Feature #5248 » perf.diff
| lib/pstore.rb | ||
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# This seems to be a newly-created file.
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table = {}
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checksum = empty_marshal_checksum
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size = empty_marshal_data.size
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size = empty_marshal_data.bytesize
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else
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table = load(data)
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checksum = Digest::MD5.digest(data)
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size = data.size
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size = data.bytesize
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if !table.is_a?(Hash)
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raise Error, "PStore file seems to be corrupted."
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end
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| ... | ... | |
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is_windows
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end
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# Check whether Marshal.dump supports the 'canonical' option. This option
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# makes sure that Marshal.dump always dumps data structures in the same order.
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# This is important because otherwise, the checksums that we generate may differ.
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def marshal_dump_supports_canonical_option?
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begin
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Marshal.dump(nil, -1, true)
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result = true
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rescue
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result = false
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end
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self.class.instance_method(:marshal_dump_supports_canonical_option?)
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self.class.__send__(:define_method, :marshal_dump_supports_canonical_option?) do
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result
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end
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result
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end
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def save_data(original_checksum, original_file_size, file)
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# We only want to save the new data if the size or checksum has changed.
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# This results in less filesystem calls, which is good for performance.
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if marshal_dump_supports_canonical_option?
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new_data = Marshal.dump(@table, -1, true)
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else
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new_data = dump(@table)
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end
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new_checksum = Digest::MD5.digest(new_data)
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new_data = dump(@table)
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if new_data.size != original_file_size || new_checksum != original_checksum
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if new_data.bytesize != original_file_size || Digest::MD5.digest(new_data) != original_checksum
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if @ultra_safe && !on_windows?
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# Windows doesn't support atomic file renames.
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save_data_with_atomic_file_rename_strategy(new_data, file)
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| ... | ... | |
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def save_data_with_fast_strategy(data, file)
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file.rewind
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file.truncate(0)
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file.write(data)
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file.truncate(data.bytesize)
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end
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