migrate usage_labels to singledispatch

subiquity/common/filesystem/labels.py

@@ -87,3 +87,55 @@ def _annotations_vg(vg):
         # Flag for a LVM volume group
         r.append(_("encrypted"))
     return r
+
+
+def _usage_labels_generic(device):
+    cd = device.constructed_device()
+    if cd is not None:
+        return [
+            _("{component_name} of {desc} {name}").format(
+                component_name=cd.component_name,
+                desc=cd.desc(),
+                name=cd.name),
+            ]
+    fs = device.fs()
+    if fs is not None:
+        if fs.preserve:
+            format_desc = _("already formatted as {fstype}")
+        elif device.original_fstype() is not None:
+            format_desc = _("to be reformatted as {fstype}")
+        else:
+            format_desc = _("to be formatted as {fstype}")
+        r = [format_desc.format(fstype=fs.fstype)]
+        if device._m.is_mounted_filesystem(fs.fstype):
+            m = fs.mount()
+            if m:
+                # A filesytem
+                r.append(_("mounted at {path}").format(path=m.path))
+            elif not getattr(device, 'is_esp', False):
+                # A filesytem
+                r.append(_("not mounted"))
+        elif fs.preserve:
+            if fs.mount() is None:
+                # A filesytem that cannot be mounted (i.e. swap)
+                # is used or unused
+                r.append(_("unused"))
+            else:
+                # A filesytem that cannot be mounted (i.e. swap)
+                # is used or unused
+                r.append(_("used"))
+        return r
+    else:
+        return [_("unused")]
+
+
+@functools.singledispatch
+def usage_labels(device):
+    return _usage_labels_generic(device)
+
+
+@usage_labels.register(Partition)
+def _usage_labels_partition(partition):
+    if partition.flag == "prep" or partition.flag == "bios_grub":
+        return []
+    return _usage_labels_generic(partition)

subiquity/models/filesystem.py

@@ -434,45 +434,6 @@ class _Formattable(ABC):
     # Raid or LVM_VolGroup for now, but one day ZPool, BCache...
     _constructed_device = attributes.backlink()
 
-    def usage_labels(self):
-        cd = self.constructed_device()
-        if cd is not None:
-            return [
-                _("{component_name} of {desc} {name}").format(
-                    component_name=cd.component_name,
-                    desc=cd.desc(),
-                    name=cd.name),
-                ]
-        fs = self.fs()
-        if fs is not None:
-            if fs.preserve:
-                format_desc = _("already formatted as {fstype}")
-            elif self.original_fstype() is not None:
-                format_desc = _("to be reformatted as {fstype}")
-            else:
-                format_desc = _("to be formatted as {fstype}")
-            r = [format_desc.format(fstype=fs.fstype)]
-            if self._m.is_mounted_filesystem(fs.fstype):
-                m = fs.mount()
-                if m:
-                    # A filesytem
-                    r.append(_("mounted at {path}").format(path=m.path))
-                elif not getattr(self, 'is_esp', False):
-                    # A filesytem
-                    r.append(_("not mounted"))
-            elif fs.preserve:
-                if fs.mount() is None:
-                    # A filesytem that cannot be mounted (i.e. swap)
-                    # is used or unused
-                    r.append(_("unused"))
-                else:
-                    # A filesytem that cannot be mounted (i.e. swap)
-                    # is used or unused
-                    r.append(_("used"))
-            return r
-        else:
-            return [_("unused")]
-
     def _is_entirely_used(self):
         return self._fs is not None or self._constructed_device is not None
 
@@ -709,13 +670,14 @@ class Disk(_Device):
     ok_for_lvm_vg = ok_for_raid
 
     def for_client(self, min_size):
+        from subiquity.common.filesystem.labels import usage_labels
         from subiquity.common.types import Disk
         return Disk(
             id=self.id,
             label=self.label,
             type=self.desc(),
             size=self.size,
-            usage_labels=self.usage_labels(),
+            usage_labels=usage_labels(self),
             partitions=[p.for_client() for p in self._partitions],
             ok_for_guided=self.size >= min_size)
 
@@ -733,11 +695,6 @@ class Partition(_Formattable):
     name = attr.ib(default=None)
     multipath = attr.ib(default=None)
 
-    def usage_labels(self):
-        if self.flag == "prep" or self.flag == "bios_grub":
-            return []
-        return super().usage_labels()
-
     def desc(self):
         return _("partition of {device}").format(device=self.device.desc())
 
@@ -817,12 +774,15 @@ class Partition(_Formattable):
     ok_for_lvm_vg = ok_for_raid
 
     def for_client(self):
-        from subiquity.common.filesystem.labels import annotations
+        from subiquity.common.filesystem.labels import (
+            annotations,
+            usage_labels,
+            )
         from subiquity.common.types import Partition
         return Partition(
             size=self.size,
             number=self._number,
-            annotations=annotations(self) + self.usage_labels())
+            annotations=annotations(self) + usage_labels(self))
 
 
 @fsobj("raid")

subiquity/models/tests/test_filesystem.py

@@ -19,6 +19,7 @@ import attr
 
 from subiquity.common.filesystem.labels import (
     annotations,
+    usage_labels,
     )
 from subiquity.models.filesystem import (
     Bootloader,
@@ -356,25 +357,25 @@ class TestFilesystemModel(unittest.TestCase):
 
     def test_partition_usage_labels(self):
         model, partition = make_model_and_partition()
-        self.assertEqual(partition.usage_labels(), ["unused"])
+        self.assertEqual(usage_labels(partition), ["unused"])
         fs = model.add_filesystem(partition, 'ext4')
         self.assertEqual(
-            partition.usage_labels(),
+            usage_labels(partition),
             ["to be formatted as ext4", "not mounted"])
         model._orig_config = model._render_actions()
         fs.preserve = True
         partition.preserve = True
         self.assertEqual(
-            partition.usage_labels(),
+            usage_labels(partition),
             ["already formatted as ext4", "not mounted"])
         model.remove_filesystem(fs)
         fs2 = model.add_filesystem(partition, 'ext4')
         self.assertEqual(
-            partition.usage_labels(),
+            usage_labels(partition),
             ["to be reformatted as ext4", "not mounted"])
         model.add_mount(fs2, '/')
         self.assertEqual(
-            partition.usage_labels(),
+            usage_labels(partition),
             ["to be reformatted as ext4", "mounted at /"])
 
     def test_is_esp(self):

subiquity/ui/views/filesystem/guided.py

@@ -44,9 +44,6 @@ from subiquitycore.ui.utils import (
     )
 from subiquitycore.view import BaseView
 
-from subiquity.common.filesystem.labels import (
-    annotations,
-    )
 from subiquity.common.types import GuidedChoice
 from subiquity.models.filesystem import humanize_size
 
@@ -93,7 +90,7 @@ def summarize_device(disk):
         ])]
     if disk.partitions:
         for part in disk.partitions:
-            details = ", ".join(annotations(part))
+            details = ", ".join(part.annotations)
             rows.append((part, [
                 Text(_("partition {number}").format(number=part.number)),
                 (2, Text(details)),

subiquity/ui/views/filesystem/helpers.py

@@ -21,6 +21,7 @@ from subiquitycore.ui.utils import (
 
 from subiquity.common.filesystem.labels import (
     annotations,
+    usage_labels,
     )
 from subiquity.models.filesystem import (
     humanize_size,
@@ -49,7 +50,7 @@ def summarize_device(device, part_filter=lambda p: True):
         for part in device.partitions():
             if not part_filter(part):
                 continue
-            details = ", ".join(annotations(part) + part.usage_labels())
+            details = ", ".join(annotations(part) + usage_labels(part))
             rows.append((part, [
                 Text(part.short_label),
                 (2, Text(details)),
@@ -57,6 +58,6 @@ def summarize_device(device, part_filter=lambda p: True):
                 ]))
     else:
         rows.append((None, [
-            (4, Color.info_minor(Text(", ".join(device.usage_labels()))))
+            (4, Color.info_minor(Text(", ".join(usage_labels(device)))))
             ]))
     return rows