lsst::ap::io::SequentialFileWriter Class Reference

A sequential writer for uncompressed files. Uses standard (blocking) IO calls. More...

#include <FileIo.h>

Inheritance diagram for lsst::ap::io::SequentialFileWriter:

Public Member Functions
	SequentialFileWriter (std::string const &fileName, bool const overwrite=false)
virtual	~SequentialFileWriter ()
virtual void	write (unsigned char const *const buf, std::size_t const len)
	Writes len bytes from buf to the underlying storage device. More...
virtual void	finish ()
	Moves modified data to the underlying storage device and marks the SequentialWriter as finished. More...
Public Member Functions inherited from lsst::ap::io::SequentialIoBase
	SequentialIoBase ()
virtual	~SequentialIoBase ()=0
bool	finished () const
	Returns true if there are no more bytes available for reading. More...
bool	failed () const
	Returns true if a read operation failed. More...
State	getState () const
	Returns the state of the SequentialReader. More...

Private Member Functions
void	cleanup ()
void	cleanup (State const state)

Private Attributes
int	_fd

Additional Inherited Members
Public Types inherited from lsst::ap::io::SequentialIoBase
enum	State { IN_PROGRESS = 0, FINISHED, FAILED }
Protected Attributes inherited from lsst::ap::io::SequentialIoBase
State	_state

Detailed Description

A sequential writer for uncompressed files. Uses standard (blocking) IO calls.

Definition at line 131 of file FileIo.h.

Constructor & Destructor Documentation

lsst::ap::io::SequentialFileWriter::SequentialFileWriter ( std::string const &  fileName, bool const  overwrite = false  )

explicit

Definition at line 147 of file FileIo.cc.

  :
    _fd(-1)
{
    int const fd = openFile(
        fileName,
        O_WRONLY | O_CREAT | O_APPEND | (overwrite ? O_TRUNC : O_EXCL),
        S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH
    );
    assert(fd != -1);
    _fd = fd;
}

lsst::ap::io::SequentialFileWriter::~SequentialFileWriter ( )

virtual

Definition at line 163 of file FileIo.cc.

{ cleanup(); }

Member Function Documentation

void lsst::ap::io::SequentialFileWriter::cleanup ( )

private

Definition at line 166 of file FileIo.cc.

                                           {
    if (_fd != -1) {
        ::close(_fd);
    }
}

void lsst::ap::io::SequentialFileWriter::cleanup ( State const  state )

inlineprivate

Definition at line 152 of file FileIo.h.

                                    {
        cleanup();
        _state = state;
    }

void lsst::ap::io::SequentialFileWriter::finish ( )

virtual

Moves modified data to the underlying storage device and marks the SequentialWriter as finished.

Implements lsst::ap::io::SequentialWriter.

Definition at line 204 of file FileIo.cc.

                                          {
    if (_state != IN_PROGRESS) {
        throw LSST_EXCEPT(ex::IoError,
                          "finish() called on a finished or failed SequentialFileWriter");
    }

    // Flush userland and kernel buffers
    while (fsync(_fd) != 0) {
        if (errno != EINTR) {
            cleanup(FAILED);
            throw LSST_EXCEPT(ex::IoError,
                              (boost::format("fsync() failed, errno: %1%") % errno).str());
        }
        errno = 0;
    }
    cleanup(FINISHED);
}

void lsst::ap::io::SequentialFileWriter::write ( unsigned char const *const  buf, std::size_t const  len  )

virtual

Writes len bytes from buf to the underlying storage device.

Implements lsst::ap::io::SequentialWriter.

Definition at line 173 of file FileIo.cc.

  {
    if (len == 0) {
        return;
    }
    if (buf == 0) {
        throw LSST_EXCEPT(ex::InvalidParameterError,
                          "null pointer to bytes to write");
    }
    if (_state != IN_PROGRESS) {
        throw LSST_EXCEPT(ex::IoError,
                          "write() called on a finished or failed SequentialFileWriter");
    }

    unsigned char const * dst = buf;
    std::size_t nb = len;
    do {
        ::ssize_t n = ::write(_fd, dst, nb);
        if (n < 0) {
            cleanup(FAILED);
            throw LSST_EXCEPT(ex::IoError,
                              (boost::format("write() failed, errno: %1%") % errno).str());
        }
        dst += n;
        nb  -= n;
    } while (nb > 0);
}

Member Data Documentation

int lsst::ap::io::SequentialFileWriter::_fd

private

Definition at line 149 of file FileIo.h.

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

• /lsst/home/lsstsw/stack/Linux64/ap/master-g60f1e072bb+1/include/lsst/ap/io/FileIo.h
• /lsst/home/lsstsw/stack/Linux64/ap/master-g60f1e072bb+1/src/io/FileIo.cc