.

Constructor & Destructor Documentation

LocalCacheFile::LocalCacheFile	(	Storage *	base,
		const std::string &	tmpdir = `""`
	)

Definition at line 24 of file LocalCacheFile.cc.

References cms::Exception::addContext(), cacheTotal_, ztee::fd, reco_application_tbsim_DetSim-Digi_cfg::File, file_, edm::errors::FileOpenError, image_, AlCaHLTBitMon_ParallelJobs::p, chain::pattern, present_, File::resize(), AlCaHLTBitMon_QueryRunRegistry::string, and groupFilesInBlocks::temp.

   : image_(base->size()),
     file_(0),
     storage_(base),
     closedFile_(false),
     cacheCount_(0),
     cacheTotal_((image_ + CHUNK_SIZE - 1) / CHUNK_SIZE)
 {
   present_.resize(cacheTotal_, 0);
 
   std::string pattern(tmpdir);
   if (pattern.empty())
     if (char *p = getenv("TMPDIR"))
       pattern = p;
   if (pattern.empty())
     pattern = "/tmp";
   pattern += "/cmssw-shadow-XXXXXX";
 
   std::vector<char> temp(pattern.c_str(), pattern.c_str()+pattern.size()+1);
   int fd = mkstemp(&temp[0]);
   if (fd == -1)
   {
     edm::Exception ex(edm::errors::FileOpenError);
     ex << "Cannot create temporary file '" << pattern << "': "
       << strerror(errno) << " (error " << errno << ")";
     ex.addContext("LocalCacheFile::LocalCacheFile");
   }
 
   unlink(&temp[0]);
   file_ = new File(fd);
   file_->resize(image_);
 }

LocalCacheFile::~LocalCacheFile ( void )

Definition at line 57 of file LocalCacheFile.cc.

References file_, and storage_.

 {
   delete file_;
   delete storage_;
 }

Member Function Documentation

void LocalCacheFile::cache	(	IOOffset	start,
		IOOffset	end
	)

private

Definition at line 64 of file LocalCacheFile.cc.

References cms::Exception::addContext(), cacheCount_, cacheTotal_, CHUNK_SIZE, Storage::close(), closedFile_, alignCSCRings::e, IOChannel::fd(), file_, edm::errors::FileReadError, image_, cmsHarvester::index, min(), present_, Storage::read(), dqm_diff::start, storage_, and svgfig::window().

Referenced by prefetch(), read(), and readv().

 {
   start = (start / CHUNK_SIZE) * CHUNK_SIZE;
   end = std::min(end, image_);
 
   IOSize nread = 0;
   IOSize index = start / CHUNK_SIZE;
 
   while (start < end)
   {
     IOSize len = std::min(image_ - start, CHUNK_SIZE);
     if (! present_[index])
     {
       void *window = mmap(0, len, PROT_READ | PROT_WRITE, MAP_SHARED, file_->fd(), start);
       if (window == MAP_FAILED)
       {
         edm::Exception ex(edm::errors::FileReadError);
         ex << "Unable to map a window of local cache file: "
        << strerror(errno) << " (error " << errno << ")";
         ex.addContext("LocalCacheFile::cache()");
         throw ex;
       }
 
       try
       {
         nread = storage_->read(window, len, start);
       }
       catch (cms::Exception &e)
       {
         munmap(window, len);
     std::ostringstream ost;
         ost << "Unable to cache " << len << " byte file segment at " << start << ": ";
         edm::Exception ex(edm::errors::FileReadError, ost.str(), e);
         ex.addContext("LocalCacheFile::cache()");
         throw ex;
       }
 
       munmap(window, len);
 
       if (nread != len)
       {
         edm::Exception ex(edm::errors::FileReadError);
         ex << "Unable to cache " << len << " byte file segment at " << start
        << ": got only " << nread << " bytes back";
         ex.addContext("LocalCacheFile::cache()");
         throw ex;
       }
 
       present_[index] = 1;
       ++cacheCount_;
       if (cacheCount_ == cacheTotal_)
       {
         storage_->close();
         closedFile_ = true;
       }
     }
 
     start += len;
     ++index;
   }
 }

void LocalCacheFile::close ( void )

virtual

Reimplemented from Storage.

Definition at line 196 of file LocalCacheFile.cc.

