40 lines
1.8 KiB
Go
40 lines
1.8 KiB
Go
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package websocket
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// CompressionMode represents the modes available to the deflate extension.
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// See https://tools.ietf.org/html/rfc7692
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//
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// A compatibility layer is implemented for the older deflate-frame extension used
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// by safari. See https://tools.ietf.org/html/draft-tyoshino-hybi-websocket-perframe-deflate-06
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// It will work the same in every way except that we cannot signal to the peer we
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// want to use no context takeover on our side, we can only signal that they should.
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// It is however currently disabled due to Safari bugs. See https://github.com/nhooyr/websocket/issues/218
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type CompressionMode int
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const (
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// CompressionNoContextTakeover grabs a new flate.Reader and flate.Writer as needed
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// for every message. This applies to both server and client side.
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//
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// This means less efficient compression as the sliding window from previous messages
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// will not be used but the memory overhead will be lower if the connections
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// are long lived and seldom used.
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//
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// The message will only be compressed if greater than 512 bytes.
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CompressionNoContextTakeover CompressionMode = iota
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// CompressionContextTakeover uses a flate.Reader and flate.Writer per connection.
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// This enables reusing the sliding window from previous messages.
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// As most WebSocket protocols are repetitive, this can be very efficient.
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// It carries an overhead of 8 kB for every connection compared to CompressionNoContextTakeover.
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//
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// If the peer negotiates NoContextTakeover on the client or server side, it will be
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// used instead as this is required by the RFC.
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CompressionContextTakeover
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// CompressionDisabled disables the deflate extension.
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//
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// Use this if you are using a predominantly binary protocol with very
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// little duplication in between messages or CPU and memory are more
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// important than bandwidth.
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CompressionDisabled
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)
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