1 files changed, 94 insertions, 90 deletions

diff --git a/repo_trace.py b/repo_trace.py
index 1ba86c79..49462174 100644
--- a/repo_trace.py
+++ b/repo_trace.py
@@ -29,138 +29,142 @@ from contextlib import ContextDecorator
 import platform_utils
 
 # Env var to implicitly turn on tracing.
-REPO_TRACE = 'REPO_TRACE'
+REPO_TRACE = "REPO_TRACE"
 
 # Temporarily set tracing to always on unless user expicitly sets to 0.
-_TRACE = os.environ.get(REPO_TRACE) != '0'
+_TRACE = os.environ.get(REPO_TRACE) != "0"
 _TRACE_TO_STDERR = False
 _TRACE_FILE = None
-_TRACE_FILE_NAME = 'TRACE_FILE'
+_TRACE_FILE_NAME = "TRACE_FILE"
 _MAX_SIZE = 70  # in MiB
-_NEW_COMMAND_SEP = '+++++++++++++++NEW COMMAND+++++++++++++++++++'
+_NEW_COMMAND_SEP = "+++++++++++++++NEW COMMAND+++++++++++++++++++"
 
 
 def IsTraceToStderr():
-  """Whether traces are written to stderr."""
-  return _TRACE_TO_STDERR
+    """Whether traces are written to stderr."""
+    return _TRACE_TO_STDERR
 
 
 def IsTrace():
-  """Whether tracing is enabled."""
-  return _TRACE
+    """Whether tracing is enabled."""
+    return _TRACE
 
 
 def SetTraceToStderr():
-  """Enables tracing logging to stderr."""
-  global _TRACE_TO_STDERR
-  _TRACE_TO_STDERR = True
+    """Enables tracing logging to stderr."""
+    global _TRACE_TO_STDERR
+    _TRACE_TO_STDERR = True
 
 
 def SetTrace():
-  """Enables tracing."""
-  global _TRACE
-  _TRACE = True
+    """Enables tracing."""
+    global _TRACE
+    _TRACE = True
 
 
 def _SetTraceFile(quiet):
-  """Sets the trace file location."""
-  global _TRACE_FILE
-  _TRACE_FILE = _GetTraceFile(quiet)
+    """Sets the trace file location."""
+    global _TRACE_FILE
+    _TRACE_FILE = _GetTraceFile(quiet)
 
 
 class Trace(ContextDecorator):
-  """Used to capture and save git traces."""
+    """Used to capture and save git traces."""
 
-  def _time(self):
-    """Generate nanoseconds of time in a py3.6 safe way"""
-    return int(time.time() * 1e+9)
+    def _time(self):
+        """Generate nanoseconds of time in a py3.6 safe way"""
+        return int(time.time() * 1e9)
 
-  def __init__(self, fmt, *args, first_trace=False, quiet=True):
-    """Initialize the object.
+    def __init__(self, fmt, *args, first_trace=False, quiet=True):
+        """Initialize the object.
 
-    Args:
-      fmt: The format string for the trace.
-      *args: Arguments to pass to formatting.
-      first_trace: Whether this is the first trace of a `repo` invocation.
-      quiet: Whether to suppress notification of trace file location.
-    """
-    if not IsTrace():
-      return
-    self._trace_msg = fmt % args
+        Args:
+            fmt: The format string for the trace.
+            *args: Arguments to pass to formatting.
+            first_trace: Whether this is the first trace of a `repo` invocation.
+            quiet: Whether to suppress notification of trace file location.
+        """
+        if not IsTrace():
+            return
+        self._trace_msg = fmt % args
 
-    if not _TRACE_FILE:
-      _SetTraceFile(quiet)
+        if not _TRACE_FILE:
+            _SetTraceFile(quiet)
 
-    if first_trace:
-      _ClearOldTraces()
-      self._trace_msg = f'{_NEW_COMMAND_SEP} {self._trace_msg}'
+        if first_trace:
+            _ClearOldTraces()
+            self._trace_msg = f"{_NEW_COMMAND_SEP} {self._trace_msg}"
 
-  def __enter__(self):
-    if not IsTrace():
-      return self
+    def __enter__(self):
+        if not IsTrace():
+            return self
 
-    print_msg = f'PID: {os.getpid()} START: {self._time()} :{self._trace_msg}\n'
+        print_msg = (
+            f"PID: {os.getpid()} START: {self._time()} :{self._trace_msg}\n"
+        )
 