References Storage::close(), File::close(), closedFile_, file_, and storage_.

Referenced by lumiQTWidget.ApplicationWindow::fileQuit(), esMonitoring.AsyncLineReaderMixin::handle_close(), esMonitoring.FDJsonServer::handle_close(), Vispa.Gui.BoxContentDialog.BoxContentDialog::keyPressEvent(), and Vispa.Gui.FindDialog.FindDialog::keyPressEvent().

 {
   if (!closedFile_)
   {
     storage_->close();
   }
   file_->close();
 }

void LocalCacheFile::flush ( void )

virtual

Reimplemented from Storage.

Definition at line 192 of file LocalCacheFile.cc.

References nowrite().

193 { nowrite("flush"); }

nowrite

static void nowrite(const std::string &why)

Definition: LocalCacheFile.cc:15

IOOffset LocalCacheFile::position	(	IOOffset	offset,
		Relative	whence = `SET`
	)

virtual

Implements Storage.

Definition at line 184 of file LocalCacheFile.cc.

References file_, and File::position().

185 { return file_->position(offset, whence); }

LocalCacheFile::file_

File * file_

Definition: LocalCacheFile.h:39

File::position

virtual IOOffset position(IOOffset offset, Relative whence=SET)

Definition: UnixFile.cc:113

hltrates_dqm_sourceclient-live_cfg.offset

tuple offset

Definition: hltrates_dqm_sourceclient-live_cfg.py:81

bool LocalCacheFile::prefetch	(	const IOPosBuffer *	what,
		IOSize	n
	)

virtual

Reimplemented from Storage.

Definition at line 206 of file LocalCacheFile.cc.

References cache(), end, file_, i, gen::n, IOPosBuffer::offset(), File::prefetch(), IOPosBuffer::size(), and dqm_diff::start.

 {
   for (IOSize i = 0; i < n; ++i)
   {
     IOOffset start = what[i].offset();
     IOOffset end = start + what[i].size();
     cache(start, end);
   }
   
   return file_->prefetch(what, n);
 }

IOSize LocalCacheFile::read	(	void *	into,
		IOSize	n
	)

virtual

Read into into at most n number of bytes.

If this is a blocking stream, the call will block until some data can be read, end of input is reached, or an exception is thrown. For a non-blocking stream the available input is returned. If none is available, an exception is thrown.

Returns: The number of bytes actually read. This is less or equal to the size of the buffer. Zero indicates that the end of the input has been reached: end of file, or remote end closing for a connected channel like a pipe or a socket. Otherwise the value can be less than requested if limited amount of input is currently available for platform or implementation reasons.

Exceptions

In	case of error, a #IOError exception is thrown. This includes the situation where the input stream is in non-blocking mode and no input is currently available (FIXME: make this simpler; clarify which exception).

Implements IOInput.

Definition at line 127 of file LocalCacheFile.cc.

References cache(), file_, File::position(), and File::read().

 {
   IOOffset here = file_->position();
   cache(here, here + n);
 
   return file_->read(into, n);
 }

IOSize LocalCacheFile::read	(	void *	into,
		IOSize	n,
		IOOffset	pos
	)

virtual

Reimplemented from Storage.

Definition at line 136 of file LocalCacheFile.cc.

References cache(), file_, and File::read().

 {
   cache(pos, pos + n);
   return file_->read(into, n, pos);
 }

IOSize LocalCacheFile::readv	(	IOBuffer *	into,
		IOSize	buffers
	)

virtual

Read from the input stream into multiple scattered buffers. There are buffers to fill in an array starting at into; the memory those buffers occupy does not need to be contiguous. The buffers are filled in the order given, eac buffer is filled fully before the subsequent buffers.

If this is a blocking stream, the call will block until some data can be read, end of input is reached, or an exception is thrown. For a non-blocking stream the available input is returned. If none is available, an exception is thrown.

The base class implementation uses read(void *, IOSize) method, but derived classes may implement a more efficient alternative.

Returns: The number of bytes actually read. This is less or equal to the size of the buffer. Zero indicates that the end of the input has been reached: end of file, or remote end closing for a connected channel like a pipe or a socket. Otherwise the value can be less than requested if limited amount of input is currently available for platform or implementation reasons. Note that the return value indicates the number of bytes read, not the number of buffers; it is the sum total of bytes filled into all the buffers.

