lsst::ap::io::SequentialFileReader Class Reference

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

#include <FileIo.h>

Inheritance diagram for lsst::ap::io::SequentialFileReader:

Public Member Functions
	SequentialFileReader (std::string const &fileName)
virtual	~SequentialFileReader ()
virtual std::size_t	read (unsigned char *const buf, std::size_t const size)
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 reader for uncompressed files. Uses standard (blocking) IO calls.

Definition at line 106 of file FileIo.h.

Constructor & Destructor Documentation

lsst::ap::io::SequentialFileReader::SequentialFileReader ( std::string const &  fileName )

explicit

Definition at line 90 of file FileIo.cc.

  :
    _fd(-1)
{
    int const fd = openFile(fileName, false, O_RDONLY);
    if (fd == -1) {
        _state = FINISHED;
        return;
    }
    _fd = fd;
}

lsst::ap::io::SequentialFileReader::~SequentialFileReader ( )

virtual

Definition at line 104 of file FileIo.cc.

{ cleanup(); }

Member Function Documentation

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

private

Definition at line 107 of file FileIo.cc.

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

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

inlineprivate

Definition at line 123 of file FileIo.h.

                                    {
        cleanup();
        _state = state;
    }

std::size_t lsst::ap::io::SequentialFileReader::read ( unsigned char *const  buf, std::size_t const  len  )

virtual

Reads up to len bytes from an underlying storage device into buf and returns the number of bytes actually read.

Implements lsst::ap::io::SequentialReader.

Definition at line 115 of file FileIo.cc.

  {
    if (len == 0) {
        return 0;
    }
    if (buf == 0) {
        throw LSST_EXCEPT(ex::InvalidParameterError,
                          "null pointer to read destination");
    }
    if (_state == FAILED) {
        throw LSST_EXCEPT(ex::IoError,
                          "read() called on a failed SequentialFileReader");
    } else if (_state == FINISHED) {
        return 0;
    }

    ::ssize_t n = ::read(_fd, buf, len);
    if (n < 0) {
        cleanup(FAILED);
        throw LSST_EXCEPT(ex::IoError,
                          (boost::format("read() failed, errno: %1%") % errno).str());
    } else if (n == 0) {
        cleanup(FINISHED);
    }
    return static_cast<std::size_t>(n);
}

Member Data Documentation

int lsst::ap::io::SequentialFileReader::_fd

private

Definition at line 120 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