Source code for opentelemetry.trace.span

import abc
import logging
import re
import types as python_types
import typing
from collections import OrderedDict

from opentelemetry.trace.status import Status
from opentelemetry.util import types

# The key MUST begin with a lowercase letter or a digit,
# and can only contain lowercase letters (a-z), digits (0-9),
# underscores (_), dashes (-), asterisks (*), and forward slashes (/).
# For multi-tenant vendor scenarios, an at sign (@) can be used to
# prefix the vendor name. Vendors SHOULD set the tenant ID
# at the beginning of the key.

# key = ( lcalpha ) 0*255( lcalpha / DIGIT / "_" / "-"/ "*" / "/" )
# key = ( lcalpha / DIGIT ) 0*240( lcalpha / DIGIT / "_" / "-"/ "*" / "/" ) "@" lcalpha 0*13( lcalpha / DIGIT / "_" / "-"/ "*" / "/" )
# lcalpha = %x61-7A ; a-z

_KEY_FORMAT = (
    r"[a-z][_0-9a-z\-\*\/]{0,255}|"
    r"[a-z0-9][_0-9a-z\-\*\/]{0,240}@[a-z][_0-9a-z\-\*\/]{0,13}"
)
_KEY_PATTERN = re.compile(_KEY_FORMAT)

# The value is an opaque string containing up to 256 printable
# ASCII [RFC0020] characters (i.e., the range 0x20 to 0x7E)
# except comma (,) and (=).
# value    = 0*255(chr) nblk-chr
# nblk-chr = %x21-2B / %x2D-3C / %x3E-7E
# chr      = %x20 / nblk-chr

_VALUE_FORMAT = (
    r"[\x20-\x2b\x2d-\x3c\x3e-\x7e]{0,255}[\x21-\x2b\x2d-\x3c\x3e-\x7e]"
)
_VALUE_PATTERN = re.compile(_VALUE_FORMAT)


_TRACECONTEXT_MAXIMUM_TRACESTATE_KEYS = 32
_delimiter_pattern = re.compile(r"[ \t]*,[ \t]*")
_member_pattern = re.compile(f"({_KEY_FORMAT})(=)({_VALUE_FORMAT})[ \t]*")
_logger = logging.getLogger(__name__)


def _is_valid_pair(key: str, value: str) -> bool:

    return (
        isinstance(key, str)
        and _KEY_PATTERN.fullmatch(key) is not None
        and isinstance(value, str)
        and _VALUE_PATTERN.fullmatch(value) is not None
    )


