iotaledger / iota / 31347301732

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Build Type

push

github

Committed by web-flow

Commit Message

feat(typed-store): add `TaggedDBMap` (#12448)

# Description of change

Three `typed-store` additions, all self-contained and with no callers
changed yet:

- **`TaggedDBMap`** — several typed maps share one column family, each
with a tag byte prefixed to its keys (the big-endian fixint
serialization of `(tag, key)` is exactly that), so each map occupies a
contiguous key range. Useful for sets of tables that are always created
and dropped together: one column family instead of one per table keeps
the column-family and SST-file counts low. Every read is scoped to the
map's tag — full scans iterate the tag's key prefix, ranges are
two-sided within it — so rows of other tags never surface and their
differently-typed values are never deserialized.
- **`Database::create_cf`** — create a column family at runtime,
mirroring the existing `drop_cf`. `RocksDB::cf_names` becomes an
`RwLock<Vec<String>>` so runtime creates and drops keep it in sync,
which in turn keeps `flush_all` covering the current set of column
families.
- **Slow-batch-write threshold scales with batch size** — the warning
fired at a flat 1s regardless of how much was written, so large bulk
batches logged `very slow batch write` as a matter of course. The
threshold is now `batch_size / 32 MiB/s`, floored at 1s, so a small
write taking a second is still reported as a genuine stall. `batch_size`
is included in the log line.

`DBMap::reopen`'s `is_deprecated` parameter is renamed to
`skip_metrics_reporting` — it always meant "don't spawn the
per-column-family metrics task", and the second reason to skip it is a
large set of rarely-touched column families. Behaviour is unchanged.

## Links to any relevant issues

None — groundwork for upcoming work that needs many short-lived tables.

## How the change has been tested

- [x] Basic tests (linting, compilation, formatting, unit/integration
tests)
- [x] Patch-specific tests (correctness, functionality coverage)
- [x] I have added tests that prove my ... (continued)

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315 of 336 new or added lines in 6 files covered. (93.75%)

172 existing lines in 16 files now uncovered.

167443 of 241003 relevant lines covered (69.48%)

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