Messages have the same types of file-based scoping mechanisms as patterns. Table 8-3 describes these scopes.
Table 8-3 Scoping Mechanisms for Messages
When a message is scoped to TT_FILE
or TT_BOTH
, the ToolTalk client library checks the database server for all sessions that have clients that are interested in the file and sends the message to all of the interested ToolTalk sessions. The ToolTalk sessions then match the messages to the appropriate clients. The message sender is not required to explicitly call to tt_file_join.
If a message that is scoped to TT_FILE_IN_SESSION
or TT_SESSION
contains a file, the database server is not contacted and the message is sent only to clients that are scoped to the message's session.