Add awareness (#171)

Author: davidbrochart

.github/workflows/test.yml

@@ -66,7 +66,7 @@ jobs:
       run: pytest --color=yes -v tests
 
     - name: Run code coverage
-      if: ${{ (matrix.python-version == '3.12') && (matrix.os == 'ubuntu-latest') }}
+      if: ${{ (matrix.python-version == '3.12') && (matrix.os == 'ubuntu') }}
       run: |
         coverage run -m pytest tests
         coverage report --show-missing --fail-under=100

python/pycrdt/__init__.py

@@ -1,5 +1,6 @@
 from ._array import Array as Array
 from ._array import ArrayEvent as ArrayEvent
+from ._awareness import Awareness as Awareness
 from ._doc import Doc as Doc
 from ._map import Map as Map
 from ._map import MapEvent as MapEvent

python/pycrdt/_array.py

@@ -382,9 +382,6 @@ def __init__(self, array: Array):
         self.length = len(array)
         self.idx = 0
 
-    def __iter__(self) -> ArrayIterator:
-        return self
-
     def __next__(self) -> Any:
         if self.idx == self.length:
             raise StopIteration

python/pycrdt/_awareness.py

@@ -0,0 +1,66 @@
+from __future__ import annotations
+
+import json
+import time
+from typing import Any
+
+from ._doc import Doc
+from ._sync import Decoder, read_message
+
+
+class Awareness:  # pragma: no cover
+    def __init__(self, ydoc: Doc):
+        self.client_id = ydoc.client_id
+        self.meta: dict[int, dict[str, Any]] = {}
+        self.states: dict[int, dict[str, Any]] = {}
+
+    def get_changes(self, message: bytes) -> dict[str, Any]:
+        message = read_message(message)
+        decoder = Decoder(message)
+        timestamp = int(time.time() * 1000)
+        added = []
+        updated = []
+        filtered_updated = []
+        removed = []
+        states = []
+        length = decoder.read_var_uint()
+        for _ in range(length):
+            client_id = decoder.read_var_uint()
+            clock = decoder.read_var_uint()
+            state_str = decoder.read_var_string()
+            state = None if not state_str else json.loads(state_str)
+            if state is not None:
+                states.append(state)
+            client_meta = self.meta.get(client_id)
+            prev_state = self.states.get(client_id)
+            curr_clock = 0 if client_meta is None else client_meta["clock"]
+            if curr_clock < clock or (
+                curr_clock == clock and state is None and client_id in self.states
+            ):
+                if state is None:
+                    if client_id == self.client_id and self.states.get(client_id) is not None:
+                        clock += 1
+                    else:
+                        if client_id in self.states:
+                            del self.states[client_id]
+                else:
+                    self.states[client_id] = state
+                self.meta[client_id] = {
+                    "clock": clock,
+                    "last_updated": timestamp,
+                }
+                if client_meta is None and state is not None:
+                    added.append(client_id)
+                elif client_meta is not None and state is None:
+                    removed.append(client_id)
+                elif state is not None:
+                    if state != prev_state:
+                        filtered_updated.append(client_id)
+                    updated.append(client_id)
+        return {
+            "added": added,
+            "updated": updated,
+            "filtered_updated": filtered_updated,
+            "removed": removed,
+            "states": states,
+        }

python/pycrdt/_sync.py

@@ -3,7 +3,7 @@
 from enum import IntEnum
 from typing import Iterator
 
-from pycrdt import Doc
+from ._doc import Doc
 
 
 class YMessageType(IntEnum):

python/pycrdt/_text.py

@@ -275,9 +275,6 @@ def __init__(self, text: Text):
         self.length = len(text)
         self.idx = 0
 
-    def __iter__(self) -> TextIterator:
-        return self
-
     def __next__(self) -> str:
         if self.idx == self.length:
             raise StopIteration

tests/test_transaction.py

@@ -7,7 +7,7 @@
 from pycrdt import Array, Doc, Map, Text
 
 if sys.version_info < (3, 11):
-    from exceptiongroup import ExceptionGroup
+    from exceptiongroup import ExceptionGroup  # pragma: no cover
 
 pytestmark = pytest.mark.anyio