More code cleanup

Remove references to a 'collection' object - it was a half-baked idea,
and the concepts it represented should be implemented in the webapp, not
in the archive itself.

.gitignore

@@ -2,3 +2,4 @@
 *.pyc
 *.sqlite
 secret_key.py
+Melodia/cache

Melodia/melodia_settings.py

@@ -19,4 +19,4 @@ SUPPORTED_AUDIO_EXTENSIONS = [ filetype[0] for filetype in SUPPORTED_AUDIO_FILET
 import django.db.models.fields
 
 HASH_FUNCTION       = hash
-HASH_RESULT_DB_TYPE = django.db.models.fields.IntegerField()
+HASH_RESULT_DB_TYPE = django.db.models.fields.IntegerField(default =  -1)

archiver/archive.py

@@ -11,17 +11,10 @@ describes a group of songs.
 In this way, you back up archives of music - you don't back up the songs in a
 playlist. Additionally, you may want to re-organize your music to use a
 cleaner directory structure - a playlist doesn't care about this.
-Note that archives are different from collections:
-		-Archives are physical organizations of songs. These are used in the backend.
-		-Collections are logical organizations of songs. These are intended to be used
-			on the frontend.
-	The difference is intended to separate the difference between logical and physical
-	operations. For example, you don't need to re-organize the directory structure of
-	a collection of songs. However, you may want to prevent kids from accessing explicit
-	songs even if they are part of the same archive folder as clean songs.
 """
 
 class Archive (models.Model):
+	import datetime
 
 	"""
 	The archive model itself, and all functions used to interact with it.
@@ -33,21 +26,21 @@ class Archive (models.Model):
 	music files under there, and takes control of them from there.
 	"""
 
-	name        = models.CharField(max_length  = 64)
+	name        = models.CharField(max_length = 64)
 
 	#Note that we're not using FilePathField since this is actually a folder
-	root_folder = models.CharField(max_length  = 255)
+	root_folder = models.CharField(max_length = 255)
 
 	#And a reference to the songs in this archive
 	songs       = models.ManyToManyField(Song)
 
 	#Backup settings
-	backup_location  = models.CharField(max_length = 255)
+	backup_location  = models.CharField(max_length = 255, default = "/dev/null")
-	backup_frequency = models.IntegerField()
+	backup_frequency = models.IntegerField(default = 604800) #1 week in seconds
-	last_backup      = models.DateTimeField()
+	last_backup      = models.DateTimeField(default = datetime.datetime.now()) #Note that this by default will be the time the archive was instantiated
 
-	def _scan_filesystem(self, progress_callback = lambda x: None):
+	def _scan_filesystem(self):
-		"Scan the archive's root filesystem and add any new songs"
+		"Scan the archive's root filesystem and add any new songs without adding metadata, delete songs that exist no more"
 		#This method is implemented since the other scan methods all need to use the same code
 		#DRY FTW
 		import re, os
@@ -58,6 +51,7 @@ class Archive (models.Model):
 		_regex = '|'.join(( '.*' + ext + '$' for ext in SUPPORTED_AUDIO_EXTENSIONS))
 		regex  = re.compile(_regex, re.IGNORECASE)
 
+		#Add new songs
 		for dirname, dirnames, filenames in os.walk(self.root_folder):
 			#For each filename
 			for filename in filenames:
@@ -69,77 +63,29 @@ class Archive (models.Model):
 
 					except ObjectDoesNotExist, e:
 						#Song needs to be added to database
-
 						full_url = os.path.join(dirname, filename)
 						new_song = Song(url = full_url)
-						new_song.populate_metadata()
 						new_song.save()
 						self.songs.add(new_song)
 
-	def quick_scan(self):
+		#Remove songs in the database if they exist no longer
-		"Scan this archive's root folder and make sure that	all songs are in the database."
-
-		from os.path import isfile
-
-		#Validate existing database results
 		for song in self.songs.all():
-			if not isfile(song.url):
+			if not os.path.isfile(song.url):
-				song.delete()
-
-		#Scan the root folder, and find if we need to add any new songs
-		self._scan_filesystem()
-
-	def scan(self):
-		"Scan this archive's root folder and make sure any local metadata are correct."
-		#Overload the regular hash function with whatever Melodia as a whole is using
-		from Melodia.melodia_settings import HASH_FUNCTION as hash
-		import os.path
-
-		for song in self.songs.all():
-
-			if not os.path.isfile(song.song_url):
 				song.delete()
 				continue
 
