## # IO wrapper that creates digests of contents written to the IO it wraps. class Gem::Package::DigestIO ## # Collected digests for wrapped writes. # # { # 'SHA1' => #, # 'SHA512' => #, # } attr_reader :digests ## # Wraps +io+ and updates digest for each of the digest algorithms in # the +digests+ Hash. Returns the digests hash. Example: # # io = StringIO.new # digests = { # 'SHA1' => OpenSSL::Digest.new('SHA1'), # 'SHA512' => OpenSSL::Digest.new('SHA512'), # } # # Gem::Package::DigestIO.wrap io, digests do |digest_io| # digest_io.write "hello" # end # # digests['SHA1'].hexdigest #=> "aaf4c61d[...]" # digests['SHA512'].hexdigest #=> "9b71d224[...]" def self.wrap io, digests digest_io = new io, digests yield digest_io return digests end ## # Creates a new DigestIO instance. Using ::wrap is recommended, see the # ::wrap documentation for documentation of +io+ and +digests+. def initialize io, digests @io = io @digests = digests end ## # Writes +data+ to the underlying IO and updates the digests def write data result = @io.write data @digests.each do |_, digest| digest << data end result end end