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::Memorywith the given initial capacity for the internal buffer. - .new(string : String)
Creates an
IO::Memorywhose contents are the exact contents of string. - .new(slice : Bytes, writeable = true)
Creates an
IO::Memorythat 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
IOis closed. - #empty? : Bool
Returns
trueif thisIO::Memoryhas 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) : Int32
See
IO#read(slice). - #read_at(offset, bytesize, & : IO -> )
Yields an
IO::Memoryto read a section of thisIO's buffer. - #rewind : self
Rewinds this
IOto 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 : IO) : Nil
Appends this internal buffer to the given
IO. - #to_s : String
Returns a new
Stringthat contains the contents of the internal buffer. - #to_slice : Bytes
Returns the underlying bytes.
- #write(slice : Bytes) : Nil
See
IO#write(slice). - #write_byte(byte : UInt8) : Nil
See
IO#write_byte.
Instance methods inherited from class IO
<<(obj) : self <<, close close, closed? : Bool closed?, each_byte(&) : Nileach_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(limit : Int, chomp = false) : String?
gets(delimiter : Char, limit : Int, chomp = false) : String?
gets(delimiter : Char, chomp = false) : String?
gets(delimiter : String, chomp = false) : String?
gets(chomp = true) : String? gets, gets_to_end : String gets_to_end, peek : Bytes? peek, pos pos, pos=(value) pos=, print(obj : _) : Nil
print(*objects : _) : Nil print, printf(format_string, args : Array | Tuple) : Nil
printf(format_string, *args) : Nil printf, puts(string : String) : Nil
puts(obj : _) : Nil
puts : Nil
puts(*objects : _) : Nil puts, read(slice : Bytes) read, read_at(offset, bytesize, & : IO -> ) 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) : Int32 read_fully, read_fully?(slice : Bytes) : Int32? 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 : UInt8? read_utf8_byte, rewind rewind, seek(offset, whence : Seek = Seek::Set) seek, set_encoding(encoding : String, invalid : Symbol? = nil) : 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) : Nil write_byte, write_bytes(object, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) : Nil write_bytes, write_utf8(slice : Bytes) : Nil write_utf8
Class methods inherited from class IO
copy(src, dst, limit : Int) : Int64copy(src, dst) : Int64 copy, pipe(read_blocking = false, write_blocking = false) : Tuple(IO::FileDescriptor, IO::FileDescriptor)
pipe(read_blocking = false, write_blocking = false, &) pipe, same_content?(stream1 : IO, stream2 : IO) : Bool same_content?
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) : Bool
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(hasher)
hash hash, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?, 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) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as
Class methods inherited from class Object
from_json(string_or_io, root : String)from_json(string_or_io) from_json, from_yaml(string_or_io : String | IO) from_yaml
Constructor Detail
Creates an empty, resizeable and writeable IO::Memory with the given initial capacity 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::ErrorCreates 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::ErrorCloses 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? # => trueReturns true if this IO::Memory has no contents.
io = IO::Memory.new io.empty? # => true io.print "hello" io.empty? # => falseReturns the current position (in bytes) of this IO.
io = IO::Memory.new "hello" io.pos # => 0 io.gets(2) # => "he" io.pos # => 2Sets 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 # => 5Returns 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.