Sha256: a575ea79133d467286801c74968a93acf6852ff3f0e358a27ae077e5768f5f5c
Contents?: true
Size: 1.07 KB
Versions: 12
Compression:
Stored size: 1.07 KB
Contents
class FileReverseReader
attr_reader :io, :step
def initialize(io, step = 1024 * 1024 * 1)
@io = io
@step = step
end
def each_line(&block)
io.seek(0, IO::SEEK_END)
buf = ""
loop do
if reach_start_of_file?
last_pos = io.pos
io.seek(0, IO::SEEK_SET)
buf.insert(0, io.read(last_pos))
split_each_line(buf, &block)
break
end
io.seek(-1 * step, IO::SEEK_CUR)
buf.insert(0, io.read(step))
io.seek(-1 * step, IO::SEEK_CUR)
next if buf[$/].nil?
gap = buf.index($/)
buf.gsub!(/\A.*?\n/, "")
split_each_line(buf, &block)
buf = ""
io.seek(gap, IO::SEEK_CUR)
end
end
def tail(limit = 10)
enum_for(:each_line).first(limit).reverse
end
def binary_file?
sample = io.read(1024) || ""
!sample.force_encoding('us-ascii').valid_encoding?
ensure
io.rewind
end
private
def split_each_line(buf, &block)
buf.split($/).reverse.each do |line|
block.call(line)
end
end
def reach_start_of_file?
step >= io.pos
end
end
Version data entries
12 entries across 12 versions & 1 rubygems