The current RleTree uses too much memory to represent the state of the text

[zxch3n]

Because bumpalo cannot deallocate, we may waste a lot of space if we use bumpalo to represent the state of text/list.

For example, after applying the Automerge paper dataset, the RleTree has

• len=104852
• InternalNodes=264
• LeafNodes=1124
• Elements=5755
• Bytes(bump.allocated_bytes())=2095872

It takes about 2MB to represent the state. However, each node only has 80 bytes, and each element only takes 8 bytes.

Solutions

• Option 1: Make Bump a generic allocator in RleTreeTrait
• Option 2: Use another data structure to represent the state

Option 1 may be dirty and inefficient because we also need to wrap the type for the allocated element.