-			#The song exists, check that the hash is the same
-			db_hash = song.file_hash
 
-			f         = open(song_url)
+	def _update_song_metadata(self, use_echonest = False, progress_callback = lambda x, y: None):
-			file_hash = hash(f.read())
+		"Scan every song in this archive (database only) and make sure all songs are correct"
-
+		#This method operates only on the songs that are in the database - if you need to make
-			if file_hash != db_hash:
+		#sure that new songs are added, use the _scan_filesystem() method in addition
-				#Something about the song has changed, rescan the metadata
+		total_songs  = self.songs.count()
-				song.populate_metadata()
+		current_song = 0
-
-		#Make sure to add any new songs as well
-		self._scan_filesystem()
-
-
-	def deep_scan(self):
-		"Scan this archive's root folder and make sure that	all songs are in the database, and use EchoNest to update metadata as necessary"
-
-		#Overload the regular hash function with whatever Melodia as a whole is using
-		from Melodia.melodia_settings import HASH_FUNCTION as hash
-		import os.path
 
 		for song in self.songs.all():
-
+			current_song += 1
-			if not os.path.isfile(song.song_url):
+			song.populate_metadata(use_echonest = use_echonest)
-				song.delete()
+			progress_callback(current_song, total_songs)
-				continue
-
-			#The song exists, check that the hash is the same
-			db_hash = song.file_hash
-			
-			f         = open(song_url)
-			file_hash = hash(f.read())
-
-			if file_hash != db_hash:
-				#Something about the song has changed, rescan the metadata
-				song.populate_metadata(use_echonest = True)
-
-		#Make sure to add any new songs as well
-		self._scan_filesystem()
 
 	def _needs_backup(self):
 		"Check if the current archive is due for a backup"
@@ -154,6 +100,28 @@ class Archive (models.Model):
 		else:
 			return False
 
+	def quick_scan(self):
+		"Scan this archive's root folder and make sure that	all songs are in the database."
+		#This is a quick scan - only validate whether or not songs should exist in the database
+
+		self._scan_filesystem()
+
+	def scan(self):
+		"Scan this archive's root folder and make sure any local metadata are correct."
+		#This is a longer scan - validate whether songs should exist, and use local data to update
+		#the database
+
+		self._scan_filesystem()
+		self._update_song_metadata()
+
+	def deep_scan(self):
+		"Scan this archive's root folder and make sure that	all songs are in the database, and use EchoNest to update metadata as necessary"
+		#This is a very long scan - validate whether songs should exist, and use Echonest to make sure
+		#that metadata is as accurate as possible.
+		self._scan_filesystem()
+		self._update_song_metadata(use_echonest = True)
+
+	
 	def run_backup(self, force_backup = False):
 		"Backup the current archive"
 		if force_backup or self._needs_backup():

archiver/song.py

@@ -1,6 +1,7 @@
 from django.db import models
 from Melodia import melodia_settings
 
+import datetime
 """
 The Song model
 Each instance of a Song represents a single music file.
@@ -8,6 +9,17 @@ This database model is used for storing the metadata information about a song,
 and helps in doing sorting etc.
 """
 
+_default_title        = "<UNAVAILABLE>"
+_default_artist       = "<UNAVAILABLE>"
+_default_album        = "<UNAVAILABLE>"
+_default_release_date = datetime.datetime.now #Function will be called per new song, rather than once at loading the file
+_default_genre        = "<UNAVAILABLE>"
+_default_bpm          = -1
+
+_default_bit_rate         = -1
+_default_duration         = -1
+_default_echonest_song_id = ""
+
 class Song (models.Model):
 	
 	"""
@@ -16,24 +28,36 @@ class Song (models.Model):
 	"""
 
 	#Standard user-populated metadata
-	title        = models.CharField(max_length = 64)
+	title        = models.CharField(max_length = 64, default = _default_title)
-	artist       = models.CharField(max_length = 64)
+	artist       = models.CharField(max_length = 64, default = _default_artist)
-	album        = models.CharField(max_length = 64)
+	album        = models.CharField(max_length = 64, default = _default_album)
-	release_date = models.DateField()
+	release_date = models.DateField(default = _default_release_date)
-	genre        = models.CharField(max_length = 64)
+	genre        = models.CharField(max_length = 64, default = _default_genre)
-	bpm          = models.IntegerField()
+	bpm          = models.IntegerField(default = _default_bpm)
 
