#MIXXX SQLITE CODE#

When Mixxx starts up or is shut down, it read/writes all of this track metadata to an XML file (mixxxtrack.xml). As you might guess, this was probably something the original Mixxx developers didn't think very hard about, because it doesn't scale well to large libraries. If you had a library with 100,000 songs, we were keeping the metadata (eg. I quickly discovered that there were two separate problems - The first being how the library was stored inside Mixxx at runtime, and the other being how it was stored on disk (XML).Īt runtime, we were using a gigantic skip-list to store the metadata of every single track in the library. Mixxx with the even newer library! (work-in-progress)īack in October at the GSoC Mentor Summit, I started hacking our library to use an integrated SQLite database to store track metadata, instead of storing them in a flat XML file on disk. Of course, this all depends on us having learned from our mistakes, and I hope that we have.

#MIXXX SQLITE CODE#

Rewriting the library code will prevent many of these bugs from reappearing, and should also prevent us from being in a quagmire like this again in the future. Some of the library-related bugs in our tracker are going to be very tough to fix because of the current poor design ( #194415, #202594, #257769, #258955, #275198, etc!). Basically, we made some design mistakes, and the only way to correct them and allow us to continue improving the library is to go back and rewrite it from scratch. Even if you grasp the MVC concepts at a high level, when you get deep into coding it, the separation between 'models', 'views', and the organization of GUI code can become mucky. or so we thought).Īs it turns out, many of the library problems that have been discovered since 1.6.0 are tied to the fact that we botched our use of MVC. One not-so-apparent difference is that the underlying code was changed to use the Model-View-Controller (MVC) paradigm, which is easy to do with Qt 4 (.

There was also significant work done on playlist handling and management. Some of the more visible changes were the addition of our search box and 'Browse' mode, which allows you to play songs off your hard drive without importing them into the library. In the (long) development cycle between Mixxx 1.5.0 and 1.6.0, several changes were made to the library.

This developer commentary explains the trials and tribulations of Mixxx's library code, and what the Mixxx developers are doing to improve it.

Mixxx sqlite