/afs/cern.ch/work/a/aaltunda/public/www/CMSSW_6_2_7/src/Utilities/StorageFactory/src/Storage.cc

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#include "Utilities/StorageFactory/interface/Storage.h"
#include "FWCore/Utilities/interface/Exception.h"
#include <cassert>

Storage::Storage (void)
{}

Storage::~Storage (void)
{}

IOSize
Storage::read (IOBuffer into, IOOffset pos)
{ return read (into.data (), into.size (), pos); }

IOSize
Storage::read (void *into, IOSize n, IOOffset pos)
{
  // FIXME: this is not thread safe!  split into separate interface
  // that a particular storage can choose to support or not?  make
  // sure that throw semantics are correct here!
  // FIXME: use saveposition object in case exceptions are thrown?
  IOOffset here = position ();
  position (pos);
  n = read (into, n);
  position (here);
  return n;
}

IOSize
Storage::readv (IOPosBuffer *into, IOSize n)
{
  IOOffset here = position();
  IOSize total = 0;
  for (IOSize i = 0; i < n; ++i)
  {
    try
    {
      position(into[i].offset());
      total += read(into[i].data(), into[i].size());
    }
    catch (cms::Exception &)
    {
      if (! total)
        throw;
      break;
    }
  }
  position(here);
  return total;
}

IOSize
Storage::write (IOBuffer from, IOOffset pos)
{ return write (from.data (), from.size (), pos); }

IOSize
Storage::write (const void *from, IOSize n, IOOffset pos)
{
  // FIXME: this is not thread safe!  split into separate interface
  // that a particular storage can choose to support or not?  make
  // sure that throw semantics are correct here!

  // FIXME: use saveposition object in case exceptions are thrown?
  IOOffset here = position ();
  position (pos);
  n = write (from, n);
  position (here);
  return n;
}

IOSize
Storage::writev (const IOPosBuffer *from, IOSize n)
{
  IOSize total = 0;
  for (IOSize i = 0; i < n; ++i)
  {
    try
    {
      total += write(from[i].data(), from[i].size(), from[i].offset());
    }
    catch (cms::Exception &)
    {
      if (! total)
        throw;
      break;
    }
  }
  return total;
}

IOOffset
Storage::position (void) const
{
  Storage *self = const_cast<Storage *> (this);
  return self->position (0, CURRENT);
}

IOOffset
Storage::size (void) const
{
  // FIXME: use saveposition object in case exceptions are thrown?
  Storage *self = const_cast<Storage *> (this);
  IOOffset here = position ();
  self->position (0, END);
  IOOffset size = position ();
  self->position (here); // FIXME: VERIFY()?
  return size;
}

void
Storage::rewind (void)
{ position(0); }

bool
Storage::prefetch (const IOPosBuffer * /* what */, IOSize /* n */)
{ return false; }

void
Storage::flush (void)
{}

void
Storage::close (void)
{}

bool
Storage::eof (void) const
{ return position () == size (); }