IOInput.cc

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#include "Utilities/StorageFactory/interface/IOInput.h"
#include "FWCore/Utilities/interface/EDMException.h"
#include <cassert>
 
IOInput::~IOInput(void) {}
 
 
int IOInput::read(void) {
  unsigned char byte;
  IOSize n = read(&byte, 1);
  return n == 0 ? -1 : byte;
}
 
IOSize IOInput::read(IOBuffer into) { return read(into.data(), into.size()); }
 
IOSize IOInput::readv(IOBuffer *into, IOSize buffers) {
  assert(!buffers || into);
 
  // Keep reading as long as possible; ignore errors if we have read
  // something, otherwise pass it on.
  IOSize status;
  IOSize done = 0;
  try {
    for (IOSize i = 0; i < buffers; done += status, ++i)
      if ((status = read(into[i])) == 0)
        break;
  } catch (cms::Exception &) {
    if (!done)
      throw;
  }
 
  return done;
}
 
 
IOSize IOInput::xread(IOBuffer into) { return xread(into.data(), into.size()); }
 
IOSize IOInput::xread(void *into, IOSize n) {
  assert(into);
 
  // Keep reading as long as possible.  Let system errors fly over
  // us, they are a hard error.
  IOSize x;
  IOSize done = 0;
  while (done < n && (x = read((char *)into + done, n - done)))
    done += x;
 
  return done;
}
 
IOSize IOInput::xreadv(IOBuffer *into, IOSize buffers) {
  // FIXME: Use read(into, buffers) and then sort out in case of
  // failure, the readv probably succeed directly with much less
  // overhead.
 
  assert(!buffers || into);
 
  // Keep reading as long as possible.  Let system errors fly
  // over us, they are a hard error.
  IOSize x;
  IOSize done = 0;
  for (IOSize i = 0; i < buffers; ++i) {
    done += (x = xread(into[i]));
    if (x < into[i].size())
      break;
  }
  return done;
}