[docs]class Span(abc.ABC): """A span represents a single operation within a trace."""
[docs] @abc.abstractmethod def end(self, end_time: typing.Optional[int] = None) -> None: """Sets the current time as the span's end time. The span's end time is the wall time at which the operation finished. Only the first call to `end` should modify the span, and implementations are free to ignore or raise on further calls. """
[docs] @abc.abstractmethod def get_span_context(self) -> "SpanContext": """Gets the span's SpanContext. Get an immutable, serializable identifier for this span that can be used to create new child spans. Returns: A :class:`opentelemetry.trace.SpanContext` with a copy of this span's immutable state. """
[docs] @abc.abstractmethod def set_attributes( self, attributes: typing.Dict[str, types.AttributeValue] ) -> None: """Sets Attributes. Sets Attributes with the key and value passed as arguments dict. Note: The behavior of `None` value attributes is undefined, and hence strongly discouraged. """
[docs] @abc.abstractmethod def set_attribute(self, key: str, value: types.AttributeValue) -> None: """Sets an Attribute. Sets a single Attribute with the key and value passed as arguments. Note: The behavior of `None` value attributes is undefined, and hence strongly discouraged. """
[docs] @abc.abstractmethod def add_event( self, name: str, attributes: types.Attributes = None, timestamp: typing.Optional[int] = None, ) -> None: """Adds an `Event`. Adds a single `Event` with the name and, optionally, a timestamp and attributes passed as arguments. Implementations should generate a timestamp if the `timestamp` argument is omitted. """
[docs] @abc.abstractmethod def update_name(self, name: str) -> None: """Updates the `Span` name. This will override the name provided via :func:`opentelemetry.trace.Tracer.start_span`. Upon this update, any sampling behavior based on Span name will depend on the implementation. """
[docs] @abc.abstractmethod def is_recording(self) -> bool: """Returns whether this span will be recorded. Returns true if this Span is active and recording information like events with the add_event operation and attributes using set_attribute. """
[docs] @abc.abstractmethod def set_status(self, status: Status) -> None: """Sets the Status of the Span. If used, this will override the default Span status. """
[docs] @abc.abstractmethod def record_exception( self, exception: Exception, attributes: types.Attributes = None, timestamp: typing.Optional[int] = None, escaped: bool = False, ) -> None: """Records an exception as a span event."""
def __enter__(self) -> "Span": """Invoked when `Span` is used as a context manager. Returns the `Span` itself. """ return self def __exit__( self, exc_type: typing.Optional[typing.Type[BaseException]], exc_val: typing.Optional[BaseException], exc_tb: typing.Optional[python_types.TracebackType], ) -> None: """Ends context manager and calls `end` on the `Span`.""" self.end()
[docs]class TraceFlags(int): """A bitmask that represents options specific to the trace. The only supported option is the "sampled" flag (``0x01``). If set, this flag indicates that the trace may have been sampled upstream. See the `W3C Trace Context - Traceparent`_ spec for details. .. _W3C Trace Context - Traceparent: https://www.w3.org/TR/trace-context/#trace-flags """ DEFAULT = 0x00 SAMPLED = 0x01
[docs] @classmethod def get_default(cls) -> "TraceFlags": return cls(cls.DEFAULT)
@property def sampled(self) -> bool: return bool(self & TraceFlags.SAMPLED)
DEFAULT_TRACE_OPTIONS = TraceFlags.get_default()
[docs]class TraceState(typing.Mapping[str, str]): """A list of key-value pairs representing vendor-specific trace info. Keys and values are strings of up to 256 printable US-ASCII characters. Implementations should conform to the `W3C Trace Context - Tracestate`_ spec, which describes additional restrictions on valid field values. .. _W3C Trace Context - Tracestate: https://www.w3.org/TR/trace-context/#tracestate-field """ def __init__( self, entries: typing.Optional[ typing.Sequence[typing.Tuple[str, str]] ] = None, ) -> None: self._dict = OrderedDict() # type: OrderedDict[str, str] if entries is None: return if len(entries) > _TRACECONTEXT_MAXIMUM_TRACESTATE_KEYS: _logger.warning( "There can't be more than %s key/value pairs.", _TRACECONTEXT_MAXIMUM_TRACESTATE_KEYS, ) return for key, value in entries: if _is_valid_pair(key, value): if key in self._dict: _logger.warning("Duplicate key: %s found.", key) continue self._dict[key] = value else: _logger.warning( "Invalid key/value pair (%s, %s) found.", key, value ) def __contains__(self, item: object) -> bool: return item in self._dict def __getitem__(self, key: str) -> str: return self._dict[key] def __iter__(self) -> typing.Iterator[str]: return iter(self._dict) def __len__(self) -> int: return len(self._dict) def __repr__(self) -> str: pairs = [ f"{{key={key}, value={value}}}" for key, value in self._dict.items() ] return str(pairs)
