Fluent::EventTime is serialized as String for JSON

[tagomoris]

["tag", Fluent::EventTime.now, {"key" => "value"}].to_json #=> '["tag","1460544188",{"key":"value"}]'

This may cause some problems in output plugins.

[kawanet]

I guess there are a reason that the nano precision second needs to be serialized as a string to keep its accuracy. It looks, however, it even looses the micro precision, by the way. I mean the bug of "1460544188" is the number of digits after the missing decimal point.

[tagomoris]

Getting as much accuracy as possible is optional API for EventTime. It behaves as integer for many operations, and provides sub-second value if requested.
I think we should keep this dogma in JSON serialization too.

[kawanet]

You mean it should be an Integer but not a Float nor String. I see.

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By the way, just as a digression, I found that JSON spec does not define the specific precision for its number representation. It could deliver Quadruple (128bit) or other extended precision (such as 80bit). Most of JSON parsers would crop it as Double (64bit), however.