lib/file-storage.cc

   1 /*
   2   file-storage.cc -- implement Mapped_file_storage
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   7   Jan Nieuwenhuizen <jan@digicash.com>
   8 */
   9 #include <sys/types.h>          // open, mmap
  10 #include <sys/stat.h>           // open
  11 #include <sys/mman.h>           // mmap
  12 #include <limits.h>             // INT_MAX
  13 #include <fcntl.h>              // open
  14 #include <unistd.h>             // close, stat
  15 #include <stdio.h>              // fdopen
  16 #include <string.h>             // strerror
  17 #include <errno.h>              // errno
  18
  19
  20
  21 #include "string.hh"
  22 #include "proto.hh"
  23 #include "warn.hh"
  24 #include "file-storage.hh"
  25
  26 Mapped_file_storage::Mapped_file_storage(String s)
  27 {
  28     data_caddr_ = 0;
  29     fildes_i_ = 0;
  30     size_off_ = 0;
  31     open(s);
  32 }
  33
  34 char const*
  35 Mapped_file_storage::ch_C()const
  36 {
  37     return (char const*)data_caddr_;
  38 }
  39
  40 void
  41 Mapped_file_storage::map()
  42 {
  43     if ( fildes_i_ == -1 )
  44         return;
  45
  46     data_caddr_ = (caddr_t)mmap( (void*)0, size_off_, PROT_READ, MAP_SHARED, fildes_i_, 0 );
  47
  48     if ( (int)data_caddr_ == -1 )
  49         warning( String( "can't map: error no: " ) + strerror( errno ));
  50 }
  51
  52
  53 void
  54 Mapped_file_storage::open(String name_str)
  55 {
  56     fildes_i_ = ::open( name_str, O_RDONLY );
  57
  58     if ( fildes_i_ == -1 )
  59       {
  60         warning( String( "can't open: " ) + name_str + String( ": " ) + strerror( errno ));
  61         return;
  62       }
  63
  64     struct stat file_stat;
  65     fstat( fildes_i_, &file_stat );
  66     size_off_ = file_stat.st_size;
  67     map();
  68 }
  69
  70 void
  71 Mapped_file_storage::unmap()
  72 {
  73     if ( data_caddr_ )
  74       {
  75         munmap( data_caddr_, size_off_ );
  76         data_caddr_ = 0;
  77         size_off_ = 0;
  78       }
  79 }
  80
  81 void
  82 Mapped_file_storage::close()
  83 {
  84     unmap();
  85     if ( fildes_i_ )
  86       {
  87         ::close( fildes_i_ );
  88         fildes_i_ = 0;
  89       }
  90 }
  91
  92 int
  93 Mapped_file_storage::length_i()const
  94 {
  95     return size_off_;
  96 }
  97
  98 Mapped_file_storage::~Mapped_file_storage()
  99 {
 100     close();
 101 }