1 files changed, 317 insertions, 278 deletions

diff --git a/git_trace2_event_log.py b/git_trace2_event_log.py
index 2edab0e1..d90e9039 100644
--- a/git_trace2_event_log.py
+++ b/git_trace2_event_log.py
@@ -41,291 +41,330 @@ from git_command import GitCommand, RepoSourceVersion
 
 
 class EventLog(object):
-  """Event log that records events that occurred during a repo invocation.
-
-  Events are written to the log as a consecutive JSON entries, one per line.
-  Entries follow the git trace2 EVENT format.
-
-  Each entry contains the following common keys:
-  - event: The event name
-  - sid: session-id - Unique string to allow process instance to be identified.
-  - thread: The thread name.
-  - time: is the UTC time of the event.
-
-  Valid 'event' names and event specific fields are documented here:
-  https://git-scm.com/docs/api-trace2#_event_format
-  """
-
-  def __init__(self, env=None):
-    """Initializes the event log."""
-    self._log = []
-    # Try to get session-id (sid) from environment (setup in repo launcher).
-    KEY = 'GIT_TRACE2_PARENT_SID'
-    if env is None:
-      env = os.environ
-
-    now = datetime.datetime.utcnow()
-
-    # Save both our sid component and the complete sid.
-    # We use our sid component (self._sid) as the unique filename prefix and
-    # the full sid (self._full_sid) in the log itself.
-    self._sid = 'repo-%s-P%08x' % (now.strftime('%Y%m%dT%H%M%SZ'), os.getpid())
-    parent_sid = env.get(KEY)
-    # Append our sid component to the parent sid (if it exists).
-    if parent_sid is not None:
-      self._full_sid = parent_sid + '/' + self._sid
-    else:
-      self._full_sid = self._sid
-
-    # Set/update the environment variable.
-    # Environment handling across systems is messy.
-    try:
-      env[KEY] = self._full_sid
-    except UnicodeEncodeError:
-      env[KEY] = self._full_sid.encode()
-
-    # Add a version event to front of the log.
-    self._AddVersionEvent()
-
-  @property
-  def full_sid(self):
-    return self._full_sid
-
-  def _AddVersionEvent(self):
-    """Adds a 'version' event at the beginning of current log."""
-    version_event = self._CreateEventDict('version')
-    version_event['evt'] = "2"
-    version_event['exe'] = RepoSourceVersion()
-    self._log.insert(0, version_event)
-
-  def _CreateEventDict(self, event_name):
-    """Returns a dictionary with the common keys/values for git trace2 events.
-
-    Args:
-      event_name: The event name.
-
-    Returns:
-      Dictionary with the common event fields populated.
-    """
-    return {
-        'event': event_name,
-        'sid': self._full_sid,
-        'thread': threading.current_thread().name,
-        'time': datetime.datetime.utcnow().isoformat() + 'Z',
-    }
-
-  def StartEvent(self):
-    """Append a 'start' event to the current log."""
-    start_event = self._CreateEventDict('start')
-    start_event['argv'] = sys.argv
-    self._log.append(start_event)
-
-  def ExitEvent(self, result):
-    """Append an 'exit' event to the current log.
-
-    Args:
-      result: Exit code of the event
-    """
-    exit_event = self._CreateEventDict('exit')
-
-    # Consider 'None' success (consistent with event_log result handling).
-    if result is None:
-      result = 0
-    exit_event['code'] = result
-    self._log.append(exit_event)
-
-  def CommandEvent(self, name, subcommands):
-    """Append a 'command' event to the current log.
-
-    Args:
-      name: Name of the primary command (ex: repo, git)
-      subcommands: List of the sub-commands (ex: version, init, sync)
-    """
-    command_event = self._CreateEventDict('command')
-    command_event['name'] = name
-    command_event['subcommands'] = subcommands
-    self._log.append(command_event)
+    """Event log that records events that occurred during a repo invocation.
 
-  def LogConfigEvents(self, config, event_dict_name):
-    """Append a |event_dict_name| event for each config key in |config|.
+    Events are written to the log as a consecutive JSON entries, one per line.
+    Entries follow the git trace2 EVENT format.
 
