124 lines
2.6 KiB
Ruby
124 lines
2.6 KiB
Ruby
# =GZip Simple
|
|
#
|
|
# A simplified interface to the gzip library +zlib+ (from the Ruby Standard Library.)
|
|
#
|
|
# Author: murphy (mail to murphy rubychan de)
|
|
#
|
|
# Version: 0.2 (2005.may.28)
|
|
#
|
|
# ==Documentation
|
|
#
|
|
# See +GZip+ module and the +String+ extensions.
|
|
#
|
|
module GZip
|
|
|
|
require 'zlib'
|
|
|
|
# The default zipping level. 7 zips good and fast.
|
|
DEFAULT_GZIP_LEVEL = 7
|
|
|
|
# Unzips the given string +s+.
|
|
#
|
|
# Example:
|
|
# require 'gzip_simple'
|
|
# print GZip.gunzip(File.read('adresses.gz'))
|
|
def GZip.gunzip s
|
|
Zlib::Inflate.inflate s
|
|
end
|
|
|
|
# Zips the given string +s+.
|
|
#
|
|
# Example:
|
|
# require 'gzip_simple'
|
|
# File.open('adresses.gz', 'w') do |file
|
|
# file.write GZip.gzip('Mum: 0123 456 789', 9)
|
|
# end
|
|
#
|
|
# If you provide a +level+, you can control how strong
|
|
# the string is compressed:
|
|
# - 0: no compression, only convert to gzip format
|
|
# - 1: compress fast
|
|
# - 7: compress more, but still fast (default)
|
|
# - 8: compress more, slower
|
|
# - 9: compress best, very slow
|
|
def GZip.gzip s, level = DEFAULT_GZIP_LEVEL
|
|
Zlib::Deflate.new(level).deflate s, Zlib::FINISH
|
|
end
|
|
end
|
|
|
|
|
|
# String extensions to use the GZip module.
|
|
#
|
|
# The methods gzip and gunzip provide an even more simple
|
|
# interface to the ZLib:
|
|
#
|
|
# # create a big string
|
|
# x = 'a' * 1000
|
|
#
|
|
# # zip it
|
|
# x_gz = x.gzip
|
|
#
|
|
# # test the result
|
|
# puts 'Zipped %d bytes to %d bytes.' % [x.size, x_gz.size]
|
|
# #-> Zipped 1000 bytes to 19 bytes.
|
|
#
|
|
# # unzipping works
|
|
# p x_gz.gunzip == x #-> true
|
|
class String
|
|
# Returns the string, unzipped.
|
|
# See GZip.gunzip
|
|
def gunzip
|
|
GZip.gunzip self
|
|
end
|
|
# Replaces the string with its unzipped value.
|
|
# See GZip.gunzip
|
|
def gunzip!
|
|
replace gunzip
|
|
end
|
|
|
|
# Returns the string, zipped.
|
|
# +level+ is the gzip compression level, see GZip.gzip.
|
|
def gzip level = GZip::DEFAULT_GZIP_LEVEL
|
|
GZip.gzip self, level
|
|
end
|
|
# Replaces the string with its zipped value.
|
|
# See GZip.gzip.
|
|
def gzip!(*args)
|
|
replace gzip(*args)
|
|
end
|
|
end
|
|
|
|
if $0 == __FILE__
|
|
eval DATA.read, nil, $0, __LINE__+4
|
|
end
|
|
|
|
__END__
|
|
#CODE
|
|
|
|
# Testing / Benchmark
|
|
x = 'a' * 1000
|
|
x_gz = x.gzip
|
|
puts 'Zipped %d bytes to %d bytes.' % [x.size, x_gz.size] #-> Zipped 1000 bytes to 19 bytes.
|
|
p x_gz.gunzip == x #-> true
|
|
|
|
require 'benchmark'
|
|
|
|
INFO = 'packed to %0.3f%%' # :nodoc:
|
|
|
|
x = Array.new(100000) { rand(255).chr + 'aaaaaaaaa' + rand(255).chr }.join
|
|
Benchmark.bm(10) do |bm|
|
|
for level in 0..9
|
|
bm.report "zip #{level}" do
|
|
$x = x.gzip level
|
|
end
|
|
puts INFO % [100.0 * $x.size / x.size]
|
|
end
|
|
bm.report 'zip' do
|
|
$x = x.gzip
|
|
end
|
|
puts INFO % [100.0 * $x.size / x.size]
|
|
bm.report 'unzip' do
|
|
$x.gunzip
|
|
end
|
|
end
|