fc::cfile Class Reference

#include <cfile.hpp>

Inheritance diagram for fc::cfile:

Public Member Functions
	cfile ()
void	set_file_path (fc::path file_path)
fc::path	get_file_path () const
bool	is_open () const
auto	fileno () const
void	open (const char *mode)
size_t	tellp () const
void	seek (long loc)
void	seek_end (long loc)
void	skip (long loc)
void	read (char *d, size_t n)
void	write (const char *d, size_t n)
void	flush ()
void	sync ()
void	punch_hole (size_t begin, size_t end)
size_t	filesystem_block_size () const
bool	eof () const
int	getc ()
void	close ()
boost::interprocess::mapping_handle_t	get_mapping_handle () const
cfile_datastream	create_datastream ()

Static Public Member Functions
static bool	supports_hole_punching ()

Static Public Attributes
static constexpr const char *	create_or_update_rw_mode = "ab+"
static constexpr const char *	update_rw_mode = "rb+"
static constexpr const char *	truncate_rw_mode = "wb+"

Detailed Description

Wrapper for c-file access that provides a similar interface as fstream without all the overhead of std streams. std::ios_base::failure exception thrown for errors.

Definition at line 31 of file cfile.hpp.

Constructor & Destructor Documentation

cfile()

fc::cfile::cfile ( )

inline

Definition at line 33 of file cfile.hpp.

     : _file(nullptr, &fclose)
   {}

Member Function Documentation

close()

void fc::cfile::close ( )

inline

Definition at line 202 of file cfile.hpp.

                {
      _file.reset();
      _open = false;
   }

Here is the caller graph for this function:

create_datastream()

cfile_datastream fc::cfile::create_datastream ( )

inline

Definition at line 249 of file cfile.hpp.

                                                 {
   return cfile_datastream(*this);
}

Here is the caller graph for this function:

eof()

bool fc::cfile::eof ( ) const

inline

Definition at line 191 of file cfile.hpp.

{ return feof(_file.get()) != 0; }

Here is the caller graph for this function:

fileno()

auto fc::cfile::fileno ( ) const

inline

Definition at line 47 of file cfile.hpp.

                       {
      int fd = ::fileno(_file.get());
      if( -1 == fd ) {
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to convert file pointer to file descriptor, error: " +
                                       std::to_string( errno ) );
      }
      return fd;
   }

Here is the call graph for this function:

Here is the caller graph for this function:

filesystem_block_size()

size_t fc::cfile::filesystem_block_size ( ) const

inline

Definition at line 189 of file cfile.hpp.

{ return _file_blk_size; }

flush()

void fc::cfile::flush ( )

inline

Definition at line 135 of file cfile.hpp.

                {
      if( 0 != fflush( _file.get() ) ) {
         int err = ferror( _file.get() );
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to flush file, ferror: " + std::to_string( err ) );
      }
   }

Here is the call graph for this function:

Here is the caller graph for this function:

get_file_path()

fc::path fc::cfile::get_file_path ( ) const

inline

Definition at line 41 of file cfile.hpp.

                                {
      return _file_path;
   }

Here is the caller graph for this function:

get_mapping_handle()

boost::interprocess::mapping_handle_t fc::cfile::get_mapping_handle ( ) const

inline

Definition at line 207 of file cfile.hpp.

                                                                {
      return {fileno(), false};
   }

Here is the call graph for this function:

getc()

int fc::cfile::getc ( )

inline

Definition at line 193 of file cfile.hpp.

              { 
      int ret = fgetc(_file.get());  
      if (ret == EOF) {
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to read 1 byte");
      }
      return ret;
   }

Here is the call graph for this function:

is_open()

bool fc::cfile::is_open ( ) const

inline

Definition at line 45 of file cfile.hpp.

{ return _open; }

Here is the caller graph for this function:

open()

void fc::cfile::open ( const char * mode )

inline

Parameters

mode	is any mode supported by fopen Tested with: "ab+" - open for binary update - create if does not exist "rb+" - open for binary update - file must exist

Definition at line 65 of file cfile.hpp.

                                 {
      _file.reset( FC_FOPEN( _file_path.generic_string().c_str(), mode ) );
      if( !_file ) {
         throw std::ios_base::failure( "cfile unable to open: " +  _file_path.generic_string() + " in mode: " + std::string( mode ) );
      }
#ifndef _WIN32
      struct stat st;
      _file_blk_size = 4096;
      if( fstat(fileno(), &st) == 0 )
         _file_blk_size = st.st_blksize;
#endif
      _open = true;
   }

Here is the call graph for this function:

Here is the caller graph for this function:

punch_hole()

void fc::cfile::punch_hole ( size_t begin, size_t end )

inline

Definition at line 159 of file cfile.hpp.

