IO::Memory
class IO::Memory
Overview
An IO
that reads and writes from a buffer in memory.
The internal buffer can be resizeable and/or writeable depending on how an IO::Memory
is constructed-
Included Modules
Defined in:
io/memory.crClass Method Summary
- .new(capacity : Int = 64)
Creates an empty, resizeable and writeable
IO::Memory
with the given initialize capactiy for the internal buffer- - .new(string : String)
Creates an
IO::Memory
whose contents are the exact contents of string- - .new(slice : Bytes, writeable = true)
Creates an
IO::Memory
that will read, and optionally write, from-to the given slice-
Instance Method Summary
- #buffer : Pointer(UInt8)
- #bytesize : Int32
Same as
#size
. - #clear
Clears the internal buffer and resets the position to zero.
- #close
Closes this
IO
. - #closed? : Bool
Determines if this
IO
is closed. - #empty?
Returns
true
if thisIO::Memory
has no contents- - #pos
Returns the current position (in bytes) of this
IO
. - #pos=(value)
Sets the current position (in bytes) of this
IO
. - #read(slice : Bytes)
See
IO#read(slice)
. - #read_at(offset, bytesize, &block)
Yields an
IO::Memory
to read a section of thisIO
's buffer. - #rewind
Rewinds this
IO
to the initial position (zero). - #seek(offset, whence : Seek = Seek::Set)
Seeks to a given offset (in bytes) according to the whence argument.
- #size : Int32
Returns the total number of bytes in this
IO
. - #tell : Int32
Same as
#pos
. - #to_s(io)
Appends this internal buffer to the given
IO
. - #to_s
Returns a new
String
that contains the contents of the internal buffer. - #to_slice : Bytes
Returns the underlying bytes.
- #write(slice : Bytes)
See
IO#write(slice)
. - #write_byte(byte : UInt8)
See
IO#write_byte
.
Instance methods inherited from module IO
< <<, close close, closed? closed?, each_byteeach_byte(&block) : Nil each_byte, each_char(&block) : Nil
each_char each_char, each_line(*args, **options, &block) : Nil
each_line(*args, **options) each_line, encoding : String encoding, flush flush, gets(limit : Int, chomp = false) : String?
gets(delimiter : Char, chomp = false) : String?
gets(delimiter : String, chomp = false) : String?
gets(chomp = true) : String?
gets(delimiter : Char, limit : Int, chomp = false) : String? gets, gets_to_end : String gets_to_end, peek : Bytes? peek, print(*objects : _) : Nil
print(obj) : Nil print, printf(format_string, args : Array | Tuple) : Nil
printf(format_string, *args) : Nil printf, puts(*objects : _) : Nil
puts : Nil
puts(obj) : Nil
puts(string : String) : Nil puts, read(slice : Bytes) read, 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, set_encoding(encoding : String, invalid : Symbol? = nil) set_encoding, skip(bytes_count : Int) : Nil skip, skip_to_end : Nil skip_to_end, 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 module IO
copy(src, dst, limit : Int)copy(src, dst) copy, pipe(read_blocking = false, write_blocking = false)
pipe(read_blocking = false, write_blocking = false, &block) pipe, select(read_ios, write_ios, error_ios, timeout_sec : LibC::TimeT | Int | Float?)
select(read_ios, write_ios = nil, error_ios = nil) select
Instance methods inherited from class Reference
==(other : self)==(other) ==, dup dup, hash 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
Class 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 hash, inspect(io : IO)
inspect 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
to_s(io : IO) to_s, to_yaml(io : IO)
to_yaml to_yaml, try(&block) try
Class methods inherited from class Object
from_json(string_or_io, root : String) : selffrom_json(string_or_io) : self from_json, from_yaml(string_or_io) : self from_yaml
Class Method Detail
def self.new(capacity : Int = 64)Source
Creates an empty, resizeable and writeable IO::Memory
with the given initialize capactiy for the internal buffer-
io = IO::Memory.new slice = Bytes.new(1) io.pos # => 0 io.read(slice) # => 0 slice # => Bytes[0]
def self.new(string : String)Source
Creates an IO::Memory
whose contents are the exact contents of string- The created IO::Memory
is non-resizeable and non-writeable.
The IO
starts at position zero for reading.
io = IO::Memory.new "hello" io.pos # => 0 io.gets(2) # => "he" io.print "hi" # raises IO::Error
def self.new(slice : Bytes, writeable = true)Source
Creates an IO::Memory
that will read, and optionally write, from-to the given slice- The created IO::Memory
is non-resizeable.
The IO starts at position zero for reading.
slice = Slice.new(6) { |i| ('a'.ord + i).to_u8 } io = IO::Memory.new slice, writeable: false io.pos # => 0 io.read(slice) # => 6 String.new(slice) # => "abcdef"
Instance Method Detail
def clearSource
Clears the internal buffer and resets the position to zero. Raises if this IO::Memory
is non-resizeable-
io = IO::Memory.new io << "abc" io.rewind io.gets(1) # => "a" io.clear io.pos # => 0 io.gets_to_end # => "" io = IO::Memory.new "hello" io.clear # raises IO::Error
def closeSource
def closed? : BoolSource
Determines if this IO
is closed.
io = IO::Memory.new "hello" io.closed? # => false io.close io.closed? # => true
def empty?Source
Returns true
if this IO::Memory
has no contents-
io = IO::Memory.new io.empty? # => true io.print "hello" io.empty? # => false
def posSource
Returns the current position (in bytes) of this IO
.
io = IO::Memory.new "hello" io.pos # => 0 io.gets(2) # => "he" io.pos # => 2
def pos=(value)Source
Sets the current position (in bytes) of this IO
.
io = IO::Memory.new "hello" io.pos = 3 io.gets # => "lo"
def read(slice : Bytes)Source
See IO#read(slice)
.
def read_at(offset, bytesize, &block)Source
Yields an IO::Memory
to read a section of this IO
's buffer.
During the block duration self
becomes read-only, so multiple concurrent open are allowed.
def rewindSource
Rewinds this IO
to the initial position (zero).
io = IO::Memory.new "hello" io.gets(2) # => "he" io.rewind io.gets(2) # => "he"
def seek(offset, whence : Seek = Seek::Set)Source
Seeks to a given offset (in bytes) according to the whence argument.
io = IO::Memory.new("abcdef") io.gets(3) # => "abc" io.seek(1, IO::Seek::Set) io.gets(2) # => "bc" io.seek(-1, IO::Seek::Current) io.gets(1) # => "c"
def size : Int32Source
Returns the total number of bytes in this IO
.
io = IO::Memory.new "hello" io.size # => 5
def to_sSource
Returns a new String
that contains the contents of the internal buffer.
io = IO::Memory.new io.print 1, 2, 3 io.to_s # => "123"
def to_slice : BytesSource
Returns the underlying bytes.
io = IO::Memory.new io.print "hello" io.to_slice # => Bytes[104, 101, 108, 108, 111]
def write(slice : Bytes)Source
See IO#write(slice)
. Raises if this IO::Memory
is non-writeable, or if it's non-resizeable and a resize is needed-
def write_byte(byte : UInt8)Source
See IO#write_byte
. Raises if this IO::Memory
is non-writeable, or if it's non-resizeable and a resize is needed-
© 2012–2017 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/0.22.0/IO/Memory.html