Exceptions

In case of error, a #IOError exception is thrown. However if some data has already been read, the error is swallowed and the method returns the data read so far. It is assumed that persistent errors will occur anyway on the next read and sporadic errors like stream becoming unvailable can be ignored. Use xread() if a different policy is desirable.

Reimplemented from IOInput.

Definition at line 143 of file LocalCacheFile.cc.

References cache(), end, file_, i, gen::n, File::position(), File::readv(), Storage::size(), and dqm_diff::start.

 {
   IOOffset start = file_->position();
   IOOffset end = start;
   for (IOSize i = 0; i < n; ++i)
     end += into[i].size();
   cache(start, end);
 
   return file_->readv(into, n);
 }

IOSize LocalCacheFile::readv	(	IOPosBuffer *	into,
		IOSize	n
	)

virtual

Reimplemented from Storage.

Definition at line 155 of file LocalCacheFile.cc.

References cache(), end, i, gen::n, IOPosBuffer::offset(), Storage::readv(), IOPosBuffer::size(), dqm_diff::start, and storage_.

 {
   for (IOSize i = 0; i < n; ++i)
   {
     IOOffset start = into[i].offset();
     IOOffset end = start + into[i].size();
     cache(start, end);
   }
 
   return storage_->readv(into, n);
 }

void LocalCacheFile::resize ( IOOffset size )

virtual

Implements Storage.

Definition at line 188 of file LocalCacheFile.cc.

References nowrite().

Referenced by Vispa.Gui.TextDialog.TextDialog::__init__(), Vispa.Plugins.ConfigEditor.ToolDialog.ToolDialog::__init__(), Vispa.Main.MainWindow.MainWindow::_loadIni(), and Vispa.Gui.PortConnection.PointToPointConnection::updateConnection().

189 { nowrite("resize"); }

nowrite

static void nowrite(const std::string &why)

Definition: LocalCacheFile.cc:15

IOSize LocalCacheFile::write	(	const void *	from,
		IOSize	n
	)

virtual

Write n bytes of data starting at address from.

Returns: The number of bytes written. Normally this will be n, but can be less, even zero, for example if the stream is non-blocking mode and cannot accept input at this time.

Exceptions

In	case of error, an exception is thrown. However if the stream is in non-blocking mode and cannot accept output, it will not throw an exception – the return value will be less than requested.

Implements IOOutput.

Definition at line 168 of file LocalCacheFile.cc.

References nowrite().

169 { nowrite("write"); return 0; }

nowrite

static void nowrite(const std::string &why)

Definition: LocalCacheFile.cc:15

IOSize LocalCacheFile::write	(	const void *	from,
		IOSize	n,
		IOOffset	pos
	)

virtual

Reimplemented from Storage.

Definition at line 172 of file LocalCacheFile.cc.

References nowrite().

173 { nowrite("write"); return 0; }

nowrite

static void nowrite(const std::string &why)

Definition: LocalCacheFile.cc:15

IOSize LocalCacheFile::writev	(	const IOBuffer *	from,
		IOSize	buffers
	)

virtual

Write to the output stream from multiple buffers. There are buffers to fill in an array starting at from. The buffers are filled in the order given, each buffer fully before the subsequent buffers. The method uses write(const void *, IOSize), but may be implemented more efficiently in derived classes.

Note that derived classes should not normally call this method, as it simply routes the call back to derived class through the other virtual functions. Use this method only at the "outside edge" when transferring calls from one object to another, not in up/down calls in the inheritance tree.

Returns: The number of bytes actually written. This is less or equal to the size of the buffers. The value can be less than requested if the stream is unable to accept all the output for platform or implementation reasons. Note that the return value indicates the number of bytes written, not the number of buffers; it is the sum total of bytes written from all the buffers.

Exceptions

In	case of error, an exception is thrown. However if the stream is in non-blocking mode and cannot accept output, it will not throw an exception – the return value will be less than requested.

Reimplemented from IOOutput.

Definition at line 176 of file LocalCacheFile.cc.

References nowrite().

177 { nowrite("writev"); return 0; }

nowrite

static void nowrite(const std::string &why)

Definition: LocalCacheFile.cc:15