class BBS::Zmodem::Input

The receiver’s side of the line as the Sender reads it: its bytes (telnet commands taken out by the session) kept until they make a header, at most MAX_PENDING of them; five CANs in a row cancel.

Public Class Methods

new (session)

Source

# File lib/bbs/zmodem/input.rb, line 10
def initialize(session)
  @session = session
  @pending = []
  @cans    = 0
end

Reads from session (anything with BBS::Telnet#read_raw_byte).

Public Instance Methods

expect (*types, timeout: WAIT, ignore_timeout: false)

Source

# File lib/bbs/zmodem/input.rb, line 20
def expect(*types, timeout: WAIT, ignore_timeout: false)
  deadline = monotonic + timeout
  loop do
    header = read_header(timeout: deadline - monotonic)
    return if header.nil? && ignore_timeout
    raise Timeout if header.nil?
    raise Cancelled if [ZCAN, ZABORT, ZFERR].include?(header.type)
    return header if types.include?(header.type)
  end
end

Waits up to timeout seconds for a header of one of types and returns it, skipping others. Raises Cancelled when the receiver gives up, Timeout when nothing came (unless ignore_timeout: nil then), Hangup when the line dropped.

poll_header ()

Source

# File lib/bbs/zmodem/input.rb, line 33
def poll_header
  while (byte = @session.read_raw_byte(0)).is_a?(Integer)
    push(byte)
  end
  raise Hangup if byte.nil?

  scan_pending
end

Takes what the receiver has sent so far without waiting, and returns the header it makes, if any.

read_header (timeout:, interruptible: false)

Source

# File lib/bbs/zmodem/input.rb, line 44
def read_header(timeout:, interruptible: false)
  deadline = monotonic + timeout
  loop do
    header = scan_pending
    return header if header

    byte = next_byte(deadline - monotonic) or return
    raise Cancelled if interruptible && CANCEL_KEYS.include?(byte)

    push(byte)
  end
end

Waits up to timeout seconds for a header and returns it, or nil. With interruptible the caller’s Esc or Ctrl-C raises Cancelled.