root/lu/SocketReader.lua

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-- Title:               SocketReader.lua
-- Description:         Like a square peg in a round hole
-- Author:              Raphaël Szwarc http://alt.textdrive.com/lua/
-- Creation Date:       February 1, 2005
-- Legal:               Copyright (C) 2005 Raphaël Szwarc
--------------------------------------------------------------------------------

-- import dependencies
local LUObject = require( "LUObject" )
local LUTask = require( "LUTask" )
local os = require( "os" )

-- define the class
local super = LUObject
local self = super()

-- constant(s)
local Timeout = 60

-- initialization method
function self:init( aSocket )
        self = super.init( self )

        self._socket = aSocket
        self._status = "timeout"
        
        return self
end

-- method to access this reader socket
function self:socket()
        return self._socket
end

 -- method to close this socket
function self:close()
        self._status = "closed"
        
        return self:socket():close()
end

 -- method to read a value
function self:read( aPattern, aTimeout )
        local aTime = os.time()
        local aValue, aStatus, aPartialValue = nil
        
        aPattern = aPattern or "*l"
        aTimeout = aTimeout or Timeout
        
        while true do
                aValue, aStatus, aPartialValue = self:socket():receive( aPattern, aPartialValue )
                
                self._status = aStatus
                
                if aValue ~= nil or aStatus ~= "timeout" then
                        return aValue, aStatus
                end
                
                if aStatus == "timeout" then
                        if os.difftime( os.time(), aTime ) >= aTimeout then
                                return nil, aStatus
                        end
                else
                        aTime = os.time()
                end

                LUTask:yield( "reader" )
        end
        
        return nil, aStatus
end

-- method to access this reader status
function self:status()
        return self._status
end

return self