Extrayendo funcionalidad de cache en su propio modulo

fetcher/cache.py

@@ -0,0 +1,79 @@
+import json
+import logging
+
+from fetcher import jobs
+from utils import get_redis_connection
+
+_log = logging.getLogger('fetcher_cache')
+_log.addHandler(logging.NullHandler())
+
+
+def get_artist(mbid):
+    _log.info('Intentando obtener artista %s desde redis', mbid)
+
+    with get_redis_connection() as redis:
+        artist = redis.get(f'artist:{mbid}')
+        if not artist:
+            _log.info('El artista no estaba en redis')
+            jobs.load_artist_on_cache.delay(mbid)
+            return None
+
+        _log.info('El artista se encontro en redis')
+        return json.loads(artist)
+
+
+def get_disc(mbid):
+    _log.info('Intentando obtener disco %s desde redis', mbid)
+
+    with get_redis_connection() as redis:
+        disc = redis.get(f'release_group:{mbid}')
+        if not disc:
+            _log.info('El disco no estaba en redis')
+            jobs.load_entities_of_release_group.delay(mbid)
+            return None
+
+        _log.info('El disco se encontro en redis')
+        return json.loads(disc)
+
+
+def get_discs_of_artist(mbid, limit, offset):
+    _log.info('Intentando obtener los discos del arista %s', mbid)
+
+    with get_redis_connection() as redis:
+        key_releases = f'artist:{mbid}:release_groups'
+
+        if key_releases not in redis:
+            _log.debug('%s no existe en redis', key_releases)
+            jobs.load_artist_on_cache.delay(mbid)
+            return None, 0
+
+        count = int(redis.get(f'{key_releases}:count'))
+        if count != redis.zcard(key_releases):
+            _log.debug('La cantidad de release_groups del artista %s no coinciden con el total',
+                       mbid)
+            jobs.load_artist_on_cache.delay(mbid)
+            return None, 0
+
+        release_ids = redis.zrange(key_releases, offset, limit)
+        keys = [f'release_group:{mbid}' for mbid in release_ids]
+        if redis.exists(*keys) != len(keys):
+            _log.debug('Aun no se cargan todas las release_groups del artista %s', mbid)
+            jobs.load_artist_on_cache.delay(mbid)
+            return None, None
+
+        _log.info('Se encontraron los discos en redis')
+        return [json.loads(disc) for disc in redis.mget(keys)]
+
+
+def get_artist_of_disc(mbid):
+    _log.info('Intentando obtener el artista del disco %s en redis', mbid)
+
+    with get_redis_connection() as redis:
+        artist_id = redis.get(f'release_group:{mbid}:artist')
+        if not artist_id:
+            _log.debug('No se encontro el artista')
+            jobs.load_entities_of_release_group.delay(mbid)
+            return None
+
+        _log.debug('Se encontro el artista')
+        return json.loads(redis.get(f'artist:{artist_id}'))