95 lines
2.6 KiB
Ruby
Executable File
95 lines
2.6 KiB
Ruby
Executable File
module Zip
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class Inflater < Decompressor #:nodoc:all
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def initialize(input_stream)
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super
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@zlib_inflater = ::Zlib::Inflate.new(-Zlib::MAX_WBITS)
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@output_buffer = ''
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@output_buffer_pos = 0
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@has_returned_empty_string = false
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end
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def sysread(number_of_bytes = nil, buf = '')
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buf ||= ''
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buf.clear
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readEverything = number_of_bytes.nil?
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if readEverything
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buf << @output_buffer[@output_buffer_pos...@output_buffer.bytesize]
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move_output_buffer_pos(buf.bytesize)
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else
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buf << @output_buffer[@output_buffer_pos, number_of_bytes]
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move_output_buffer_pos(buf.bytesize)
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if buf.bytesize == number_of_bytes
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return buf
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end
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end
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while readEverything || buf.bytesize + @output_buffer.bytesize < number_of_bytes
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break if internal_input_finished?
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@output_buffer << internal_produce_input
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end
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return value_when_finished(number_of_bytes, buf) if @output_buffer.bytesize == 0 && input_finished?
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end_index = (number_of_bytes.nil? ? @output_buffer.bytesize : number_of_bytes) - buf.bytesize
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data = @output_buffer[0...end_index]
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move_output_buffer_pos(data.bytesize)
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buf << data
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end
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def produce_input
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sysread()
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end
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# to be used with produce_input, not read (as read may still have more data cached)
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# is data cached anywhere other than @outputBuffer? the comment above may be wrong
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def input_finished?
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@output_buffer.empty? && internal_input_finished?
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end
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alias :eof :input_finished?
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alias :eof? :input_finished?
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private
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def move_output_buffer_pos(inc)
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@output_buffer_pos += inc
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if @output_buffer_pos == @output_buffer.bytesize
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@output_buffer.clear
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@output_buffer_pos = 0
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end
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end
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def internal_produce_input
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buf = ''
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retried = 0
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begin
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@zlib_inflater.inflate(@input_stream.read(Decompressor::CHUNK_SIZE, buf))
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rescue Zlib::BufError
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raise if retried >= 5 # how many times should we retry?
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retried += 1
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retry
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end
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end
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def internal_input_finished?
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@zlib_inflater.finished?
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end
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def value_when_finished(number_of_bytes, buf) # mimic behaviour of ruby File object.
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if number_of_bytes.nil?
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buf
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elsif buf.bytesize == 0
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nil
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else
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buf
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end
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end
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end
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end
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# Copyright (C) 2002, 2003 Thomas Sondergaard
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# rubyzip is free software; you can redistribute it and/or
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# modify it under the terms of the ruby license.
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