def cache_render_result(workflow: Workflow, wf_module: WfModule, delta_id: int,
result: RenderResult) -> None:
"""
Save `result` for later viewing.
Raise AssertionError if `delta_id` is not what we expect.
Since this alters data, be sure to call it within a lock:
with workflow.cooperative_lock():
wf_module.refresh_from_db() # may change delta_id
cache_render_result(workflow, wf_module, delta_id, result)
"""
assert delta_id == wf_module.last_relevant_delta_id
assert result is not None
json_bytes = json_encode(result.json).encode("utf-8")
if not result.table.metadata.columns:
if result.errors:
status = "error"
else:
status = "unreachable"
else:
status = "ok"
wf_module.cached_render_result_delta_id = delta_id
wf_module.cached_render_result_errors = result.errors
wf_module.cached_render_result_error = "" # DELETEME
wf_module.cached_render_result_quick_fixes = [] # DELETEME
wf_module.cached_render_result_status = status
wf_module.cached_render_result_json = json_bytes
wf_module.cached_render_result_columns = result.table.metadata.columns
wf_module.cached_render_result_nrows = result.table.metadata.n_rows
# Now we get to the part where things can end up inconsistent. Try to
# err on the side of not-caching when that happens.
delete_parquet_files_for_wf_module(
workflow.id, wf_module.id) # makes old cache inconsistent
wf_module.save(
update_fields=WF_MODULE_FIELDS) # makes new cache inconsistent
if result.table.metadata.columns: # only write non-zero-column tables
with tempfile_context() as parquet_path:
parquet.write(parquet_path, result.table.table)
minio.fput_file(BUCKET,
parquet_key(workflow.id, wf_module.id, delta_id),
parquet_path) # makes new cache consistent
def clear_cached_render_result_for_wf_module(wf_module: WfModule) -> None:
"""
Delete a CachedRenderResult, if it exists.
This deletes the Parquet file from disk, _then_ empties relevant
database fields and saves them (and only them).
"""
delete_parquet_files_for_wf_module(wf_module.workflow_id, wf_module.id)
wf_module.cached_render_result_delta_id = None
wf_module.cached_render_result_errors = []
wf_module.cached_render_result_error = ""
wf_module.cached_render_result_json = b"null"
wf_module.cached_render_result_quick_fixes = []
wf_module.cached_render_result_status = None
wf_module.cached_render_result_columns = None
wf_module.cached_render_result_nrows = None
wf_module.save(update_fields=WF_MODULE_FIELDS)
