# Copyright (c) 2016-2018 Uber Technologies, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import absolute_import
import six
import threading
import time
import logging
import opentracing
from opentracing.ext import tags as ext_tags
from . import codecs, thrift
from .constants import SAMPLED_FLAG, DEBUG_FLAG
logger = logging.getLogger('jaeger_tracing')
class Span(opentracing.Span):
"""Implements opentracing.Span."""
__slots__ = ['_tracer', '_context',
'operation_name', 'start_time', 'end_time',
'logs', 'tags', 'finished', 'update_lock']
def __init__(self, context, tracer, operation_name,
tags=None, start_time=None, references=None):
super(Span, self).__init__(context=context, tracer=tracer)
self.operation_name = operation_name
self.start_time = start_time or time.time()
self.end_time = None
self.finished = False
self.update_lock = threading.Lock()
self.references = references
# we store tags and logs as Thrift objects to avoid extra allocations
self.tags = []
self.logs = []
if tags:
for k, v in six.iteritems(tags):
self.set_tag(k, v)
def set_operation_name(self, operation_name):
"""
Set or change the operation name.
:param operation_name: the new operation name
:return: Returns the Span itself, for call chaining.
"""
with self.update_lock:
self.operation_name = operation_name
return self
def finish(self, finish_time=None):
"""Indicate that the work represented by this span has been completed
or terminated, and is ready to be sent to the Reporter.
If any tags / logs need to be added to the span, it should be done
before calling finish(), otherwise they may be ignored.
:param finish_time: an explicit Span finish timestamp as a unix
timestamp per time.time()
"""
if not self.is_sampled():
return
with self.update_lock:
if self.finished:
logger.warning('Span has already been finished; will not be reported again.')
return
self.finished = True
self.end_time = finish_time or time.time()
self.tracer.report_span(self)
def set_tag(self, key, value):
"""
:param key:
:param value:
"""
with self.update_lock:
if key == ext_tags.SAMPLING_PRIORITY and not self._set_sampling_priority(value):
return self
if self.is_sampled():
tag = thrift.make_tag(
key=key,
value=value,
max_length=self.tracer.max_tag_value_length,
max_traceback_length=self._tracer.max_traceback_length,
)
self.tags.append(tag)
return self
def _set_sampling_priority(self, value):
"""
N.B. Caller must be holding update_lock.
"""
# Ignore debug spans trying to re-enable debug.
if self.is_debug() and value:
return False
try:
value_num = int(value)
except ValueError:
return False
if value_num == 0:
self.context.flags &= ~(SAMPLED_FLAG | DEBUG_FLAG)
return False
if self.tracer.is_debug_allowed(self.operation_name):
self.context.flags |= SAMPLED_FLAG | DEBUG_FLAG
return True
return False
def log_kv(self, key_values, timestamp=None):
if self.is_sampled():
timestamp = timestamp if timestamp else time.time()
# TODO handle exception logging, 'python.exception.type' etc.
log = thrift.make_log(
timestamp=timestamp if timestamp else time.time(),
fields=key_values,
max_length=self._tracer.max_tag_value_length,
max_traceback_length=self._tracer.max_traceback_length,
)
with self.update_lock:
self.logs.append(log)
return self
def set_baggage_item(self, key, value):
prev_value = self.get_baggage_item(key=key)
new_context = self.context.with_baggage_item(key=key, value=value)
with self.update_lock:
self._context = new_context
if self.is_sampled():
logs = {
'event': 'baggage',
'key': key,
'value': value,
}
if prev_value:
# TODO add metric for this
logs['override'] = 'true'
self.log_kv(key_values=logs)
return self
def get_baggage_item(self, key):
return self.context.baggage.get(key)
def is_sampled(self):
return self.context.flags & SAMPLED_FLAG == SAMPLED_FLAG
def is_debug(self):
return self.context.flags & DEBUG_FLAG == DEBUG_FLAG
def is_rpc(self):
for tag in self.tags:
if tag.key == ext_tags.SPAN_KIND:
return tag.vStr == ext_tags.SPAN_KIND_RPC_CLIENT or \
tag.vStr == ext_tags.SPAN_KIND_RPC_SERVER
return False
def is_rpc_client(self):
for tag in self.tags:
if tag.key == ext_tags.SPAN_KIND:
return tag.vStr == ext_tags.SPAN_KIND_RPC_CLIENT
return False
@property
def trace_id(self):
return self.context.trace_id
@property
def span_id(self):
return self.context.span_id
@property
def parent_id(self):
return self.context.parent_id
@property
def flags(self):
return self.context.flags
def __repr__(self):
c = codecs.span_context_to_string(
trace_id=self.context.trace_id, span_id=self.context.span_id,
parent_id=self.context.parent_id, flags=self.context.flags)
return '%s %s.%s' % (c, self.tracer.service_name, self.operation_name)
def info(self, message, payload=None):
"""DEPRECATED"""
if payload:
self.log(event=message, payload=payload)
else:
self.log(event=message)
return self
def error(self, message, payload=None):
"""DEPRECATED"""
self.set_tag('error', True)
if payload:
self.log(event=message, payload=payload)
else:
self.log(event=message)
return self
