The process of appending to a std::string always includes a size check in
case the internal storage needs to expand. Given that we know a
canonicalized version of a query string is never larger than the original
string and that we pre-allocate enough memory to cope with the worst-case
scenario, the extra logic in std::string::push_back is unnecessary and an
extra cost. Writing directly into the string avoids this cost and improves
the performance.
Switched from default character type functions to ones that use lookup
tables. Eliminated the internal state and replaced with in-place iteration
of the query. Added code to allow single-lookup detection of normal
characters.
The log message should now contain enough information to more easily debug
any configuration issues that result from updating the main config file
after runtime changes have been done.
Also fixed the theoretical race condition in detection of persisted
configuration files by only checking for their existence once.
All global parameters are now handled by the runtime configuration
modification code. The parameters that are trivial to update can now be
updated at runtime. All other global parameters cause a new error message
to be returned stating that the parameter in question cannot be modified
at runtime.
Also updated the list of modifiable parameters in MaxCtrl. This list
should not be stored in MaxCtrl and should be created by MaxScale at
runtime.
The old behavior is to not start MaxScale if any listeners fail to
bind. This behavior is convenient when there are conflicts with other
applications so it should remain. This change prevents the internal
service restarts from functioning which might have already been broken.
The "restarting" of services after a failure to bind to an interface is
somewhat questionable. Almost no transient errors are expected at startup
with the exception of running out of sockets. This should probably be the
only case when the internal service restart is done and in other cases it
causes more harm than good.
Since we know the worst-case size of a canonical statement is the size of
the query string, we can reduce the number of memory allocations to one in
the get_canonical function.
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 an attempt to accept a client DCB fails, the session should only be
deleted directly if the allocation of the client DCB fails. Otherwise the
closing of the DCB triggers the session deletion.
When doing a loop over each DCB, don't process DCBs without sessions. For
now this is correct behavior as only DCBs in the persistent pool have no
session.
When a listener was created at runtime but it failed to start, it would
not be automatically removed from the system. This caused the MaxCtrl
cluster sync test to fail.
Fixed the use of DCBs and sessions in the mock testing framework and
adapted them to the changes done to the objects in question. Extended the
testing utility functions to allow preloading modules as well as making it
possible to only partially initialize the query classifier.
The REST API and MaxCtrl tests relied upon the implicit sessions that were
created by the listeners. This can be corrected and improved by creating
an actual connection to MaxScale to check that a client session is indeed
created.
