DCacheFile Class Reference

#include <DCacheFile.h>

Inheritance diagram for DCacheFile:

Public Member Functions
virtual void	abort (void)
virtual void	close (void)
virtual void	create (const char *name, bool exclusive=false, int perms=0666)
virtual void	create (const std::string &name, bool exclusive=false, int perms=0666)
	DCacheFile (void)
	DCacheFile (IOFD fd)
	DCacheFile (const char *name, int flags=IOFlags::OpenRead, int perms=0666)
	DCacheFile (const std::string &name, int flags=IOFlags::OpenRead, int perms=0666)
virtual void	open (const char *name, int flags=IOFlags::OpenRead, int perms=0666)
virtual void	open (const std::string &name, int flags=IOFlags::OpenRead, int perms=0666)
virtual IOOffset	position (IOOffset offset, Relative whence=SET)
virtual IOSize	read (void *into, IOSize n)
virtual IOSize	readv (IOBuffer *into, IOSize buffers)
virtual IOSize	readv (IOPosBuffer *into, IOSize buffers)
virtual void	resize (IOOffset size)
virtual IOSize	write (const void *from, IOSize n)
	~DCacheFile (void)
Public Member Functions inherited from Storage
virtual bool	eof (void) const
virtual void	flush (void)
virtual IOOffset	position (void) const
virtual bool	prefetch (const IOPosBuffer *what, IOSize n)
virtual IOSize	read (void *into, IOSize n, IOOffset pos)
IOSize	read (IOBuffer into, IOOffset pos)
virtual void	rewind (void)
virtual IOOffset	size (void) const
	Storage (void)
virtual IOSize	write (const void *from, IOSize n, IOOffset pos)
IOSize	write (IOBuffer from, IOOffset pos)
virtual IOSize	writev (const IOPosBuffer *from, IOSize buffers)
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)
virtual IOSize	writev (const IOBuffer *from, IOSize buffers)
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 Attributes
bool	m_close
IOFD	m_fd
std::string	m_name

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

Detailed Description

Definition at line 8 of file DCacheFile.h.

Constructor & Destructor Documentation

DCacheFile::DCacheFile

(

void

)

Definition at line 10 of file DCacheFile.cc.

  : m_fd (EDM_IOFD_INVALID),
    m_close (false)
{}

DCacheFile::DCacheFile

(

IOFD

fd

)

Definition at line 15 of file DCacheFile.cc.

  : m_fd (fd),
    m_close (true)
{}

DCacheFile::DCacheFile	(	const char *	name,
		int	flags = IOFlags::OpenRead,
		int	perms = 0666
	)

Definition at line 20 of file DCacheFile.cc.

References open().

  : m_fd (EDM_IOFD_INVALID),
    m_close (false)
{ open (name, flags, perms); }

DCacheFile::DCacheFile	(	const std::string &	name,
		int	flags = IOFlags::OpenRead,
		int	perms = 0666
	)

Definition at line 27 of file DCacheFile.cc.

References flags, and open().

  : m_fd (EDM_IOFD_INVALID),
    m_close (false)
{ open (name.c_str (), flags, perms); }

DCacheFile::~DCacheFile

(

void

)

Definition at line 34 of file DCacheFile.cc.

References m_close, and m_name.

{
  if (m_close)
    edm::LogError("DCacheFileError")
      << "Destructor called on dCache file '" << m_name
      << "' but the file is still open";
}

Member Function Documentation

void DCacheFile::abort ( void  )

virtual

Definition at line 171 of file DCacheFile.cc.

References EDM_IOFD_INVALID, m_close, and m_fd.

{
  if (m_fd != EDM_IOFD_INVALID)
    dc_close (m_fd);

  m_close = false;
  m_fd = EDM_IOFD_INVALID;
}

void DCacheFile::close ( void  )

virtual

Reimplemented from Storage.

Definition at line 145 of file DCacheFile.cc.

References EDM_IOFD_INVALID, m_close, m_fd, and m_name.

Referenced by python.Vispa.Gui.BoxContentDialog.BoxContentDialog::keyPressEvent(), python.Vispa.Gui.FindDialog.FindDialog::keyPressEvent(), and open().

