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 initial capacity 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 : Nil
Clears the internal buffer and resets the position to zero.
-
#close : Nil
Closes this
IO
. -
#closed? : Bool
Determines if this
IO
is closed. -
#empty? : Bool
Returns
true
if thisIO::Memory
has no contents. - #getb_to_end : Bytes
- #gets_to_end : String
-
#peek : Bytes
Peeks into this IO, if possible.
-
#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::Memory
to read a section of thisIO
's buffer. -
#read_byte : UInt8 | Nil
Reads a single byte from this
IO
. -
#rewind : self
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
. -
#skip_to_end : Nil
Reads and discards bytes from
self
until there are no more bytes. -
#to_s(io : IO) : Nil
Appends this internal buffer to the given
IO
. -
#to_s : String
Returns a new
String
that 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, getb_to_end : Bytes getb_to_end, gets(limit : Int, chomp = false) : String | Nil
gets(delimiter : Char, limit : Int, chomp = false) : String | Nil
gets(delimiter : Char, chomp = false) : String | Nil
gets(delimiter : String, chomp = false) : String | Nil
gets(chomp = true) : String | Nil gets, gets_to_end : String gets_to_end, peek : Bytes | Nil 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 | Nil read_byte, read_bytes(type, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) read_bytes, read_char : Char | Nil read_char, read_fully(slice : Bytes) : Int32 read_fully, read_fully?(slice : Bytes) : Int32 | Nil 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 | Nil read_utf8_byte, rewind rewind, seek(offset, whence : Seek = Seek::Set) seek, set_encoding(encoding : String, invalid : Symbol | Nil = 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_string(slice : Bytes) : Nil write_string, 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, initialize initialize, 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,
unsafe_construct(address : Pointer, *args, **opts) : self
unsafe_construct
Class methods inherited from class Reference
pre_initialize(address : Pointer)
pre_initialize
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!(message)
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::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
Reads the rest of this IO
data as a writable Bytes
.
io = IO::Memory.new Bytes[0, 1, 3, 6, 10, 15]
io.getb_to_end # => Bytes[0, 1, 3, 6, 10, 15]
io.getb_to_end # => Bytes[]
Reads the rest of this IO
data as a String
.
io = IO::Memory.new "hello world"
io.gets_to_end # => "hello world"
io.gets_to_end # => ""
Peeks into this IO, if possible.
It returns:
nil
if this IO isn't peekable at this moment or at all- 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.
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.
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
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
Reads and discards bytes from self
until there
are no more bytes.
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.