[docs] def add(self, key: str, value: str) -> "TraceState": """Adds a key-value pair to tracestate. The provided pair should adhere to w3c tracestate identifiers format. Args: key: A valid tracestate key to add value: A valid tracestate value to add Returns: A new TraceState with the modifications applied. If the provided key-value pair is invalid or results in tracestate that violates tracecontext specification, they are discarded and same tracestate will be returned. """ if not _is_valid_pair(key, value): _logger.warning( "Invalid key/value pair (%s, %s) found.", key, value ) return self # There can be a maximum of 32 pairs if len(self) >= _TRACECONTEXT_MAXIMUM_TRACESTATE_KEYS: _logger.warning("There can't be more 32 key/value pairs.") return self # Duplicate entries are not allowed if key in self._dict: _logger.warning("The provided key %s already exists.", key) return self new_state = [(key, value)] + list(self._dict.items()) return TraceState(new_state)
[docs] def update(self, key: str, value: str) -> "TraceState": """Updates a key-value pair in tracestate. The provided pair should adhere to w3c tracestate identifiers format. Args: key: A valid tracestate key to update value: A valid tracestate value to update for key Returns: A new TraceState with the modifications applied. If the provided key-value pair is invalid or results in tracestate that violates tracecontext specification, they are discarded and same tracestate will be returned. """ if not _is_valid_pair(key, value): _logger.warning( "Invalid key/value pair (%s, %s) found.", key, value ) return self prev_state = self._dict.copy() prev_state[key] = value prev_state.move_to_end(key, last=False) new_state = list(prev_state.items()) return TraceState(new_state)
[docs] def delete(self, key: str) -> "TraceState": """Deletes a key-value from tracestate. Args: key: A valid tracestate key to remove key-value pair from tracestate Returns: A new TraceState with the modifications applied. If the provided key-value pair is invalid or results in tracestate that violates tracecontext specification, they are discarded and same tracestate will be returned. """ if key not in self._dict: _logger.warning("The provided key %s doesn't exist.", key) return self prev_state = self._dict.copy() prev_state.pop(key) new_state = list(prev_state.items()) return TraceState(new_state)
[docs] def to_header(self) -> str: """Creates a w3c tracestate header from a TraceState. Returns: A string that adheres to the w3c tracestate header format. """ return ",".join(key + "=" + value for key, value in self._dict.items())
[docs] @classmethod def from_header(cls, header_list: typing.List[str]) -> "TraceState": """Parses one or more w3c tracestate header into a TraceState. Args: header_list: one or more w3c tracestate headers. Returns: A valid TraceState that contains values extracted from the tracestate header. If the format of one headers is illegal, all values will be discarded and an empty tracestate will be returned. If the number of keys is beyond the maximum, all values will be discarded and an empty tracestate will be returned. """ pairs = OrderedDict() for header in header_list: for member in re.split(_delimiter_pattern, header): # empty members are valid, but no need to process further. if not member: continue match = _member_pattern.fullmatch(member) if not match: _logger.warning( "Member doesn't match the w3c identifiers format %s", member, ) return cls() key, _eq, value = match.groups() # duplicate keys are not legal in header if key in pairs: return cls() pairs[key] = value return cls(list(pairs.items()))
[docs] @classmethod def get_default(cls) -> "TraceState": return cls()
[docs] def keys(self) -> typing.KeysView[str]: return self._dict.keys()
[docs] def items(self) -> typing.ItemsView[str, str]: return self._dict.items()
