mpd-now-playable/src/mpd_now_playable/mpd/artwork_cache.py
Danielle McLean 27d8c37139
Significantly overhaul configuration management
Everything now uses bog-standard Python dataclasses, with Pydantic
providing validation and type conversion through separate classes using
its type adapter feature. It's also possible to define your classes
using Pydantic's own model type directly, making the type adapter
unnecessary, but I didn't want to do things that way because no actual
validation is needed when constructing a Song instance for example.
Having Pydantic do its thing only on-demand was preferable.

I tried a number of validation libraries before settling on Pydantic for
this. It's not the fastest option out there (msgspec is I think), but it
makes adding support for third-party types like yarl.URL really easy, it
generates a nice clean JSON Schema which is easy enough to adjust to my
requirements through its GenerateJsonSchema hooks, and raw speed isn't
all that important anyway since this is a single-user desktop program
that reads its configuration file once on startup.

Also, MessagePack is now mandatory if you're caching to an external
service. It just didn't make a whole lot sense to explicitly install
mpd-now-playable's Redis or Memcached support and then use pickling with
them.

With all this fussing around done, I'm probably finally ready to
actually use that configuration file to configure new features! Yay!
2024-07-01 00:10:17 +10:00

61 lines
1.8 KiB
Python

from __future__ import annotations
from yarl import URL
from ..cache import Cache, make_cache
from ..song import Artwork, ArtworkSchema, to_artwork
from ..tools.asyncio import run_background_task
from ..tools.types import un_maybe_plural
from .types import CurrentSongResponse, MpdStateHandler
CACHE_TTL = 60 * 60 # seconds = 1 hour
def calc_album_key(song: CurrentSongResponse) -> str:
artist = sorted(
un_maybe_plural(song.get("albumartist", song.get("artist", "Unknown Artist")))
)
album = sorted(un_maybe_plural(song.get("album", "Unknown Album")))
return ":".join(";".join(t).replace(":", "-") for t in (artist, album))
def calc_track_key(song: CurrentSongResponse) -> str:
return song["file"]
MEMORY = URL("memory://")
class MpdArtworkCache:
mpd: MpdStateHandler
album_cache: Cache[Artwork]
track_cache: Cache[Artwork]
def __init__(self, mpd: MpdStateHandler, cache_url: URL = MEMORY):
self.mpd = mpd
self.album_cache = make_cache(ArtworkSchema, cache_url, "album")
self.track_cache = make_cache(ArtworkSchema, cache_url, "track")
async def get_cached_artwork(self, song: CurrentSongResponse) -> bytes | None:
art = await self.track_cache.get(calc_track_key(song))
if art:
return art.data
# If we don't have track artwork cached, go find some.
run_background_task(self.cache_artwork(song))
# Even if we don't have cached track art, we can try looking for cached album art.
art = await self.album_cache.get(calc_album_key(song))
if art:
return art.data
return None
async def cache_artwork(self, song: CurrentSongResponse) -> None:
art = to_artwork(await self.mpd.get_art(song["file"]))
try:
await self.album_cache.add(calc_album_key(song), art, ttl=CACHE_TTL)
except ValueError:
pass
await self.track_cache.set(calc_track_key(song), art, ttl=CACHE_TTL)
await self.mpd.refresh()