class MemoryIO
Overview
An IO that reads and writes from a buffer in memory.
The internal buffer can be resizeable and/or writeable depending on how a MemoryIO is constructed.
Included Modules
Defined in:
io/memory_io.crClass Method Summary
-
.new(string : String)
Creates a MemoryIO whose contents are the exact contents of string.
-
.new(slice : Slice(UInt8), writeable = true)
Creates a MemoryIO that will read, and optionally write, from/to the given slice.
-
.new(capacity : Int = 64)
Creates an empty, resizeable and writeable MemoryIO with the given initialize capactiy for the internal buffer.
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 this MemoryIO 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 : Slice(UInt8))
See
IO#read(slice)
. -
#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
Returns a Slice over the internal buffer.
-
#write(slice : Slice(UInt8))
See
IO#write(slice)
. -
#write_byte(byte : UInt8)
See
IO#write_byte
.
Instance methods inherited from module IO
<<(obj) : self
<<,
close
close,
closed?
closed?,
each_byte(&block)each_byte each_byte, each_char(&block)
each_char each_char, each_line(*args, **options)
each_line(*args, **options, &block) each_line, encoding : String encoding, flush flush, gets(limit : Int) : String | Nil
gets(delimiter : Char, limit : Int) : String | Nil
gets(delimiter : Char) : String | Nil
gets : String | Nil
gets(delimiter : String) : String | Nil gets, gets_to_end : String gets_to_end, print(obj) : Nil
print(*objects : _) : Nil print, printf(format_string, *args) : Nil
printf(format_string, args : Array | Tuple) : Nil printf, puts(*objects : _) : Nil
puts : Nil
puts(string : String) : Nil
puts(obj) : Nil puts, read(slice : Slice(UInt8)) read, 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 : Slice(UInt8)) read_fully, read_line(*args, **options) : String | Nil read_line, read_utf8(slice : Slice(UInt8)) read_utf8, read_utf8_byte read_utf8_byte, rewind rewind, set_encoding(encoding : String, invalid : Symbol | Nil = nil) set_encoding, skip(bytes_count : Int) : Nil skip, tty? : Bool tty?, write(slice : Slice(UInt8)) : Nil write, write_byte(byte : UInt8) write_byte, write_bytes(object, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) write_bytes, write_utf8(slice : Slice(UInt8)) write_utf8
Class methods inherited from module IO
copy(src, dst, limit : Int)copy(src, dst) copy, pipe(read_blocking = false, write_blocking = false, &block)
pipe(read_blocking = false, write_blocking = false) pipe, select(read_ios, write_ios, error_ios, timeout_sec : LibC::TimeT | Int | Float | Nil)
select(read_ios, write_ios = nil, error_ios = nil) select
Instance methods inherited from module JSON::Builder
json_array(&block)
json_array,
json_object(&block)
json_object
Instance methods inherited from class Reference
==(other)==(other : self) ==, dup dup, hash hash, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, same?(other : Reference)
same?(other : Nil) same?, to_s(io : IO) : Nil to_s
Instance methods inherited from class Object
!=(other)
!=,
!~(other)
!~,
==(other)
==,
===(other)===(other : YAML::Any)
===(other : JSON::Any) ===, =~(other) =~, class class, crystal_type_id crystal_type_id, dup dup, hash hash, inspect(io : IO)
inspect inspect, itself itself, not_nil! not_nil!, tap(&block) tap, 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
to_yaml(io : IO) to_yaml, try(&block) try
Class methods inherited from class Object
==(other : Class)
==,
===(other)
===,
cast(other) : self
cast,
clone
clone,
dup
dup,
from_json(string_or_io) : selffrom_json(string_or_io, root : String) : self from_json, from_yaml(string : String) : self from_yaml, hash hash, inspect(io) inspect, name : String name, nilable? nilable?, to_s(io) to_s, |(other : U.class) forall U |
Class Method Detail
Creates a MemoryIO whose contents are the exact contents of string. The created MemoryIO is non-resizeable and non-writeable.
The IO starts at position zero for reading.
io = MemoryIO.new "hello"
io.pos # => 0
io.gets(2) # => "he"
io.print "hi" # raises
Creates a MemoryIO that will read, and optionally write, from/to the given slice. The created MemoryIO is non-resizeable.
The IO starts at position zero for reading.
slice = Slice.new(6) { |i| ('a'.ord + i).to_u8 }
io = MemoryIO.new slice, writeable: false
io.pos # => 0
io.read # => "abcdef"
Creates an empty, resizeable and writeable MemoryIO with the given initialize capactiy for the internal buffer.
io = MemoryIO.new
io.pos # => 0
io.read # => ""
Instance Method Detail
Clears the internal buffer and resets the position to zero. Raises if this MemoryIO is non-resizeable.
io = MemoryIO.new "hello"
io.gets(3) # => "hel"
io.clear
io.pos # => 0
io.gets_to_end # => ""
Closes this IO. Further operations on this IO will raise an IO::Error
.
io = MemoryIO.new "hello"
io.close
io.gets_to_end # => IO::Error: closed stream
Determines if this IO is closed.
io = MemoryIO.new "hello"
io.closed? # => false
io.close
io.closed? # => true
Returns true
if this MemoryIO has no contents.
io = MemoryIO.new
io.empty? # => true
io.print "hello"
io.empty? # => false
Returns the current position (in bytes) of this IO.
io = MemoryIO.new "hello"
io.pos # => 0
io.gets(2) # => "he"
io.pos # => 2
Sets the current position (in bytes) of this IO.
io = MemoryIO.new "hello"
io.pos = 3
io.gets # => "lo"
Rewinds this IO to the initial position (zero).
io = MemoryIO.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 = MemoryIO.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 = MemoryIO.new "hello"
io.size # => 5
Returns a new String that contains the contents of the internal buffer.
io = MemoryIO.new
io.print 1, 2, 3
io.to_s # => "123"
Returns a Slice over the internal buffer. Modifying the slice modifies the internal buffer.
io = MemoryIO.new "hello"
slice = io.to_slice
slice[0] = 97_u8
io.gets_to_end # => "aello"
See IO#write(slice)
. Raises if this MemoryIO is non-writeable,
or if it's non-resizeable and a resize is needed.
See IO#write_byte
. Raises if this MemoryIO is non-writeable,
or if it's non-resizeable and a resize is needed.