diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/log_contexts.rst | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/docs/log_contexts.rst b/docs/log_contexts.rst index 27cde11cf7..f5cd5de8ab 100644 --- a/docs/log_contexts.rst +++ b/docs/log_contexts.rst @@ -1,4 +1,4 @@ -Log contexts +Log Contexts ============ .. contents:: @@ -12,7 +12,7 @@ record. Logcontexts are also used for CPU and database accounting, so that we can track which requests were responsible for high CPU use or database activity. -The ``synapse.util.logcontext`` module provides a facilities for managing the +The ``synapse.logging.context`` module provides a facilities for managing the current log context (as well as providing the ``LoggingContextFilter`` class). Deferreds make the whole thing complicated, so this document describes how it @@ -27,19 +27,19 @@ found them: .. code:: python - from synapse.util import logcontext # omitted from future snippets + from synapse.logging import context # omitted from future snippets def handle_request(request_id): - request_context = logcontext.LoggingContext() + request_context = context.LoggingContext() - calling_context = logcontext.LoggingContext.current_context() - logcontext.LoggingContext.set_current_context(request_context) + calling_context = context.LoggingContext.current_context() + context.LoggingContext.set_current_context(request_context) try: request_context.request = request_id do_request_handling() logger.debug("finished") finally: - logcontext.LoggingContext.set_current_context(calling_context) + context.LoggingContext.set_current_context(calling_context) def do_request_handling(): logger.debug("phew") # this will be logged against request_id @@ -51,7 +51,7 @@ written much more succinctly as: .. code:: python def handle_request(request_id): - with logcontext.LoggingContext() as request_context: + with context.LoggingContext() as request_context: request_context.request = request_id do_request_handling() logger.debug("finished") @@ -74,7 +74,7 @@ blocking operation, and returns a deferred: @defer.inlineCallbacks def handle_request(request_id): - with logcontext.LoggingContext() as request_context: + with context.LoggingContext() as request_context: request_context.request = request_id yield do_request_handling() logger.debug("finished") @@ -179,7 +179,7 @@ though, we need to make up a new Deferred, or we get a Deferred back from external code. We need to make it follow our rules. The easy way to do it is with a combination of ``defer.inlineCallbacks``, and -``logcontext.PreserveLoggingContext``. Suppose we want to implement ``sleep``, +``context.PreserveLoggingContext``. Suppose we want to implement ``sleep``, which returns a deferred which will run its callbacks after a given number of seconds. That might look like: @@ -204,13 +204,13 @@ That doesn't follow the rules, but we can fix it by wrapping it with This technique works equally for external functions which return deferreds, or deferreds we have made ourselves. -You can also use ``logcontext.make_deferred_yieldable``, which just does the +You can also use ``context.make_deferred_yieldable``, which just does the boilerplate for you, so the above could be written: .. code:: python def sleep(seconds): - return logcontext.make_deferred_yieldable(get_sleep_deferred(seconds)) + return context.make_deferred_yieldable(get_sleep_deferred(seconds)) Fire-and-forget @@ -279,7 +279,7 @@ Obviously that option means that the operations done in that might be fixed by setting a different logcontext via a ``with LoggingContext(...)`` in ``background_operation``). -The second option is to use ``logcontext.run_in_background``, which wraps a +The second option is to use ``context.run_in_background``, which wraps a function so that it doesn't reset the logcontext even when it returns an incomplete deferred, and adds a callback to the returned deferred to reset the logcontext. In other words, it turns a function that follows the Synapse rules @@ -293,7 +293,7 @@ It can be used like this: def do_request_handling(): yield foreground_operation() - logcontext.run_in_background(background_operation) + context.run_in_background(background_operation) # this will now be logged against the request context logger.debug("Request handling complete") @@ -332,7 +332,7 @@ gathered: result = yield defer.gatherResults([d1, d2]) In this case particularly, though, option two, of using -``logcontext.preserve_fn`` almost certainly makes more sense, so that +``context.preserve_fn`` almost certainly makes more sense, so that ``operation1`` and ``operation2`` are both logged against the original logcontext. This looks like: @@ -340,8 +340,8 @@ logcontext. This looks like: @defer.inlineCallbacks def do_request_handling(): - d1 = logcontext.preserve_fn(operation1)() - d2 = logcontext.preserve_fn(operation2)() + d1 = context.preserve_fn(operation1)() + d2 = context.preserve_fn(operation2)() with PreserveLoggingContext(): result = yield defer.gatherResults([d1, d2]) @@ -381,7 +381,7 @@ off the background process, and then leave the ``with`` block to wait for it: .. code:: python def handle_request(request_id): - with logcontext.LoggingContext() as request_context: + with context.LoggingContext() as request_context: request_context.request = request_id d = do_request_handling() @@ -414,7 +414,7 @@ runs its callbacks in the original logcontext, all is happy. The business of a Deferred which runs its callbacks in the original logcontext isn't hard to achieve — we have it today, in the shape of -``logcontext._PreservingContextDeferred``: +``context._PreservingContextDeferred``: .. code:: python |