Added LocalMediaSearcher class to index local files and provide faster results to media.search when the index is available

This commit is contained in:
Fabio Manganiello 2019-02-17 02:37:23 +01:00
parent 7d1c9275f5
commit b204d477ac
2 changed files with 308 additions and 0 deletions

View file

@ -300,6 +300,13 @@ class MediaPlugin(Plugin):
@action
def file_search(self, query):
try:
from .local import LocalMediaSearcher
return LocalMediaSearcher(self.media_dirs).search(query)
except Exception as e:
self.logger.warning('Could not load the local file indexer: {}. '.
format(str(e)) + 'Falling back to directory scan')
results = []
query_tokens = [_.lower() for _ in re.split('\s+', query.strip())]

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@ -0,0 +1,301 @@
import datetime
import logging
import os
import re
import time
from sqlalchemy import create_engine, func, or_, Column, Integer, String, \
DateTime, PrimaryKeyConstraint, ForeignKey
from sqlalchemy.orm import sessionmaker, scoped_session
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.sql.expression import func
from platypush.config import Config
from platypush.plugins.media import MediaPlugin
Base = declarative_base()
Session = scoped_session(sessionmaker())
class LocalMediaSearcher:
"""
This class will search for media in the local configured directories. It
will index the media files for a faster search, it will detect which
directories have been changed since the last scan and re-index their content
if needed.
Requires:
* **sqlalchemy** (``pip install sqlalchemy``)
"""
_filename_separators = '[.,_\-@()\[\]\{\}\s\'\"]+'
def __init__(self, dirs, *args, **kwargs):
self.logger = logging.getLogger(self.__class__.__name__)
self.dirs = dirs
db_dir = os.path.join(Config.get('workdir'), 'media')
os.makedirs(db_dir, exist_ok=True)
self.db_file = os.path.join(db_dir, 'media.db')
self._db_engine = None
def _get_db_session(self):
if not self._db_engine:
self._db_engine = create_engine(
'sqlite:///{}'.format(self.db_file),
connect_args = { 'check_same_thread': False })
Base.metadata.create_all(self._db_engine)
Session.configure(bind=self._db_engine)
return Session()
def _get_or_create_dir_entry(self, session, path):
record = session.query(MediaDirectory).filter_by(path=path).first()
if record is None:
record = MediaDirectory.build(path=path)
session.add(record)
session.commit()
return record
@classmethod
def _get_last_modify_time(cls, path, recursive=False):
return max([os.path.getmtime(p) for p,_,_ in os.walk(path)]) \
if recursive else os.path.getmtime(path)
@classmethod
def _has_directory_changed_since_last_indexing(self, dir_record):
if not dir_record.last_indexed_at:
return True
return datetime.datetime.fromtimestamp(
self._get_last_modify_time(dir_record.path)) > dir_record.last_indexed_at
@classmethod
def _matches_query(cls, filename, query):
filename = filename.lower()
query_tokens = [_.lower() for _ in re.split(
cls._filename_separators, query.strip())]
for token in query_tokens:
if token not in filename:
return False
return True
@classmethod
def _sync_token_records(cls, session, *tokens):
tokens = list(tokens)
if not tokens:
return []
records = { record.token: record for record in
session.query(MediaToken).filter(
MediaToken.token.in_(tokens)).all() }
for token in tokens:
if token in records:
continue
record = MediaToken.build(token=token)
session.add(record)
session.commit()
return session.query(MediaToken).filter(
MediaToken.token.in_(tokens)).all()
@classmethod
def _get_file_records(cls, dir_record, session):
return session.query(MediaFile).filter_by(
directory_id=dir_record.id).all()
def scan(self, media_dir, session=None, dir_record=None):
"""
Scans a media directory and stores the search results in the internal
SQLite index
"""
if not session:
session = self._get_db_session()
self.logger.info('Indexing directory {}'.format(media_dir))
index_start_time = time.time()
if not dir_record:
dir_record = self._get_or_create_dir_entry(session, media_dir)
stored_file_records = {
f.path: f for f in self._get_file_records(dir_record, session) }
for path, dirs, files in os.walk(media_dir):
for filename in files:
filepath = os.path.join(path, filename)
if filepath in stored_file_records:
