---

XrdFile Class Reference

#include <Utilities/XrdAdaptor/src/XrdFile.h>

Inheritance diagram for XrdFile:

List of all members.

Public Member Functions
virtual void	abort (void)
virtual void	close (void)
virtual void	create (const std::string &name, bool exclusive=false, int perms=0666)
virtual void	create (const char *name, bool exclusive=false, int perms=0666)
virtual void	open (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 IOOffset	position (IOOffset offset, Relative whence=SET)
virtual bool	prefetch (const IOPosBuffer *what, IOSize n)
virtual IOSize	read (void *into, IOSize n, IOOffset pos)
virtual IOSize	read (void *into, IOSize n)
	Read into into at most n number of bytes.
virtual IOSize	readv (IOPosBuffer *into, IOSize n)
virtual IOSize	readv (IOBuffer *into, IOSize n)
	Read from the input stream into multiple scattered buffers.
virtual void	resize (IOOffset size)
virtual IOSize	write (const void *from, IOSize n, IOOffset pos)
virtual IOSize	write (const void *from, IOSize n)
	Write n bytes of data starting at address from.
	XrdFile (const std::string &name, int flags=IOFlags::OpenRead, int perms=0666)
	XrdFile (const char *name, int flags=IOFlags::OpenRead, int perms=0666)
	XrdFile (IOFD fd)
	XrdFile (void)
	~XrdFile (void)
Private Attributes
XrdClient *	m_client
bool	m_close
std::string	m_name
IOOffset	m_offset
XrdClientStatInfo	m_stat

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Detailed Description

Definition at line 9 of file XrdFile.h.

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Constructor & Destructor Documentation

XrdFile::XrdFile

(

void

)

Definition at line 5 of file XrdFile.cc.

  : m_client (0),
    m_offset (0),
    m_close (false)
{}

XrdFile::XrdFile

(

IOFD

fd

)

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

Definition at line 11 of file XrdFile.cc.

References open().

  : m_client (0),
    m_offset (0),
    m_close (false)
{ open (name, flags, perms); }

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

Definition at line 19 of file XrdFile.cc.

References open().

  : m_client (0),
    m_offset (0),
    m_close (false)
{ open (name.c_str (), flags, perms); }

XrdFile::~XrdFile

(

void

)

Definition at line 27 of file XrdFile.cc.

References m_close, and m_name.

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

---

Member Function Documentation

void XrdFile::abort

(

void

)

[virtual]

Definition at line 157 of file XrdFile.cc.

References m_client, m_close, m_offset, and m_stat.

Referenced by open().

{
  delete m_client;
  m_client = 0;
  m_close = false;
  m_offset = 0;
  memset(&m_stat, 0, sizeof (m_stat));
}

void XrdFile::close

(

void

)

[virtual]

Reimplemented from Storage.

Definition at line 131 of file XrdFile.cc.

References m_client, m_close, m_name, m_offset, and m_stat.

Referenced by open().

{
  if (! m_client)
  {
    edm::LogError("XrdFileError")
      << "XrdFile::close(name='" << m_name
      << "') called but the file is not open";
    m_close = false;
    return;
  }

  if (! m_client->Close())
    edm::LogWarning("XrdFileWarning")
      << "XrdFile::close(name='" << m_name
      << "') failed with error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";
  delete m_client;
  m_client = 0;

  m_close = false;
  m_offset = 0;
  memset(&m_stat, 0, sizeof (m_stat));
  edm::LogInfo("XrdFileInfo") << "Closed " << m_name;
}

void XrdFile::create	(	const std::string &	name,
		bool	exclusive = false,
		int	perms = 0666
	)			[virtual]

Definition at line 48 of file XrdFile.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 XrdFile::create	(	const char *	name,
		bool	exclusive = false,
		int	perms = 0666
	)			[virtual]

Definition at line 37 of file XrdFile.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 XrdFile::open	(	const std::string &	name,
		int	flags = IOFlags::OpenRead,
		int	perms = 0666
	)			[virtual]

Definition at line 59 of file XrdFile.cc.

References open().

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

void XrdFile::open	(	const char *	name,
		int	flags = IOFlags::OpenRead,
		int	perms = 0666
	)			[virtual]

Definition at line 65 of file XrdFile.cc.

References abort(), close(), Exception, m_client, m_close, m_name, m_offset, m_stat, IOFlags::OpenAppend, IOFlags::OpenCreate, IOFlags::OpenExclusive, IOFlags::OpenRead, IOFlags::OpenTruncate, and IOFlags::OpenWrite.

