[REACTOR] Cleanup and improve map array containers

[tqchen]

This PR runs the following refactor of the map and array containers.

• Remove InplaceArrayBase since it is not as useful
• Extract MapObj into map_base.h so it can be used for other different subclass and variant of map if needed.
• Add extra helper methods such as clean

We also reorganized SmallBaseMapObj after DenseMapObj as SmallBaseMapObj is a specialization, which can help possible future refactors to make SmallBaseMapObj be aware of DenseMapObj.

The split out of map_base.h is roughly manual copy and a few extra manual edits to reduce unexpected surprises.

[gemini-code-assist]

Summary of Changes

Hello @tqchen, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly refactors the internal implementation of array and map container classes. The primary goal is to improve modularity and maintainability by separating common map functionalities into a new base class, removing an underutilized array base class, and introducing new utility methods. These changes consolidate shared logic and simplify the container's internal structure without altering external API behavior.

Highlights

• Refactored Map Container Hierarchy: The core implementation logic for map containers (SmallMapObj and DenseMapObj) has been extracted into a new base class hierarchy (MapBaseObj, SmallMapBaseObj, DenseMapBaseObj) located in map_base.h. The original MapObj now inherits from MapBaseObj, streamlining the design and preparing for future extensions.
• Removed InplaceArrayBase: The InplaceArrayBase utility class, previously used for array-like memory layouts, has been removed from container_details.h. This simplifies the underlying array implementation.
• Updated ArrayObj Implementation: The ArrayObj class no longer relies on InplaceArrayBase, and its internal data pointer initialization has been updated to reflect this change, using direct memory offset calculation.
• Added clear() Helper Method: A new clear() method has been introduced to the map base classes, providing a convenient way to empty map contents and release associated memory.
• Templated Map Creation and Insertion Methods: Static helper methods for map creation, copying, and insertion (Empty, CreateFromRange, InsertMaybeReHash, CopyFrom) have been updated to accept template arguments for the specific MapObjType, enhancing flexibility and type safety.

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Changelog

• include/tvm/ffi/container/array.h
  • Removed inheritance from details::InplaceArrayBase for ArrayObj.
  • Updated data pointer initialization in make_inplace_array_object to directly calculate memory offset.
  • Removed friend InplaceArrayBase declaration.
• include/tvm/ffi/container/container_details.h
  • Removed the entire InplaceArrayBase template class definition.
• include/tvm/ffi/container/map.h
  • Included new header tvm/ffi/container/map_base.h.
  • Changed MapObj to inherit from MapBaseObj instead of Object.
  • Removed extensive map implementation details, delegating them to the new base classes.
  • Updated calls to static map helper methods (Empty, CreateFromRange, InsertMaybeReHash, CopyFrom) to include explicit template arguments.
• include/tvm/ffi/container/map_base.h
  • Added new file to define MapBaseObj, DenseMapBaseObj, and SmallMapBaseObj.
  • Implemented all core map functionalities (e.g., size, count, at, iterator, Empty, CreateFromRange, InsertMaybeReHash, CopyFrom) within these new base classes.
  • Introduced a clear() method for map objects.
  • Templated static map helper methods to allow specification of the concrete map object type.
  • Adjusted SmallMapBaseObj data initialization to use direct memory offset.
• include/tvm/ffi/extra/stl.h
  • Updated CopyToMap and MoveToMap methods to use the templated MapObj::CreateFromRange<MapObj>.

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[tqchen]

To simplify the review, the PR is structured in two commits

• The first commit splits out the related files into map_base.h and cleans up the sequence
  • Copy of MapObj implementation is just copy with no editing
• The second commit contains the related edits of map_base.h to allow subclass

[gemini-code-assist]

Code Review

This pull request provides a good cleanup and refactoring of the map and array containers. Removing InplaceArrayBase simplifies the array implementation. Extracting the map implementation into map_base.h with MapBaseObj is a great step towards better modularity and reusability, allowing different map specializations. The addition of the clear() method is also a useful enhancement. The code changes look solid overall. I've found a couple of minor points regarding confusing static_asserts in the new map_base.h that could be improved for better maintainability.

[tqchen]

/gemini review

[gemini-code-assist]

Code Review

This PR is a nice refactoring of the map and array containers. Removing InplaceArrayBase and extracting the map implementation into a new map_base.h file are good steps towards better modularity and code clarity. The changes across the modified files are consistent with this goal.

However, I've identified a critical issue in the instantiation logic for DenseMapBaseObj within the new map_base.h file. This issue will likely cause a compilation failure due to an incorrect assumption about object sizes and the use of make_object on a non-registered type. Please see the detailed comment for more information.

[tqchen]

/gemini review

[gemini-code-assist]

Code Review

This pull request is a nice refactoring of the map and array containers. The removal of InplaceArrayBase simplifies the class hierarchy, and extracting the map implementation into map_base.h improves modularity. The changes are consistent and well-executed. I have one minor suggestion to restore a sanity check that was lost during the refactoring.