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Versions: 66
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Contents
require 'memory_buffer'
module Iso9660
class FileData
attr_reader :pos
# Initialization
def initialize(dirEntry, bootSector)
raise "Nil directory entry" if dirEntry.nil?
raise "Nil boot sector" if bootSector.nil?
@bs = bootSector
@de = dirEntry
@last_sect = @de.fileSize.divmod(@bs.sectorSize)
@last_sect[0] += 1 if @last_sect[1] > 0
@last_sect = @last_sect[0]
rewind
end
def rewind
@pos = 0
end
def seek(offset, method = IO::SEEK_SET)
@pos = case method
when IO::SEEK_SET then offset
when IO::SEEK_CUR then @pos + offset
when IO::SEEK_END then @de.length - offset
end
@pos = 0 if @pos < 0
@pos = @de.fileSize if @pos > @de.fileSize
@pos
end
def read(bytes = @de.fileSize)
return nil if @pos >= @de.fileSize
bytes = @de.fileSize - @pos if @pos + bytes > @de.fileSize
# Get start & end locs.
ss = @bs.sectorSize
startSector, startOffset = @pos.divmod(ss)
endSector, endOffset = (@pos + (bytes - 1)).divmod(ss)
# Single sector.
if startSector == endSector
@pos += (endOffset - startOffset)
return getSector(startSector)[startOffset..endOffset]
end
# Span sectors.
out = MemoryBuffer.create(bytes)
totalLen = 0
(startSector..endSector).each do |sect|
offset = 0; len = ss
if sect == startSector
offset = startOffset
len -= offset
end
len -= (ss - (endOffset + 1)) if sect == endSector
out[totalLen, len] = getSector(sect)[offset, len]
totalLen += len
@pos += len
end
out[0..totalLen]
end
def getSector(vsn)
lsn = getLSN(vsn)
raise "No logical sector for virtual sector #{vsn}." if lsn == -1
@bs.getSectors(lsn, 1)
end
def getLSN(vsn)
return -1 if vsn > @last_sect
@de.fileStart + vsn
end
end
end # module Iso9660
Version data entries
66 entries across 66 versions & 1 rubygems