shithub: mc

ref: b5bfee96de8a7fae9bdda140f630bea0b5997737
dir: /lib/std/listen+plan9.myr/

use sys

use "alloc"
use "cstrconv"
use "die"
use "dirname"
use "fmt"
use "mk"
use "option"
use "result"
use "sldup"
use "strfind"
use "syswrap"
use "utf"


pkg std =
	type announce = struct
		afd	: fd
		lpath	: byte[:]
		netdir	: byte[:]
	;;

	const announce	: (ds : byte[:] -> result(announce#, byte[:]))
	const aclose	: (a : announce# -> void)
	const accept	: (a : announce# -> result(fd, byte[:]))
;;

const Maxpath = 256

const announce = {ds
	var a, abuf : byte[Maxpath]
	var f, fbuf : byte[Maxpath]
	var nbuf : byte[32]
	var dir, ctl, n

	/* announce */
	match translate(ds, abuf[:], fbuf[:])
	| `Err _:	-> `Err "invalid dial string"
	| `Ok (addr, file):
		put("addr: {}, file: {}\n", addr, file)
		a = addr
		f = file
		match strrfind(f, "/")
		| `Some i:	dir = i
		| `None:	-> `Err "invalid net dir"
		;;
	;;

	match open(f, Ordwr)
	| `Ok fd:	ctl = fd
	| `Err e:	-> `Err "could not open ctl fd"
	;;

	match read(ctl, nbuf[:])
	| `Err e:	->`Err "unable to read ctl fd"
	| `Ok nn:
		n = fput(ctl, "announce {}", a)
		if n <= 0
			close(ctl)
			-> `Err "writing announce"
		;;
	
		-> `std.Ok mk([
			.afd=ctl,
			.lpath = fmt("{}/{}/listen", f[:dir], nbuf[:nn]),
			.netdir = sldup(f[:dir]),
		])
	;;

}

const aclose = {a
	slfree(a.netdir)
	slfree(a.lpath)
	close(a.afd)
	free(a)
}

const accept = {a -> result(fd, byte[:])
	var num, numbuf : byte[16]
	var dat, datbuf : byte[Maxpath]
	var lfd

	match open(a.lpath, Ordwr)
	| `Err e:	-> `Err "could not open ctl"
	| `Ok fd:	lfd = fd
	;;

	match read(lfd, numbuf[:])
	| `Ok n:	num = numbuf[:n]
	| `Err e:	-> `Err "could not accept"
	;;

	dat = bfmt(datbuf[:], "{}/{}/data", a.netdir, num)
	match open(dat, Ordwr)
	| `Ok fd:	-> `Ok fd
	| `Err e:	-> `Err "could not open data fd"
	;;
}

const translate = {ds, addrbuf, filebuf
	var cs, csbuf : byte[Maxpath]
	var r, rbuf : byte[Maxpath]
	var netdir, rest
	var addr, file

	match strfind(ds, "!")
	| `None:	-> `Err void
	| `Some sep:
		if decode(ds[:sep]) == '#' || decode(ds[:sep]) == '/'
			match strrfind(ds[:sep], "/")
			| `None:	-> `Err void
			| `Some idx:
				netdir = ds[:idx]
				addr = ""
				rest = ds[idx+1:]
			;;
		else
			netdir = "/net"
			addr = ds
			rest = ""
		;;
	;;

	cs = bfmt(csbuf[:], "{}/cs", netdir)
	match open(cs, Ordwr)
	| `Err e:	-> identtrans(rest, netdir, addrbuf, filebuf)
	| `Ok fd:
		match write(fd, addr)
		| `Err e:
			close(fd)
			-> `Err void
		| `Ok _:
		;;

		seek(fd, 0, Seekset)
		match read(fd, rbuf[:])
		| `Err e:
			close(fd)
			-> `Err void
		| `Ok n:
			r = rbuf[:n]
		;;
		close(fd)
	;;

	match strfind(r, " ")
	| `None:	-> `Err void
	| `Some i:
		addr = bfmt(addrbuf, "{}", r[i+1:])
		if decode(r) == '/'
			match strfind(r[:i], "/")
			| `None:	-> `Err void
			| `Some 0:	file = bfmt(filebuf, "{}{}", netdir, r[:i])
			| `Some n:	file = bfmt(filebuf, "{}{}", netdir, r[n+1:])
			;;
		else
			file = bfmt(filebuf, "{}/{}", netdir, r[:i])
		;;
	;;
	-> `Ok (addr, file) 
}

const identtrans = {ds, netdir, addrbuf, filebuf
	var a, f

	match strfind(ds, "!")
	| `None:
		-> `Err void
	| `Some sep:
		a = bfmt(addrbuf, "{}", ds[sep + 1:])
		f = bfmt(filebuf, "{}/{}/clone", netdir, ds[:sep])
		-> `Ok (a, f)
	;;
}