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/Crystal 0.31

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

<self <<, close close, closed? closed?, each_byte(&block) : Nil
each_byte each_byte
, each_char(&block) : 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 : UNDERSCORE) : Nil
print(obj) : Nil print
, printf(format_string, *args) : Nil
printf(format_string, args : Array | Tuple) : Nil printf
, puts(*objects : UNDERSCORE) : Nil
puts : Nil
puts(obj) : Nil
puts(string : String) : Nil puts
, read(slice : Bytes) read, read_at(offset, bytesize, &block) 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, &block) 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

!=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===
, =~(other) =~, class class, dup dup, hash(hasher)
hash hash
, inspect(io : IO) : Nil
inspect : String inspect
, itself itself, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, tap(&block) 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(&block) 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)Source

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.

Instance Method Detail

def closeSource

Description copied from class IO

Closes this IO.

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

def closed? : BoolSource

Description copied from class IO

Returns true if this IO is closed.

IO defines returns false, but including types may override.

def peekSource

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.

def read(slice : Bytes)Source

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

def read_byteSource

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

def read_remaining : UInt64Source

The number of remaining bytes to be read.

def skip(bytes_count) : NilSource

def sync_close=(sync_close : Bool)Source

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

def sync_close? : BoolSource

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

def write(slice : Bytes) : NoReturnSource

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"

© 2012–2019 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/0.31.1/IO/Sized.html