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codebotenocelotlmauriciovasquezbernal
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Adding Context API (open-telemetry#395)
This change implements the Context API portion of OTEP open-telemetry#66. The CorrelationContext API and Propagation API changes will come in future PRs. We're leveraging entrypoints to support other implementations of the Context API if/when necessary. For backwards compatibility, this change uses aiocontextvars for Python versions older than 3.7. Co-authored-by: Diego Hurtado <ocelotl@users.noreply.github.com> Co-authored-by: Mauricio Vásquez <mauricio@kinvolk.io>
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‎docs/opentelemetry.context.base_context.rst renamed to ‎docs/opentelemetry.context.context.rst

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opentelemetry.context.base\_context module
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==========================================
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.. automodule:: opentelemetry.context.base_context
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.. automodule:: opentelemetry.context.context
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:members:
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:undoc-members:
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:show-inheritance:

‎docs/opentelemetry.context.rst

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.. toctree::
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opentelemetry.context.base_context
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opentelemetry.context.context
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Module contents
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---------------

‎ext/opentelemetry-ext-http-requests/src/opentelemetry/ext/http_requests/__init__.py

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from requests.sessions import Session
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from opentelemetry import propagators
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from opentelemetry.context import Context
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from opentelemetry import context, propagators
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from opentelemetry.ext.http_requests.version import __version__
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from opentelemetry.trace import SpanKind
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@functools.wraps(wrapped)
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def instrumented_request(self, method, url, *args, **kwargs):
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if Context.suppress_instrumentation:
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if context.get_value("suppress_instrumentation"):
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return wrapped(self, method, url, *args, **kwargs)
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# See

‎opentelemetry-api/setup.py

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"/tree/master/opentelemetry-api"
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),
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zip_safe=False,
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entry_points={
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"opentelemetry_context": [
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"default_context = "
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"opentelemetry.context.default_context:"
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"DefaultRuntimeContext",
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]
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},
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)

