PHPC-1891, PHPC-1892, PHPC-1893: Implement TopologyDescription, SDAMSubscriber, and TopologyChangedEvent

[tanlisu]

https://jira.mongodb.org/browse/PHPC-1891
https://jira.mongodb.org/browse/PHPC-1892
https://jira.mongodb.org/browse/PHPC-1893

[tanlisu]

@jmikola For updating the libmongoc submodule, how do I determine what to update LIBMONGOC_VERSION_CURRENT to?

[jmikola]

For updating the libmongoc submodule, how do I determine what to update LIBMONGOC_VERSION_CURRENT to?

This was already covered in Ensure libmongoc version information is correct within the contributing docs. I added a note about the script's outstanding issue with detecting a version for a non-release, non-master branch (similar to what I noted in #1243 (comment)).

I've also amended the Update libmongoc submodule section to outline the process for pointing the submodule to a specific fork, which covers your case where you need to point to the commit in mongodb/mongo-c-driver#785.

[jmikola]

Note: another step for bumping libmongoc submodules is to Update sources in build configurations. I recently did this in ac49353 and have since merged master into the feature/sdam-monitoring branch so you may want to update feature/sdam-monitoring and rebase this PR to incorporate those changes.

[tanlisu]

The GitHub CI build failures (https://github.com/mongodb/mongo-php-driver/pull/1244/checks?check_run_id=3256294983) say "implicit declaration of function ‘mongoc_topology_description_new_copy’" - is this because I didn't update the libmongoc submodule correctly? I updated src/LIBMONGOC_VERSION_CURRENT using make libmongoc-version-current and checked that PHP_MONGODB_MONGOC_SOURCES was updated in both config.m4 and config.w32.

[jmikola]

Is this because I didn't update the libmongoc submodule correctly?

Most likely. I don't see any commits in this PR updating .gitmodules or the src/libmongoc submodule. If you look at previous commits in PHPC where we update the libmongoc submodule, you'll see that we change src/LIBMONGOC_VERSION_CURRENT and the submodule concurrently. In your case, since you also need to update the submodule to point to a different repository, you also need to update .gitmodules (as discussed in #1244 (comment) and the recently updated docs linked therein).

[tanlisu]

Hmm I've updated .gitmodules and src/libmongoc (20ca7fc) but the src/libmongoc submodule doesn't seem to be updating - do you know what might be wrong?

[tanlisu]

@jmikola I realize I didn't add arginfo for the TopologyDescription class as in #1245 - does it sound right to add that for just the hasReadableServer function which takes a read preference as argument?

[jmikola]

I realize I didn't add arginfo for the TopologyDescription class as in #1245 - does it sound right to add that for just the hasReadableServer function which takes a read preference as argument?

Yes. Arginfo should definitely be correct for any method. The arginfo for hasReadableServer will resemble that for Manager::selectServer(), but you'll need to change some parameters in both macros to convey that the ReadPreference argument is optional and can be null.

Consider the following definitions of both macros from LXR:

• ZEND_BEGIN_ARG_INFO_EX
• ZEND_ARG_OBJ_INFO

[jmikola]

This test would be improved by capturing the final TopologyDescription and asserting that hasReadableServer() returns true.

[jmikola]

Related to my earlier comments, we can change this test to capture the last TopologyDescription object and expect true here.

[tanlisu]

The manager-ctor-auth_mechanism-error-001.phpt test fails for me locally and on the GitHub CI (https://github.com/mongodb/mongo-php-driver/pull/1244/checks?check_run_id=3304714843); I think it's caused by the most recent libmongoc submodule update since the test works when I revert the submodule and run it locally.
Note: it still doesn't seem to be working after updating to the most recent commit (mongodb/mongo-c-driver@6abd837)

[jmikola]

@tanlisu Also note that mongodb/mongo-c-driver#785 (for CDRIVER-3909) has been merged. You can revert the change to .gitmodules in this PR and update the submodule to mongodb/mongo-c-driver@d283803 (current HEAD of master). Switching back to the master branch should also mean make libmongoc-version-current should detect the correct version as well.