Extra auto classgeneration on import of hdmf.common types

[oruebel]

Description

In the function TypeMap.get_container_cls function in hdmf.build.manager the internal helper function TypeMap.__get_container_cls call initially returns None for classes from hdmf.common. When importing a container class from hdmf.common this results in a sequence of calls where first Container classes are autogenerated and the later on the correct custom classes from hdmf.common are detected. When I add a print(cls, namespace, data_type) in TypeMap.get_container_cls and import DynamicTable I get the following:

from hdmf.common.table import DynamicTable
None hdmf-common Data
None hdmf-common Container
None hdmf-common SimpleMultiContainer
None hdmf-common VectorData
None hdmf-common VectorIndex
None hdmf-common ElementIdentifiers
None hdmf-common DynamicTableRegion
None hdmf-common DynamicTable
None hdmf-common AlignedDynamicTable
None hdmf-common CSRMatrix
<class 'hdmf.common.table.DynamicTable'> hdmf-common DynamicTable
<class 'hdmf.common.table.VectorData'> hdmf-common VectorData
<class 'hdmf.common.table.VectorIndex'> hdmf-common VectorIndex
<class 'hdmf.common.table.ElementIdentifiers'> hdmf-common ElementIdentifiers
<class 'hdmf.common.table.DynamicTableRegion'> hdmf-common DynamicTableRegion
<class 'hdmf.common.table.EnumData'> hdmf-experimental EnumData
<class 'hdmf.common.sparse.CSRMatrix'> hdmf-common CSRMatrix
<class 'hdmf.common.resources.ExternalResources'> hdmf-experimental ExternalResources
<class 'hdmf.common.multi.SimpleMultiContainer'> hdmf-common SimpleMultiContainer

I.e., there is a first round where TypeMap.__get_container_cls returns None which in turn triggers the automatic class generation and then in a second round the correct classes are found.

While the end-behavior for the user is correct but having classes autogenerated for all types seems like an unnecessary that could slow down import of HDMF. I found this behavior as part of PR #551 to integrate AlignedDynamicTable , because automatic class generation currently fails for this type (see Issue #554) and the behavior described in this issues triggers that behavior.

Steps to Reproduce

from hdmf.common.table import DynamicTable

Environment

Python Executable: Installed HDMF from latest dev
Python Version: Python  3.8
Operating System:  macOS
HDMF Version: dev

Checklist

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