‎opentelemetry-api/src/opentelemetry/context/__init__.py

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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""
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The OpenTelemetry context module provides abstraction layer on top of
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thread-local storage and contextvars. The long term direction is to switch to
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contextvars provided by the Python runtime library.
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A global object ``Context`` is provided to access all the context related
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functionalities::
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>>> from opentelemetry.context import Context
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>>> Context.foo = 1
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>>> Context.foo = 2
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>>> Context.foo
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2
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When explicit thread is used, a helper function
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``Context.with_current_context`` can be used to carry the context across
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threads::
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from threading import Thread
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from opentelemetry.context import Context
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def work(name):
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print('Entering worker:', Context)
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Context.operation_id = name
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print('Exiting worker:', Context)
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if __name__ == '__main__':
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print('Main thread:', Context)
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Context.operation_id = 'main'
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print('Main thread:', Context)
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# by default context is not propagated to worker thread
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thread = Thread(target=work, args=('foo',))
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thread.start()
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thread.join()
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print('Main thread:', Context)
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# user can propagate context explicitly
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thread = Thread(
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target=Context.with_current_context(work),
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args=('bar',),
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)
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thread.start()
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thread.join()
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print('Main thread:', Context)
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Here goes another example using thread pool::
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import time
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import threading
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from multiprocessing.dummy import Pool as ThreadPool
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from opentelemetry.context import Context
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_console_lock = threading.Lock()
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def println(msg):
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with _console_lock:
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print(msg)
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def work(name):
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println('Entering worker[{}]: {}'.format(name, Context))
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Context.operation_id = name
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time.sleep(0.01)
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println('Exiting worker[{}]: {}'.format(name, Context))
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if __name__ == "__main__":
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println('Main thread: {}'.format(Context))
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Context.operation_id = 'main'
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pool = ThreadPool(2) # create a thread pool with 2 threads
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pool.map(Context.with_current_context(work), [
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'bear',
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'cat',
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'dog',
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'horse',
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'rabbit',
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])
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pool.close()
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pool.join()
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println('Main thread: {}'.format(Context))
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Here goes a simple demo of how async could work in Python 3.7+::
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import asyncio
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from opentelemetry.context import Context
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class Span(object):
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def __init__(self, name):
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self.name = name
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self.parent = Context.current_span
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def __repr__(self):
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return ('{}(name={}, parent={})'
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.format(
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type(self).__name__,
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self.name,
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self.parent,
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))
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async def __aenter__(self):
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Context.current_span = self
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async def __aexit__(self, exc_type, exc, tb):
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Context.current_span = self.parent
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async def main():
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print(Context)
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async with Span('foo'):
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print(Context)
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await asyncio.sleep(0.1)
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async with Span('bar'):
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print(Context)
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await asyncio.sleep(0.1)
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print(Context)
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await asyncio.sleep(0.1)
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print(Context)
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if __name__ == '__main__':
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asyncio.run(main())
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"""
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from .base_context import BaseRuntimeContext
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__all__ = ["Context"]
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try:
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from .async_context import AsyncRuntimeContext
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Context = AsyncRuntimeContext() # type: BaseRuntimeContext
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except ImportError:
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from .thread_local_context import ThreadLocalRuntimeContext
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Context = ThreadLocalRuntimeContext()
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import logging
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import typing
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from os import environ
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from pkg_resources import iter_entry_points
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from opentelemetry.context.context import Context, RuntimeContext
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logger = logging.getLogger(__name__)
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_RUNTIME_CONTEXT = None # type: typing.Optional[RuntimeContext]
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def get_value(key: str, context: typing.Optional[Context] = None) -> "object":
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"""To access the local state of a concern, the RuntimeContext API
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provides a function which takes a context and a key as input,
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and returns a value.
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Args:
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key: The key of the value to retrieve.
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context: The context from which to retrieve the value, if None, the current context is used.
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"""
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return context.get(key) if context is not None else get_current().get(key)
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def set_value(
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key: str, value: "object", context: typing.Optional[Context] = None
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) -> Context:
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"""To record the local state of a cross-cutting concern, the
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RuntimeContext API provides a function which takes a context, a
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key, and a value as input, and returns an updated context
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which contains the new value.
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Args:
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key: The key of the entry to set
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value: The value of the entry to set
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context: The context to copy, if None, the current context is used
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"""
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if context is None:
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context = get_current()
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new_values = context.copy()
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new_values[key] = value
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return Context(new_values)
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def remove_value(
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key: str, context: typing.Optional[Context] = None
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) -> Context:
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"""To remove a value, this method returns a new context with the key
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cleared. Note that the removed value still remains present in the old
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context.
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Args:
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key: The key of the entry to remove
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context: The context to copy, if None, the current context is used
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"""
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if context is None:
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context = get_current()
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new_values = context.copy()
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new_values.pop(key, None)
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return Context(new_values)
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def get_current() -> Context:
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"""To access the context associated with program execution,
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the RuntimeContext API provides a function which takes no arguments
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and returns a RuntimeContext.
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"""
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global _RUNTIME_CONTEXT # pylint: disable=global-statement
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if _RUNTIME_CONTEXT is None:
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# FIXME use a better implementation of a configuration manager to avoid having
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# to get configuration values straight from environment variables
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configured_context = environ.get(
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"OPENTELEMETRY_CONTEXT", "default_context"
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) # type: str
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try:
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_RUNTIME_CONTEXT = next(
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iter_entry_points("opentelemetry_context", configured_context)
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).load()()
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except Exception: # pylint: disable=broad-except
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logger.error("Failed to load context: %s", configured_context)
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return _RUNTIME_CONTEXT.get_current() # type:ignore
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def set_current(context: Context) -> Context:
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"""To associate a context with program execution, the Context
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API provides a function which takes a Context.
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Args:
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context: The context to use as current.
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"""
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old_context = get_current()
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_RUNTIME_CONTEXT.set_current(context) # type:ignore
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return old_context
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def with_current_context(
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func: typing.Callable[..., "object"]
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) -> typing.Callable[..., "object"]:
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"""Capture the current context and apply it to the provided func."""
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caller_context = get_current()
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def call_with_current_context(
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*args: "object", **kwargs: "object"
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) -> "object":
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try:
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backup = get_current()
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set_current(caller_context)
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return func(*args, **kwargs)
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finally:
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set_current(backup)
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return call_with_current_context

‎opentelemetry-api/src/opentelemetry/context/async_context.py

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