class IO::Sized

Overview

An IO that wraps another IO, setting a limit for the number of bytes that can be read.

io = IO::Memory.new "abcde"
sized = IO::Sized.new(io, read_size: 3)

sized.gets_to_end # => "abc"
sized.gets_to_end # => ""
io.gets_to_end    # => "de"

Defined in:

io/sized.cr

Constructors

Instance Method Summary

Instance methods inherited from class IO

<<(obj) : self <<, close close, closed? closed?, each_byte(&) : Nil
each_byte
each_byte
, each_char(&) : Nil
each_char
each_char
, each_line(*args, **options, &block : String -> ) : Nil
each_line(*args, **options)
each_line
, encoding : String encoding, flush flush, gets(delimiter : Char, limit : Int, chomp = false) : String?
gets(delimiter : Char, chomp = false) : String?
gets(chomp = true) : String?
gets(limit : Int, chomp = false) : String?
gets(delimiter : String, chomp = false) : String?
gets
, gets_to_end : String gets_to_end, peek : Bytes? peek, pos pos, pos=(value) pos=, print(*objects : _) : Nil
print(obj) : Nil
print
, printf(format_string, *args) : Nil
printf(format_string, args : Array | Tuple) : Nil
printf
, puts(*objects : _) : Nil
puts : Nil
puts(obj) : Nil
puts(string : String) : Nil
puts
, read(slice : Bytes) read, read_at(offset, bytesize, &) read_at, read_byte : UInt8? read_byte, read_bytes(type, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) read_bytes, read_char : Char? read_char, read_fully(slice : Bytes) read_fully, read_fully?(slice : Bytes) read_fully?, read_line(*args, **options) : String read_line, read_string(bytesize : Int) : String read_string, read_utf8(slice : Bytes) read_utf8, read_utf8_byte read_utf8_byte, rewind rewind, seek(offset, whence : Seek = Seek::Set) seek, set_encoding(encoding : String, invalid : Symbol? = nil) set_encoding, skip(bytes_count : Int) : Nil skip, skip_to_end : Nil skip_to_end, tell tell, tty? : Bool tty?, write(slice : Bytes) : Nil write, write_byte(byte : UInt8) write_byte, write_bytes(object, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) write_bytes, write_utf8(slice : Bytes) write_utf8

Class methods inherited from class IO

copy(src, dst, limit : Int) : UInt64
copy(src, dst) : UInt64
copy
, pipe(read_blocking = false, write_blocking = false) : Tuple(IO::FileDescriptor, IO::FileDescriptor)
pipe(read_blocking = false, write_blocking = false, &)
pipe

Instance methods inherited from class Reference

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other)
==
, dup dup, hash(hasher) hash, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference)
same?(other : Nil)
same?
, to_s(io : IO) : Nil to_s

Constructor methods inherited from class Reference

new new

Instance methods inherited from class Object

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other)
===
, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash
hash(hasher)
hash
, inspect(io : IO) : Nil
inspect : String
inspect
, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO)
to_json
to_json
, to_pretty_json(indent : String = " ")
to_pretty_json(io : IO, indent : String = " ")
to_pretty_json
, to_s : String
to_s(io : IO) : Nil
to_s
, to_yaml(io : IO)
to_yaml
to_yaml
, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

Constructor methods inherited from class Object

from_json(string_or_io, root : String) : self
from_json(string_or_io) : self
from_json
, from_yaml(string_or_io : String | IO) : self from_yaml

Constructor Detail

def self.new(io : IO, read_size : Int, sync_close = false) #

Creates a new IO::Sized which wraps io, and can read a maximum of read_size bytes. If sync_close is set, calling #close calls #close on the underlying IO.


[View source]

Instance Method Detail

def close #
Description copied from class IO

Closes this IO.

IO defines this is a no-op method, but including types may override.


[View source]
def closed? : Bool #
Description copied from class IO

Returns true if this IO is closed.

IO defines returns false, but including types may override.


[View source]
def peek #
Description copied from class IO

Peeks into this IO, if possible.

It returns:

  • nil if this IO isn't peekable
  • an empty slice if it is, but EOF was reached
  • a non-empty slice if some data can be peeked

The returned bytes are only valid data until a next call to any method that reads from this IO is invoked.

By default this method returns nil, but IO implementations that provide buffering or wrap other IOs should override this method.


[View source]
def read(slice : Bytes) #
Description copied from class IO

Reads at most slice.size bytes from this IO into slice. Returns the number of bytes read, which is 0 if and only if there is no more data to read (so checking for 0 is the way to detect end of file).

io = IO::Memory.new "hello"
slice = Bytes.new(4)
io.read(slice) # => 4
slice          # => Bytes[104, 101, 108, 108]
io.read(slice) # => 1
slice          # => Bytes[111, 101, 108, 108]
io.read(slice) # => 0

[View source]
def read_byte #
Description copied from class IO

Reads a single byte from this IO. Returns nil if there is no more data to read.

io = IO::Memory.new "a"
io.read_byte # => 97
io.read_byte # => nil

[View source]
def read_remaining : UInt64 #

The number of remaining bytes to be read.


[View source]
def skip(bytes_count) : Nil #

[View source]
def sync_close=(sync_close : Bool) #

If #sync_close? is true, closing this IO will close the underlying IO.


[View source]
def sync_close? : Bool #

If #sync_close? is true, closing this IO will close the underlying IO.


[View source]
def write(slice : Bytes) : NoReturn #
Description copied from class IO

Writes the contents of slice into this IO.

io = IO::Memory.new
slice = Bytes.new(4) { |i| ('a'.ord + i).to_u8 }
io.write(slice)
io.to_s # => "abcd"

[View source]