Class: IO

Inherits:
Object
  • Object
show all
Defined in:
_doc/io.rb

Overview

See IO

Instance Method Summary collapse

Instance Method Details

#nread ⇒ Integer

Returns number of bytes that can be read without blocking. Returns zero if no information available.

You must require ‘io/wait’ to use this method.



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# File 'ext/io/wait/wait.c', line 79

static VALUE
io_nread(VALUE io)
{
    rb_io_t *fptr;
    int len;
    ioctl_arg n;

    rb_category_warn(RB_WARN_CATEGORY_DEPRECATED, "IO#nread is deprecated; use wait_readable instead");
    GetOpenFile(io, fptr);
    rb_io_check_char_readable(fptr);
    len = rb_io_read_pending(fptr);
    if (len > 0) return INT2FIX(len);

#ifdef HAVE_RB_IO_DESCRIPTOR
    int fd = rb_io_descriptor(io);
#else
    int fd = fptr->fd;
#endif

    if (!FIONREAD_POSSIBLE_P(fd)) return INT2FIX(0);
    if (ioctl(fd, FIONREAD, &n)) return INT2FIX(0);
    if (n > 0) return ioctl_arg2num(n);
    return INT2FIX(0);
}

#ready? ⇒ Boolean

Returns a truthy value if input available without blocking, or a falsy value.

You must require ‘io/wait’ to use this method.



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# File 'ext/io/wait/wait.c', line 138

static VALUE
io_ready_p(VALUE io)
{
    rb_io_t *fptr;
#ifndef HAVE_RB_IO_WAIT
    struct timeval tv = {0, 0};
#endif

    rb_category_warn(RB_WARN_CATEGORY_DEPRECATED, "IO#ready? is deprecated; use wait_readable instead");
    GetOpenFile(io, fptr);
    rb_io_check_char_readable(fptr);
    if (rb_io_read_pending(fptr)) return Qtrue;

#ifndef HAVE_RB_IO_WAIT
    return wait_for_single_fd(fptr, RB_WAITFD_IN, &tv) ? Qtrue : Qfalse;
#else
    return io_wait_event(io, RUBY_IO_READABLE, RB_INT2NUM(0), 1);
#endif
}

#wait(events, timeout) ⇒ false? #wait(*event_symbols[, timeout]) ⇒ self, ...

Waits until the IO becomes ready for the specified events and returns the subset of events that become ready, or a falsy value when times out.

The events can be a bit mask of IO::READABLE, IO::WRITABLE or IO::PRIORITY.

Returns an event mask (truthy value) immediately when buffered data is available.

The second form: if one or more event symbols (:read, :write, or :read_write) are passed, the event mask is the bit OR of the bitmask corresponding to those symbols. In this form, timeout is optional, the order of the arguments is arbitrary, and returns io if any of the events is ready.

You must require ‘io/wait’ to use this method.



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# File 'ext/io/wait/wait.c', line 337

static VALUE
io_wait(int argc, VALUE *argv, VALUE io)
{
#ifndef HAVE_RB_IO_WAIT
    rb_io_t *fptr;
    struct timeval timerec;
    struct timeval *tv = NULL;
    int event = 0;
    int i;

    GetOpenFile(io, fptr);
    for (i = 0; i < argc; ++i) {
        if (SYMBOL_P(argv[i])) {
            event |= wait_mode_sym(argv[i]);
        }
        else {
            *(tv = &timerec) = rb_time_interval(argv[i]);
        }
    }
    /* rb_time_interval() and might_mode() might convert the argument */
    rb_io_check_closed(fptr);
    if (!event) event = RB_WAITFD_IN;
    if ((event & RB_WAITFD_IN) && rb_io_read_pending(fptr))
        return Qtrue;
    if (wait_for_single_fd(fptr, event, tv))
        return io;
    return Qnil;
#else
    VALUE timeout = Qundef;
    rb_io_event_t events = 0;
    int i, return_io = 0;

    if (argc != 2 || (RB_SYMBOL_P(argv[0]) || RB_SYMBOL_P(argv[1]))) {
        /* We'd prefer to return the actual mask, but this form would return the io itself: */
        return_io = 1;

