html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,issue,performed_via_github_app
https://github.com/simonw/datasette/issues/1576#issuecomment-999874484,https://api.github.com/repos/simonw/datasette/issues/1576,999874484,IC_kwDOBm6k_c47mN-0,9599,2021-12-22T20:54:52Z,2021-12-22T20:54:52Z,OWNER,"Here's the full current relevant code from `tracer.py`: https://github.com/simonw/datasette/blob/ace86566b28280091b3844cf5fbecd20158e9004/datasette/tracer.py#L8-L64
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-999874886,https://api.github.com/repos/simonw/datasette/issues/1576,999874886,IC_kwDOBm6k_c47mOFG,9599,2021-12-22T20:55:42Z,2021-12-22T20:57:28Z,OWNER,"One way to solve this would be to introduce a `set_task_id()` method, which sets an ID which will be returned by `get_task_id()` instead of using `id(current_task(loop=loop))`.
It would be really nice if I could solve this using `with` syntax somehow. Something like:
```python
with trace_child_tasks():
(
suggested_facets,
(facet_results, facets_timed_out),
) = await asyncio.gather(
execute_suggested_facets(),
execute_facets(),
)
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-999876666,https://api.github.com/repos/simonw/datasette/issues/1576,999876666,IC_kwDOBm6k_c47mOg6,9599,2021-12-22T20:59:22Z,2021-12-22T21:18:09Z,OWNER,"This article is relevant: [Context information storage for asyncio](https://blog.sqreen.com/asyncio/) - in particular the section https://blog.sqreen.com/asyncio/#context-inheritance-between-tasks which describes exactly the problem I have and their solution, which involves this trickery:
```python
def request_task_factory(loop, coro):
child_task = asyncio.tasks.Task(coro, loop=loop)
parent_task = asyncio.Task.current_task(loop=loop)
current_request = getattr(parent_task, 'current_request', None)
setattr(child_task, 'current_request', current_request)
return child_task
loop = asyncio.get_event_loop()
loop.set_task_factory(request_task_factory)
```
They released their solution as a library: https://pypi.org/project/aiocontext/ and https://github.com/sqreen/AioContext - but that company was acquired by Datadog back in April and doesn't seem to be actively maintaining their open source stuff any more: https://twitter.com/SqreenIO/status/1384906075506364417","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-999878907,https://api.github.com/repos/simonw/datasette/issues/1576,999878907,IC_kwDOBm6k_c47mPD7,9599,2021-12-22T21:03:49Z,2021-12-22T21:10:46Z,OWNER,"`context_vars` can solve this but they were introduced in Python 3.7: https://www.python.org/dev/peps/pep-0567/
Python 3.6 support ends in a few days time, and it looks like Glitch has updated to 3.7 now - so maybe I can get away with Datasette needing 3.7 these days?
Tweeted about that here: https://twitter.com/simonw/status/1473761478155010048","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-999987418,https://api.github.com/repos/simonw/datasette/issues/1576,999987418,IC_kwDOBm6k_c47mpja,9599,2021-12-23T01:59:58Z,2021-12-23T02:02:12Z,OWNER,"Another option: https://github.com/Skyscanner/aiotask-context - looks like it might be better as it's been updated for Python 3.7 in this commit https://github.com/Skyscanner/aiotask-context/commit/67108c91d2abb445655cc2af446fdb52ca7890c4
The Skyscanner one doesn't attempt to wrap any existing factories, but that's OK for my purposes since I don't need to handle arbitrary `asyncio` code written by other people.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-999990414,https://api.github.com/repos/simonw/datasette/issues/1576,999990414,IC_kwDOBm6k_c47mqSO,9599,2021-12-23T02:08:39Z,2021-12-23T18:16:35Z,OWNER,"It's tiny: I'm tempted to vendor it. https://github.com/Skyscanner/aiotask-context/blob/master/aiotask_context/__init__.py
No, I'll add it as a pinned dependency, which I can then drop when I drop 3.6 support.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-1000935523,https://api.github.com/repos/simonw/datasette/issues/1576,1000935523,IC_kwDOBm6k_c47qRBj,9599,2021-12-24T21:33:05Z,2021-12-24T21:33:05Z,OWNER,"Another option would be to attempt to import `contextvars` and, if the import fails (for Python 3.6) continue using the current mechanism - then let Python 3.6 users know in the documentation that under Python 3.6 they will miss out on nested traces.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-1017112543,https://api.github.com/repos/simonw/datasette/issues/1576,1017112543,IC_kwDOBm6k_c48n-ff,9599,2022-01-20T04:35:00Z,2022-02-05T04:33:46Z,OWNER,I dropped support for Python 3.6 in fae3983c51f4a3aca8335f3e01ff85ef27076fbf so now free to use `contextvars` for this.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-1027635925,https://api.github.com/repos/simonw/datasette/issues/1576,1027635925,IC_kwDOBm6k_c49QHrV,9599,2022-02-02T06:47:20Z,2022-02-02T06:47:20Z,OWNER,"Here's what I was hacking around with when I uncovered this problem:
```diff
diff --git a/datasette/views/table.py b/datasette/views/table.py
index 77fb285..8c57d08 100644
--- a/datasette/views/table.py
+++ b/datasette/views/table.py
@@ -1,3 +1,4 @@
+import asyncio
import urllib
import itertools
import json
@@ -615,44 +616,37 @@ class TableView(RowTableShared):
if request.args.get(""_timelimit""):
extra_args[""custom_time_limit""] = int(request.args.get(""_timelimit""))
- # Execute the main query!
