each flush region has a left write and a right write. these are passed to the constructor. a flush can happen two ways: 1 - new flush. starts with nothing in it. adds only writes. 2 - old flush. starts with a previous flush and no writes. new writes can break up the reference to the previous flush.

i'm a little confused around the difference in code paths between new flushes and old flushes. but, noting that adding writes to an empty flush is the same as adding writes that are sparsely distant from the bounds of a previous flush.

it seems the core behavior is adding a write. this branches various conditions depending on whether it intersects a previous flush, a previous write, opens rebalancing, etc.

so a write has two ends, a start and an end, and each one can either be within an old write, within an old flush, or in a new area. then similarly, they can span all or parts of writes and flushes, as well. the old code uses start_idx and end_idx and then excises that range. the ends are treated specially. the most important part seems to be adjusting their bounds. if a write or a flush is partially cut, its bounds can be adjusted, and if it is a flush then it can be further optimised as it will have lost leaves.

what happens if a write does not overlap a region ...? maybe it would make sense to think of the region of note as being the one prior to the upper index

class Region: def __init__(self, *entries, left_write = None, right_write = None): self.entries = entries self.left_write = left_write self.right_write = right_write class Write(Chunk): def __init__(self, offset, data, flush, left_region = None, right_region = None) super().__init__(offset, offset + len(data), data, age=flush.age) self.left_region = left_region self.right_region = right_region def __init__(self, prev_flush = None): self.regions = [] self.writes = []

so there are two factoring concepts here one is the linked lists, for organising of functionality the other is the semibalanced trees.

the linked lists swap back and forth with regard to the types of data linked it makes sense to have two different classes for these, so they can have separate methods.

a nice thing here is that i have existing stable code so as i conceptualise and lose things more, a workable approach may trend toward changes to stable code, that keep the code stable.

maybe Chunk can be the linked list node, since everything that is a chunk is a member of a linked list. noting also that the list index is available when accessing the nodes, so the link members might be mostly for simplification, or a nonverbal possible plan i'm not thinking of much yet

next step i think: find recent stable code, such as whatever was last posted regarding thinking/spamming, could use more stabilisation around idea of separating writes from flush regions into peer classes possibly with different methods. this plan could be tuned more by planning the semibalancing.

regarding thinking/spamming, could use more stabilisation around idea of separating writes from flush regions into peer classes possibly with different methods. this plan could be tuned more by planning the semibalancing.