ARLASTITEMS

Returns the most recently inserted elements.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	ARLASTITEMS
Catalog group	Array commands
Upstream since	8.8.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

ARLASTITEMS key count [REV]

ffkv behavior and limits

Indices reach 2^64−2; ARSEEK also accepts terminal 2^64−1. Dense ranges cap at one million positions. ARSCAN returns index/value pairs, not a SCAN cursor. Integer aggregates use exact integer arithmetic; mixed/real aggregates use binary64.

Source: README.md:300–304, 359–361; tests/bdd/features/arrays.feature.

All requests share the 8 MiB framing/1,024-argument ingress limit; normal RESP replies have 64 MiB wire/logical budgets with bounded nesting/value counts. Management and Lua origins impose smaller budgets. These are not a process RSS cap. Catalog inclusion is not exhaustive option or wire-format parity. See limits and compatibility.

Upstream metadata

The following fields come from the pinned Redis metadata, not measured ffkv performance or an assertion that ffkv enforces every upstream flag. Running COMMAND INFO/COMMAND DOCS describe the current engine.

Upstream Redis complexity: O(N) where N is the count

Upstream arity: -3 (includes the command name; a negative number is a minimum).

Command flags: READONLY.

ACL categories: ARRAY.

Argument structure

Argument	Type	Constraints / metadata
key	key	key_spec_index: 0
count	integer	Required
rev	pure-token	optional; token: REV

Key specifications

Upstream key discovery descriptors (indexes are relative to the full command vector):

[
  {
    "flags": [
      "RO",
      "ACCESS"
    ],
    "begin_search": {
      "index": {
        "pos": 1
      }
    },
    "find_keys": {
      "range": {
        "lastkey": 0,
        "step": 1,
        "limit": 0
      }
    }
  }
]

Additional pinned upstream metadata

{
  "group": "array",
  "since": "8.8.0"
}

Metadata source · Local snapshot: src/command_metadata.json, key arlastitems.

BDD coverage and source examples

These are source observations, not a test run performed by this documentation build. A tag identifies scenario intent; an extracted vector identifies a command invocation, which may intentionally produce an error. Scenarios may require setup, multiple connections, persistence, cluster nodes or native-module fixtures.

• Ring wrapping overwrites the oldest slot while latest items retain chronological order — tests/bdd/features/arrays.feature:218; command tag and invocation observed.

Extracted command vectors

The following JSON arrays are the test harness’s argument vectors, not shell commands. Numeric arguments are converted by the harness; objects of the form {"base64":"…"} represent decoded binary bytes, not a literal JSON command argument. Preserve scenario setup and connection ordering. See the CLI guide for shell quoting and binary stdin. No reply is invented or inferred.

Ring wrapping overwrites the oldest slot while latest items retain chronological order — tests/bdd/features/arrays.feature:244 (I execute:)

[
  "ARLASTITEMS",
  "readings",
  3
]

Next source assertion: the reply equals:

["v1","v2","v3"]

Ring wrapping overwrites the oldest slot while latest items retain chronological order — tests/bdd/features/arrays.feature:252 (I execute:)

[
  "ARLASTITEMS",
  "readings",
  2,
  "REV"
]

Next source assertion: the reply equals:

["v3","v2"]