protojure.grpc.codec.lpm — protojure 1.0.1

Utility functions for GRPC length-prefixed-message encoding.

decode clj

(decode f
        input
        output
        {:keys [codecs content-coding tmo]
         :or {codecs compression/builtin-codecs tmo 5000}
         :as options})

Takes a parsing function, a pair of input/output core.async channels, and an optional codec and decodes a stream of length-prefixed-message (LPM).

Parameters

Value	Type	Description
f	(fn [is])	A protobuf decoder function with an arity of 1 that accepts an instance of InputStream, such as the pb-> functions produced by the protoc-gen-clojure compiler
input	core.async/channel	A core.async channel that carries LPM encoded bytes, one byte per (take!). Closing the input will shut down the pipeline.
output	core.async/channel	A core.async channel that carries decoded protobuf records. Will be closed when the pipeline shuts down.
options	map	See Options

Options

| Value | Type | Default | Description | |--------------------|-----------------------------------------------------------------| | content-coding | string | "identity" | See Content-coding table | | codecs | map | protojure.grpc.codec.compression/builtin-codecs | The dictionary of codecs to utilize | | tmo | unsigned int | 5000ms | A timeout, in ms, for receiving the remaining LPM payload bytes once the header has been received. |

Example

{:content-coding "gzip"
 :codecs mycodecs
 :tmo 1000}

Content-coding

The value for the content-coding option must be one of

Value	Comment
nil	no compression
"identity"	no compression
other string	retrieves the codec from codecs option

encode clj

(encode f
        input
        output
        {:keys [codecs content-coding max-frame-size]
         :or {codecs compression/builtin-codecs}
         :as options})

Takes an input and output core.async channel, along with an optional codec and encodes a stream of 0 or more length-prefixed-message messages.

Parameters

Value	Type	Description
f	(fn [init])	A protobuf encoder function with an arity of 1 that accepts an init-map, such as the new-XX functions produced by the protoc-gen-clojure compiler
input	core.async/channel	A core.async channel expected to carry maps that will be transformed to protobuf messages based on f
output	core.async/channel	A core.async channel that will carry bytes representing the encoded messages. See max-frame-size. Will be closed when the pipeline shuts down.
options	map	See Options

Options

| Value | Type | Default | Description | |--------------------|---------------------------------------------------------------------------------------------------------------| | content-coding | String | "identity" | See the content-coding section of decode | | codecs | map | protojure.grpc.codec.compression/builtin-codecs | The dictionary of codecs to utilize | | max-frame-size | UInt32 | 0 | Maximum frame-size emitted on output channel. See Output channel details below |

Output channel details

The max-frame-size option dictates how bytes are encoded on the output channel:

• 0: (Default) Indicates 'stream' mode: Bytes are encoded one byte per (put!).
• >0: Indicates 'framed' mode: The specified value will dictate the upper bound on byte-array based frames emitted to the output channel.

Example

{:content-coding "gzip"
 :codecs mycodecs
 :max-frame-size 16384}