Class: SimpleMmap::MappedFile

Inherits:
Object
  • Object
show all
Defined in:
ext/simple_mmap/mapped_file.c

Defined Under Namespace

Classes: MmapData

Instance Method Summary collapse

Instance Method Details

#close ⇒ Object

munmap() the current mmapped file



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# File 'ext/simple_mmap/mapped_file.c', line 94

static VALUE sm_mapped_file_close(VALUE vself)
{
  VALUE vsm_map;
  simple_mmap_map *sm_map;
  
  sm_map = ALLOC(simple_mmap_map);
  vsm_map = rb_ivar_get(vself, rb_intern("@mmap_data"));
  Data_Get_Struct(vsm_map, simple_mmap_map, sm_map);
  
  if (sm_map->map != (caddr_t) -1)
    munmap(sm_map->map, sm_map->len);
  if (sm_map->fd != -1)
    close(sm_map->fd);
  
  return Qtrue;
}

#read_window_data(offset, length) ⇒ Object

Read length bytes starting at offset



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# File 'ext/simple_mmap/mapped_file.c', line 117

static VALUE sm_mapped_file_read_window_data(VALUE vself, VALUE voffset, VALUE vlength) 
{
  size_t offset = NUM2INT(voffset);
  size_t length = NUM2INT(vlength);
  char buff[length];
  VALUE vsm_map;
  simple_mmap_map *sm_map;
  
  sm_map = ALLOC(simple_mmap_map);
  vsm_map = rb_ivar_get(vself, rb_intern("@mmap_data"));
  Data_Get_Struct(vsm_map, simple_mmap_map, sm_map);
  
  if (offset > sm_map->len) {
    return Qnil;
  }
  
  size_t curr = offset;
  size_t i;
  for(i = 0; i < length; ++i) {
    //printf("i=%i offset=%i length=%i curr=%i map->len=%i\n", i, offset, length, curr, sm_map->len);
    if ((offset + i) > sm_map->len)
      break;
    buff[i] = sm_map->map[curr++];
  }
  
  // If the range overflows, return part that overlaps
  if ((offset + length) > sm_map->len)
    return rb_str_new(buff, sm_map->len - offset);
      
  return rb_str_new(buff, length);
}

#size ⇒ Object

Return size of mapped file



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# File 'ext/simple_mmap/mapped_file.c', line 156

static VALUE sm_mapped_file_size(VALUE vself)
{
  VALUE vsm_map;
  simple_mmap_map *sm_map;

  sm_map = ALLOC(simple_mmap_map);
  vsm_map = rb_ivar_get(vself, rb_intern("@mmap_data"));
  Data_Get_Struct(vsm_map, simple_mmap_map, sm_map);
  return UINT2NUM(sm_map->len);
}