77 lines
2.2 KiB
Plaintext
77 lines
2.2 KiB
Plaintext
#lang racket
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;; New imports:
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(require xml net/url)
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;; No changes to `serve' or `accept-and-handle'...
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(define (serve port-no)
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(define main-cust (make-custodian))
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(parameterize ([current-custodian main-cust])
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(define listener (tcp-listen port-no 5 #t))
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(define (loop)
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(accept-and-handle listener)
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(loop))
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(thread loop))
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(lambda ()
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(custodian-shutdown-all main-cust)))
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(define (accept-and-handle listener)
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(define cust (make-custodian))
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(parameterize ([current-custodian cust])
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(define-values (in out) (tcp-accept listener))
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(thread (lambda ()
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(handle in out)
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(close-input-port in)
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(close-output-port out))))
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;; Watcher thread:
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(thread (lambda ()
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(sleep 10)
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(custodian-shutdown-all cust))))
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;; The `handle' function now parses the request into `req', and it
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;; calls the new `dispatch' function to get the response, which is an
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;; xexpr instead of a string.
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(define (handle in out)
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(define req
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;; Match the first line to extract the request:
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(regexp-match #rx"^GET (.+) HTTP/[0-9]+\\.[0-9]+"
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(read-line in)))
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(when req
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;; Discard the rest of the header (up to blank line):
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(regexp-match #rx"(\r\n|^)\r\n" in)
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;; Dispatch:
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(let ([xexpr (dispatch (list-ref req 1))])
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;; Send reply:
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(display "HTTP/1.0 200 Okay\r\n" out)
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(display "Server: k\r\nContent-Type: text/html\r\n\r\n" out)
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(display (xexpr->string xexpr) out))))
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;; New: the `dispatch' function and `dispatch-table':
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(define (dispatch str-path)
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;; Parse the request as a URL:
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(define url (string->url str-path))
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;; Extract the path part:
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(define path (map path/param-path (url-path url)))
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;; Find a handler based on the path's first element:
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(define h (hash-ref dispatch-table (car path) #f))
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(if h
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;; Call a handler:
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(h (url-query url))
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;; No handler found:
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`(html (head (title "Error"))
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(body
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(font ((color "red"))
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"Unknown page: "
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,str-path)))))
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(define dispatch-table (make-hash))
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;; A simple dispatcher:
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(hash-set! dispatch-table "hello"
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(lambda (query)
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`(html (body "Hello, World!"))))
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