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.
Defined in:
io/memory.crConstructors
-
.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 : Int32
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
. -
#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 class IO
<<(obj) : self
<<,
close
close,
closed?
closed?,
each_byte(&block) : Nileach_byte 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(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, &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)copy(src, dst) 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)
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, unsafe_as(type : T.class) forall T unsafe_as
Constructor 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 : String | IO) : self from_yaml
Constructor Detail
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]
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
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
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
Closes this IO
. Further operations on this IO
will raise an IO::Error
.
io = IO::Memory.new "hello"
io.close
io.gets_to_end # raises IO::Error (closed stream)
Determines if this IO
is closed.
io = IO::Memory.new "hello"
io.closed? # => false
io.close
io.closed? # => true
Returns true
if this IO::Memory
has no contents.
io = IO::Memory.new
io.empty? # => true
io.print "hello"
io.empty? # => false
Returns the current position (in bytes) of this IO
.
io = IO::Memory.new "hello"
io.pos # => 0
io.gets(2) # => "he"
io.pos # => 2
Sets the current position (in bytes) of this IO
.
io = IO::Memory.new "hello"
io.pos = 3
io.gets # => "lo"
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.
Rewinds this IO
to the initial position (zero).
io = IO::Memory.new "hello"
io.gets(2) # => "he"
io.rewind
io.gets(2) # => "he"
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"
Returns the total number of bytes in this IO
.
io = IO::Memory.new "hello"
io.size # => 5
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"
Returns the underlying bytes.
io = IO::Memory.new
io.print "hello"
io.to_slice # => Bytes[104, 101, 108, 108, 111]
See IO#write(slice)
. Raises if this IO::Memory
is non-writeable,
or if it's non-resizeable and a resize is needed.
See IO#write_byte
. Raises if this IO::Memory
is non-writeable,
or if it's non-resizeable and a resize is needed.