        /* Slow/messy path: */
        for (i = 0; i < argc; i += 1) {
            if (RB_SYMBOL_P(argv[i])) {
                events |= wait_mode_sym(argv[i]);
            }
            else if (timeout == Qundef) {
                rb_time_interval(timeout = argv[i]);
            }
            else {
                rb_raise(rb_eArgError, "timeout given more than once");
            }
        }

        if (timeout == Qundef) timeout = Qnil;

        if (events == 0) {
            events = RUBY_IO_READABLE;
        }
    }
    else /* argc == 2 and neither are symbols */ {
        /* This is the fast path: */
        events = io_event_from_value(argv[0]);
        timeout = argv[1];
    }

    if (events & RUBY_IO_READABLE) {
        rb_io_t *fptr = NULL;
        RB_IO_POINTER(io, fptr);

        if (rb_io_read_pending(fptr)) {
            /* This was the original behaviour: */
            if (return_io) return Qtrue;
            /* New behaviour always returns an event mask: */
            else return RB_INT2NUM(RUBY_IO_READABLE);
        }
    }

    return io_wait_event(io, events, timeout, return_io);
#endif
}

#wait_priority ⇒ Object #wait_priority(timeout) ⇒ Object

Waits until IO is priority and returns a truthy value or a falsy value when times out. Priority data is sent and received using the Socket::MSG_OOB flag and is typically limited to streams.

You must require ‘io/wait’ to use this method.



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# File 'ext/io/wait/wait.c', line 251

static VALUE
io_wait_priority(int argc, VALUE *argv, VALUE io)
{
    rb_io_t *fptr = NULL;

    RB_IO_POINTER(io, fptr);
    rb_io_check_char_readable(fptr);

    if (rb_io_read_pending(fptr)) return Qtrue;

    rb_check_arity(argc, 0, 1);
    VALUE timeout = argc == 1 ? argv[0] : Qnil;

    return io_wait_event(io, RUBY_IO_PRIORITY, timeout, 1);
}

#wait_readable ⇒ Object #wait_readable(timeout) ⇒ Object

Waits until IO is readable and returns a truthy value, or a falsy value when times out. Returns a truthy value immediately when buffered data is available.

You must require ‘io/wait’ to use this method.



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# File 'ext/io/wait/wait.c', line 173

static VALUE
io_wait_readable(int argc, VALUE *argv, VALUE io)
{
    rb_io_t *fptr;
#ifndef HAVE_RB_IO_WAIT
    struct timeval timerec;
    struct timeval *tv;
#endif

    GetOpenFile(io, fptr);
    rb_io_check_char_readable(fptr);

#ifndef HAVE_RB_IO_WAIT
    tv = get_timeout(argc, argv, &timerec);
#endif
    if (rb_io_read_pending(fptr)) return Qtrue;

#ifndef HAVE_RB_IO_WAIT
    if (wait_for_single_fd(fptr, RB_WAITFD_IN, tv)) {
        return io;
    }
    return Qnil;
#else
    rb_check_arity(argc, 0, 1);
    VALUE timeout = (argc == 1 ? argv[0] : Qnil);

    return io_wait_event(io, RUBY_IO_READABLE, timeout, 1);
#endif
}

#wait_writable ⇒ Object #wait_writable(timeout) ⇒ Object

Waits until IO is writable and returns a truthy value or a falsy value when times out.

You must require ‘io/wait’ to use this method.



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# File 'ext/io/wait/wait.c', line 213

static VALUE
io_wait_writable(int argc, VALUE *argv, VALUE io)
{
    rb_io_t *fptr;
#ifndef HAVE_RB_IO_WAIT
    struct timeval timerec;
    struct timeval *tv;
#endif

    GetOpenFile(io, fptr);
    rb_io_check_writable(fptr);

#ifndef HAVE_RB_IO_WAIT
    tv = get_timeout(argc, argv, &timerec);
    if (wait_for_single_fd(fptr, RB_WAITFD_OUT, tv)) {
        return io;
    }
    return Qnil;
#else
    rb_check_arity(argc, 0, 1);
    VALUE timeout = (argc == 1 ? argv[0] : Qnil);

    return io_wait_event(io, RUBY_IO_WRITABLE, timeout, 1);
#endif
}