emmental/trackdb/__init__.py

# Copyright 2020 (c) Anna Schumaker.
from . import allocator
from . import tags
from . import track
import lib
import pathlib
import threading

File = "trackdb.pickle"
Bus = lib.bus.Bus(500)
Tracks = allocator.TrackAllocator()

class LibraryTag(lib.tag.Tag):
    def __init__(self, path):
        super().__init__(path)
        self.clear = lib.thread.Thread(self.__do_clear__)
        self.scan = lib.thread.Thread(self.__do_scan__)

    def __setstate__(self, state):
        super().__setstate__(state)
        self.tracks = [ Tracks[i] for i in state["tracks"] ]
        self.clear = lib.thread.Thread(self.__do_clear__)
        self.scan = lib.thread.Thread(self.__do_scan__)

    def __do_scan__(self):
        for trak in Tracks.autoremove(self):
            self.remove_track(trak)

        track_set = set([ t.filepath() for t in Tracks.list_tracks(self) ])
        for f in self.name.rglob("*"):
            if f not in track_set and f.is_file():
                if (track := Tracks.allocate(self, f)) != None:
                    self.add_track(track)

    def __do_clear__(self):
        for trak in self.tracks:
            Tracks.remove(trak)
        self.tracks.clear()


class LibraryStore(lib.tagstore.TagStore):
    def __alloc_tag__(self, name, sort):
        return LibraryTag(name)

    def add(self, name):
        return super().__add_tag__(name, None, None)

    def remove(self, lib):
        lib.clear()
        super().remove(lib)

Library = LibraryStore()


def _do_save():
    with lib.data.DataFile(File, lib.data.WRITE) as f:
            f.pickle([ tags.get_state(), Tracks, Library ])

def save(*args):
    Bus.board(_do_save)

def load():
    global Library
    global Tracks
    with lib.data.DataFile(File, lib.data.READ) as f:
        if f.exists():
            (tagstate, Tracks, Library) = f.unpickle()
            tags.set_state(*tagstate)

def __register_callbacks():
    Library.Added.register(save)
    Library.Removed.register(save)
    Tracks.Added.register(save)
    Tracks.Removed.register(save)
    Tracks.Updated.register(save)
__register_callbacks()

def reset():
    Tracks.reset()
    Library.reset()
    tags.reset()
    Bus.clear()

    lib.data.DataFile(File, lib.data.READ).remove()
    __register_callbacks()