BITFIELD_RO

Performs arbitrary read-only bitfield integer operations on strings.

Browse all commands · Upstream source documentation

Reference field	Value
Canonical name	BITFIELD_RO
Catalog group	Bitmap commands
Upstream since	6.0.0 — upstream Redis/module version, not an ffkv release
Pinned catalog	Redis 8.10.0

Syntax

BITFIELD_RO key [GET encoding offset [GET encoding offset ...]]

The catalog’s command-name typography is corrected here to the exact canonical spelling; the source catalog is unchanged.

ffkv behavior and limits

Bitmap/bitfield values share string key storage. Bitfield overflow policy and signedness affect arithmetic; request and reply budgets still apply.

Source: README.md:275–280, 784–797; tests/bdd/features/bitmaps.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(1) for each subcommand specified

Upstream arity: -2 (includes the command name; a negative number is a minimum).

Command flags: READONLY, FAST.

ACL categories: BITMAP.

Argument structure

Argument	Type	Constraints / metadata
key	key	key_spec_index: 0
get-block	block	optional; multiple; multiple token; token: GET
↳ encoding	string	Required
↳ offset	integer	Required

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": "bitmap",
  "since": "6.0.0"
}

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

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.

• Bitfield overflow modes and read-only commands preserve values — tests/bdd/features/bitmaps.feature:167; command tag and invocation observed.
• BITOP AND applies zero padding and its full truth table — tests/bdd/features/bitmaps.feature:237; invocation observed.
• BITOP OR applies zero padding and its full truth table — tests/bdd/features/bitmaps.feature:261; invocation observed.
• BITOP XOR applies zero padding and its full truth table — tests/bdd/features/bitmaps.feature:285; invocation observed.
• BITOP DIFF applies zero padding and its full truth table — tests/bdd/features/bitmaps.feature:309; invocation observed.
• BITOP DIFF1 applies zero padding and its full truth table — tests/bdd/features/bitmaps.feature:333; invocation observed.
• BITOP ANDOR applies zero padding and its full truth table — tests/bdd/features/bitmaps.feature:357; invocation observed.
• BITOP ONE applies zero padding and its full truth table — tests/bdd/features/bitmaps.feature:381; invocation observed.
• NOT is unary and aliases use original source data — tests/bdd/features/bitmaps.feature:405; invocation observed.
• BITFIELD_RO rejects non-string inputs without mutation — tests/bdd/features/bitmaps.feature:611; 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.

Bitfield overflow modes and read-only commands preserve values — tests/bdd/features/bitmaps.feature:214 (I execute:)

[
  "BITFIELD_RO",
  "missing",
  "GET",
  "i8",
  "0"
]

Next source assertion: the reply equals:

[0]

NOT is unary and aliases use original source data — tests/bdd/features/bitmaps.feature:419 (I execute:)

[
  "BITFIELD_RO",
  "x",
  "GET",
  "u8",
  "0",
  "GET",
  "u8",
  "8"
]

Next source assertion: the reply equals:

[30,127]

BITOP AND applies zero padding and its full truth table — tests/bdd/features/bitmaps.feature:251 (I execute:)

[
  "BITFIELD_RO",
  "out",
  "GET",
  "u8",
  "0",
  "GET",
  "u8",
  "8"
]

Next source assertion: the reply equals:

[128,0]