Class: FFI::StructLayout::Array

Inherits:
Field
  • Object
show all
Defined in:
ext/ffi_c/StructLayout.c,
ext/ffi_c/StructLayout.c

Overview

An array Field in a FFI::StructLayout.

Instance Method Summary collapse

Methods inherited from Field

#alignment, #initialize, #name, #offset, #size, #type

Constructor Details

This class inherits a constructor from FFI::StructLayout::Field

Instance Method Details

#get(pointer) ⇒ FFI::StructLayout::CharArray, FFI::Struct::InlineArray

Get an array from a Type::Struct.

Parameters:

Returns:



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# File 'ext/ffi_c/StructLayout.c', line 313

static VALUE
array_field_get(VALUE self, VALUE pointer)
{
    StructField* f;
    ArrayType* array;
    VALUE argv[2];

    Data_Get_Struct(self, StructField, f);
    Data_Get_Struct(f->rbType, ArrayType, array);

    argv[0] = pointer;
    argv[1] = self;

    return rb_class_new_instance(2, argv, isCharArray(array)
            ? rbffi_StructLayoutCharArrayClass : rbffi_StructInlineArrayClass);
}

#put(pointer, value) ⇒ value

Set an array in a Type::Struct.

Parameters:

Returns:

  • (value) 


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# File 'ext/ffi_c/StructLayout.c', line 337

static VALUE
array_field_put(VALUE self, VALUE pointer, VALUE value)
{
    StructField* f;
    ArrayType* array;
    

    Data_Get_Struct(self, StructField, f);
    Data_Get_Struct(f->rbType, ArrayType, array);
    
    if (isCharArray(array) && rb_obj_is_instance_of(value, rb_cString)) {
        VALUE argv[2];

        argv[0] = INT2FIX(f->offset);
        argv[1] = value;

        rb_funcall2(pointer, rb_intern("put_string"), 2, argv);

    } else {
#ifdef notyet
        MemoryOp* op;
        int count = RARRAY_LEN(value);
        int i;
        AbstractMemory* memory = MEMORY(pointer);

        if (count > array->length) {
            rb_raise(rb_eIndexError, "array too large");
        }

        /* clear the contents in case of a short write */
        checkWrite(memory);
        checkBounds(memory, f->offset, f->type->ffiType->size);
        if (count < array->length) {
            memset(memory->address + f->offset + (count * array->componentType->ffiType->size),
                    0, (array->length - count) * array->componentType->ffiType->size);
        }

        /* now copy each element in */
        if ((op = get_memory_op(array->componentType)) != NULL) {

            for (i = 0; i < count; ++i) {
                (*op->put)(memory, f->offset + (i * array->componentType->ffiType->size), rb_ary_entry(value, i));
            }

        } else if (array->componentType->nativeType == NATIVE_STRUCT) {

            for (i = 0; i < count; ++i) {
                VALUE entry = rb_ary_entry(value, i);
                Struct* s;

                if (!rb_obj_is_kind_of(entry, rbffi_StructClass)) {
                    rb_raise(rb_eTypeError, "array element not an instance of FFI::Struct");
                    break;
                }

                Data_Get_Struct(entry, Struct, s);
                checkRead(s->pointer);
                checkBounds(s->pointer, 0, array->componentType->ffiType->size);

                memcpy(memory->address + f->offset + (i * array->componentType->ffiType->size),
                        s->pointer->address, array->componentType->ffiType->size);
            }

        } else {
            rb_raise(rb_eNotImpError, "put not supported for arrays of type %s", rb_obj_classname(array->rbComponentType));
        }
#else
        rb_raise(rb_eNotImpError, "cannot set array field");
#endif
    }

    return value;
}