core: add --detect_file_replacement flag and plumbing (redo)

tensorboard/backend/event_processing/data_ingester.py

@@ -69,6 +69,7 @@ def __init__(self, flags):
             purge_orphaned_data=flags.purge_orphaned_data,
             max_reload_threads=flags.max_reload_threads,
             event_file_active_filter=_get_event_file_active_filter(flags),
+            detect_file_replacement=flags.detect_file_replacement,
         )
         self._data_provider = data_provider.MultiplexerDataProvider(
             self._multiplexer, flags.logdir or flags.logdir_spec

tensorboard/backend/event_processing/data_ingester_test.py

@@ -32,6 +32,7 @@
 class FakeFlags(object):
     def __init__(
         self,
+        detect_file_replacement=None,
         generic_data="auto",
         logdir="",
         logdir_spec="",
@@ -45,6 +46,7 @@ def __init__(
         samples_per_plugin=None,
         window_title="",
     ):
+        self.detect_file_replacement = detect_file_replacement
         self.generic_data = generic_data
         self.logdir = logdir
         self.logdir_spec = logdir_spec

tensorboard/backend/event_processing/plugin_event_accumulator.py

@@ -99,6 +99,7 @@ def __init__(
         tensor_size_guidance=None,
         purge_orphaned_data=True,
         event_file_active_filter=None,
+        detect_file_replacement=None,
     ):
         """Construct the `EventAccumulator`.
 
@@ -122,6 +123,9 @@ def __init__(
           event_file_active_filter: Optional predicate for determining whether an
             event file latest load timestamp should be considered active. If passed,
             this will enable multifile directory loading.
+          detect_file_replacement: Optional boolean; if True, event file loading
+            will try to detect when a file has been replaced with a new version
+            that contains additional data, by monitoring the file size.
         """
         size_guidance = dict(size_guidance or DEFAULT_SIZE_GUIDANCE)
         sizes = {}
@@ -155,7 +159,9 @@ def __init__(
         self._plugin_tag_lock = threading.Lock()
 
         self.path = path
-        self._generator = _GeneratorFromPath(path, event_file_active_filter)
+        self._generator = _GeneratorFromPath(
+            path, event_file_active_filter, detect_file_replacement
+        )
         self._generator_mutex = threading.Lock()
 
         self.purge_orphaned_data = purge_orphaned_data
@@ -639,23 +645,33 @@ def _GetPurgeMessage(
     )
 
 
-def _GeneratorFromPath(path, event_file_active_filter=None):
+def _GeneratorFromPath(
+    path, event_file_active_filter=None, detect_file_replacement=None
+):
     """Create an event generator for file or directory at given path string."""
     if not path:
         raise ValueError("path must be a valid string")
     if io_wrapper.IsSummaryEventsFile(path):
-        return event_file_loader.EventFileLoader(path)
+        return event_file_loader.EventFileLoader(path, detect_file_replacement)
     elif event_file_active_filter:
+        loader_factory = (
+            lambda path: event_file_loader.TimestampedEventFileLoader(
+                path, detect_file_replacement
+            )
+        )
         return directory_loader.DirectoryLoader(
             path,
-            event_file_loader.TimestampedEventFileLoader,
+            loader_factory,
             path_filter=io_wrapper.IsSummaryEventsFile,
             active_filter=event_file_active_filter,
         )
     else:
+        loader_factory = lambda path: event_file_loader.EventFileLoader(
+            path, detect_file_replacement
+        )
         return directory_watcher.DirectoryWatcher(
             path,
-            event_file_loader.EventFileLoader,
+            loader_factory,
             io_wrapper.IsSummaryEventsFile,
         )
 

tensorboard/backend/event_processing/plugin_event_multiplexer.py

@@ -77,6 +77,7 @@ def __init__(
         purge_orphaned_data=True,
         max_reload_threads=None,
         event_file_active_filter=None,
+        detect_file_replacement=None,
     ):
         """Constructor for the `EventMultiplexer`.
 
