This changes greatly improves the speed of `beet export` and `beet info`
when the `--include-keys` option is used. It also removes the globbing
feature of `--include-keys` that was added in #1295. (See #3762 for
discussion).
Listing all fields for an item requires querying the database to find
any flex attributes. This is slow when done for every item being
exported. We already have a way for the user to specify a fixed set
of keys, but we previously queried everything and filtered it afterwards.
The new approach is more efficient.
Code that iterates through all fields now have to handle invalid field
names. The export and info plugins output invalid fields as None.
Timings before:
> /usr/bin/time beet export -i title,path,artist -l Bob Dylan
13.26user 20.22system 0:34.01elapsed 98%CPU (0avgtext+0avgdata 52544maxresident)k
> /usr/bin/time beet export -l Bob Dylan
12.93user 20.15system 0:33.58elapsed 98%CPU (0avgtext+0avgdata 53632maxresident)k
Timings after:
> /usr/bin/time beet export -l Bob Dylan
13.33user 20.17system 0:34.02elapsed 98%CPU (0avgtext+0avgdata 53500maxresident)k
> /usr/bin/time beet export -i title,path,artist -l Bob Dylan
0.49user 0.07system 0:00.56elapsed 98%CPU (0avgtext+0avgdata 50496maxresident)k
Notice the dramatic speedup in the last example!
Fallout from #2188. Following @jrobeson's suggestion, I just turned the check
in LibModel.__format__ into an assert. This turned up a few badly-behaved
clients, which are also fixed.
* Make emitters produce a pair (dict, Item), in order to preserve the output
at print_data (dict is used if no custom format is specified, Item otherwise).
* Simplify the handling of the paths, printed at the top of print_data. The
path key is removed from the dict entirely and fetched from the Item.
* Add custom output formatting via a format string to InfoPlugin. The command
accepts a formatting string via the "-f" parameter, which is handled by its
CommonOptionsParser and applied during print_data().
* Modify the emitters in order to include an Item into the list of fields, that
is formatted according to the format string if specified.
* Add an argument to allow the user to choose if track lengths are displayed as
raw floats or using a human-readable form (mm:ss), defaulting to human-readable
form.
Include import of __future__ features division, absolute_imports and
print_function everywhere. Don't add unicode_literals yet for it is
harder to convert.
Goal is smoothing the transition to python 3.
This restores the -v flag affecting plugins. By default, plugin loggers use
the NOTSET level, which just reuses the base `beets` logger level. The level
is only auto-adjusted for the importer when not in verbose mode.
