Class: Protocol::GRPC::Header::Timeout

Inherits:
String
  • Object
show all
Defined in:
lib/protocol/grpc/header/timeout.rb

Overview

The grpc-timeout header represents the gRPC request timeout.

The grpc-timeout header specifies how long the client is willing to wait for an RPC to complete. The format is: value + unit (H=hours, M=minutes, S=seconds, m=milliseconds, u=microseconds, n=nanoseconds). This header appears only in request headers, not in trailers.

Constant Summary collapse

FORMAT =

The wire format for a gRPC timeout value.

/\A(?<amount>[1-9]\d{0,7})(?<unit>[HMSmun])\z/

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(value) ⇒ Timeout

Initialize the timeout header with the given value.



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# File 'lib/protocol/grpc/header/timeout.rb', line 62

def initialize(value)
	super(value.to_s)
end

Class Method Details

.coerce(value) ⇒ Object

Coerce a value to a Timeout instance.

If a Numeric is provided, it will be formatted as a gRPC timeout string using format.



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# File 'lib/protocol/grpc/header/timeout.rb', line 51

def self.coerce(value)
	if value.is_a?(Numeric)
		return new(format(value))
	else
		return new(value.to_s)
	end
end

.format(timeout) ⇒ Object

Format a timeout duration for the grpc-timeout header.



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# File 'lib/protocol/grpc/header/timeout.rb', line 21

def self.format(timeout)
	if timeout >= 3600
		"#{(timeout / 3600).to_i}H"
	elsif timeout >= 60
		"#{(timeout / 60).to_i}M"
	elsif timeout >= 1
		"#{timeout.to_i}S"
	elsif timeout >= 0.001
		"#{(timeout * 1000).to_i}m"
	elsif timeout >= 0.000001
		"#{(timeout * 1_000_000).to_i}u"
	else
		"#{(timeout * 1_000_000_000).to_i}n"
	end
end

.parse(value) ⇒ Object

Parse a timeout from a header value.



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# File 'lib/protocol/grpc/header/timeout.rb', line 41

def self.parse(value)
	new(value)
end

.trailer? ⇒ Boolean

Whether this header is acceptable in HTTP trailers. The grpc-timeout header is request-only and does not appear in trailers.

Returns:

  • (Boolean) 


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# File 'lib/protocol/grpc/header/timeout.rb', line 98

def self.trailer?
	false
end

Instance Method Details

#<<(value) ⇒ Object

Merge another timeout value (takes the new value, as timeout should only appear once)



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# File 'lib/protocol/grpc/header/timeout.rb', line 89

def <<(value)
	replace(value.to_s)
	
	return self
end

#to_seconds ⇒ Object

Parse the timeout value to seconds.



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# File 'lib/protocol/grpc/header/timeout.rb', line 70

def to_seconds
	unless match = FORMAT.match(self)
		raise ArgumentError, "Invalid grpc-timeout: #{self.inspect}"
	end
	
	amount = match[:amount].to_i
	
	case match[:unit]
	when "H" then amount * 3600
	when "M" then amount * 60
	when "S" then amount
	when "m" then amount / 1000.0
	when "u" then amount / 1_000_000.0
	when "n" then amount / 1_000_000_000.0
	end
end