@@ -98,6 +99,9 @@ def __init__(
           event_file_active_filter: Optional predicate for determining whether an
             event file latest load timestamp should be considered active. If passed,
             this will enable multifile directory loading.
+          detect_file_replacement: Optional boolean; if True, event file loading
+            will try to detect when a file has been replaced with a new version
+            that contains additional data, by monitoring the file size.
         """
         logger.info("Event Multiplexer initializing.")
         self._accumulators_mutex = threading.Lock()
@@ -111,6 +115,7 @@ def __init__(
         self.purge_orphaned_data = purge_orphaned_data
         self._max_reload_threads = max_reload_threads or 1
         self._event_file_active_filter = event_file_active_filter
+        self._detect_file_replacement = detect_file_replacement
         if run_path_map is not None:
             logger.info(
                 "Event Multplexer doing initialization load for %s",
@@ -159,6 +164,7 @@ def AddRun(self, path, name=None):
                     tensor_size_guidance=self._tensor_size_guidance,
                     purge_orphaned_data=self.purge_orphaned_data,
                     event_file_active_filter=self._event_file_active_filter,
+                    detect_file_replacement=self._detect_file_replacement,
                 )
                 self._accumulators[name] = accumulator
                 self._paths[name] = path

tensorboard/backend/event_processing/plugin_event_multiplexer_test.py

@@ -94,13 +94,9 @@ def Reload(self):
 
 def _GetFakeAccumulator(
     path,
-    size_guidance=None,
-    tensor_size_guidance=None,
-    purge_orphaned_data=None,
-    event_file_active_filter=None,
+    **unused_kwargs,
 ):
-    del size_guidance, tensor_size_guidance, purge_orphaned_data  # Unused.
-    del event_file_active_filter  # unused
+    del unused_kwargs
     return _FakeAccumulator(path)
 
 

tensorboard/plugins/core/core_plugin.py

@@ -646,6 +646,26 @@ def define_flags(self, parser):
 means keep all samples of that type. For instance "scalars=500,images=0"
 keeps 500 scalars and all images. Most users should not need to set this
 flag.\
+""",
+        )
+
+        parser.add_argument(
+            "--detect_file_replacement",
+            metavar="BOOL",
+            # Custom str-to-bool converter since regular bool() doesn't work.
+            type=lambda v: {"true": True, "false": False}.get(v.lower(), v),
+            choices=[True, False],
+            default=None,
+            help="""\
+[experimental] If true, this enables experimental support for detecting when
+event files are replaced with new versions that contain additional data. This is
+not needed in the normal case where new data is either appended to an existing
+file or written to a brand new file, but it arises, for example, when using
+rsync without the --inplace option, in which new versions of the original file
+are first written to a temporary file, then swapped into the final location.
+
+This option is currently incompatible with --load_fast=true, and if passed will
+disable fast-loading mode. (default: false)\
 """,
         )
 
@@ -683,6 +703,13 @@ def fix_flags(self, flags):
             )
         elif flags.host is not None and flags.bind_all:
             raise FlagsError("Must not specify both --host and --bind_all.")
+        elif (
+            flags.load_fast == "true" and flags.detect_file_replacement is True
+        ):
+            raise FlagsError(
+                "Must not specify both --load_fast=true and"
+                "--detect_file_replacement=true"
+            )
 
         flags.path_prefix = flags.path_prefix.rstrip("/")
         if flags.path_prefix and not flags.path_prefix.startswith("/"):

tensorboard/plugins/core/core_plugin_test.py

@@ -53,6 +53,7 @@ def __init__(
         grpc_data_provider="",
         host=None,
         inspect=False,
+        load_fast="auto",
         logdir="",
         logdir_spec="",
         path_prefix="",
@@ -66,6 +67,7 @@ def __init__(
         self.grpc_data_provider = grpc_data_provider
         self.host = host
         self.inspect = inspect
+        self.load_fast = load_fast
         self.logdir = logdir
         self.logdir_spec = logdir_spec
         self.path_prefix = path_prefix

tensorboard/program.py

@@ -491,6 +491,13 @@ def _should_use_data_server(flags):
             "paths; falling back to slower Python-only load path."
         )
         return False
+    if flags.detect_file_replacement is True:
+        logger.info(
+            "Note: --detect_file_replacement=true is not supported with "
+            "--load_fast behavior; falling back to slower Python-only load "
+            "path."
+        )
+        return False
     return True
 
 

tensorboard/program_test.py

@@ -86,6 +86,7 @@ def test_should_use_data_server(self):
         def f(**kwargs):
             kwargs.setdefault("logdir", "")
             kwargs.setdefault("logdir_spec", "")
+            kwargs.setdefault("detect_file_replacement", None)
             flags = argparse.Namespace()
             for k, v in kwargs.items():
                 setattr(flags, k, v)
@@ -96,6 +97,7 @@ def f(**kwargs):
         self.assertTrue(f(logdir="logs/mnist/"))
         self.assertTrue(f(logdir="gs://logs"))
         self.assertFalse(f(logdir="notgs://logs"))
+        self.assertFalse(f(logdir="foo", detect_file_replacement=True))
 
 
 class WerkzeugServerTest(tb_test.TestCase):