Class: Dtrace::Dof::File

Inherits:
Object
  • Object
show all
Includes:
Constants
Defined in:
lib/dtrace/dof/file.rb,
ext/dof/dof_api.c

Overview

Ruby-Dtrace © 2008 Chris Andrews <[email protected]>

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ File

Returns a new instance of File.



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# File 'lib/dtrace/dof/file.rb', line 10

def initialize
  @sections = []
end

Instance Attribute Details

#sections ⇒ Object

Returns the value of attribute sections.



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# File 'lib/dtrace/dof/file.rb', line 8

def sections
  @sections
end

Instance Method Details

#<<(data) ⇒ Object

Appends the given string to the DOF file.



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# File 'ext/dof/file.c', line 56

VALUE dof_file_append(VALUE self, VALUE data)
{
  dof_file_t *file;
  Data_Get_Struct(self, dof_file_t, file);

  if ((file->offset + RSTRING(data)->len) > file->len) {
    rb_raise(eDtraceDofException, "DOF allocation insufficient: %d > %d",
	     (file->offset + RSTRING(data)->len), file->len);
    return Qnil;
  }
  
  memcpy((file->dof + file->offset), RSTRING(data)->ptr, RSTRING(data)->len);
  file->offset += RSTRING(data)->len;
}

#addr ⇒ Object

Returns the memory address of the DOF file.



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# File 'ext/dof/file.c', line 72

VALUE dof_file_addr(VALUE self)
{
  dof_file_t *file;
  Data_Get_Struct(self, dof_file_t, file);
  if (file->dof == NULL) {
    rb_raise(eDtraceDofException, "must allocate DOF buffer before calling addr");
    return Qnil;
  }
  return INT2FIX(file->dof);
}

#allocate(size) ⇒ Object

:nodoc:



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# File 'ext/dof/file.c', line 40

VALUE dof_file_allocate_dof(VALUE self, VALUE size)
{
  dof_file_t *file;
  Data_Get_Struct(self, dof_file_t, file);

  file->len = FIX2INT(size);
  file->dof = (char *)ALLOC_N(char, file->len);
  if (file->dof == NULL) {
    rb_raise(eDtraceDofException, "failed to allocate %d bytes for DOF", file->len);
    return Qnil;
  }

  return Qnil;
}

#data ⇒ Object

Returns the DOF itself.



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# File 'ext/dof/file.c', line 84

VALUE dof_file_data(VALUE self)
{
  dof_file_t *file;
  Data_Get_Struct(self, dof_file_t, file);
  return rb_str_new(file->dof, file->offset);
}

#generate ⇒ Object 



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# File 'lib/dtrace/dof/file.rb', line 14

def generate
  hdr = Dtrace::Dof::Header.new
  hdr.secnum = @sections.length
  filesz = hdr.hdrlen
  loadsz = filesz
  dof_version = 1

  @sections.each do |s|
    # Presence of is_enabled probes forces DOF version 2.
    if s.section_type == DOF_SECT_PRENOFFS
      dof_version = 2
    end
    
    length = s.generate
    s.offset = filesz

    pad = 0
    if s.align > 1
      i = s.offset.to_f % s.align
      if i > 0
        pad = (s.align - i).to_i
        s.offset = pad + s.offset
        s.pad = "\000" * pad
      end
    end

    s.size = length

    loadsz += (s.size + pad) if (s.flags & 1) == 1 # DOF_SECF_LOAD
    filesz += (s.size + pad)

  end
  
  hdr.loadsz = loadsz
  hdr.filesz = filesz
  hdr.dof_version = dof_version

  self << hdr.generate
  
  @sections.each do |s|
    self << s.generate_header
  end
    
  @sections.each do |s|
    self << s.pad if s.pad
    self << s.dof
  end

end