{
  if (m_fd == EDM_IOFD_INVALID)
  {
    edm::LogError("DCacheFileError")
      << "DCacheFile::close(name='" << m_name
      << "') called but the file is not open";
    m_close = false;
    return;
  }

  dc_errno = 0;
  if (dc_close (m_fd) == -1)
    edm::LogWarning("DCacheFileWarning")
      << "dc_close(name='" << m_name
      << "') failed with error '" << dc_strerror (dc_errno)
      << "' (dc_errno=" << dc_errno << ")";

  m_close = false;
  m_fd = EDM_IOFD_INVALID;

  // Caused hang.  Will be added back after problem is fixed.
  // edm::LogInfo("DCacheFileInfo") << "Closed " << m_name;
}

void DCacheFile::create ( const char *  name, bool  exclusive = false, int  perms = 0666  )

virtual

Definition at line 44 of file DCacheFile.cc.

References open(), IOFlags::OpenCreate, IOFlags::OpenExclusive, IOFlags::OpenTruncate, and IOFlags::OpenWrite.

{
  open (name,
        (IOFlags::OpenCreate | IOFlags::OpenWrite | IOFlags::OpenTruncate
         | (exclusive ? IOFlags::OpenExclusive : 0)),
        perms);
}

void DCacheFile::create ( const std::string &  name, bool  exclusive = false, int  perms = 0666  )

virtual

Definition at line 55 of file DCacheFile.cc.

References open(), IOFlags::OpenCreate, IOFlags::OpenExclusive, IOFlags::OpenTruncate, and IOFlags::OpenWrite.

{
  open (name.c_str (),
        (IOFlags::OpenCreate | IOFlags::OpenWrite | IOFlags::OpenTruncate
         | (exclusive ? IOFlags::OpenExclusive : 0)),
        perms);
}

void DCacheFile::open ( const char *  name, int  flags = IOFlags::OpenRead, int  perms = 0666  )

virtual

Definition at line 72 of file DCacheFile.cc.

References close(), EDM_IOFD_INVALID, edm::hlt::Exception, m_close, m_fd, m_name, mergeVDriftHistosByStation::name, O_NONBLOCK, IOFlags::OpenAppend, IOFlags::OpenCreate, IOFlags::OpenExclusive, IOFlags::OpenNonBlock, IOFlags::OpenRead, IOFlags::OpenTruncate, IOFlags::OpenUnbuffered, and IOFlags::OpenWrite.

Referenced by create(), DCacheFile(), and open().

{
  m_name = name;

  // Actual open
  if ((name == 0) || (*name == 0))
    throw cms::Exception("DCacheFile::open()")
      << "Cannot open a file without a name";

  if ((flags & (IOFlags::OpenRead | IOFlags::OpenWrite)) == 0)
    throw cms::Exception("DCacheFile::open()")
      << "Must open file '" << name << "' at least for read or write";

  // If I am already open, close old file first
  if (m_fd != EDM_IOFD_INVALID && m_close)
    close ();

  // Translate our flags to system flags
  int openflags = 0;

  if ((flags & IOFlags::OpenRead) && (flags & IOFlags::OpenWrite))
    openflags |= O_RDWR;
  else if (flags & IOFlags::OpenRead)
    openflags |= O_RDONLY;
  else if (flags & IOFlags::OpenWrite)
    openflags |= O_WRONLY;

  if (flags & IOFlags::OpenNonBlock)
    openflags |= O_NONBLOCK;

  if (flags & IOFlags::OpenAppend)
    openflags |= O_APPEND;

  if (flags & IOFlags::OpenCreate)
    openflags |= O_CREAT;

  if (flags & IOFlags::OpenExclusive)
    openflags |= O_EXCL;

  if (flags & IOFlags::OpenTruncate)
    openflags |= O_TRUNC;

