Make SquashFs a contextmanager

fix small stuff

lib/inputstreamhelper/unsquash.py

@@ -26,7 +26,7 @@
 from .kodiutils import log
 
 
-class ZstdDecompressor:
+class ZstdDecompressor: # pylint: disable=too-few-public-methods
     """
     zstdandard decompressor class
 
@@ -53,7 +53,7 @@ def decompress(self, comp_data, comp_size, outsize=8*2**10):
 
 
 @dataclass(frozen=True)
-class SBlk:
+class SBlk:  # pylint: disable=too-many-instance-attributes
     """superblock as dataclass, does some checks after initialization"""
     s_magic: int
     inodes: int
@@ -129,7 +129,7 @@ class BasicFileInode:
     fragment: int
     offset: int
     file_size: int
-    block_list: tuple[int]
+    block_list: tuple  # once we remove support for python below 3.9 this can be: tuple[int]
 
 
 @dataclass(frozen=True)
@@ -174,11 +174,17 @@ class SquashFs:
     """
     def __init__(self, fpath):
         self.zdecomp = ZstdDecompressor()
-        self.imfile = open(fpath, "rb")
+        self.imfile = open(fpath, "rb")  # pylint: disable=consider-using-with  # we have our own context manager
         self.sblk = self._get_sblk()
         self.frag_entries = self._get_fragment_table()
         log(0, "squashfs image initialized")
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.imfile.close()
+
     def _get_sblk(self):
         """
         Read and check the superblock.
@@ -404,7 +410,7 @@ def read_file_blocks(self, filename):
         for bsize in inode.block_list:
             compressed, size = self._get_size(bsize)
 
-            if not curr_pos == self.imfile.tell():
+            if curr_pos != self.imfile.tell():
                 log(3, "Pointer not at correct position. Moving.")
                 self.imfile.seek(curr_pos)
 
@@ -431,11 +437,5 @@ def extract_file(self, filename, target_dir):
         Extracts file <filename> to <target_dir>
         """
         with open(os.path.join(target_dir, filename), "wb") as outfile:
-            try:
-                for block in self.read_file_blocks(filename):
-                    outfile.write(block)
-
-                return True
-            except FileNotFoundError as err:
-                log(4, err)
-                return False
+            for block in self.read_file_blocks(filename):
+                outfile.write(block)

lib/inputstreamhelper/widevine/arm_lacros.py

@@ -30,29 +30,29 @@ def extract_widevine_lacros(dl_path, backup_path, img_version):
     progress = progress_dialog()
     progress.create(heading=localize(30043), message=localize(30044))  # Extracting Widevine CDM, prepping image
 
+    fnames = (config.WIDEVINE_CDM_FILENAME[system_os()], config.WIDEVINE_MANIFEST_FILE, "LICENSE")  # Here it's not LICENSE.txt, as defined in the config.py
+    bpath = os.path.join(backup_path, img_version)
+    if not exists(bpath):
+        mkdirs(bpath)
+
     try:
-        sfs = SquashFs(dl_path)
-    except IOError as err:
-        log(4, "SquashFs raised IOError")
+        with SquashFs(dl_path) as sfs:
+            for num, fname in enumerate(fnames):
+                sfs.extract_file(fname, bpath)
+                progress.update(int(90 / len(fnames) * (num + 1)), localize(30048))  # Extracting from image
+
+    except (IOError, FileNotFoundError) as err:
+        log(4, "SquashFs raised an error")
         log(4, err)
         return False
 
-    fnames = (config.WIDEVINE_CDM_FILENAME[system_os()], config.WIDEVINE_MANIFEST_FILE, "LICENSE")  # Here it's not LICENSE.txt, as defined in the config.py
-    mkdirs(os.path.join(backup_path, img_version))
-    for num, fname in enumerate(fnames):
-        extracted = sfs.extract_file(fname, os.path.join(backup_path, img_version))
-        if not extracted:
-            log(4, f"{fname} not found in {os.path.basename(dl_path)}")
-            return False
-
-        progress.update(int(90 / len(fnames) * (num + 1)), localize(30048))  # Extracting from image
 
-    with open_file(os.path.join(backup_path, img_version, config.WIDEVINE_MANIFEST_FILE), "r") as manifest_file:
+    with open_file(os.path.join(bpath, config.WIDEVINE_MANIFEST_FILE), "r") as manifest_file:
         manifest_json = json.load(manifest_file)
 
     manifest_json.update({"img_version": img_version})
 
-    with open_file(os.path.join(backup_path, img_version, config.WIDEVINE_MANIFEST_FILE), "w") as manifest_file:
+    with open_file(os.path.join(bpath, config.WIDEVINE_MANIFEST_FILE), "w") as manifest_file:
         json.dump(manifest_json, manifest_file, indent=2)
 
     log(0, f"Successfully extracted all files from lacros image {os.path.basename(dl_path)}")

lib/inputstreamhelper/widevine/repo.py

@@ -29,14 +29,19 @@ def widevines_available_from_repo():
         if http_status == 200:
             available_cdms.append({'version': cdm_version, 'url': cdm_url})
 
+    if not available_cdms:
+        log(4, "could not find any available cdm in repo")
+
     return available_cdms
 
 
 def latest_widevine_available_from_repo(available_cdms=None):
     """Returns the latest available Widevine CDM version and url from Google's library CDM repository"""
     if not available_cdms:
         available_cdms = widevines_available_from_repo()
+
     latest = available_cdms[-1]  # That's probably correct, but the following for loop makes sure
+
     for cdm in available_cdms:
         if parse_version(cdm['version']) > parse_version(latest['version']):
             latest = cdm