[docs] def values(self) -> typing.ValuesView[str]: return self._dict.values()
DEFAULT_TRACE_STATE = TraceState.get_default() _TRACE_ID_MAX_VALUE = 2 ** 128 - 1 _SPAN_ID_MAX_VALUE = 2 ** 64 - 1
[docs]class SpanContext( typing.Tuple[int, int, bool, "TraceFlags", "TraceState", bool] ): """The state of a Span to propagate between processes. This class includes the immutable attributes of a :class:`.Span` that must be propagated to a span's children and across process boundaries. Args: trace_id: The ID of the trace that this span belongs to. span_id: This span's ID. is_remote: True if propagated from a remote parent. trace_flags: Trace options to propagate. trace_state: Tracing-system-specific info to propagate. """ def __new__( cls, trace_id: int, span_id: int, is_remote: bool, trace_flags: typing.Optional["TraceFlags"] = DEFAULT_TRACE_OPTIONS, trace_state: typing.Optional["TraceState"] = DEFAULT_TRACE_STATE, ) -> "SpanContext": if trace_flags is None: trace_flags = DEFAULT_TRACE_OPTIONS if trace_state is None: trace_state = DEFAULT_TRACE_STATE is_valid = ( INVALID_TRACE_ID < trace_id <= _TRACE_ID_MAX_VALUE and INVALID_SPAN_ID < span_id <= _SPAN_ID_MAX_VALUE ) return tuple.__new__( cls, (trace_id, span_id, is_remote, trace_flags, trace_state, is_valid), ) def __getnewargs__( self, ) -> typing.Tuple[int, int, bool, "TraceFlags", "TraceState"]: return ( self.trace_id, self.span_id, self.is_remote, self.trace_flags, self.trace_state, ) @property def trace_id(self) -> int: return self[0] # pylint: disable=unsubscriptable-object @property def span_id(self) -> int: return self[1] # pylint: disable=unsubscriptable-object @property def is_remote(self) -> bool: return self[2] # pylint: disable=unsubscriptable-object @property def trace_flags(self) -> "TraceFlags": return self[3] # pylint: disable=unsubscriptable-object @property def trace_state(self) -> "TraceState": return self[4] # pylint: disable=unsubscriptable-object @property def is_valid(self) -> bool: return self[5] # pylint: disable=unsubscriptable-object def __setattr__(self, *args: str) -> None: _logger.debug( "Immutable type, ignoring call to set attribute", stack_info=True ) def __delattr__(self, *args: str) -> None: _logger.debug( "Immutable type, ignoring call to set attribute", stack_info=True ) def __repr__(self) -> str: return f"{type(self).__name__}(trace_id=0x{format_trace_id(self.trace_id)}, span_id=0x{format_span_id(self.span_id)}, trace_flags=0x{self.trace_flags:02x}, trace_state={self.trace_state!r}, is_remote={self.is_remote})"
[docs]class NonRecordingSpan(Span): """The Span that is used when no Span implementation is available. All operations are no-op except context propagation. """ def __init__(self, context: "SpanContext") -> None: self._context = context
[docs] def get_span_context(self) -> "SpanContext": return self._context
[docs] def is_recording(self) -> bool: return False
[docs] def end(self, end_time: typing.Optional[int] = None) -> None: pass
[docs] def set_attributes( self, attributes: typing.Dict[str, types.AttributeValue] ) -> None: pass
[docs] def set_attribute(self, key: str, value: types.AttributeValue) -> None: pass
[docs] def add_event( self, name: str, attributes: types.Attributes = None, timestamp: typing.Optional[int] = None, ) -> None: pass
[docs] def update_name(self, name: str) -> None: pass
[docs] def set_status(self, status: Status) -> None: pass
[docs] def record_exception( self, exception: Exception, attributes: types.Attributes = None, timestamp: typing.Optional[int] = None, escaped: bool = False, ) -> None: pass
def __repr__(self) -> str: return f"NonRecordingSpan({self._context!r})"
INVALID_SPAN_ID = 0x0000000000000000 INVALID_TRACE_ID = 0x00000000000000000000000000000000 INVALID_SPAN_CONTEXT = SpanContext( trace_id=INVALID_TRACE_ID, span_id=INVALID_SPAN_ID, is_remote=False, trace_flags=DEFAULT_TRACE_OPTIONS, trace_state=DEFAULT_TRACE_STATE, ) INVALID_SPAN = NonRecordingSpan(INVALID_SPAN_CONTEXT)
[docs]def format_trace_id(trace_id: int) -> str: """Convenience trace ID formatting method Args: trace_id: Trace ID int Returns: The trace ID as 32-byte hexadecimal string """ return format(trace_id, "032x")
[docs]def format_span_id(span_id: int) -> str: """Convenience span ID formatting method Args: span_id: Span ID int Returns: The span ID as 16-byte hexadecimal string """ return format(span_id, "016x")