Class: Resedit::BitStream

Inherits:
Object
  • Object
show all
Defined in:
lib/resedit/convert/bitstream.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(bytes = nil, chunksize = 1) ⇒ BitStream

Returns a new instance of BitStream.



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# File 'lib/resedit/convert/bitstream.rb', line 7

def initialize(bytes=nil, chunksize=1)
    @bytes = bytes ? bytes : ''
    @chunksize = chunksize
    @bytes.force_encoding(Encoding::ASCII_8BIT)
    @buf = 0
    @bsize = 0
    @pos = 0
end

Instance Attribute Details

#bytes ⇒ Object (readonly)

Returns the value of attribute bytes.



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# File 'lib/resedit/convert/bitstream.rb', line 5

def bytes
  @bytes
end

Instance Method Details

#eof? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/resedit/convert/bitstream.rb', line 16

def eof?; @pos>=@bytes.length end

#finish ⇒ Object 



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# File 'lib/resedit/convert/bitstream.rb', line 47

def finish()
    if @bsize!=0
        write(0, @chunksize*8-@bsize)
    end
    return @bytes
end

#read(bits) ⇒ Object 



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# File 'lib/resedit/convert/bitstream.rb', line 18

def read(bits)
    while @bsize < bits
        for _ in 1..@chunksize
            raise "End of stream" if @pos==@bytes.length
            @buf |= (@pos<@bytes.length ? (@bytes[@pos].ord & 0xFF) : 0) << @bsize
            @pos += 1
            @bsize += 8
        end
    end
    mask = (1 << bits) - 1
    ret = @buf & mask
    @buf >>= bits
    @bsize -= bits
    return ret
end

#write(val, bits = 8) ⇒ Object 



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# File 'lib/resedit/convert/bitstream.rb', line 34

def write(val, bits=8)
    mask = (1 << bits) - 1
    @buf |= (val & mask) << @bsize
    @bsize += bits
    if @bsize >= @chunksize*8
        for _ in 1..@chunksize
            @bytes += (@buf & 0xFF).chr
            @bsize -= 8
            @buf>>=8
        end
    end
end