monitor: tweak Context() to auto recalculate id, rename methods

This commit tweaks Context a bit so that any write will automatically
reset the `_id`. This ensures that we do not forget to reset `_id`
when the code changes.

It also tweaks the naming a bit, before there was a "setter" for
origin and functions to set "pipeline" and "stage". They are all
functions now with a "set_" prefix for symetry mostly.

osbuild/monitor.py

@@ -32,7 +32,7 @@ def omitempty(d: dict):
 
 
 class Context:
-    """Context for a single log line. Automatically calculates hash/id when read."""
+    """Context for a single log entry. Automatically calculates hash/id when read."""
 
     def __init__(self,
                  origin: Optional[str] = None,
@@ -46,13 +46,17 @@ class Context:
         self._id = None
         self._id_history: Set[str] = set()
 
+    def __setattr__(self, name, value):
+        super().__setattr__(name, value)
+        # reset "_id" on any write so that the hash is automatically recalculated
+        if name != "_id":
+            super().__setattr__("_id", None)
+
     @property
     def origin(self):
         return self._origin
 
-    @origin.setter
-    def origin(self, origin: str):
-        self._id = None
+    def set_origin(self, origin: str):
         self._origin = origin
 
     @property
@@ -63,8 +67,7 @@ class Context:
     def pipeline_id(self):
         return self._pipeline_id
 
-    def pipeline(self, pipeline: osbuild.Pipeline):
-        self._id = None
+    def set_pipeline(self, pipeline: osbuild.Pipeline):
         self._pipeline_name = pipeline.name
         self._pipeline_id = pipeline.id
 
@@ -76,8 +79,7 @@ class Context:
     def stage_id(self):
         return self._stage_id
 
-    def stage(self, stage: osbuild.Stage):
-        self._id = None
+    def set_stage(self, stage: osbuild.Stage):
         self._stage_name = stage.name
         self._stage_id = stage.id
 
@@ -303,7 +305,7 @@ class JSONSeqMonitor(BaseMonitor):
         pass
 
     def begin(self, pipeline: osbuild.Pipeline):
-        self._context.pipeline(pipeline)
+        self._context.set_pipeline(pipeline)
         self._progress.sub_progress(Progress("stages", len(pipeline.stages)))
         self._progress.incr()
 
@@ -314,17 +316,17 @@ class JSONSeqMonitor(BaseMonitor):
         self._module(assembler)
 
     def _module(self, module):
-        self._context.stage(module)
+        self._context.set_stage(module)
         self._progress.incr(depth=1)
 
     def log(self, message, origin: Optional[str] = None):
         oo = self._context.origin
         if origin is not None:
-            self._context.origin = origin
+            self._context.set_origin(origin)
         entry = log_entry(message=message, context=self._context, progress=self._progress)
         self._jsonseq(entry)
         # restore old origin
-        self._context.origin = oo
+        self._context.set_origin(oo)
 
     def _jsonseq(self, entry):
         # follow rfc7464 (application/json-seq)

test/mod/test_monitor.py

@@ -143,7 +143,7 @@ def test_context():
     assert ctx_dict["id"] == "e6305b7e8ccbc39ec88415ea955b89149faf6f51fb6c89831658068bc6850411"
     assert len(ctx_dict) == 1
 
-    ctx.origin = "org.osbuild.test-2"
+    ctx.set_origin("org.osbuild.test-2")
     ctx_dict = ctx.as_dict()
     # should be a full dict again
     assert "origin" in ctx_dict
@@ -151,7 +151,7 @@ def test_context():
     assert ctx_dict["pipeline"]["name"] == "test-pipeline"
     assert ctx_dict["pipeline"]["stage"]["name"] == "org.osbuild.noop"
 
-    ctx.origin = "org.osbuild.test"
+    ctx.set_origin("org.osbuild.test")
     ctx_dict = ctx.as_dict()
     # should only have id again (old context ID)
     assert ctx_dict["id"] == "e6305b7e8ccbc39ec88415ea955b89149faf6f51fb6c89831658068bc6850411"
@@ -260,3 +260,10 @@ def test_log_line_with_entries():
     assert isinstance(entry["context"], dict)
     assert isinstance(entry["progress"], dict)
     assert entry["timestamp"] > 0
+
+
+def test_context_id():
+    ctx = Context()
+    assert ctx.id == "00d202e4fc9d917def414d1c9f284b137287144087ec275f2d146d9d47b3c8bb"
+    ctx._origin = "foo"
+    assert ctx.id != "00d202e4fc9d917def414d1c9f284b137287144087ec275f2d146d9d47b3c8bb"