# This file is part of beets. # Copyright 2016, Bruno Cauet # # Permission is hereby granted, free of charge, to any person obtaining # a copy of this software and associated documentation files (the # "Software"), to deal in the Software without restriction, including # without limitation the rights to use, copy, modify, merge, publish, # distribute, sublicense, and/or sell copies of the Software, and to # permit persons to whom the Software is furnished to do so, subject to # the following conditions: # # The above copyright notice and this permission notice shall be # included in all copies or substantial portions of the Software. """Create freedesktop.org-compliant thumbnails for album folders This plugin is POSIX-only. Spec: standards.freedesktop.org/thumbnail-spec/latest/index.html """ import ctypes import ctypes.util import os import shutil from hashlib import md5 from pathlib import PurePosixPath from xdg import BaseDirectory from beets import util from beets.plugins import BeetsPlugin from beets.ui import Subcommand, decargs from beets.util import bytestring_path, displayable_path, syspath from beets.util.artresizer import ArtResizer BASE_DIR = os.path.join(BaseDirectory.xdg_cache_home, "thumbnails") NORMAL_DIR = bytestring_path(os.path.join(BASE_DIR, "normal")) LARGE_DIR = bytestring_path(os.path.join(BASE_DIR, "large")) class ThumbnailsPlugin(BeetsPlugin): def __init__(self): super().__init__() self.config.add( { "auto": True, "force": False, "dolphin": False, } ) if self.config["auto"] and self._check_local_ok(): self.register_listener("art_set", self.process_album) def commands(self): thumbnails_command = Subcommand( "thumbnails", help="Create album thumbnails" ) thumbnails_command.parser.add_option( "-f", "--force", dest="force", action="store_true", default=False, help="force regeneration of thumbnails deemed fine (existing & " "recent enough)", ) thumbnails_command.parser.add_option( "--dolphin", dest="dolphin", action="store_true", default=False, help="create Dolphin-compatible thumbnail information (for KDE)", ) thumbnails_command.func = self.process_query return [thumbnails_command] def process_query(self, lib, opts, args): self.config.set_args(opts) if self._check_local_ok(): for album in lib.albums(decargs(args)): self.process_album(album) def _check_local_ok(self): """Check that everything is ready: - local capability to resize images - thumbnail dirs exist (create them if needed) - detect whether we'll use PIL or IM - detect whether we'll use GIO or Python to get URIs """ if not ArtResizer.shared.local: self._log.warning( "No local image resizing capabilities, " "cannot generate thumbnails" ) return False for dir in (NORMAL_DIR, LARGE_DIR): if not os.path.exists(syspath(dir)): os.makedirs(syspath(dir)) if not ArtResizer.shared.can_write_metadata: raise RuntimeError( f"Thumbnails: ArtResizer backend {ArtResizer.shared.method}" f" unexpectedly cannot write image metadata." ) self._log.debug(f"using {ArtResizer.shared.method} to write metadata") uri_getter = GioURI() if not uri_getter.available: uri_getter = PathlibURI() self._log.debug("using {0.name} to compute URIs", uri_getter) self.get_uri = uri_getter.uri return True def process_album(self, album): """Produce thumbnails for the album folder.""" self._log.debug("generating thumbnail for {0}", album) if not album.artpath: self._log.info("album {0} has no art", album) return if self.config["dolphin"]: self.make_dolphin_cover_thumbnail(album) size = ArtResizer.shared.get_size(album.artpath) if not size: self._log.warning( "problem getting the picture size for {0}", album.artpath ) return wrote = True if max(size) >= 256: wrote &= self.make_cover_thumbnail(album, 256, LARGE_DIR) wrote &= self.make_cover_thumbnail(album, 128, NORMAL_DIR) if wrote: self._log.info("wrote thumbnail for {0}", album) else: self._log.info("nothing