Class: FFI::Struct

Inherits:
Object
  • Object
show all
Defined in:
lib/ffi/struct.rb,
ext/ffi_c/Struct.c

Direct Known Subclasses

ManagedStruct, Union

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object 



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# File 'ext/ffi_c/Struct.c', line 107

static VALUE
struct_initialize(int argc, VALUE* argv, VALUE self)
{
    Struct* s;
    VALUE rbPointer = Qnil, rest = Qnil, klass = CLASS_OF(self);
    int nargs;

    Data_Get_Struct(self, Struct, s);
    
    nargs = rb_scan_args(argc, argv, "01*", &rbPointer, &rest);

    /* Call up into ruby code to adjust the layout */
    if (nargs > 1) {
        s->rbLayout = rb_funcall2(CLASS_OF(self), id_layout, RARRAY_LEN(rest), RARRAY_PTR(rest));
    } else {
        s->rbLayout = struct_class_layout(klass);
    }

    if (!rb_obj_is_kind_of(s->rbLayout, rbffi_StructLayoutClass)) {
        rb_raise(rb_eRuntimeError, "Invalid Struct layout");
    }

    Data_Get_Struct(s->rbLayout, StructLayout, s->layout);
    
    if (rbPointer != Qnil) {
        s->pointer = MEMORY(rbPointer);
        s->rbPointer = rbPointer;
    } else {
        struct_malloc(s);
    }

    return self;
}

Class Method Details

.align ⇒ Object 



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# File 'lib/ffi/struct.rb', line 117

def self.align
  @layout.alignment
end

.alignment ⇒ Object 



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# File 'lib/ffi/struct.rb', line 113

def self.alignment
  @layout.alignment
end

.by_value ⇒ Object 



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# File 'lib/ffi/struct.rb', line 141

def self.by_value
  ::FFI::StructByValue.new(self)
end

.in ⇒ Object 



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# File 'lib/ffi/struct.rb', line 133

def self.in
  :buffer_in
end

.layout(*spec) ⇒ Object 



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# File 'lib/ffi/struct.rb', line 150

def layout(*spec)
  return @layout if spec.size == 0

  builder = FFI::StructLayoutBuilder.new
  builder.union = self < Union
  if spec[0].kind_of?(Hash)
    hash_layout(builder, spec)
  else
    array_layout(builder, spec)
  end
  builder.size = @size if defined?(@size) && @size > builder.size
  cspec = builder.build
  @layout = cspec unless self == FFI::Struct
  @size = cspec.size
  return cspec
end

.members ⇒ Object 



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# File 'lib/ffi/struct.rb', line 121

def self.members
  @layout.members
end

.offset_of(name) ⇒ Object 



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# File 'lib/ffi/struct.rb', line 129

def self.offset_of(name)
  @layout.offset_of(name)
end

.offsets ⇒ Object 



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# File 'lib/ffi/struct.rb', line 125

def self.offsets
  @layout.offsets
end

.out ⇒ Object 



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# File 'lib/ffi/struct.rb', line 137

def self.out
  :buffer_out
end

.size ⇒ Object 



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# File 'lib/ffi/struct.rb', line 104

def self.size
  defined?(@layout) ? @layout.size : defined?(@size) ? @size : 0
end

.size=(size) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/ffi/struct.rb', line 108

def self.size=(size)
  raise ArgumentError, "Size already set" if defined?(@size) || defined?(@layout)
  @size = size
end

Instance Method Details

#[](fieldName) ⇒ Object 



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# File 'ext/ffi_c/Struct.c', line 225

static VALUE
struct_aref(VALUE self, VALUE fieldName)
{
    Struct* s;
    VALUE rbField;
    StructField* f;

    s = struct_validate(self);

    rbField = struct_field(s, fieldName);
    f = (StructField *) DATA_PTR(rbField);

    if (f->get != NULL) {
        return (*f->get)(f, s);
    
    } else if (f->memoryOp != NULL) {
        return (*f->memoryOp->get)(s->pointer, f->offset);

    } else {
    
        /* call up to the ruby code to fetch the value */
        return rb_funcall2(rbField, id_get, 1, &s->rbPointer);
    }
}

#[]=(fieldName, value) ⇒ Object 



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# File 'ext/ffi_c/Struct.c', line 250

static VALUE
struct_aset(VALUE self, VALUE fieldName, VALUE value)
{
    Struct* s;
    VALUE rbField;
    StructField* f;


    s = struct_validate(self);

    rbField = struct_field(s, fieldName);
    f = (StructField *) DATA_PTR(rbField);
    if (f->put != NULL) {
        (*f->put)(f, s, value);

    } else if (f->memoryOp != NULL) {

        (*f->memoryOp->put)(s->pointer, f->offset, value);
    
    } else {
        /* call up to the ruby code to set the value */
        VALUE argv[2];
        argv[0] = s->rbPointer;
        argv[1] = value;
        rb_funcall2(rbField, id_put, 2, argv);
    }
    
    return value;
}

#align ⇒ Object 



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# File 'lib/ffi/struct.rb', line 77

def alignment
  self.class.alignment
end

#alignment ⇒ Object 



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# File 'lib/ffi/struct.rb', line 74

def alignment
  self.class.alignment
end

#clear ⇒ Object 



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# File 'lib/ffi/struct.rb', line 95

def clear
  pointer.clear
  self
end

#layout ⇒ Object 



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# File 'ext/ffi_c/Struct.c', line 338

static VALUE
struct_get_layout(VALUE self)
{
    Struct* s;

    Data_Get_Struct(self, Struct, s);

    return s->rbLayout;
}

#members ⇒ Object 



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# File 'lib/ffi/struct.rb', line 83

def members
  self.class.members
end

#offset_of(name) ⇒ Object 



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# File 'lib/ffi/struct.rb', line 79

def offset_of(name)
  self.class.offset_of(name)
end

#offsets ⇒ Object 



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# File 'lib/ffi/struct.rb', line 91

def offsets
  self.class.offsets
end

#pointer ⇒ Object 



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# File 'ext/ffi_c/Struct.c', line 310

static VALUE
struct_get_pointer(VALUE self)
{
    Struct* s;

    Data_Get_Struct(self, Struct, s);

    return s->rbPointer;
}

#size ⇒ Object 



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# File 'lib/ffi/struct.rb', line 70

def size
  self.class.size
end

#to_ptr ⇒ Object 



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# File 'lib/ffi/struct.rb', line 100

def to_ptr
  pointer
end

#values ⇒ Object 



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# File 'lib/ffi/struct.rb', line 87

def values
  members.map { |m| self[m] }
end