Merged Whippet into libguile/whippet

libguile/whippet/ctf_to_json.py

@@ -0,0 +1,160 @@
+#!/usr/bin/env python3
+# Any copyright is dedicated to the Public Domain.
+# https://creativecommons.org/publicdomain/zero/1.0/
+#
+# Originally written by Andy Wingo <wingo@igalia.com>.
+
+import bt2 # From the babeltrace2 package.
+import sys
+import json
+from enum import Enum
+
+# Usage: ./ctf_to_json.py ~/lttng-traces/name-of-your-trace > foo.json
+#
+# Convert a Common Trace Format (CTF) trace, for example as produced by
+# LTTng, to the JSON-based Trace Event Format (TEF), for example as
+# consumed by `chrome://tracing`, `https://ui.perfetto.dev/`, or
+# `https://profiler.firefox.com`.
+
+# The Trace Event Format is documented here:
+#
+# https://docs.google.com/document/d/1CvAClvFfyA5R-PhYUmn5OOQtYMH4h6I0nSsKchNAySU/preview?tab=t.0
+
+# By default, events are emitted as EventPhase.INSTANT.  We also support
+# rewriting the event stream so as to generate EventPhase.BEGIN /
+# EventPhase.END events for specific named events.
+
+synthetic_events = {
+    'gc': ['whippet:mutator_cause_gc',
+           'whippet:restarting_mutators'],
+    'stop-the-world': ['whippet:requesting_stop',
+                       'whippet:mutators_stopped'],
+    'trace': ['whippet:prepare_gc',
+              'whippet:restarting_mutators'],
+    'mutator-stopped': ['whippet:mutator_stopping',
+                        'whippet:mutator_restarted'],
+    'trace-roots': ['whippet:trace_roots_begin',
+                    'whippet:trace_roots_end'],
+    'trace-check-termination': ['whippet:trace_check_termination_begin',
+                                'whippet:trace_check_termination_end'],
+    'trace-objects': ['whippet:trace_objects_begin',
+                      'whippet:trace_objects_end'],
+    'trace-worker': ['whippet:trace_worker_begin',
+                     'whippet:trace_worker_end']
+}
+
+class EventPhase(Enum):
+    BEGIN = 'B'
+    END = 'E'
+    COMPLETE = 'X'
+    INSTANT = 'i'
+    COUNTER = 'C'
+    NESTABLE_START = 'b'
+    NESTABLE_INSTANT = 'n'
+    NESTABLE_END = 'e'
+    FLOW_START = 's'
+    FLOW_STEP = 't'
+    FLOW_END = 'f'
+    SAMPLE = 'P'
+    OBJECT_CREATED = 'N'
+    OBJECT_SNAPSHOT = 'O'
+    OBJECT_DESTROYED = 'D'
+    METADATA = 'M'
+    MEMORY_DUMP_GLOBAL = 'V'
+    MEMORY_DUMP_PROCESS = 'V'
+    MARK = 'R'
+    CLOCK_SYNC = 'c'
+    CONTEXT_BEGIN = '('
+    CONTEXT_END = ')'
+
+base_time = None
+def event_us(msg):
+    assert(msg.default_clock_snapshot.clock_class.name == 'monotonic')
+    assert(msg.default_clock_snapshot.clock_class.frequency == 1e9)
+    global base_time
+    ns = msg.default_clock_snapshot.value
+    if base_time is None:
+        base_time = ns
+    return (ns - base_time) * 1e-3
+
+def lower(x):
+    if isinstance(x, str) or isinstance(x, int) or isinstance(x, float):
+        return x
+    if isinstance(x, dict) or isinstance(x, bt2._StructureFieldConst):
+        return {lower(k):lower(v) for k, v in x.items()}
+    if isinstance(x, bt2._BoolValueConst) or isinstance(x, bt2._BoolFieldConst):
+        return bool(x)
+    if isinstance(x, bt2._EnumerationFieldConst):
+        return repr(x)
+    if isinstance(x, bt2._IntegerValueConst) or isinstance(x, bt2._IntegerFieldConst):
+        return int(x)
+    if isinstance(x, bt2._RealValueConst) or isinstance(x, bt2._RealFieldConst):
+        return float(x)
+    if isinstance(x, bt2._StringValueConst) or isinstance(x, bt2._StringFieldConst):
+        return str(x)
+    raise ValueError("Unexpected value from trace", x)
+
+# Specific Whippet events.
+synthetic_begin = {}
+synthetic_end = {}
+for synthetic, [begin, end] in synthetic_events.items():
+    synthetic_begin[begin] = []
+    synthetic_end[end] = []
+for synthetic, [begin, end] in synthetic_events.items():
+    synthetic_begin[begin].append(synthetic)
+    synthetic_end[end].append(synthetic)
+
+def put(str):
+    sys.stdout.write(str)
+
+need_comma = False
+def print_event(ev):
+    global need_comma
+    if need_comma:
+        sys.stdout.write(',\n    ')
+    else:
+        need_comma = True
+    # It appears to be faster to make a string, then print the string,
+    # than to call json.dump with a file object.
+    # json.dump(ev, sys.stdout, ensure_ascii=False, check_circular=False)
+    put(json.dumps(ev, ensure_ascii=False, check_circular=False))
+
+def emit_event(msg, name, phase):
+    ev = {'name': name,
+          'cat': 'whippet',
+          'ph': phase.value,
+          'ts': event_us(msg),
+          'pid': lower(msg.event.common_context_field['vpid']),
+          'tid': lower(msg.event.common_context_field['vtid']),
+          'args': lower(msg.event.payload_field)}
+    print_event(ev)
+def emit_begin_event(msg, name):
+    emit_event(msg, name, EventPhase.BEGIN)
+def emit_end_event(msg, name):
+    emit_event(msg, name, EventPhase.END)
+
+def emit_events(msg):
+    emit_event(msg, msg.event.name, EventPhase.INSTANT)
+    for begin in synthetic_begin.get(msg.event.name, []):
+        emit_begin_event(msg, begin)
+    for end in synthetic_end.get(msg.event.name, []):
+        emit_end_event(msg, end)
+
+def ctf_to_json(path):
+    msg_it = bt2.TraceCollectionMessageIterator(path)
+    put('{\n')
+    put('  "traceEvents": [\n    ')
+    for msg in msg_it:
+        if hasattr(msg, 'event'):
+            emit_events(msg)
+    put('\n')
+    put('\n  ],\n')
+    put('  "displayTimeUnit": "ns"\n')
+    put('}\n')
+
+if len(sys.argv) != 2:
+    sys.stderr.write(
+        'usage: ' + sys.argv[0] + ' ~/lttng-traces/name-of-your-trace\n')
+    sys.exit(1)
+else:
+    ctf_to_json(sys.argv[1])