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.
For lifetime management keep RWBackends in a vector of unique_ptrs.
RWSplitSession keeps the unique_ptrs very private, and provides a vector
of plain pointers for all other interfaces.
This is essentially just a search and replace to change SRWBackend to
RWBackend* and SRWBackendList to PRWBackends, a vector of a raw
pointers. In the next few commits vector<unique_ptr<RWBackend>>
will be used for life time management.
There are a lot of diffs from the global search and replace. Only a few manual
edits had to be done.
list-src -x build | xargs sed -ri 's/SRWBackends/prwbackends/g'
list-src -x build | xargs sed -ri 's/const mxs::SRWBackend\&/const mxs::RWBackend\*/g'
list-src -x build | xargs sed -ri 's/const SRWBackend\&/const RWBackend\*/g'
list-src -x build | xargs sed -ri 's/mxs::SRWBackend\&/mxs::RWBackend\*/g'
list-src -x build | xargs sed -ri 's/mxs::SRWBackend/mxs::RWBackend\*/g'
list-src -x build | xargs sed -ri 's/SRWBackend\(\)/nullptr/g'
list-src -x build | xargs sed -ri 's/mxs::SRWBackend\&/mxs::RWBackend\*/g'
list-src -x build | xargs sed -ri 's/mxs::SRWBackend/mxs::RWBackend\*/g'
list-src -x build | xargs sed -ri 's/SRWBackend\&/RWBackend\*/g'
list-src -x build | xargs sed -ri 's/SRWBackend\b/RWBackend\*/g'
list-src -x build | xargs sed -ri 's/prwbackends/PRWBackends/g'
Allocating the session before a DCB guarantees that at no point will a DCB
have a null session. This further clarifies the concept of the session and
also allows the listener reference to be moved there.
Ideally, the session itself would allocate and assign the client DCB but
since the Listener is the only one who does it, it's acceptable for now.
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.
Whenever a client DCB is accepted, a session for it is allocated. This
simplifies the handling of shared data between DCBs by allowing it to be
placed inside the session object. Currently, the data is stashed away in
the client DCB.
By doing the actual accepting of the new DCB in the core, the protocol
modules can only do the actual protocol level work. This removes some of
the redundant code that was in the protocol modules.
Allocating DCB with new allows the use of C++ objects in the DCB
struct. Also the explicit poll field can be replaced by inheriting from
MXB_POLL_DATA.
Modified the functions to use a listener instead of a DCB in the accepting
process. This removes some of the dependenices that the listeners have on
the DCB system.
The iteration of listeners is now done via the global list of
listeners. This removes the need to have a service before a listener is
accessed which also reflects how the actual configuration is laid out. It
also guarantees that any results returned by the find functions will be
valid as long as the results are used.
If the server where a query is being executed is shutting down,
readwritesplit should treat it as an error to make retrying of the query
possible.
By treating server shutdowns as network errors, the same code path that is
used for actual network errors can be taken. This removes the need for any
extra retrying logic for this particular case.
If the client sends two different sets of capability bits during the
authentication phase of an SSL enabled connection, both sets need to be
combined. This prevents capabilities from degrading mid-connection which
is the case when Oracle Connector/J drops the SSL capability bit
mid-authentication.
If the service doesn't require collection of complete packets, the user
reauthentication done with COM_CHANGE_USER would be skipped. This caused
the change_user test to fail.
By temporarily switching to full packet collection mode for the duration
of the COM_CHANGE_USER, we avoid duplicating the code for the streaming
router types.
If the initial handshake that is sent by the accepting thread is buffered,
the subsequent flushing of it is done by the owning thread. As
cross-thread buffer usage is not allowed, the initial handshake must be
sent by the owning thread.
The intention was to send the lowest backend version string automatically
to the client instead of the default handshake version. This did not work
as the service version string was used instead of the server version.
By splitting the processing and state querying into two separate
functions, the result can be inspected multiple times without triggering
the result processing.
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.