- results = await db.execute(sql, params, truncate=True, **extra_args)
-
- # Calculate the total count for this query
- filtered_table_rows_count = None
- if (
- not db.is_mutable
- and self.ds.inspect_data
- and count_sql == f""select count(*) from {table} ""
- ):
- # We can use a previously cached table row count
- try:
- filtered_table_rows_count = self.ds.inspect_data[database][""tables""][
- table
- ][""count""]
- except KeyError:
- pass
-
- # Otherwise run a select count(*) ...
- if count_sql and filtered_table_rows_count is None and not nocount:
- try:
- count_rows = list(await db.execute(count_sql, from_sql_params))
- filtered_table_rows_count = count_rows[0][0]
- except QueryInterrupted:
- pass
-
- # Faceting
- if not self.ds.setting(""allow_facet"") and any(
- arg.startswith(""_facet"") for arg in request.args
- ):
- raise BadRequest(""_facet= is not allowed"")
+ async def execute_count():
+ # Calculate the total count for this query
+ filtered_table_rows_count = None
+ if (
+ not db.is_mutable
+ and self.ds.inspect_data
+ and count_sql == f""select count(*) from {table} ""
+ ):
+ # We can use a previously cached table row count
+ try:
+ filtered_table_rows_count = self.ds.inspect_data[database][
+ ""tables""
+ ][table][""count""]
+ except KeyError:
+ pass
+
+ if count_sql and filtered_table_rows_count is None and not nocount:
+ try:
+ count_rows = list(await db.execute(count_sql, from_sql_params))
+ filtered_table_rows_count = count_rows[0][0]
+ except QueryInterrupted:
+ pass
+
+ return filtered_table_rows_count
+
+ filtered_table_rows_count = await execute_count()
# pylint: disable=no-member
facet_classes = list(
itertools.chain.from_iterable(pm.hook.register_facet_classes())
)
- facet_results = {}
- facets_timed_out = []
facet_instances = []
for klass in facet_classes:
facet_instances.append(
@@ -668,33 +662,58 @@ class TableView(RowTableShared):
)
)
- if not nofacet:
- for facet in facet_instances:
- (
- instance_facet_results,
- instance_facets_timed_out,
- ) = await facet.facet_results()
- for facet_info in instance_facet_results:
- base_key = facet_info[""name""]
- key = base_key
- i = 1
- while key in facet_results:
- i += 1
- key = f""{base_key}_{i}""
- facet_results[key] = facet_info
- facets_timed_out.extend(instance_facets_timed_out)
-
- # Calculate suggested facets
- suggested_facets = []
- if (
- self.ds.setting(""suggest_facets"")
- and self.ds.setting(""allow_facet"")
- and not _next
- and not nofacet
- and not nosuggest
- ):
- for facet in facet_instances:
- suggested_facets.extend(await facet.suggest())
+ async def execute_suggested_facets():
+ # Calculate suggested facets
+ suggested_facets = []
+ if (
+ self.ds.setting(""suggest_facets"")
+ and self.ds.setting(""allow_facet"")
+ and not _next
+ and not nofacet
+ and not nosuggest
+ ):
+ for facet in facet_instances:
+ suggested_facets.extend(await facet.suggest())
+ return suggested_facets
+
+ async def execute_facets():
+ facet_results = {}
+ facets_timed_out = []
+ if not self.ds.setting(""allow_facet"") and any(
+ arg.startswith(""_facet"") for arg in request.args
+ ):
+ raise BadRequest(""_facet= is not allowed"")
+
+ if not nofacet:
+ for facet in facet_instances:
+ (
+ instance_facet_results,
+ instance_facets_timed_out,
+ ) = await facet.facet_results()
+ for facet_info in instance_facet_results:
+ base_key = facet_info[""name""]
+ key = base_key
+ i = 1
+ while key in facet_results:
+ i += 1
+ key = f""{base_key}_{i}""
+ facet_results[key] = facet_info
+ facets_timed_out.extend(instance_facets_timed_out)
+
+ return facet_results, facets_timed_out
+
+ # Execute the main query, facets and facet suggestions in parallel:
+ (
+ results,
+ suggested_facets,
+ (facet_results, facets_timed_out),
+ ) = await asyncio.gather(
+ db.execute(sql, params, truncate=True, **extra_args),
+ execute_suggested_facets(),
+ execute_facets(),
+ )
+
+ results = await db.execute(sql, params, truncate=True, **extra_args)
# Figure out columns and rows for the query
columns = [r[0] for r in results.description]
```
It's a hacky attempt at running some of the table page queries in parallel to see what happens.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-1030525218,https://api.github.com/repos/simonw/datasette/issues/1576,1030525218,IC_kwDOBm6k_c49bJEi,9599,2022-02-05T04:45:11Z,2022-02-05T04:45:11Z,OWNER,"Got a prototype working with `contextvars` - it identified two parallel executing queries using the patch from above:
![CleanShot 2022-02-04 at 20 41 50@2x](https://user-images.githubusercontent.com/9599/152628949-cf766b13-13cf-4831-b48d-2f23cadb6a05.png)
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-1030528532,https://api.github.com/repos/simonw/datasette/issues/1576,1030528532,IC_kwDOBm6k_c49bJ4U,9599,2022-02-05T05:09:57Z,2022-02-05T05:09:57Z,OWNER,Needs documentation. I'll document `from datasette.tracer import trace` too.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,
https://github.com/simonw/datasette/issues/1576#issuecomment-1030530071,https://api.github.com/repos/simonw/datasette/issues/1576,1030530071,IC_kwDOBm6k_c49bKQX,9599,2022-02-05T05:21:35Z,2022-02-05T05:21:35Z,OWNER,New documentation section: https://docs.datasette.io/en/latest/internals.html#datasette-tracer,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1087181951,