-    Args:
-      config: Configuration dictionary.
-      event_dict_name: Name of the event dictionary for items to be logged under.
-    """
-    for param, value in config.items():
-      event = self._CreateEventDict(event_dict_name)
-      event['param'] = param
-      event['value'] = value
-      self._log.append(event)
-
-  def DefParamRepoEvents(self, config):
-    """Append a 'def_param' event for each repo.* config key to the current log.
+    Each entry contains the following common keys:
+    - event: The event name
+    - sid: session-id - Unique string to allow process instance to be
+          identified.
+    - thread: The thread name.
+    - time: is the UTC time of the event.
 
-    Args:
-      config: Repo configuration dictionary
+    Valid 'event' names and event specific fields are documented here:
+    https://git-scm.com/docs/api-trace2#_event_format
     """
-    # Only output the repo.* config parameters.
-    repo_config = {k: v for k, v in config.items() if k.startswith('repo.')}
-    self.LogConfigEvents(repo_config, 'def_param')
-
-  def GetDataEventName(self, value):
-    """Returns 'data-json' if the value is an array else returns 'data'."""
-    return 'data-json' if value[0] == '[' and value[-1] == ']' else 'data'
 
-  def LogDataConfigEvents(self, config, prefix):
-    """Append a 'data' event for each config key/value in |config| to the current log.
-
-    For each keyX and valueX of the config, "key" field of the event is '|prefix|/keyX'
-    and the "value" of the "key" field is valueX.
-
-    Args:
-      config: Configuration dictionary.
-      prefix: Prefix for each key that is logged.
-    """
-    for key, value in config.items():
-      event = self._CreateEventDict(self.GetDataEventName(value))
-      event['key'] = f'{prefix}/{key}'
-      event['value'] = value
-      self._log.append(event)
-
-  def ErrorEvent(self, msg, fmt):
-    """Append a 'error' event to the current log."""
-    error_event = self._CreateEventDict('error')
-    error_event['msg'] = msg
-    error_event['fmt'] = fmt
-    self._log.append(error_event)
-
-  def _GetEventTargetPath(self):
-    """Get the 'trace2.eventtarget' path from git configuration.
-
-    Returns:
-      path: git config's 'trace2.eventtarget' path if it exists, or None
-    """
-    path = None
-    cmd = ['config', '--get', 'trace2.eventtarget']
-    # TODO(https://crbug.com/gerrit/13706): Use GitConfig when it supports
-    # system git config variables.
-    p = GitCommand(None, cmd, capture_stdout=True, capture_stderr=True,
-                   bare=True)
-    retval = p.Wait()
-    if retval == 0:
-      # Strip trailing carriage-return in path.
-      path = p.stdout.rstrip('\n')
-    elif retval != 1:
-      # `git config --get` is documented to produce an exit status of `1` if
-      # the requested variable is not present in the configuration. Report any
-      # other return value as an error.
-      print("repo: error: 'git config --get' call failed with return code: %r, stderr: %r" % (
-          retval, p.stderr), file=sys.stderr)
-    return path
-
-  def _WriteLog(self, write_fn):
-    """Writes the log out using a provided writer function.
-
-    Generate compact JSON output for each item in the log, and write it using
-    write_fn.
-
-    Args:
-      write_fn: A function that accepts byts and writes them to a destination.
-    """
-
-    for e in self._log:
-      # Dump in compact encoding mode.
-      # See 'Compact encoding' in Python docs:
-      # https://docs.python.org/3/library/json.html#module-json
-      write_fn(json.dumps(e, indent=None, separators=(',', ':')).encode('utf-8') + b'\n')
-
-  def Write(self, path=None):
-    """Writes the log out to a file or socket.
-
-    Log is only written if 'path' or 'git config --get trace2.eventtarget'
-    provide a valid path (or socket) to write logs to.
+    def __init__(self, env=None):
+        """Initializes the event log."""
+        self._log = []
+        # Try to get session-id (sid) from environment (setup in repo launcher).
+        KEY = "GIT_TRACE2_PARENT_SID"
+        if env is None:
+            env = os.environ
+
+        now = datetime.datetime.utcnow()
+
+        # Save both our sid component and the complete sid.
+        # We use our sid component (self._sid) as the unique filename prefix and
+        # the full sid (self._full_sid) in the log itself.
+        self._sid = "repo-%s-P%08x" % (
+            now.strftime("%Y%m%dT%H%M%SZ"),
+            os.getpid(),
+        )
+        parent_sid = env.get(KEY)
+        # Append our sid component to the parent sid (if it exists).
+        if parent_sid is not None:
+            self._full_sid = parent_sid + "/" + self._sid
+        else:
+            self._full_sid = self._sid
+
+        # Set/update the environment variable.
+        # Environment handling across systems is messy.
+        try:
+            env[KEY] = self._full_sid
+        except UnicodeEncodeError:
+            env[KEY] = self._full_sid.encode()
+
+        # Add a version event to front of the log.
+        self._AddVersionEvent()
+
+    @property
+    def full_sid(self):
+        return self._full_sid
+
+    def _AddVersionEvent(self):
+        """Adds a 'version' event at the beginning of current log."""
+        version_event = self._CreateEventDict("version")
+        version_event["evt"] = "2"
+        version_event["exe"] = RepoSourceVersion()
+        self._log.insert(0, version_event)
+
+    def _CreateEventDict(self, event_name):
+        """Returns a dictionary with common keys/values for git trace2 events.
+
+        Args:
+            event_name: The event name.
+
+        Returns:
+            Dictionary with the common event fields populated.
+        """
+        return {
+            "event": event_name,
+            "sid": self._full_sid,
+            "thread": threading.current_thread().name,
+            "time": datetime.datetime.utcnow().isoformat() + "Z",
+        }
+
+    def StartEvent(self):
+        """Append a 'start' event to the current log."""
