module AppleTvConverter::MovieHasher
Constants
- CHUNK_SIZE
Public Class Methods
compute_hash(filename)
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# File lib/apple_tv_converter/movie_hasher.rb, line 6 def self.compute_hash(filename) filesize = File.size(filename) hash = filesize # Read 64 kbytes, divide up into 64 bits and add each # to hash. Do for beginning and end of file. File.open(filename, 'rb') do |f| # Q = unsigned long long = 64 bit f.read(CHUNK_SIZE).unpack("Q*").each do |n| hash = hash + n & 0xffffffffffffffff # to remain as 64 bit number end f.seek([0, filesize - CHUNK_SIZE].max, IO::SEEK_SET) # And again for the end of the file f.read(CHUNK_SIZE).unpack("Q*").each do |n| hash = hash + n & 0xffffffffffffffff end end sprintf("%016x", hash) end