Class: Async::IO::Stream

Inherits:
Object
  • Object
show all
Defined in:
lib/async/io/stream.rb

Constant Summary collapse

BLOCK_SIZE =

The default block size for IO buffers. BLOCK_SIZE = ENV.fetch(‘BLOCK_SIZE’, 1024*16).to_i

1024*8

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io, block_size: BLOCK_SIZE, sync: true) ⇒ Stream

Returns a new instance of Stream.



31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/async/io/stream.rb', line 31

def initialize(io, block_size: BLOCK_SIZE, sync: true)
	@io = io
	@eof = false
	
	# We don't want Ruby to do any IO buffering.
	@io.sync = sync
	
	@block_size = block_size
	
	@read_buffer = Buffer.new
	@write_buffer = Buffer.new
	
	# Used as destination buffer for underlying reads.
	@input_buffer = Buffer.new
end

Instance Attribute Details

#block_size ⇒ Object (readonly)

Returns the value of attribute block_size.



48
49
50
 
# File 'lib/async/io/stream.rb', line 48

def block_size
  @block_size
end

#io ⇒ Object (readonly)

Returns the value of attribute io.



47
48
49
 
# File 'lib/async/io/stream.rb', line 47

def io
  @io
end

Instance Method Details

#<<(string) ⇒ Object

Writes ‘string` to the stream and returns self.



127
128
129
130
131
 
# File 'lib/async/io/stream.rb', line 127

def <<(string)
	write(string)
	
	return self
end

#close ⇒ Object

Closes the stream and flushes any unwritten data.



162
163
164
165
166
167
168
169
170
171
172
173
 
# File 'lib/async/io/stream.rb', line 162

def close
	return if @io.closed?
	
	begin
		flush
	rescue
		# We really can't do anything here unless we want #close to raise exceptions.
		Async.logger.error(self) {$!}
	ensure
		@io.close
	end
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


157
158
159
 
# File 'lib/async/io/stream.rb', line 157

def closed?
	@io.closed?
end

#connected? ⇒ Boolean

Returns:

  • (Boolean) 


153
154
155
 
# File 'lib/async/io/stream.rb', line 153

def connected?
	@io.connected?
end

#eof! ⇒ Object

Raises:

  • (EOFError) 


184
185
186
187
188
189
 
# File 'lib/async/io/stream.rb', line 184

def eof!
	@read_buffer.clear
	@eof = true
	
	raise EOFError
end

#eof? ⇒ Boolean Also known as: eof

Returns true if the stream is at file which means there is no more data to be read.

Returns:

  • (Boolean) 


176
177
178
179
180
 
# File 'lib/async/io/stream.rb', line 176

def eof?
	fill_read_buffer if !@eof && @read_buffer.empty?
	
	return @eof && @read_buffer.empty?
end

#flush ⇒ Object

Flushes buffered data to the stream.



134
135
136
137
138
139
 
# File 'lib/async/io/stream.rb', line 134

def flush
	unless @write_buffer.empty?
		syswrite(@write_buffer)
		@write_buffer.clear
	end
end

#gets(separator = $/, **options) ⇒ Object 



141
142
143
 
# File 'lib/async/io/stream.rb', line 141

def gets(separator = $/, **options)
	read_until(separator, **options)
end

#peek ⇒ Object 



101
102
103
104
105
 
# File 'lib/async/io/stream.rb', line 101

def peek
	until yield(@read_buffer) or @eof
		fill_read_buffer
	end
end

#puts(*args, separator: $/) ⇒ Object 



145
146
147
148
149
150
151
 
# File 'lib/async/io/stream.rb', line 145

def puts(*args, separator: $/)
	args.each do |arg|
		@write_buffer << arg << separator
	end
	
	flush
end

#read(size = nil) ⇒ Object

Reads ‘size` bytes from the stream. If size is not specified, read until end of file.



51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
 
# File 'lib/async/io/stream.rb', line 51

def read(size = nil)
	return '' if size == 0
	
	if size
		until @eof or @read_buffer.size >= size
			# Compute the amount of data we need to read from the underlying stream:
			read_size = size - @read_buffer.bytesize
			
			# Don't read less than @block_size to avoid lots of small reads:
			fill_read_buffer(read_size > @block_size ? read_size : @block_size)
		end
	else
		until @eof
			fill_read_buffer
		end
	end
	
	return consume_read_buffer(size)
end

#read_partial(size = nil) ⇒ Object Also known as: readpartial

Read at most ‘size` bytes from the stream. Will avoid reading from the underlying stream if possible.



72
73
74
75
76
77
78
79
80
 
# File 'lib/async/io/stream.rb', line 72

def read_partial(size = nil)
	return '' if size == 0
	
	if @read_buffer.empty? and !@eof
		fill_read_buffer
	end
	
	return consume_read_buffer(size)
end

#read_until(pattern, offset = 0, chomp: true) ⇒ String

Efficiently read data from the stream until encountering pattern.

Parameters:

  • pattern (String) —

    The pattern to match.

Returns:

  • (String) —

    The contents of the stream up until the pattern, which is consumed but not returned.



87
88
89
90
91
92
93
94
95
96
97
98
99
 
# File 'lib/async/io/stream.rb', line 87

def read_until(pattern, offset = 0, chomp: true)
	until index = @read_buffer.index(pattern, offset)
		offset = @read_buffer.size
		
		return unless fill_read_buffer
	end
	
	@read_buffer.freeze
	matched = @read_buffer.byteslice(0, index+(chomp ? 0 : pattern.bytesize))
	@read_buffer = @read_buffer.byteslice(index+pattern.bytesize, @read_buffer.bytesize)
	
	return matched
end

#write(string) ⇒ Object

Writes ‘string` to the buffer. When the buffer is full or #sync is true the buffer is flushed to the underlying `io`.

Parameters:

  • string —

    the string to write to the buffer.

Returns:

  • the number of bytes appended to the buffer.



111
112
113
114
115
116
117
118
119
120
121
122
123
124
 
# File 'lib/async/io/stream.rb', line 111

def write(string)
	if @write_buffer.empty? and string.bytesize >= @block_size
		syswrite(string)
	else
		@write_buffer << string
		
		if @write_buffer.size >= @block_size
			syswrite(@write_buffer)
			@write_buffer.clear
		end
	end
	
	return string.bytesize
end