+        start_event = self._CreateEventDict("start")
+        start_event["argv"] = sys.argv
+        self._log.append(start_event)
+
+    def ExitEvent(self, result):
+        """Append an 'exit' event to the current log.
+
+        Args:
+            result: Exit code of the event
+        """
+        exit_event = self._CreateEventDict("exit")
+
+        # Consider 'None' success (consistent with event_log result handling).
+        if result is None:
+            result = 0
+        exit_event["code"] = result
+        self._log.append(exit_event)
+
+    def CommandEvent(self, name, subcommands):
+        """Append a 'command' event to the current log.
+
+        Args:
+            name: Name of the primary command (ex: repo, git)
+            subcommands: List of the sub-commands (ex: version, init, sync)
+        """
+        command_event = self._CreateEventDict("command")
+        command_event["name"] = name
+        command_event["subcommands"] = subcommands
+        self._log.append(command_event)
+
+    def LogConfigEvents(self, config, event_dict_name):
+        """Append a |event_dict_name| event for each config key in |config|.
+
+        Args:
+            config: Configuration dictionary.
+            event_dict_name: Name of the event dictionary for items to be logged
+                under.
+        """
+        for param, value in config.items():
+            event = self._CreateEventDict(event_dict_name)
+            event["param"] = param
+            event["value"] = value
+            self._log.append(event)
+
+    def DefParamRepoEvents(self, config):
+        """Append 'def_param' events for repo config keys to the current log.
+
+        This appends one event for each repo.* config key.
+
+        Args:
+            config: Repo configuration dictionary
+        """
+        # Only output the repo.* config parameters.
+        repo_config = {k: v for k, v in config.items() if k.startswith("repo.")}
+        self.LogConfigEvents(repo_config, "def_param")
+
+    def GetDataEventName(self, value):
+        """Returns 'data-json' if the value is an array else returns 'data'."""
+        return "data-json" if value[0] == "[" and value[-1] == "]" else "data"
+
+    def LogDataConfigEvents(self, config, prefix):
+        """Append a 'data' event for each entry in |config| to the current log.
+
+        For each keyX and valueX of the config, "key" field of the event is
+        '|prefix|/keyX' and the "value" of the "key" field is valueX.
+
+        Args:
+            config: Configuration dictionary.
+            prefix: Prefix for each key that is logged.
+        """
+        for key, value in config.items():
+            event = self._CreateEventDict(self.GetDataEventName(value))
+            event["key"] = f"{prefix}/{key}"
+            event["value"] = value
+            self._log.append(event)
+
+    def ErrorEvent(self, msg, fmt):
+        """Append a 'error' event to the current log."""
+        error_event = self._CreateEventDict("error")
+        error_event["msg"] = msg
+        error_event["fmt"] = fmt
+        self._log.append(error_event)
+
+    def _GetEventTargetPath(self):
+        """Get the 'trace2.eventtarget' path from git configuration.
+
+        Returns:
+            path: git config's 'trace2.eventtarget' path if it exists, or None
+        """
+        path = None
+        cmd = ["config", "--get", "trace2.eventtarget"]
+        # TODO(https://crbug.com/gerrit/13706): Use GitConfig when it supports
+        # system git config variables.
+        p = GitCommand(
+            None, cmd, capture_stdout=True, capture_stderr=True, bare=True
+        )
+        retval = p.Wait()
+        if retval == 0:
+            # Strip trailing carriage-return in path.
+            path = p.stdout.rstrip("\n")
+        elif retval != 1:
+            # `git config --get` is documented to produce an exit status of `1`
+            # if the requested variable is not present in the configuration.
+            # Report any other return value as an error.
+            print(
+                "repo: error: 'git config --get' call failed with return code: "
+                "%r, stderr: %r" % (retval, p.stderr),
+                file=sys.stderr,
+            )
+        return path
+
+    def _WriteLog(self, write_fn):
+        """Writes the log out using a provided writer function.
+
+        Generate compact JSON output for each item in the log, and write it
+        using write_fn.
+
+        Args:
+            write_fn: A function that accepts byts and writes them to a
+                destination.
+        """
+
+        for e in self._log:
+            # Dump in compact encoding mode.
+            # See 'Compact encoding' in Python docs:
+            # https://docs.python.org/3/library/json.html#module-json
+            write_fn(
+                json.dumps(e, indent=None, separators=(",", ":")).encode(
+                    "utf-8"
+                )
+                + b"\n"
+            )
+
+    def Write(self, path=None):
+        """Writes the log out to a file or socket.
+
+        Log is only written if 'path' or 'git config --get trace2.eventtarget'
+        provide a valid path (or socket) to write logs to.
+
+        Logging filename format follows the git trace2 style of being a unique
+        (exclusive writable) file.
+
+        Args:
+            path: Path to where logs should be written. The path may have a
+                prefix of the form "af_unix:[{stream|dgram}:]", in which case
+                the path is treated as a Unix domain socket. See
+                https://git-scm.com/docs/api-trace2#_enabling_a_target for
+                details.
+
+        Returns:
+            log_path: Path to the log file or socket if log is written,
+                otherwise None
+        """
+        log_path = None
+        # If no logging path is specified, get the path from
+        # 'trace2.eventtarget'.
+        if path is None:
+            path = self._GetEventTargetPath()
+
+        # If no logging path is specified, exit.
+        if path is None:
+            return None
 
