Class: FFI::Buffer

Inherits:
AbstractMemoryClass
  • Object
show all
Defined in:
ext/ffi_c/Buffer.c

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Object 



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# File 'ext/ffi_c/Buffer.c', line 74

static VALUE
buffer_initialize(int argc, VALUE* argv, VALUE self)
{
    VALUE rbSize = Qnil, rbCount = Qnil, rbClear = Qnil;
    Buffer* p;
    int nargs;

    Data_Get_Struct(self, Buffer, p);

    nargs = rb_scan_args(argc, argv, "12", &rbSize, &rbCount, &rbClear);
    p->memory.typeSize = rbffi_type_size(rbSize);
    p->memory.size = p->memory.typeSize * (nargs > 1 ? NUM2LONG(rbCount) : 1);

    p->storage = xmalloc(p->memory.size + 7);
    if (p->storage == NULL) {
        rb_raise(rb_eNoMemError, "Failed to allocate memory size=%lu bytes", p->memory.size);
    }

    /* ensure the memory is aligned on at least a 8 byte boundary */
    p->memory.address = (void *) (((uintptr_t) p->storage + 0x7) & (uintptr_t) ~0x7UL);
    
    if (nargs > 2 && (RTEST(rbClear) || rbClear == Qnil) && p->memory.size > 0) {
        memset(p->memory.address, 0, p->memory.size);
    }

    if (rb_block_given_p()) {
        return rb_ensure(rb_yield, self, buffer_free, self);
    }

    return self;
}

Class Method Details

.alloc_in(*args) ⇒ Object 



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# File 'ext/ffi_c/Buffer.c', line 106

static VALUE
buffer_alloc_inout(int argc, VALUE* argv, VALUE klass)
{
    return buffer_initialize(argc, argv, buffer_allocate(klass));
}

.alloc_inout(*args) ⇒ Object 



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# File 'ext/ffi_c/Buffer.c', line 106

static VALUE
buffer_alloc_inout(int argc, VALUE* argv, VALUE klass)
{
    return buffer_initialize(argc, argv, buffer_allocate(klass));
}

.alloc_out(*args) ⇒ Object 



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# File 'ext/ffi_c/Buffer.c', line 106

static VALUE
buffer_alloc_inout(int argc, VALUE* argv, VALUE klass)
{
    return buffer_initialize(argc, argv, buffer_allocate(klass));
}

Instance Method Details

#+(rbOffset) ⇒ Object 



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# File 'ext/ffi_c/Buffer.c', line 112

static VALUE
buffer_plus(VALUE self, VALUE rbOffset)
{
    Buffer* ptr;
    Buffer* result;
    VALUE obj = Qnil;
    long offset = NUM2LONG(rbOffset);

    Data_Get_Struct(self, Buffer, ptr);
    checkBounds(&ptr->memory, offset, 1);

    obj = Data_Make_Struct(BufferClass, Buffer, buffer_mark, -1, result);
    result->memory.address = ptr->memory.address + offset;
    result->memory.size = ptr->memory.size - offset;
    result->memory.ops = ptr->memory.ops;
    result->memory.access = ptr->memory.access;
    result->memory.typeSize = ptr->memory.typeSize;
    result->rbParent = self;

    return obj;
}

#inspect ⇒ Object 



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# File 'ext/ffi_c/Buffer.c', line 134

static VALUE
buffer_inspect(VALUE self)
{
    char tmp[100];
    Buffer* ptr;

    Data_Get_Struct(self, Buffer, ptr);

    snprintf(tmp, sizeof(tmp), "#<FFI:Buffer:%p address=%p size=%ld>", ptr, ptr->memory.address, ptr->memory.size);
    
    return rb_str_new2(tmp);
}