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# frozen_string_literal: true
require "stringio"
module HTTP
module FormData
# Provides IO interface across multiple IO objects.
class CompositeIO
# @param [Array<IO>] ios Array of IO objects
def initialize(ios)
@index = 0
@buffer = "".b
@ios = ios.map do |io|
if io.is_a?(String)
StringIO.new(io)
elsif io.respond_to?(:read)
io
else
raise ArgumentError,
"#{io.inspect} is neither a String nor an IO object"
end
end
end
# Reads and returns partial content acrosss multiple IO objects.
#
# @param [Integer] length Number of bytes to retrieve
# @param [String] outbuf String to be replaced with retrieved data
#
# @return [String, nil]
def read(length = nil, outbuf = nil)
data = outbuf.clear.force_encoding(Encoding::BINARY) if outbuf
data ||= "".b
read_chunks(length) { |chunk| data << chunk }
data unless length && data.empty?
end
# Returns sum of all IO sizes.
def size
@size ||= @ios.map(&:size).inject(0, :+)
end
# Rewinds all IO objects and set cursor to the first IO object.
def rewind
@ios.each(&:rewind)
@index = 0
end
private
# Yields chunks with total length up to `length`.
def read_chunks(length = nil)
while (chunk = readpartial(length))
yield chunk.force_encoding(Encoding::BINARY)
next if length.nil?
length -= chunk.bytesize
break if length.zero?
end
end
# Reads chunk from current IO with length up to `max_length`.
def readpartial(max_length = nil)
while current_io
chunk = current_io.read(max_length, @buffer)
return chunk if chunk && !chunk.empty?
advance_io
end
end
# Returns IO object under the cursor.
def current_io
@ios[@index]
end
# Advances cursor to the next IO object.
def advance_io
@index += 1
end
end
end
end
|