-    Logging filename format follows the git trace2 style of being a unique
-    (exclusive writable) file.
+        path_is_socket = False
+        socket_type = None
+        if isinstance(path, str):
+            parts = path.split(":", 1)
+            if parts[0] == "af_unix" and len(parts) == 2:
+                path_is_socket = True
+                path = parts[1]
+                parts = path.split(":", 1)
+                if parts[0] == "stream" and len(parts) == 2:
+                    socket_type = socket.SOCK_STREAM
+                    path = parts[1]
+                elif parts[0] == "dgram" and len(parts) == 2:
+                    socket_type = socket.SOCK_DGRAM
+                    path = parts[1]
+            else:
+                # Get absolute path.
+                path = os.path.abspath(os.path.expanduser(path))
+        else:
+            raise TypeError("path: str required but got %s." % type(path))
+
+        # Git trace2 requires a directory to write log to.
+
+        # TODO(https://crbug.com/gerrit/13706): Support file (append) mode also.
+        if not (path_is_socket or os.path.isdir(path)):
+            return None
 
-    Args:
-      path: Path to where logs should be written. The path may have a prefix of
-          the form "af_unix:[{stream|dgram}:]", in which case the path is
-          treated as a Unix domain socket. See
-          https://git-scm.com/docs/api-trace2#_enabling_a_target for details.
+        if path_is_socket:
+            if socket_type == socket.SOCK_STREAM or socket_type is None:
+                try:
+                    with socket.socket(
+                        socket.AF_UNIX, socket.SOCK_STREAM
+                    ) as sock:
+                        sock.connect(path)
+                        self._WriteLog(sock.sendall)
+                    return f"af_unix:stream:{path}"
+                except OSError as err:
+                    # If we tried to connect to a DGRAM socket using STREAM,
+                    # ignore the attempt and continue to DGRAM below. Otherwise,
+                    # issue a warning.
+                    if err.errno != errno.EPROTOTYPE:
+                        print(
+                            f"repo: warning: git trace2 logging failed: {err}",
+                            file=sys.stderr,
+                        )
+                        return None
+            if socket_type == socket.SOCK_DGRAM or socket_type is None:
+                try:
+                    with socket.socket(
+                        socket.AF_UNIX, socket.SOCK_DGRAM
+                    ) as sock:
+                        self._WriteLog(lambda bs: sock.sendto(bs, path))
+                        return f"af_unix:dgram:{path}"
+                except OSError as err:
+                    print(
+                        f"repo: warning: git trace2 logging failed: {err}",
+                        file=sys.stderr,
+                    )
+                    return None
+            # Tried to open a socket but couldn't connect (SOCK_STREAM) or write
+            # (SOCK_DGRAM).
+            print(
+                "repo: warning: git trace2 logging failed: could not write to "
+                "socket",
+                file=sys.stderr,
+            )
+            return None
 
