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author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
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committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
tree | 2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/net/tcp_read_line.v | |
download | cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.tar.gz cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.tar.bz2 cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.zip |
Diffstat (limited to 'v_windows/v/vlib/net/tcp_read_line.v')
-rw-r--r-- | v_windows/v/vlib/net/tcp_read_line.v | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/v_windows/v/vlib/net/tcp_read_line.v b/v_windows/v/vlib/net/tcp_read_line.v new file mode 100644 index 0000000..ec4a18e --- /dev/null +++ b/v_windows/v/vlib/net/tcp_read_line.v @@ -0,0 +1,90 @@ +module net + +const ( + crlf = '\r\n' + msg_peek = 0x02 + max_read = 400 +) + +// get_blocking returns whether the connection is in a blocking state, +// that is calls to .read_line, C.recv etc will block till there is new +// data arrived, instead of returning immediately. +pub fn (mut con TcpConn) get_blocking() bool { + // flags := C.fcntl(con.sock.handle, C.F_GETFL, 0) + // return 0 == flags & C.O_NONBLOCK + return con.is_blocking +} + +// set_blocking will change the state of the connection to either blocking, +// when state is true, or non blocking (false). +// The default for `net` tcp connections is the non blocking mode. +// Calling .read_line will set the connection to blocking mode. +pub fn (mut con TcpConn) set_blocking(state bool) ? { + con.is_blocking = state + $if windows { + mut t := u32(0) + if !con.is_blocking { + t = 1 + } + socket_error(C.ioctlsocket(con.sock.handle, fionbio, &t)) ? + } $else { + mut flags := C.fcntl(con.sock.handle, C.F_GETFL, 0) + if state { + flags &= ~C.O_NONBLOCK + } else { + flags |= C.O_NONBLOCK + } + socket_error(C.fcntl(con.sock.handle, C.F_SETFL, flags)) ? + } +} + +// read_line is a *simple*, *non customizable*, blocking line reader. +// It will *always* return a line, ending with CRLF, or just '', on EOF. +// NB: if you want more control over the buffer, please use a buffered IO +// reader instead: `io.new_buffered_reader({reader: io.make_reader(con)})` +pub fn (mut con TcpConn) read_line() string { + mut buf := [net.max_read]byte{} // where C.recv will store the network data + mut res := '' // The final result, including the ending \n. + if !con.is_blocking { + con.set_blocking(true) or {} + } + for { + mut line := '' // The current line. Can be a partial without \n in it. + n := C.recv(con.sock.handle, &buf[0], net.max_read - 1, net.msg_peek | msg_nosignal) + if n == -1 { + return res + } + if n == 0 { + return res + } + buf[n] = `\0` + mut eol_idx := -1 + for i in 0 .. n { + if int(buf[i]) == `\n` { + eol_idx = i + // Ensure that tos_clone(buf) later, + // will return *only* the first line (including \n), + // and ignore the rest + buf[i + 1] = `\0` + break + } + } + line = unsafe { tos_clone(&buf[0]) } + if eol_idx > 0 { + // At this point, we are sure that recv returned valid data, + // that contains *at least* one line. + // Ensure that the block till the first \n (including it) + // is removed from the socket's receive queue, so that it does + // not get read again. + C.recv(con.sock.handle, &buf[0], eol_idx + 1, msg_nosignal) + res += line + break + } + // recv returned a buffer without \n in it . + C.recv(con.sock.handle, &buf[0], n, msg_nosignal) + res += line + res += net.crlf + break + } + return res +} |