DCBs can now have a null session pointer and if they do, they are in the
persistent pool. The no-null-session assertions are no longer valid but
with a reorganization of the pooling code to only use file descriptors,
the assertions can be added back.
Minor renaming of the session state enum values. Also exposed the session
state stringification function in the public header and removed the
stringification macro.
The error flag was set before the function was called which caused the
function to never be used. As the core should handle the filtering of
multiple errors on the same DCB, the protocol modules should not check it.
When a response to a prepared statement was processed, the number of EOF
packets was used to see whether the response was complete. This code used
a function that does not work with the special packet returned by a PS
preparation that is similar to an OK packet.
The correct method is to count the total number of packets in the
response.
As each connection now immediately gets a session the dummy session is no
longer required. The next step would be to combine parts of the session
and the client DCB into one entity. This would prevent the possibility of
a client DCB with no associated session. Backend DCBs are different as
they can move from one session to another when the persistent connection
pool is in use.
The collection of resultsets needs to be disabled by default when a
response is received to cover the cases where an error is returned.
The collection of results should also not be set for queries that do not
generate any responses.
See script directory for method. The script to run in the top level
MaxScale directory is called maxscale-uncrustify.sh, which uses
another script, list-src, from the same directory (so you need to set
your PATH). The uncrustify version was 0.66.
The result collection now covers more cases, including the use of
COM_CHANGE_USER. The addition of COM_STMT_EXECUTE to the list of commands
that generate result set responses is needed in order for the code to take
the correct branch.
With the removal of the old session command implementation, the code that
used it can be removed or replaced with newer constructs. As a result, the
backend protocol no longer does any session command processing.
The three buffer types, GWBUF_TYPE_SESCMD_RESPONSE,
GWBUF_TYPE_RESPONSE_END and GWBUF_TYPE_SESCMD as well as their related
macros are no longer used and can be removed.
When a client connection is closed by MaxScale before the client initiates
a controlled closing of the connection, an error message is sent. This
error message now also explains why the connection was closed to make
problem resolution easier.
The protocol now allows protocol modules to return JSON formatted
information about the protocol module internals. Currently this is only
implemented by the mariadbbackend module and it returns the current
connection ID on the backend server.
Removed unused and properly documented all entry points in the protocol
module API. As the removal of the `session` entry point is an backwards
incompatible change, the protocol API version was updated.
The re-authentication done in MaxScale caused multiple error packets to be
sent for the same COM_CHANGE_USER. In addition to this, the failure of
authentication did not terminate the client connection.
The change in behavior requires the test case to be changed as well.
Session commands that span multiple packets are now allowed and will
work. However, if one is executed the session command history is disabled
as no interface for appending to session commands exists.
The backend protocol modules now also correctly track the current
command. This was a pre-requisite for large session commands as they
needed to be gathered into a single buffer and to do this the current
command had to be accurate.
Updated tests to expect success instead of failure for large prepared
statements.
