bionic (3) megaco_flex_scanner.3erl.gz

NAME

       megaco_flex_scanner - Interface module to the flex scanner linked in driver.

DESCRIPTION

       This module contains the public interface to the flex scanner linked in driver. The flex scanner performs
       the scanning phase of text message decoding.

       The flex scanner is written using a tool called flex. In order to be able to  compile  the  flex  scanner
       driver, this tool has to be available.

       By  default  the  flex  scanner  reports line-number of an error. But it can be built without line-number
       reporting. Instead token number is used. This will speed up  the  scanning  some  5-10%.  Use  --disable-
       megaco-flex-scanner-lineno when configuring the application.

       The  scanner  will,  by  default,  be  built as a reentrant scanner if the flex utility supports this (it
       depends on the version of flex). It is possible to explicitly disable this even when flex  support  this.
       Use --disable-megaco-reentrant-flex-scanner when configuring the application.

DATA TYPES

       megaco_ports() = term()
       megaco_version() = integer() >= 1

EXPORTS

       start() -> {ok, PortOrPorts} | {error, Reason}

              Types:

                 PortOrPorts = megaco_ports()
                 Reason = term()

              This  function  is  used to start the flex scanner. It locates the library and loads the linked in
              driver.

              On a single core system or if it's a non-reentrant scanner, a single port is created. On a  multi-
              core system with a reentrant scanner, several ports will be created (one for each scheduler).

              Note  that  the  process  that calls this function must be permanent. If it dies, the port(s) will
              exit and the driver unload.

       stop(PortOrPorts) -> stopped

              Types:

                 PortOrPorts = megaco_ports()

              This function is used to stop the flex scanner. It also unloads the driver.

       is_reentrant_enabled() -> Boolean

              Types:

                 Boolean = boolean()

              Is the flex scanner reentrant or not.

       is_scanner_port(Port, PortOrPorts) -> Boolean

              Types:

                 Port = port()
                 PortOrPorts = megaco_ports()
                 Boolean = boolean()

              Checks if a port is a flex scanner port or not (useful when if a port exits).

       scan(Binary, PortOrPorts) -> {ok, Tokens, Version, LatestLine} | {error, Reason, LatestLine}

              Types:

                 Binary = binary()
                 PortOrPorts = megaco_ports()
                 Tokens = list()
                 Version = megaco_version()
                 LatestLine = integer()
                 Reason = term()

              Scans a megaco message and generates a token list to be passed on the parser.