-    Returns:
-      log_path: Path to the log file or socket if log is written, otherwise None
-    """
-    log_path = None
-    # If no logging path is specified, get the path from 'trace2.eventtarget'.
-    if path is None:
-      path = self._GetEventTargetPath()
-
-    # If no logging path is specified, exit.
-    if path is None:
-      return None
-
-    path_is_socket = False
-    socket_type = None
-    if isinstance(path, str):
-      parts = path.split(':', 1)
-      if parts[0] == 'af_unix' and len(parts) == 2:
-        path_is_socket = True
-        path = parts[1]
-        parts = path.split(':', 1)
-        if parts[0] == 'stream' and len(parts) == 2:
-          socket_type = socket.SOCK_STREAM
-          path = parts[1]
-        elif parts[0] == 'dgram' and len(parts) == 2:
-          socket_type = socket.SOCK_DGRAM
-          path = parts[1]
-      else:
-        # Get absolute path.
-        path = os.path.abspath(os.path.expanduser(path))
-    else:
-      raise TypeError('path: str required but got %s.' % type(path))
-
-    # Git trace2 requires a directory to write log to.
-
-    # TODO(https://crbug.com/gerrit/13706): Support file (append) mode also.
-    if not (path_is_socket or os.path.isdir(path)):
-      return None
-
-    if path_is_socket:
-      if socket_type == socket.SOCK_STREAM or socket_type is None:
+        # Path is an absolute path
+        # Use NamedTemporaryFile to generate a unique filename as required by
+        # git trace2.
         try:
-          with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as sock:
-            sock.connect(path)
-            self._WriteLog(sock.sendall)
-          return f'af_unix:stream:{path}'
-        except OSError as err:
-          # If we tried to connect to a DGRAM socket using STREAM, ignore the
-          # attempt and continue to DGRAM below. Otherwise, issue a warning.
-          if err.errno != errno.EPROTOTYPE:
-            print(f'repo: warning: git trace2 logging failed: {err}', file=sys.stderr)
+            with tempfile.NamedTemporaryFile(
+                mode="xb", prefix=self._sid, dir=path, delete=False
+            ) as f:
+                # TODO(https://crbug.com/gerrit/13706): Support writing events
+                # as they occur.
+                self._WriteLog(f.write)
+                log_path = f.name
+        except FileExistsError as err:
+            print(
+                "repo: warning: git trace2 logging failed: %r" % err,
+                file=sys.stderr,
+            )
             return None
-      if socket_type == socket.SOCK_DGRAM or socket_type is None:
-        try:
-          with socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM) as sock:
-            self._WriteLog(lambda bs: sock.sendto(bs, path))
-            return f'af_unix:dgram:{path}'
-        except OSError as err:
-          print(f'repo: warning: git trace2 logging failed: {err}', file=sys.stderr)
-          return None
-      # Tried to open a socket but couldn't connect (SOCK_STREAM) or write
-      # (SOCK_DGRAM).
-      print('repo: warning: git trace2 logging failed: could not write to socket', file=sys.stderr)
-      return None
-
-    # Path is an absolute path
-    # Use NamedTemporaryFile to generate a unique filename as required by git trace2.
-    try:
-      with tempfile.NamedTemporaryFile(mode='xb', prefix=self._sid, dir=path,
-                                       delete=False) as f:
-        # TODO(https://crbug.com/gerrit/13706): Support writing events as they
-        # occur.
-        self._WriteLog(f.write)
-        log_path = f.name
-    except FileExistsError as err:
-      print('repo: warning: git trace2 logging failed: %r' % err,
-            file=sys.stderr)
-      return None
-    return log_path
+        return log_path