29 lines
955 B
Racket
29 lines
955 B
Racket
#lang syndicate
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(provide (struct-out tcp-channel-line))
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(require "tcp.rkt")
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(struct tcp-channel-line (source destination bytes) #:prefab)
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;; This should probably be in the standard library.
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(define (bytes-index bs b)
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(define len (bytes-length bs))
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(let loop ((i 0))
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(cond [(= i len) #f]
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[(eqv? (bytes-ref bs i) b) i]
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[else (loop (+ i 1))])))
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(spawn #:name 'line-reader-factory
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(during/spawn (observe (tcp-channel-line $src $dst _))
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#:name `(line-reader ,src ,dst)
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(field [buffer #""])
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(on (message (tcp-channel src dst $bs))
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(buffer (bytes-append (buffer) bs)))
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(begin/dataflow
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(define newline-pos (bytes-index (buffer) (char->integer #\newline)))
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(when newline-pos
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(define line (subbytes (buffer) 0 newline-pos))
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(buffer (subbytes (buffer) (+ newline-pos 1)))
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(send! (tcp-channel-line src dst line))))))
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