                                             {
      if(begin % _file_blk_size) {
         begin &= ~(_file_blk_size-1);
         begin += _file_blk_size;
      }
      end &= ~(_file_blk_size-1);
 
      if(begin >= end)
         return;
 
      int ret = 0;
#if defined(__linux__)
      ret = fallocate(fileno(), FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, begin, end-begin);
#elif defined(__APPLE__)
      struct fpunchhole puncher = {0, 0, static_cast<off_t>(begin), static_cast<off_t>(end-begin)};
      ret = fcntl(fileno(), F_PUNCHHOLE, &puncher);
#endif
      if(ret == -1)
         wlog("Failed to punch hole in file ${f}: ${e}", ("f", _file_path)("e", strerror(errno)));
 
      flush();
   }

Here is the call graph for this function:

read()

void fc::cfile::read ( char * d, size_t n )

inline

Definition at line 114 of file cfile.hpp.

                                  {
      size_t result = fread( d, 1, n, _file.get() );
      if( result != n ) {
         int err = ferror(_file.get());
         int eof = feof(_file.get());
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to read " + std::to_string( n ) + " bytes;"
                                       " only read " + std::to_string( result ) +
                                       ", eof: " + (eof == 0 ? "false" : "true") +
                                       ", ferror: " + std::to_string(err) );
      }
   }

Here is the call graph for this function:

Here is the caller graph for this function:

seek()

void fc::cfile::seek ( long loc )

inline

Definition at line 87 of file cfile.hpp.

                         {
      if( 0 != fseek( _file.get(), loc, SEEK_SET ) ) {
         int err = ferror(_file.get());
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to SEEK_SET to: " + std::to_string(loc) +
                                       ", ferror: " + std::to_string(err) );
      }
   }

Here is the call graph for this function:

Here is the caller graph for this function:

seek_end()

void fc::cfile::seek_end ( long loc )

inline

Definition at line 96 of file cfile.hpp.

                             {
      if( 0 != fseek( _file.get(), loc, SEEK_END ) ) {
         int err = ferror(_file.get());
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to SEEK_END to: " + std::to_string(loc) +
                                       ", ferror: " + std::to_string(err) );
      }
   }

Here is the call graph for this function:

Here is the caller graph for this function:

set_file_path()

void fc::cfile::set_file_path ( fc::path file_path )

inline

Definition at line 37 of file cfile.hpp.

                                          {
      _file_path = std::move( file_path );
   }

Here is the caller graph for this function:

skip()

void fc::cfile::skip ( long loc )

inline

Definition at line 105 of file cfile.hpp.

                        {
      if( 0 != fseek( _file.get(), loc, SEEK_CUR ) ) {
         int err = ferror(_file.get());
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to SEEK_CUR to: " + std::to_string(loc) +
                                       ", ferror: " + std::to_string(err) );
      }
   }

Here is the call graph for this function:

Here is the caller graph for this function:

supports_hole_punching()

static bool fc::cfile::supports_hole_punching ( )

inlinestatic

Definition at line 182 of file cfile.hpp.

                                        {
#if defined(__linux__) || defined(__APPLE__)
      return true;
#endif
      return false;
   }

Here is the caller graph for this function:

sync()

void fc::cfile::sync ( )

inline

Definition at line 143 of file cfile.hpp.

               {
      const int fd = fileno();
      if( -1 == fsync( fd ) ) {
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to sync file, error: " + std::to_string( errno ) );
      }
#ifdef __APPLE__
      if( -1 == fcntl( fd, F_FULLFSYNC ) ) {
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to F_FULLFSYNC file, error: " + std::to_string( errno ) );
      }
#endif
   }

Here is the call graph for this function:

tellp()

size_t fc::cfile::tellp ( ) const

inline

Definition at line 79 of file cfile.hpp.

                        {
      long result = ftell( _file.get() );
      if (result == -1)
         throw std::ios_base::failure("cfile: " + get_file_path().generic_string() +
                                      " unable to get the current position of the file, error: " + std::to_string( errno ));
      return static_cast<size_t>(result);
   }

Here is the call graph for this function:

Here is the caller graph for this function:

write()

void fc::cfile::write ( const char * d, size_t n )

inline

Definition at line 127 of file cfile.hpp.

                                         {
      size_t result = fwrite( d, 1, n, _file.get() );
      if( result != n ) {
         throw std::ios_base::failure( "cfile: " + _file_path.generic_string() +
                                       " unable to write " + std::to_string( n ) + " bytes; only wrote " + std::to_string( result ) );
      }
   }

Here is the call graph for this function:

Here is the caller graph for this function:

Member Data Documentation

create_or_update_rw_mode

const char* fc::cfile::create_or_update_rw_mode = "ab+"

staticconstexpr

Definition at line 57 of file cfile.hpp.

truncate_rw_mode

const char* fc::cfile::truncate_rw_mode = "wb+"

staticconstexpr

Definition at line 59 of file cfile.hpp.

update_rw_mode

const char* fc::cfile::update_rw_mode = "rb+"

staticconstexpr

Definition at line 58 of file cfile.hpp.

---

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

• libraries/fc/include/fc/io/cfile.hpp