# stored_file_records will be used to keep track of the
# files that have been removed from media_dir. If the file
# is still there, don't index it again
del stored_file_records[filepath]
continue
if not MediaPlugin._is_video_file(filename) and \
not MediaPlugin._is_audio_file(filename):
continue
self.logger.debug('Syncing item {}'.format(filepath))
tokens = [_.lower() for _ in re.split(self._filename_separators,
filename.strip())]
token_records = self._sync_token_records(session, *tokens)
file_record = MediaFile.build(directory_id=dir_record.id,
path=filepath)
session.add(file_record)
session.commit()
file_record = session.query(MediaFile).filter_by(
directory_id=dir_record.id, path=filepath).one()
for token_record in token_records:
file_token = MediaFileToken.build(file_id=file_record.id,
token_id=token_record.id)
session.add(file_token)
# stored_file_records should now only contain the records of the files
# that have been removed from the directory
if stored_file_records:
self.logger.info(
'Removing references to {} deleted media items from {}'.format(
len(stored_file_records), media_dir))
session.query(MediaFile).filter(MediaFile.id.in_(
[ record.id for record in stored_file_records.values() ]
)).delete()
dir_record.last_indexed_at = datetime.datetime.now()
self.logger.info('Scanned {} in {} seconds'.format(
media_dir, int(time.time()-index_start_time)))
session.commit()
def search(self, query):
"""
Searches in the configured media directories given a query. It uses the
built-in SQLite index if available. If any directory has changed since
the last scan then it will be indexed again and the up-to-date results
will be returned.
"""
session = self._get_db_session()
results = {}
for media_dir in self.dirs:
self.logger.info('Searching {} for "{}"'.format(media_dir, query))
dir_record = self._get_or_create_dir_entry(session, media_dir)
if self._has_directory_changed_since_last_indexing(dir_record):
self.logger.info('{} has changed since last indexing, '.format(
media_dir) + 're-indexing')
self.scan(media_dir, session=session, dir_record=dir_record)
query_tokens = [_.lower() for _ in re.split(
self._filename_separators, query.strip())]
for file_record in session.query(MediaFile). \
join(MediaFileToken). \
join(MediaToken). \
filter(MediaToken.token.in_(query_tokens)). \
group_by(MediaFile.id). \
order_by(func.count(MediaFileToken.token_id)):
results[file_record.path] = {
'url': 'file://' + file_record.path,
'title': os.path.basename(file_record.path),
}
return results.values()
# --- Table definitions
class MediaDirectory(Base):
""" Models the MediaDirectory table """
__tablename__ = 'MediaDirectory'
__table_args__ = ({ 'sqlite_autoincrement': True })
id = Column(Integer, primary_key=True)
path = Column(String)
last_indexed_at = Column(DateTime)
@classmethod
def build(cls, path, last_indexed_at=None, id=None):
record = cls()
record.id = id
record.path = path
record.last_indexed_at = last_indexed_at
return record
class MediaFile(Base):
""" Models the MediaFile table """
__tablename__ = 'MediaFile'
__table_args__ = ({ 'sqlite_autoincrement': True })
id = Column(Integer, primary_key=True)
directory_id = Column(Integer, ForeignKey(
'MediaDirectory.id', ondelete='CASCADE'), nullable=False)
path = Column(String, nullable=False)
indexed_at = Column(DateTime)
@classmethod
def build(cls, directory_id, path, indexed_at=None, id=None):
record = cls()
record.id = id
record.directory_id = directory_id
record.path = path
record.indexed_at = indexed_at or datetime.datetime.now()
return record
class MediaToken(Base):
""" Models the MediaToken table """
__tablename__ = 'MediaToken'
__table_args__ = ({ 'sqlite_autoincrement': True })
id = Column(Integer, primary_key=True)
token = Column(String, nullable=False, unique=True)
@classmethod
def build(cls, token, id=None):
record = cls()
record.id = id
record.token = token
return record
class MediaFileToken(Base):
""" Models the MediaFileToken table """
__tablename__ = 'MediaFileToken'
file_id = Column(Integer, ForeignKey('MediaFile.id', ondelete='CASCADE'),
nullable=False)
token_id = Column(Integer, ForeignKey('MediaToken.id', ondelete='CASCADE'),
nullable=False)
__table_args__ = ( PrimaryKeyConstraint(file_id, token_id), {} )
@classmethod
def build(cls, file_id, token_id, id=None):
record = cls()
record.id = id
record.file_id = file_id
record.token_id = token_id
return record
# vim:sw=4:ts=4:et: