OP-3908 - revert back to PS cache

Standard approach doesn't handle legacy instances, eg. instance without creator_identifier.

openpype/hosts/photoshop/api/pipeline.py

@@ -1,6 +1,6 @@
 import os
 from Qt import QtWidgets
-
+import collections
 import pyblish.api
 
 from openpype.lib import register_event_callback, Logger
@@ -290,3 +290,18 @@ def containerise(
     stub.imprint(layer.id, data)
 
     return layer
+
+
+def cache_and_get_instances(creator):
+    """Cache instances in shared data.
+
+    Storing all instances as a list as legacy instances might be still present.
+    Args:
+        creator (Creator): Plugin which would like to get instances from host.
+    Returns:
+        List[]: list of all instances stored in metadata
+    """
+    shared_key = "openpype.photoshop.instances"
+    if shared_key not in creator.collection_shared_data:
+        creator.collection_shared_data[shared_key] = creator.list_instances()
+    return creator.collection_shared_data[shared_key]

openpype/hosts/photoshop/plugins/create/create_image.py

@@ -9,7 +9,7 @@ from openpype.pipeline import (
 )
 from openpype.lib import prepare_template_data
 from openpype.pipeline.create import SUBSET_NAME_ALLOWED_SYMBOLS
-from openpype.pipeline.create.creator_plugins import cache_and_get_instances
+from openpype.hosts.photoshop.api.pipeline import cache_and_get_instances
 
 
 class ImageCreator(Creator):
@@ -20,10 +20,7 @@ class ImageCreator(Creator):
     description = "Image creator"
 
     def collect_instances(self):
-        instances = cache_and_get_instances(self,
-                                            "openpype.photoshop.instances",
-                                            self.host.list_instances)
-        for instance_data in instances.values():
+        for instance_data in cache_and_get_instances(self):
             # legacy instances have family=='image'
             creator_id = (instance_data.get("creator_identifier") or
                           instance_data.get("family"))

openpype/hosts/photoshop/plugins/create/workfile_creator.py

@@ -5,7 +5,7 @@ from openpype.pipeline import (
     CreatedInstance,
     legacy_io
 )
-from openpype.pipeline.create.creator_plugins import cache_and_get_instances
+from openpype.hosts.photoshop.api.pipeline import cache_and_get_instances
 
 
 class PSWorkfileCreator(AutoCreator):
@@ -18,10 +18,7 @@ class PSWorkfileCreator(AutoCreator):
         return []
 
     def collect_instances(self):
-        instances = cache_and_get_instances(self,
-                                            "openpype.photoshop.instances",
-                                            self.host.list_instances)
-        for instance_data in instances.values():
+        for instance_data in cache_and_get_instances(self):
             creator_id = instance_data.get("creator_identifier")
             if creator_id == self.identifier:
                 subset_name = instance_data["subset"]