1 files changed, 80 insertions, 0 deletions
diff --git a/cloud_mdir_sync/mailbox.py b/cloud_mdir_sync/mailbox.py
new file mode 100644
index 0000000..24c64cd
--- /dev/null
+++ b/cloud_mdir_sync/mailbox.py
@@ -0,0 +1,80 @@
+# SPDX-License-Identifier: GPL-2.0+
+import asyncio
+import functools
+import inspect
+from abc import abstractmethod
+from typing import TYPE_CHECKING, Dict
+
+if TYPE_CHECKING:
+    from . import config
+    from messages import MessageDB
+    from messages import CHMsgDict_Type
+    from messages import CHMsgMappingDict_Type
+
+
+def update_on_failure(func):
+    """Decorator for mailbox class methods that cause the mailbox to need a full
+    update if the method throws an exception."""
+    @functools.wraps(func)
+    def wrapper(self, *args, **kwargs):
+        try:
+            return func(self, *args, **kwargs)
+        except:
+            self.need_update = True
+            Mailbox.changed_event.set()
+            raise
+
+    @functools.wraps(func)
+    async def async_wrapper(self, *args, **kwargs):
+        try:
+            return await func(self, *args, **kwargs)
+        except:
+            self.need_update = True
+            Mailbox.changed_event.set()
+            raise
+
+    if inspect.iscoroutinefunction(func):
+        return async_wrapper
+    return wrapper
+
+
+class Mailbox(object):
+    messages: "CHMsgDict_Type" = {}
+    changed_event = asyncio.Event()
+    need_update = True
+
+    @abstractmethod
+    async def setup_mbox(self, cfg: "config.Config") -> None:
+        pass
+
+    @abstractmethod
+    def force_content(self, msgdb: "MessageDB",
+                      msgs: "CHMsgDict_Type") -> None:
+        pass
+
+    @abstractmethod
+    async def merge_content(self, msgs: "CHMsgMappingDict_Type") -> None:
+        pass
+
+    def same_messages(self,
+                      mdict: "CHMsgMappingDict_Type",
+                      tuple_form=False) -> bool:
+        """Return true if mdict is the same as the local messages"""
+        if len(self.messages) != len(mdict):
+            return False
+
+        for ch, mmsg in self.messages.items():
+            omsg = mdict.get(ch)
+            if omsg is None:
+                return False
+
+            # update_cloud_from_local use a different dict format
+            if tuple_form:
+                omsg = omsg[0]  # Check the local mbox
+                if omsg is None:
+                    return False
+
+            if (mmsg.content_hash != omsg.content_hash
+                    or mmsg.flags != omsg.flags):
+                return False
+        return True