-    with open(_TRACE_FILE, 'a') as f:
-      print(print_msg, file=f)
+        with open(_TRACE_FILE, "a") as f:
+            print(print_msg, file=f)
 
-    if _TRACE_TO_STDERR:
-      print(print_msg, file=sys.stderr)
+        if _TRACE_TO_STDERR:
+            print(print_msg, file=sys.stderr)
 
-    return self
+        return self
 
-  def __exit__(self, *exc):
-    if not IsTrace():
-      return False
+    def __exit__(self, *exc):
+        if not IsTrace():
+            return False
 
-    print_msg = f'PID: {os.getpid()} END: {self._time()} :{self._trace_msg}\n'
+        print_msg = (
+            f"PID: {os.getpid()} END: {self._time()} :{self._trace_msg}\n"
+        )
 
-    with open(_TRACE_FILE, 'a') as f:
-      print(print_msg, file=f)
+        with open(_TRACE_FILE, "a") as f:
+            print(print_msg, file=f)
 
-    if _TRACE_TO_STDERR:
-      print(print_msg, file=sys.stderr)
+        if _TRACE_TO_STDERR:
+            print(print_msg, file=sys.stderr)
 
-    return False
+        return False
 
 
 def _GetTraceFile(quiet):
-  """Get the trace file or create one."""
-  # TODO: refactor to pass repodir to Trace.
-  repo_dir = os.path.dirname(os.path.dirname(__file__))
-  trace_file = os.path.join(repo_dir, _TRACE_FILE_NAME)
-  if not quiet:
-    print(f'Trace outputs in {trace_file}', file=sys.stderr)
-  return trace_file
+    """Get the trace file or create one."""
+    # TODO: refactor to pass repodir to Trace.
+    repo_dir = os.path.dirname(os.path.dirname(__file__))
+    trace_file = os.path.join(repo_dir, _TRACE_FILE_NAME)
+    if not quiet:
+        print(f"Trace outputs in {trace_file}", file=sys.stderr)
+    return trace_file
 
 
 def _ClearOldTraces():
-  """Clear the oldest commands if trace file is too big."""
-  try:
-    with open(_TRACE_FILE, 'r', errors='ignore') as f:
-      if os.path.getsize(f.name) / (1024 * 1024) <= _MAX_SIZE:
+    """Clear the oldest commands if trace file is too big."""
+    try:
+        with open(_TRACE_FILE, "r", errors="ignore") as f:
+            if os.path.getsize(f.name) / (1024 * 1024) <= _MAX_SIZE:
+                return
+            trace_lines = f.readlines()
+    except FileNotFoundError:
         return
-      trace_lines = f.readlines()
-  except FileNotFoundError:
-    return
-
-  while sum(len(x) for x in trace_lines) / (1024 * 1024) > _MAX_SIZE:
-    for i, line in enumerate(trace_lines):
-      if 'END:' in line and _NEW_COMMAND_SEP in line:
-        trace_lines = trace_lines[i + 1:]
-        break
-    else:
-      # The last chunk is bigger than _MAX_SIZE, so just throw everything away.
-      trace_lines = []
-
-  while trace_lines and trace_lines[-1] == '\n':
-    trace_lines = trace_lines[:-1]
-  # Write to a temporary file with a unique name in the same filesystem
-  # before replacing the original trace file.
-  temp_dir, temp_prefix = os.path.split(_TRACE_FILE)
-  with tempfile.NamedTemporaryFile('w',
-                                   dir=temp_dir,
-                                   prefix=temp_prefix,
-                                   delete=False) as f:
-    f.writelines(trace_lines)
-  platform_utils.rename(f.name, _TRACE_FILE)
+
+    while sum(len(x) for x in trace_lines) / (1024 * 1024) > _MAX_SIZE:
+        for i, line in enumerate(trace_lines):
+            if "END:" in line and _NEW_COMMAND_SEP in line:
+                trace_lines = trace_lines[i + 1 :]
+                break
+        else:
+            # The last chunk is bigger than _MAX_SIZE, so just throw everything
+            # away.
+            trace_lines = []
+
+    while trace_lines and trace_lines[-1] == "\n":
+        trace_lines = trace_lines[:-1]
+    # Write to a temporary file with a unique name in the same filesystem
+    # before replacing the original trace file.
+    temp_dir, temp_prefix = os.path.split(_TRACE_FILE)
+    with tempfile.NamedTemporaryFile(
+        "w", dir=temp_dir, prefix=temp_prefix, delete=False
+    ) as f:
+        f.writelines(trace_lines)
+    platform_utils.rename(f.name, _TRACE_FILE)