to do for {0}", album) def make_cover_thumbnail(self, album, size, target_dir): """Make a thumbnail of given size for `album` and put it in `target_dir`. """ target = os.path.join(target_dir, self.thumbnail_file_name(album.path)) if ( os.path.exists(syspath(target)) and os.stat(syspath(target)).st_mtime > os.stat(syspath(album.artpath)).st_mtime ): if self.config["force"]: self._log.debug( "found a suitable {1}x{1} thumbnail for {0}, " "forcing regeneration", album, size, ) else: self._log.debug( "{1}x{1} thumbnail for {0} exists and is " "recent enough", album, size, ) return False resized = ArtResizer.shared.resize(size, album.artpath, target) self.add_tags(album, resized) shutil.move(syspath(resized), syspath(target)) return True def thumbnail_file_name(self, path): """Compute the thumbnail file name See https://standards.freedesktop.org/thumbnail-spec/latest/x227.html """ uri = self.get_uri(path) hash = md5(uri.encode("utf-8")).hexdigest() return bytestring_path(f"{hash}.png") def add_tags(self, album, image_path): """Write required metadata to the thumbnail See https://standards.freedesktop.org/thumbnail-spec/latest/x142.html """ mtime = os.stat(syspath(album.artpath)).st_mtime metadata = { "Thumb::URI": self.get_uri(album.artpath), "Thumb::MTime": str(mtime), } try: ArtResizer.shared.write_metadata(image_path, metadata) except Exception: self._log.exception( "could not write metadata to {0}", displayable_path(image_path) ) def make_dolphin_cover_thumbnail(self, album): outfilename = os.path.join(album.path, b".directory") if os.path.exists(syspath(outfilename)): return artfile = os.path.split(album.artpath)[1] with open(syspath(outfilename), "w") as f: f.write("[Desktop Entry]\n") f.write("Icon=./{}".format(artfile.decode("utf-8"))) f.close() self._log.debug("Wrote file {0}", displayable_path(outfilename)) class URIGetter: available = False name = "Abstract base" def uri(self, path): raise NotImplementedError() class PathlibURI(URIGetter): available = True name = "Python Pathlib" def uri(self, path): return PurePosixPath(os.fsdecode(path)).as_uri() def copy_c_string(c_string): """Copy a `ctypes.POINTER(ctypes.c_char)` value into a new Python string and return it. The old memory is then safe to free. """ # This is a pretty dumb way to get a string copy, but it seems to # work. A more surefire way would be to allocate a ctypes buffer and copy # the data with `memcpy` or somesuch. s = ctypes.cast(c_string, ctypes.c_char_p).value return b"" + s class GioURI(URIGetter): """Use gio URI function g_file_get_uri. Paths must be utf-8 encoded.""" name = "GIO" def __init__(self): self.libgio = self.get_library() self.available = bool(self.libgio) if self.available: self.libgio.g_type_init() # for glib < 2.36 self.libgio.g_file_new_for_path.argtypes = [ctypes.c_char_p] self.libgio.g_file_new_for_path.restype = ctypes.c_void_p self.libgio.g_file_get_uri.argtypes = [ctypes.c_void_p] self.libgio.g_file_get_uri.restype = ctypes.POINTER(ctypes.c_char) self.libgio.g_object_unref.argtypes = [ctypes.c_void_p] def get_library(self): lib_name = ctypes.util.find_library("gio-2") try: if not lib_name: return False return ctypes.cdll.LoadLibrary(lib_name) except OSError: return False def uri(self, path): g_file_ptr = self.libgio.g_file_new_for_path(path) if not g_file_ptr: raise RuntimeError( "No gfile pointer received for {}".format( displayable_path(path) ) ) try: uri_ptr = self.libgio.g_file_get_uri(g_file_ptr) finally: self.libgio.g_object_unref(g_file_ptr) if not uri_ptr: self.libgio.g_free(uri_ptr) raise RuntimeError( f"No URI received from the gfile pointer for {displayable_path(path)}" ) try: uri = copy_c_string(uri_ptr) finally: self.libgio.g_free(uri_ptr) try: return uri.decode(util._fsencoding()) except UnicodeDecodeError: raise RuntimeError(f"Could not decode filename from GIO: {uri!r}")