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

{
  m_name = name;

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

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

  // If I am already open, close old file first
  if (m_client && m_close)
    close();
  else
    abort();

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

  if (flags & IOFlags::OpenWrite)
    openflags |= kXR_open_updt;
  else if (flags & IOFlags::OpenRead)
    openflags |= kXR_open_read;

  if (flags & IOFlags::OpenAppend)
    throw cms::Exception("XrdFile::open()")
      << "Opening file '" << name << "' in append mode not supported";

  if (flags & IOFlags::OpenCreate)
  {
    if (! (flags & IOFlags::OpenExclusive))
      openflags |= kXR_delete;
    openflags |= kXR_new;
    openflags |= kXR_mkpath;
  }

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

  m_client = new XrdClient(name);
  if (! m_client->Open(perms, openflags)
      || m_client->LastServerResp()->status != kXR_ok)
    throw cms::Exception("XrdFile::open()")
      << "XrdClient::Open(name='" << name
      << "', flags=0x" << std::hex << openflags
      << ", permissions=0" << std::oct << perms << std::dec
      << ") => error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";

  if (! m_client->Stat(&m_stat))
    throw cms::Exception("XrdFile::open()")
      << "XrdClient::Stat(name='" << name
      << ") => error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";

  m_offset = 0;
  m_close = true;
  edm::LogInfo("XrdFileInfo") << "Opened " << m_name;
}

IOOffset XrdFile::position	(	IOOffset	offset,
		Relative	whence = SET
	)			[virtual]

Implements Storage.

Definition at line 359 of file XrdFile.cc.

References Storage::CURRENT, Storage::END, Exception, m_client, m_offset, m_stat, and Storage::SET.

{
  if (! m_client)
    throw cms::Exception("XrdFile::position()")
      << "XrdFile::position() called on a closed file";

  switch (whence)
  {
  case SET:
    m_offset = offset;
    break;

  case CURRENT:
    m_offset += offset;
    break;

  case END:
    m_offset = m_stat.size + offset;
    break;

  default:
    throw cms::Exception("XrdFile::position()")
      << "XrdFile::position() called with incorrect 'whence' parameter";
  }

  if (m_offset < 0)
    m_offset = 0;
  if (m_offset > m_stat.size)
    m_stat.size = m_offset;

  return m_offset;
}

bool XrdFile::prefetch	(	const IOPosBuffer *	what,
		IOSize	n
	)			[virtual]

Reimplemented from Storage.

Definition at line 347 of file XrdFile.cc.

References i, m_client, IOPosBuffer::offset(), r, and IOPosBuffer::size().

{
  XReqErrorType r = kOK;
  for (IOSize i = 0; i < n && r == kOK; ++i)
    r = m_client->Read_Async(what[i].offset(), what[i].size());
  return r == kOK;
}

IOSize XrdFile::read	(	void *	into,
		IOSize	n,
		IOOffset	pos
	)			[virtual]

Reimplemented from Storage.

Definition at line 187 of file XrdFile.cc.

References Exception, m_client, m_name, m_offset, and s.

{
  if (n > 0x7fffffff)
    throw cms::Exception("XrdFile::read()")
      << "XrdFile::read(name='" << m_name << "', n=" << n
      << ") exceeds read size limit 0x7fffffff";

  int s = m_client->Read(into, pos, n);
  if (s < 0)
    throw cms::Exception("XrdFile::read()")
      << "XrdClient::Read(name='" << m_name
      << "', offset=" << m_offset << ", n=" << n
      << ") failed with error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";
  return s;
}

IOSize XrdFile::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 168 of file XrdFile.cc.

References Exception, m_client, m_name, m_offset, and s.

{
  if (n > 0x7fffffff)
    throw cms::Exception("XrdFile::read()")
      << "XrdFile::read(name='" << m_name << "', n=" << n
      << ") too many bytes, limit is 0x7fffffff";

  int s = m_client->Read(into, m_offset, n);
  if (s < 0)
    throw cms::Exception("XrdFile::read()")
      << "XrdClient::Read(name='" << m_name
      << "', offset=" << m_offset << ", n=" << n
      << ") failed with error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";
  m_offset += s;
  return s;
}

IOSize XrdFile::readv	(	IOPosBuffer *	into,
		IOSize	n
	)			[virtual]

Reimplemented from Storage.

Definition at line 259 of file XrdFile.cc.

References data, Exception, i, len, m_client, m_name, IOPosBuffer::offset(), s, and IOPosBuffer::size().

{
  // See comments in readv() above.
  std::vector<long long> offsets (n);
  std::vector<int> lengths (n);
  for (IOSize i = 0; i < n; ++i)
  {
    IOSize len = into[i].size();
    if (len > 0x7fffffff)
      throw cms::Exception("XrdFile::readv()")
        << "XrdFile::readv(name='" << m_name << "')[" << i
        << "].size=" << len << " exceeds read size limit 0x7fffffff";
    offsets[i] = into[i].offset();
    lengths[i] = len;
  }

  // Prefetch into the cache (if any).
  if (m_client->ReadV(0, &offsets[0], &lengths[0], n) < 0)
    throw cms::Exception("XrdFile::readv()")
      << "XrdClient::ReadV(name='" << m_name
      << "') failed with error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";

  // Issue actual reads.
  IOSize total = 0;
  for (IOSize i = 0; i < n; ++i)
  {
    int s = m_client->Read(into[i].data(), offsets[i], lengths[i]);
    if (s < 0)
    {
      if (i > 0)
        break;
      throw cms::Exception("XrdFile::readv()")
        << "XrdClient::Read(name='" << m_name
        << "', offset=" << offsets[i] << ", n=" << lengths[i]
        << ") failed with error '" << m_client->LastServerError()->errmsg
        << "' (errno=" << m_client->LastServerError()->errnum << ")";
    }
    total += s;
  }

  return total;
}

IOSize XrdFile::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 205 of file XrdFile.cc.

