After ordering in September, I finally received my Raspberry Pi a few weeks ago (the upside of the long time between order and delivery is that mine is the new revision with 512Mb RAM).
I have no specific plans with the device other than playing a bit around with it. One of the things I obviously had to try was to run Bluefish as editor on the Pi. Installing all the build dependencies and compiling takes a few hours, but Bluefish was running as expected. Entirely true? No, some bits were slow, most notably the auto completion popup. So I dug into the code to find out why.
In the auto-completion popup, Bluefish has a “reference pane”. This shows some rerefence information about the item you are trying to auto-complete. For an HTML tag this might show the valid attributes, for a C function it might shown the arguments and the return codes etc. This is implemented with a hash-table and the “changed” signal on the GtkTreeSelection: if the selection changes, a lookup in the hash table is performed to see if there is reference information available. On the next key-press, bluefish re-calucalates the possible auto-completion candidates, and re-fills the GtkListStore that lies underneath the GtkTreeView. And this is where the problem was: before filling the list of items, Bluefish has to clear the old items. And the selection changed signal is called for each item that is removed from the GtkListStore, which in it’s turn does a hash table lookup and renders the reference information in the reference pane. Do that for 15000 items and you’ll have 100% cpu load for a second on the Raspberry Pi.
So what is improved now: first, the number of items in the auto-completion popup is limited to 500 items. Second a boolean is added that is set to TRUE whenever the popup is clearing or filling items. As long as that boolean is TRUE, the selection changed signal will do nothing at all.
The result: even on the Raspberry Pi, Bluefish auto-completion is again much faster than you can type, and every bit of sluggishness is gone. We’re close to the 2.2.4 release, and this fix will be part of 2.2.4!