python: reimplement the babeltrace package as a bt2 wrapper

[babeltrace.git] / bindings / python / babeltrace / babeltrace / reader_trace_handle.py

diff --git a/bindings/python/babeltrace/babeltrace/reader_trace_handle.py b/bindings/python/babeltrace/babeltrace/reader_trace_handle.py
new file mode 100644 (file)
index 0000000..07c36bb
--- /dev/null
+++ b/bindings/python/babeltrace/babeltrace/reader_trace_handle.py
@@ -0,0 +1,137 @@
+# The MIT License (MIT)
+#
+# Copyright (c) 2013-2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+import bt2
+import itertools
+from babeltrace import reader_event_declaration
+
+
+class TraceHandle:
+    """
+    A :class:`TraceHandle` is a handle allowing the user to manipulate
+    a specific trace directly. It is a unique identifier representing a
+    trace, and is not meant to be instantiated by the user.
+    """
+
+    def __init__(self):
+        raise NotImplementedError("TraceHandle cannot be instantiated")
+
+    def __repr__(self):
+        # TODO print an id or some information about component / query result?
+        return "Babeltrace TraceHandle: trace_id('{0}')".format(self._id)
+
+    def __hash__(self):
+        return hash((self.path, self.id))
+
+    def __eq__(self, other):
+        if type(other) is not type(self):
+            return False
+
+        return (self.path, self.id) == (other.path, other.id)
+
+    @property
+    def id(self):
+        """
+        Numeric ID of this trace handle.
+        """
+
+        return self._id
+
+    @property
+    def path(self):
+        """
+        Path of the underlying trace.
+        """
+
+        return self._path
+
+    def _query_trace_info(self):
+        try:
+            result = bt2.QueryExecutor().query(self._trace_collection._fs_comp_cls,
+                                               'trace-info', {'path': self._path})
+        except:
+            raise ValueError
+
+        assert(len(result) == 1)
+        return result
+
+    @property
+    def timestamp_begin(self):
+        """
+        Buffers creation timestamp (nanoseconds since Epoch) of the
+        underlying trace.
+        """
+
+        result = self._query_trace_info()
+
+        try:
+            return int(result[0]['range-ns']['begin'])
+        except:
+            raise ValueError
+
+    @property
+    def timestamp_end(self):
+        """
+        Buffers destruction timestamp (nanoseconds since Epoch) of the
+        underlying trace.
+        """
+
+        result = self._query_trace_info()
+
+        try:
+            return int(result[0]['range-ns']['end'])
+        except:
+            raise ValueError
+
+    @property
+    def _has_intersection(self):
+        result = self._query_trace_info()
+
+        try:
+            return 'intersection-range-ns' in result[0]
+        except:
+            raise ValueError
+
+    def _get_event_declarations(self):
+        notif_iter = bt2.TraceCollectionNotificationIterator([
+            bt2.SourceComponentSpec('ctf', 'fs', self._path)
+        ])
+
+        # raises if the trace contains no streams
+        first_notif = next(notif_iter)
+        assert(type(first_notif) is bt2.StreamBeginningNotification)
+        trace = first_notif.stream.stream_class.trace
+        ec_iters = [sc.values() for sc in trace.values()]
+        return map(reader_event_declaration._create_event_declaration,
+                   itertools.chain(*ec_iters))
+
+    @property
+    def events(self):
+        """
+        Generates all the :class:`EventDeclaration` objects of the
+        underlying trace.
+        """
+
+        try:
+            return self._get_event_declarations()
+        except:
+            return