  IOFD newfd = EDM_IOFD_INVALID;
  dc_errno = 0;
  if ((newfd = dc_open (name, openflags, perms)) == -1)
    throw cms::Exception("DCacheFile::open()")
      << "dc_open(name='" << name
      << "', flags=0x" << std::hex << openflags
      << ", permissions=0" << std::oct << perms << std::dec
      << ") => error '" << dc_strerror(dc_errno)
      << "' (dc_errno=" << dc_errno << ")";

  m_fd = newfd;

  // Turn off read-ahead, or adjust read-ahead size depending on
  // whether buffering has been requested.  This is a very tricky
  // balance here.  Without read-ahead data processing appears to
  // become exceedingly slow, and with default (1MB) read-ahead
  // it appears to saturate disk servers and network.  Try tread
  // reasonable middle ground here.
  if (flags & IOFlags::OpenUnbuffered)
    dc_noBuffering(m_fd);
  else
    dc_setBufferSize(m_fd, 64000);

  m_close = true;

  edm::LogInfo("DCacheFileInfo") << "Opened " << m_name;
}

void DCacheFile::open ( const std::string &  name, int  flags = IOFlags::OpenRead, int  perms = 0666  )

virtual

Definition at line 66 of file DCacheFile.cc.

References flags, and open().

{ open (name.c_str (), flags, perms); }

IOOffset DCacheFile::position ( IOOffset  offset, Relative  whence = SET  )

virtual

Implements Storage.

Definition at line 318 of file DCacheFile.cc.

References Storage::CURRENT, EDM_IOFD_INVALID, Storage::END, edm::hlt::Exception, m_fd, m_name, query::result, and Storage::SET.

{
  if (m_fd == EDM_IOFD_INVALID)
    throw cms::Exception("DCacheFile::position()")
      << "DCacheFile::position() called on a closed file";
  if (whence != CURRENT && whence != SET && whence != END)
    throw cms::Exception("DCacheFile::position()")
      << "DCacheFile::position() called with incorrect 'whence' parameter";

  IOOffset  result;
  int       mywhence = (whence == SET ? SEEK_SET
                    : whence == CURRENT ? SEEK_CUR
                : SEEK_END);

  dc_errno = 0;
  if ((result = dc_lseek64 (m_fd, offset, mywhence)) == -1)
    throw cms::Exception("DCacheFile::position()")
      << "dc_lseek64(name='" << m_name << "', offset=" << offset
      << ", whence=" << mywhence << ") failed with error '"
      << dc_strerror (dc_errno) << "' (dc_errno=" << dc_errno << ")";

  // FIXME: dCache returns incorrect value on SEEK_END.
  // Remove this hack when dcap has been fixed.
  if (whence == SEEK_END && (result = dc_lseek64 (m_fd, result, SEEK_SET)) == -1)
    throw cms::Exception("DCacheFile::position()")
      << "dc_lseek64(name='" << m_name << "', offset=" << offset
      << ", whence=" << SEEK_SET << ") failed with error '"
      << dc_strerror (dc_errno) << "' (dc_errno=" << dc_errno << ")";
  
  return result;
}

IOSize DCacheFile::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 197 of file DCacheFile.cc.

References BUGLINE, generateEDF::done, edm::hlt::Exception, m_fd, m_name, and asciidump::s.

{
  IOSize done = 0;
  while (done < n)
  {
    dc_errno = 0;
    ssize_t s = dc_read (m_fd, (char *) into + done, n - done);
    if (s == -1)
      throw cms::Exception("DCacheFile::read()")
        << "dc_read(name='" << m_name << "', n=" << (n-done)
        << ") failed with error '" << dc_strerror(dc_errno)
        << "' (dc_errno=" << dc_errno << ")";
    else if (s == 0)
      // end of file
      break;
    else if (s < ssize_t (n-done))
      edm::LogInfo("DCacheFileWarning")
        << "dc_read(name='" << m_name << "', n=" << (n-done)
        << ") returned a short read of " << s << " bytes; "
        << "please report a bug in dCache referencing the "
        << "comment on line " << BUGLINE << " of " << __FILE__;
    done += s;
  }

  return done;
}

IOSize DCacheFile::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 250 of file DCacheFile.cc.

References runTheMatrix::data, edm::hlt::Exception, i, m_fd, m_name, n, and IOBuffer::size().

