Class: FFI::Struct

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

Direct Known Subclasses

ManagedStruct, Union

Defined Under Namespace

Classes: ManagedStructConverter

Class Method Summary (collapse)

Instance Method Summary (collapse)

Constructor Details

- (Object) initialize 



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# File 'ext/ffi_c/Struct.c', line 93

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, (int) 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

+ (Object) alignment 



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# File 'lib/ffi/struct.rb', line 123

def self.alignment
  @layout.alignment
end

+ (Object) array_layout(builder, spec) (private) 



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# File 'lib/ffi/struct.rb', line 264

def array_layout(builder, spec)
  i = 0
  while i < spec.size
    name, type = spec[i, 2]
    i += 2

    # If the next param is a Integer, it specifies the offset
    if spec[i].kind_of?(Integer)
      offset = spec[i]
      i += 1
    else
      offset = nil
    end

    builder.add name, find_field_type(type), offset
  end
end

+ (Object) auto_ptr 



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# File 'lib/ffi/struct.rb', line 177

def self.auto_ptr
  @managed_type ||= Type::Mapped.new(ManagedStructConverter.new(self))
end

+ (Object) by_ref(flags = :inout) 



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# File 'lib/ffi/struct.rb', line 159

def self.by_ref(flags = :inout)
  self.ptr(flags)
end

+ (Object) by_value 



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# File 'lib/ffi/struct.rb', line 155

def self.by_value
  self.val
end

+ (Object) hash_layout(builder, spec) (private) 



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# File 'lib/ffi/struct.rb', line 257

def hash_layout(builder, spec)
  raise "Ruby version not supported" if RUBY_VERSION =~ /1.8.*/
  spec[0].each do |name, type|
    builder.add name, find_field_type(type), nil
  end
end

+ (Object) in 



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# File 'lib/ffi/struct.rb', line 139

def self.in
  ptr(:in)
end

+ (Object) layout(*spec) 



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# File 'lib/ffi/struct.rb', line 185

def layout(*spec)
#        raise RuntimeError, "struct layout already defined for #{self.inspect}" if defined?(@layout)
  return @layout if spec.size == 0

  builder = StructLayoutBuilder.new
  builder.union = self < Union
  builder.packed = @packed if defined?(@packed)
  builder.alignment = @min_alignment if defined?(@min_alignment)

  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 == Struct
  @size = cspec.size
  return cspec
end

+ (Object) members 



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# File 'lib/ffi/struct.rb', line 127

def self.members
  @layout.members
end

+ (Object) offset_of(name) 



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# File 'lib/ffi/struct.rb', line 135

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

+ (Object) offsets 



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# File 'lib/ffi/struct.rb', line 131

def self.offsets
  @layout.offsets
end

+ (Object) out 



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# File 'lib/ffi/struct.rb', line 143

def self.out
  ptr(:out)
end

+ (Object) ptr(flags = :inout) 



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# File 'lib/ffi/struct.rb', line 147

def self.ptr(flags = :inout)
  @ref_data_type ||= Type::Mapped.new(StructByReference.new(self))
end

+ (Object) size 



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# File 'lib/ffi/struct.rb', line 114

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

+ (Object) size=(size)

Raises:

  • (ArgumentError) 


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# File 'lib/ffi/struct.rb', line 118

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

+ (Object) val 



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# File 'lib/ffi/struct.rb', line 151

def self.val
  @val_data_type ||= StructByValue.new(self)
end

Instance Method Details

- (Object) [] 



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# File 'ext/ffi_c/Struct.c', line 282

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);
    }
}

- (Object) []= 



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# File 'ext/ffi_c/Struct.c', line 307

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);
    }

    if (f->referenceRequired) {
        store_reference_value(f, s, value);
    }
    
    return value;
}

- (Object) align 



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

def alignment
  self.class.alignment
end

- (Object) alignment 



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# File 'lib/ffi/struct.rb', line 84

def alignment
  self.class.alignment
end

- (Object) clear 



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# File 'lib/ffi/struct.rb', line 105

def clear
  pointer.clear
  self
end

- (Object) initialize_copy 



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# File 'ext/ffi_c/Struct.c', line 127

static VALUE
struct_initialize_copy(VALUE self, VALUE other)
{
    Struct* src;
    Struct* dst;
    
    Data_Get_Struct(self, Struct, dst);
    Data_Get_Struct(other, Struct, src);
    if (dst == src) {
        return self;
    }
    
    dst->rbLayout = src->rbLayout;
    dst->layout = src->layout;
    