 	#File metadata
-	bit_rate         = models.IntegerField()
+	bit_rate         = models.IntegerField(default = _default_bit_rate)
-	duration         = models.IntegerField()
+	duration         = models.IntegerField(default = _default_bit_rate)
-	echonest_song_id = models.CharField(max_length = 64)
+	echonest_song_id = models.CharField(max_length = 64, default = _default_echonest_song_id)
 	url              = models.CharField(max_length = 64)
 	file_hash        = melodia_settings.HASH_RESULT_DB_TYPE
 
-	def populate_metadata(self, use_echonest = False, use_musicbrainz = False):
+	def populate_metadata(self, use_echonest = False):
-		"Populate the metadata of this song"
+		"Populate the metadata of this song (only if file hash has changed)"
-		import datetime
+		#Overload the hash function with whatever Melodia as a whole is using
+		from Melodia.melodia_settings import HASH_FUNCTION as hash
 
+		#Check if there's a hash entry - if there is, the song may not have changed,
+		#and we can go ahead and return
+		if self.file_hash != None:
+			song_file = open(self.url, 'rb')
+			current_file_hash = hash(song_file.read())
+
+			if current_file_hash == self.file_hash:
+				#The song data hasn't changed at all, we don't need to do anything
+				return
+
+		#If we've gotten to here, we do actually need to fully update the metadata
 		if use_echonest:
 			#Code to grab metadata from echonest here
 			pass
@@ -49,38 +73,31 @@ class Song (models.Model):
 				track                 = audiotools.open(self.url)
 				track_metadata        = track.get_metadata()
 
-				self.title            = track_metadata.track_name             or '<UNAVAILABLE>'
+				self.title            = track_metadata.track_name  or _default_title
-				self.artist           = track_metadata.artist_name            or '<UNAVAILABLE>'
+				self.artist           = track_metadata.artist_name or _default_artist
-				self.album            = track_metadata.album_name             or '<UNAVAILABLE>'
+				self.album            = track_metadata.album_name  or _default_album
 				self.release_date     = datetime.date(int(track_metadata.year or 1), 1, 1)
-				self.bpm              = -1
+				self.bpm              = _default_bpm
 
-				self.bit_rate         = track.bits_per_sample()               or '<UNAVAILABLE>'
+				self.bit_rate         = track.bits_per_sample() or _default_bit_rate
-				self.duration         = int(track.seconds_length())             or '<UNAVAILABLE>'
+				self.duration         = int(track.seconds_length()) or _default_duration
-				self.echonest_song_id = ''
+				self.echonest_song_id = _default_echonest_song_id
 
 			except audiotools.UnsupportedFile, e:
-				#Couldn't grab the local data
+				#Couldn't grab the local data - fill in the remaining data for this record, preserving
-				#doesn't support the file, or because reading from it caused an error
+				#anything that already exists.
-				self.title            = "<UNAVAILABLE>"
+				self.title            = self.title            or _default_title
-				self.artist           = "<UNAVAILABLE>"
+				self.artist           = self.artist           or _default_artist
-				self.album            = "<UNAVAILABLE>"
+				self.album            = self.album            or _default_album
-				self.release_date     = datetime.datetime.now()
+				self.release_date     = self.release_date     or _default_release_date()
-				self.bpm              = -1
 
-				self.bit_rate         = -1
+				self.bpm              = self.bpm              or _default_bpm
-				self.duration         = -1
+				self.bit_rate         = self.bit_rate         or _default_bitrate
-				self.echonest_song_id = ''
+				self.duration         = self.bit_rate         or _default_duration
-
+				self.echonest_song_id = self.echonest_song_id or _default_echonest_song_id
-		#Hash check is run regardless of what metadata method is used
-		if self.file_hash == None:
-			#Only get the hash if we really must, it's an expensive operation...
-			from Melodia.melodia_settings import HASH_FUNCTION as hash
-			f              = open(self.url, 'rb')
-			self.file_hash = hash(f.read())
 
 	def convert(self, output_location, output_format, progress_func = lambda x, y: None):
-		"Convert a song to a new format, optionally specifying what format to convert to."
+		"Convert a song to a new format."
 		#Note that output_format over-rides the format guessed by output_location
 
 		from Melodia.resources import add_resource_dir

archiver/tests.py

@@ -20,7 +20,7 @@ class FilesystemScanTest(TestCase):
 		#We must save the archive before we can start adding songs to it
 		new_archive.save()
 
-		new_archive._scan_filesystem()
+		new_archive.quick_scan()
 
 class ScanTest(TestCase):
 	def test_archive_scan(self):