megaco_transport
Megaco transport behaviour.
The following functions should be exported from a
megaco_transport callback module:
-
send_message/2 [
mandatory] -
send_message/3 [
optional] -
resend_message/2 [
optional]
Functions
Module:send_message(Handle, Msg) -> ok | {cancel, Reason} | Error
Module:send_message(Handle, Msg, Resend) -> ok | {cancel, Reason} | Error
Handle = term()Msg = binary() | iolist()Resend = boolean()Reason = term()Error = term()
Send a megaco message.
If the function returns {cancel, Reason},
this means the transport module decided not to send the message.
This is not an error. No error messages will be issued
and no error counters incremented.
What actions this will result in depends on what kind of
message was sent.
In the case of requests, megaco will cancel the message in much
the same way as if megaco:cancel had been called
(after a successfull send). The information will be propagated
back to the user differently depending on how the request(s) where
issued: For requests issued using
megaco:call, the info
will be delivered in the return value. For requests issued
using megaco:cast the info will be delivered
via a call to the callback function
handle_trans_reply.
In the case of reply, megaco will cancel the reply and information of this will be returned to the user via a call to the callback function handle_trans_ack.
The function send_message/3 will only be called if the
resend_indication
config option has been set to the value flag. The third
argument, Resend then indicates if the message send is
a resend or not.
Module:resend_message(Handle, Msg) -> ok | {cancel, Reason} | Error
Handle = term()Msg = binary() | iolist()Reason = term()Error = term()
Re-send a megaco message.
Note that this function will only be called if the user has set the
resend_indication
config option to trueand it is in fact a message
resend. If not both of these condition's are meet,
send_message will be called.
If the function returns {cancel, Reason}, this means the
transport module decided not to send the message.
This is not an error. No error messages will be issued
and no error counters incremented.
What actions this will result in depends on what kind of
message was sent.
In the case of requests, megaco will cancel the message in much
the same way as if megaco:cancel had been called
(after a successfull send). The information will be propagated
back to the user differently depending on how the request(s) where
issued: For requests issued using
megaco:call, the info
will be delivered in the return value. For requests issued
using megaco:cast the info will be delivered via a call
to the callback function
handle_trans_reply.
In the case of reply, megaco will cancel the reply and information of this will be returned to the user via a call to the callback function handle_trans_ack.