The code only handled the basic version of the command, returning incorrect
results if modifiers were used. The code is now removed, causing the command
to be routed to the backend of the current database. This will give correct
results as long as that backend contains all the tables of the database e.g.
no table sharding.
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.
Changes with ResultSet caused the send_databases and send_tables
functions to always return false. Also changed send_database to
return void since it shouldn't be able to fail anymore.
get_shard_target had become little bloated with the recent changes so
some routing cases were moved to their own functions. Also removed
some code that was not needed.
Add support for binary protocol prepared statements for schemarouter.
This implementation doesn't yet attempt to handle all the edge cases.
Prepared statements are routed to the server that contains the affected
tables, the internal id from the server is then mapped to the session
command id that is inceremented for each prepared statement. This unique
session command id is returned to the client because internal id given
by server might be same around different servers and this way it is
possible to keep track of them and route them to the right servers when
executed.
The schemarouter now also uses versioned configurations implemented by
shared pointers to configuration objects. Moved all the configuration
management into the Config class. Removed router options from
schemarouter.
Previously schemarouter only mapped databases to the servers
they were resided on. Now all the tables are also mapped to allow the
router to route queries to the right server based on the tables used in
that query.
Using the same implementation of the Backend and SessionCommand classes in
both schemarouter and readwritesplit will prevent duplication of code.
This commit only splits the generic parts of the class to a Backend class
which the schemarouter then extends. The session commands for both routers
are similar so they require no special handling.
The SERVER_REF and DCB members of the Backend class are now
private. Access to the stored SERVER_REF is provided with the backend()
function. No accompanying setter function is provided as the backend
server should not change during the lifetime of the session.
The creation of the internal DCB is hidden behind the connect()
function. It simplifies the process of connecting to a server by removing
the need to manually do the bookkeeping of the server reference connection
counts. Access to the DCB is provided by the dcb() function.
The closing of the backend is done with the close() function which
contains the code that was previously in closeSession. If the backend
isn't closed when the destructor is called, it will be done
automatically. This should prevent connection leakage.
The pending command queues and the methods used to write them are now also
internal to the backends. They are simple wrappers around dcb->func.write
and the interfaces provided by the Buffer class. The mapping command queue
is still public. It needs to be combined with the generic command queue.
The schemarouter now uses shared pointers. This removes the need to copy
the class.
Following changes move the member variables inside the Backend class.
The functions that handle Backend classes are now methods of the class
itself.
Prefix all member variables with `m_` to distinct them from other
variables.
Changed the backend_ref_t struct into a Backend class. Replaced static
arrays with lists. Altered functions to make the code compile.
Further refactoring is needed, a part of the functions should be moved
into this new class.
Configuration errors can be resolved before the instance is created. This
avoids the unnecessary throws that were generated when an error occured.
As the configuration is stored in the router, the router sessions can use
a pointer to it instead of copying it locally. This should avoid some
unnecessary copying if more complex configuration parameters are added.
The use of a pointer instead of a reference conveys the message that the
lifetime of the object being pointed can, and most likely will, exceed the
lifetime of the function.
Also shuffled the member variables and internal functions around and
removed unneeded function declarations.