References data, Exception, i, len, m_client, m_name, m_offset, s, and IOBuffer::size().

{
  // Note that the XROOTD and our interfaces do not match.
  // XROOTD expects readv() into a single monolithic buffer
  // from multiple file locations, whereas we expect scatter
  // gather buffers read from a single file location.
  //
  // We work around this mismatch for now by issuing a cache
  // read on the background, and then individual reads.
  IOOffset pos = m_offset;
  std::vector<long long> offsets (n);
  std::vector<int> lengths (n);
  for (IOSize i = 0; i < n; ++i)
  {
    IOSize len = into[i].size();
    if (len > 0x7fffffff)
      throw cms::Exception("XrdFile::readv()")
        << "XrdFile::readv(name='" << m_name << "')[" << i
        << "].size=" << len << " exceeds read size limit 0x7fffffff";
    offsets[i] = pos;
    lengths[i] = len;
    pos += len;
  }

  // Prefetch into the cache (if any).
  if (m_client->ReadV(0, &offsets[0], &lengths[0], n) < 0)
    throw cms::Exception("XrdFile::readv()")
      << "XrdClient::ReadV(name='" << m_name
      << "') failed with error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";

  // Issue actual reads.
  IOSize total = 0;
  for (IOSize i = 0; i < n; ++i)
  {
    int s = m_client->Read(into[i].data(), offsets[i], lengths[i]);
    if (s < 0)
    {
      if (i > 0)
        break;
      throw cms::Exception("XrdFile::readv()")
        << "XrdClient::Read(name='" << m_name
        << "', offset=" << offsets[i] << ", n=" << lengths[i]
        << ") failed with error '" << m_client->LastServerError()->errmsg
        << "' (errno=" << m_client->LastServerError()->errnum << ")";
    }
    total += s;
    m_offset += s;
  }

  return total;
}

void XrdFile::resize

(

IOOffset

size

)

[virtual]

Implements Storage.

Definition at line 393 of file XrdFile.cc.

References Exception, and m_name.

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

IOSize XrdFile::write	(	const void *	from,
		IOSize	n,
		IOOffset	pos
	)			[virtual]

Reimplemented from Storage.

Definition at line 326 of file XrdFile.cc.

References Exception, m_client, m_name, m_stat, and s.

{
  if (n > 0x7fffffff)
    throw cms::Exception("XrdFile::write()")
      << "XrdFile::write(name='" << m_name << "', n=" << n
      << ") too many bytes, limit is 0x7fffffff";

  ssize_t s = m_client->Write(from, pos, n);
  if (s < 0)
    throw cms::Exception("XrdFile::write()")
      << "XrdFile::write(name='" << m_name << "', n=" << n
      << ") failed with error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";

  if (pos + s > m_stat.size)
    m_stat.size = pos + s;

  return s;
}

IOSize XrdFile::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 304 of file XrdFile.cc.

References Exception, m_client, m_name, m_offset, m_stat, and s.

{
  if (n > 0x7fffffff)
    throw cms::Exception("XrdFile::write()")
      << "XrdFile::write(name='" << m_name << "', n=" << n
      << ") too many bytes, limit is 0x7fffffff";

  ssize_t s = m_client->Write(from, m_offset, n);
  if (s < 0)
    throw cms::Exception("XrdFile::write()")
      << "XrdFile::write(name='" << m_name << "', n=" << n
      << ") failed with error '" << m_client->LastServerError()->errmsg
      << "' (errno=" << m_client->LastServerError()->errnum << ")";

  m_offset += s;
  if (m_offset > m_stat.size)
    m_stat.size = m_offset;

  return s;
}

---

Member Data Documentation

XrdClient* XrdFile::m_client [private]

Definition at line 51 of file XrdFile.h.

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

bool XrdFile::m_close [private]

Definition at line 54 of file XrdFile.h.

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

std::string XrdFile::m_name [private]

Definition at line 55 of file XrdFile.h.

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

IOOffset XrdFile::m_offset [private]

Definition at line 52 of file XrdFile.h.

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

XrdClientStatInfo XrdFile::m_stat [private]

Definition at line 53 of file XrdFile.h.

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

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The documentation for this class was generated from the following files:

• Utilities/XrdAdaptor/src/XrdFile.h
• Utilities/XrdAdaptor/src/XrdFile.cc

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