    /*
     * A new MemoryPointer instance is allocated here instead of just calling
     * #dup on rbPointer, since the Pointer may not know its length, or may
     * be longer than just this struct.
     */
    if (src->pointer->address != NULL) {
        dst->rbPointer = rbffi_MemoryPointer_NewInstance(1, src->layout->size, false);
        dst->pointer = MEMORY(dst->rbPointer);
        memcpy(dst->pointer->address, src->pointer->address, src->layout->size);
    } else {
        dst->rbPointer = src->rbPointer;
        dst->pointer = src->pointer;
    }

    if (src->layout->referenceFieldCount > 0) {
        dst->rbReferences = ALLOC_N(VALUE, dst->layout->referenceFieldCount);
        memcpy(dst->rbReferences, src->rbReferences, dst->layout->referenceFieldCount * sizeof(VALUE));
    }
        
    return self;
}

- (Object) layout 



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# File 'ext/ffi_c/Struct.c', line 399

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

    Data_Get_Struct(self, Struct, s);

    return s->rbLayout;
}

- (Object) layout= (private) 



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# File 'ext/ffi_c/Struct.c', line 381

static VALUE
struct_set_layout(VALUE self, VALUE layout)
{
    Struct* s;
    Data_Get_Struct(self, Struct, s);

    if (!rb_obj_is_kind_of(layout, rbffi_StructLayoutClass)) {
        rb_raise(rb_eTypeError, "wrong argument type %s (expected %s)",
                rb_obj_classname(layout), rb_class2name(rbffi_StructLayoutClass));
        return Qnil;
    }

    Data_Get_Struct(layout, StructLayout, s->layout);
    rb_ivar_set(self, id_layout_ivar, layout);

    return self;
}

- (Object) members 



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# File 'lib/ffi/struct.rb', line 93

def members
  self.class.members
end

- (Boolean) null?

Returns:

  • (Boolean) 


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# File 'ext/ffi_c/Struct.c', line 410

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

    Data_Get_Struct(self, Struct, s);

    return s->pointer->address == NULL ? Qtrue : Qfalse;
}

- (Object) offset_of(name) 



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# File 'lib/ffi/struct.rb', line 89

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

- (Object) offsets 



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# File 'lib/ffi/struct.rb', line 101

def offsets
  self.class.offsets
end

- (Object) order 



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# File 'ext/ffi_c/Struct.c', line 420

static VALUE
struct_order(int argc, VALUE* argv, VALUE self)
{
    Struct* s;

    Data_Get_Struct(self, Struct, s);
    if (argc == 0) {
        return rb_funcall(s->rbPointer, rb_intern("order"), 0);

    } else {
        VALUE retval = rb_obj_dup(self);
        VALUE rbPointer = rb_funcall2(s->rbPointer, rb_intern("order"), argc, argv);
        struct_set_pointer(retval, rbPointer);
        
        return retval;
    }
}

- (Object) pointer 



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# File 'ext/ffi_c/Struct.c', line 371

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

    Data_Get_Struct(self, Struct, s);

    return s->rbPointer;
}

- (Object) pointer= (private) 



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# File 'ext/ffi_c/Struct.c', line 341

static VALUE
struct_set_pointer(VALUE self, VALUE pointer)
{
    Struct* s;
    StructLayout* layout;
    AbstractMemory* memory;

    if (!rb_obj_is_kind_of(pointer, rbffi_AbstractMemoryClass)) {
        rb_raise(rb_eTypeError, "wrong argument type %s (expected Pointer or Buffer)",
                rb_obj_classname(pointer));
        return Qnil;
    }

    
    Data_Get_Struct(self, Struct, s);
    Data_Get_Struct(pointer, AbstractMemory, memory);
    layout = struct_layout(self);

    if ((int) layout->base.ffiType->size > memory->size) {
        rb_raise(rb_eArgError, "memory of %ld bytes too small for struct %s (expected at least %ld)",
                memory->size, rb_obj_classname(self), (long) layout->base.ffiType->size);
    }
    
    s->pointer = MEMORY(pointer);
    s->rbPointer = pointer;
    rb_ivar_set(self, id_pointer_ivar, pointer);

    return self;
}

- (Object) size 



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# File 'lib/ffi/struct.rb', line 80

def size
  self.class.size
end

- (Object) to_ptr 



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# File 'lib/ffi/struct.rb', line 110

def to_ptr
  pointer
end

- (Object) values 



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# File 'lib/ffi/struct.rb', line 97

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