method

dump

v1_9_3_392 - Show latest stable - 0 notes - Class: Marshal

dump(p1, p2 = v2, p3 = v3) public

Serializes obj and all descendant objects. If anIO is specified, the serialized data will be written to it, otherwise the data will be returned as a String. If limit is specified, the traversal of subobjects will be limited to that depth. If limit is negative, no checking of depth will be performed.

class Klass
  def initialize(str)
    @str = str
  end
  def say_hello
    @str
  end
end

(produces no output)

o = Klass.new("hello\n")
data = Marshal.dump(o)
obj = Marshal.load(data)
obj.say_hello  #=> "hello\n"

Marshal can’t dump following objects:

anonymous Class/Module.
objects which related to its system (ex: Dir, File::Stat, IO, File, Socket and so on)
an instance of MatchData, Data, Method, UnboundMethod, Proc, Thread, ThreadGroup, Continuation
objects which defines singleton methods

Show source

static VALUE
marshal_dump(int argc, VALUE *argv)
{
    VALUE obj, port, a1, a2;
    int limit = -1;
    struct dump_arg *arg;
    volatile VALUE wrapper;

    port = Qnil;
    rb_scan_args(argc, argv, "12", &obj, &a1, &a2);
    if (argc == 3) {
        if (!NIL_P(a2)) limit = NUM2INT(a2);
        if (NIL_P(a1)) goto type_error;
        port = a1;
    }
    else if (argc == 2) {
        if (FIXNUM_P(a1)) limit = FIX2INT(a1);
        else if (NIL_P(a1)) goto type_error;
        else port = a1;
    }
    wrapper = TypedData_Make_Struct(rb_cData, struct dump_arg, &dump_arg_data, arg);
    arg->dest = 0;
    arg->symbols = st_init_numtable();
    arg->data    = st_init_numtable();
    arg->infection = 0;
    arg->compat_tbl = st_init_numtable();
    arg->encodings = 0;
    arg->str = rb_str_buf_new(0);
    if (!NIL_P(port)) {
        if (!rb_respond_to(port, s_write)) {
          type_error:
            rb_raise(rb_eTypeError, "instance of IO needed");
        }
        arg->dest = port;
        if (rb_respond_to(port, s_binmode)) {
            rb_funcall2(port, s_binmode, 0, 0);
            check_dump_arg(arg, s_binmode);
        }
    }
    else {
        port = arg->str;
    }

    w_byte(MARSHAL_MAJOR, arg);
    w_byte(MARSHAL_MINOR, arg);

    w_object(obj, arg, limit);
    if (arg->dest) {
        rb_io_write(arg->dest, arg->str);
        rb_str_resize(arg->str, 0);
    }
    clear_dump_arg(arg);
    RB_GC_GUARD(wrapper);

    return port;
}

dump

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