Currently when an MQTT topic filter contains characters from the
configured wildcard syntax the conversion to/from this syntax breaks.
For example, when using the default wildcard syntax if an MQTT topic
filter contains a . the conversion from the MQTT wildcard syntax to the
core wildcard syntax and back will result in the `.` being replaced with
a `/.`.
This commit fixes that plus a few other things...
- Implements proper conversions to/from one WildcardConfiguration to
another.
- Refactors the MQTT code which invokes these conversion methods. This
includes simplifying a lot of test code.
- Adds lots of tests for everything.
- Clarifies some variable naming to better distinguish between core and
MQTT.
This commit:
- Eliminates MQTT session storage on every successful connection.
Instead data is only written when subsriptions are created or
destroyed.
- Adds a configuration property for the storage timeout.
- Updates the documentation with relevant information.
- Refactors a few bits of code to eliminate unnecessary variables, etc.
Durable subscrption state is part of the MQTT specification which has
not been supported until now. This functionality is implemented via an
internal last-value queue. When an MQTT client creates, updates, or
adds a subscription a message using the client-ID as the last-value is
sent to the internal queue. When the broker restarts this data is read
from the queue and populates the in-memory MQTT data-structures.
Therefore subscribers can reconnect and resume their session's
subscriptions without have to manually resubscribe.
MQTT state is now managed centrally per-broker rather than in the
MQTTProtocolManager since there is one instance of MQTTProtocolManager
for each acceptor allowing MQTT connections. Managing state per acceptor
would allow odd behavior with clients connecting to different acceptors
with the same client ID.
The subscriptions are serialized as raw bytes with a "version" byte for
potential future use, but I intentionally avoided adding complex
scaffolding to support multiple versions. We can add that complexity
later if necessary.
Some tests needed to be changed since instantiating an MQTT protocol
manager now creates an internal queue. A handful of tests assume that no
queues will exist other than the ones they create themselves. I updated
the main test super-class so that an MQTT protocol manager is not
automatically instantiated when configuring a broker for in-vm support.
Markdown, which is currently used for user-facing documentation, is good
for a lot of things. However, it's not great for the kind of complex
documentation we have and our need to produce both multi-page HTML and
single-page PDF output via Maven.
Markdown lacks features which would make the documentation easier to
read, easier to navigate, and just look better overall.
The current tool-chain uses honkit and a tool called Calibre. Honkit is
written in TypeScript and is installed via NPM. Calibre is a native tool
so it must be installed via an OS-specific package manager. All this
complexity makes building, releasing, uploading, etc. a pain.
AsciiDoc is relatively simple like Markdown, but it has more features
for presentation and navigation not to mention Java-based Maven tooling
to generate both HTML and PDF. Migrating will improve both the
appearance of the documentation as well as the processes to generate and
upload it.
This commit contains the following changes:
- Convert all the Markdown for the User Manual, Migration Guide, and
Hacking guide to AsciiDoc via kramdown [1].
- Update the `artemis-website` build to use AsciiDoctor Maven tooling.
- Update `RELEASING.md` with simplified instructions.
- Update Hacking Guide with simplified instructions.
- Use AsciiDoc link syntax in Artemis Maven doc plugin.
- Drop EPUB & MOBI docs for User Manual as well as PDF for the Hacking
Guide. All docs will be HTML only except for the User Manual which
will have PDF.
- Move all docs up out of their respective "en" directory. This was a
hold-over from when we had docs in different languages.
- Migration & Hacking Guides are now single-page HTML since they are
relatively short.
- Refactor README.md to simplify and remove redundant content.
Benefits of the change:
- Much simplified tooling. No more NPM packages or native tools.
- Auto-generated table of contents for every chapter.
- Auto-generated anchor links for every sub-section.
- Overall more appealing presentation.
- All docs will use the ActiveMQ favicon.
- No more manual line-wrapping! AsciiDoc recommends one sentence per
line and paragraphs are separated by a blank line.
- AsciiDoctor plugins for IDEA are quite good.
- Resulting HTML is less than *half* of the previous size.
All previous links/bookmarks should continue to work.
[1] https://github.com/asciidoctor/kramdown-asciidoc
Justin Bertram
Robbie Gemmell