This PR adds another trimming strategy to XADD and XTRIM named MINID
(complements the existing MAXLEN).
It also adds a new LIMIT argument that allows incremental trimming by repeated
calls (rather than all at once).
This provides the ability to trim all records older than a certain ID (which makes it
possible for the user to trim by age too).
Example:
XTRIM mystream MINID ~ 1608540753 will trim entries with id < 1608540753,
but might not trim all (because of the ~ modifier)
The purpose is to ease the use of streams. many users use streams as logs and
the common case is wanting a log
of the last X seconds rather than a log that contains maximum X entries (new
MINID vs existing MAXLEN)
The new LIMIT modifier is only supported when the trim strategy uses ~.
i.e. when the user asked for exact trimming, it all happens in one go (no
possibility for incremental trimming).
However, when ~ is provided, we trim full rax nodes, up to the limit number
of records.
The default limit is 100*stream_node_max_entries (used when LIMIT is not
provided).
I.e. this is a behavior change (even if the existing MAXLEN strategy is used).
An explicit limit of 0 means unlimited (but note that it's not the default).
Other changes:
Refactor arg parsing code for XADD and XTRIM to use common code.
814aad65f1