{
  assert (! buffers || into);

  // readv may not support zero buffers.
  if (! buffers)
    return 0;

  // Convert the buffers to system format.
  std::vector<iovec> bufs (buffers);
  for (IOSize i = 0; i < buffers; ++i)
  {
    bufs [i].iov_len  = into [i].size ();
    bufs [i].iov_base = (caddr_t) into [i].data ();
  }

  // Read as long as signals cancel the read before doing anything.
  dc_errno = 0;
  ssize_t n = dc_readv (m_fd, &bufs [0], buffers);

  // If it was serious error, throw it.
  if (n == -1)
    throw cms::Exception("DCacheFile::readv()")
      << "dc_readv(name='" << m_name << "', iov[" << buffers
      << "]) failed with error '" << dc_strerror(dc_errno)
      << "' (dc_errno=" << dc_errno << ")";

  // Return the number of bytes actually read.
  return n;
}

IOSize DCacheFile::readv ( IOPosBuffer *  into, IOSize  buffers  )

virtual

Reimplemented from Storage.

Definition at line 282 of file DCacheFile.cc.

References runTheMatrix::data, edm::hlt::Exception, i, m_fd, m_name, n, IOPosBuffer::offset(), and IOPosBuffer::size().

{
  assert (! buffers || into);

  // readv may not support zero buffers.
  if (! buffers)
    return 0;

  // Convert the buffers to system format.
  std::vector<iovec2> bufs (buffers);
  for (IOSize i = 0; i < buffers; ++i)
  {
    bufs [i].offset = into [i].offset ();
    bufs [i].len    = into [i].size ();
    bufs [i].buf    = (char *) into [i].data ();
  }

  // Read as long as signals cancel the read before doing anything.
  dc_errno = 0;
  ssize_t n = dc_readv2 (m_fd, &bufs [0], buffers);

  // If it was serious error, throw it.
  if (n == -1)
    throw cms::Exception("DCacheFile::readv()")
      << "dc_readv2(name='" << m_name << "', iov2[" << buffers
      << "]) failed with error '" << dc_strerror(dc_errno)
      << "' (dc_errno=" << dc_errno << ")";

  // Return the number of bytes actually read.
  return n;
}

void DCacheFile::resize ( IOOffset  size )

virtual

Implements Storage.

Definition at line 351 of file DCacheFile.cc.

References edm::hlt::Exception, and m_name.

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

{
  throw cms::Exception("DCacheFile::resize()")
    << "DCacheFile::resize(name='" << m_name << "') not implemented";
}

IOSize DCacheFile::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 225 of file DCacheFile.cc.

References BUGLINE, generateEDF::done, edm::hlt::Exception, m_fd, m_name, and asciidump::s.

{
  IOSize done = 0;
  while (done < n)
  {
    dc_errno = 0;
    ssize_t s = dc_write (m_fd, (const char *) from + done, n - done);
    if (s == -1)
      throw cms::Exception("DCacheFile::write()")
        << "dc_write(name='" << m_name << "', n=" << (n-done)
        << ") failed with error '" << dc_strerror(dc_errno)
        << "' (dc_errno=" << dc_errno << ")";
    else if (s < ssize_t (n-done))
      edm::LogInfo("DCacheFileWarning")
        << "dc_write(name='" << m_name << "', n=" << (n-done)
        << ") returned a short write of " << s << " bytes; "
        << "please report a bug in dCache referencing the "
        << "comment on line " << BUGLINE << " of " << __FILE__;
    done += s;
  }

  return done;
}

Member Data Documentation

bool DCacheFile::m_close

private

Definition at line 47 of file DCacheFile.h.

Referenced by abort(), close(), open(), and ~DCacheFile().

IOFD DCacheFile::m_fd

private

Definition at line 46 of file DCacheFile.h.

Referenced by abort(), close(), open(), position(), read(), readv(), and write().

std::string DCacheFile::m_name

private

Definition at line 48 of file DCacheFile.h.

Referenced by close(), open(), position(), read(), readv(), resize(), write(), and ~DCacheFile().