Redis.Commands.Bitmap (Redis v0.8.0)

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Command builders for Redis bitmap operations.

Provides pure functions that build command lists for manipulating individual bits within string values. Supports setting and reading bits (SETBIT/GETBIT), counting set bits (BITCOUNT), finding bit positions (BITPOS), bitwise operations between keys (BITOP), and the compound BITFIELD command for multi-bit integer access. Each function returns a plain list of strings suitable for passing to Redis.command/2 or Redis.pipeline/2.

These functions contain no connection or networking logic -- they only construct the Redis protocol command as a list.

Examples

Set and read individual bits (useful for feature flags or presence tracking):

iex> Redis.Commands.Bitmap.setbit("user:1:features", 7, 1)
["SETBIT", "user:1:features", "7", "1"]
iex> Redis.Commands.Bitmap.getbit("user:1:features", 7)
["GETBIT", "user:1:features", "7"]

Count the number of set bits in a key:

iex> Redis.Commands.Bitmap.bitcount("user:1:features")
["BITCOUNT", "user:1:features"]

Use BITFIELD for multi-bit integer operations:

iex> Redis.Commands.Bitmap.bitfield("mykey", ["GET", "u8", "0", "SET", "u8", "0", "100"])
["BITFIELD", "mykey", "GET", "u8", "0", "SET", "u8", "0", "100"]

Summary

Functions

bitcount(key, opts \\ [])

Builds a BITCOUNT command to count the number of set bits (population count).

bitfield(key, subcommands)

Builds a BITFIELD command for multi-bit integer operations on a string key.

bitfield_ro(key, subcommands)
bitop(operation, destkey, keys)
bitpos(key, bit, opts \\ [])
getbit(key, offset)
setbit(key, offset, value)

Builds a SETBIT command to set or clear the bit at the given offset.

Functions

bitcount(key, opts \\ [])

@spec bitcount(
  String.t(),
  keyword()
) :: [String.t()]

Builds a BITCOUNT command to count the number of set bits (population count).

Without options, counts all bits in the value. Use :start and :end to limit the range, and :byte or :bit to specify whether the range is in bytes or bits.

Examples

iex> Redis.Commands.Bitmap.bitcount("flags")
["BITCOUNT", "flags"]

iex> Redis.Commands.Bitmap.bitcount("flags", start: 0, end: 10, byte: true)
["BITCOUNT", "flags", "0", "10", "BYTE"]

bitfield(key, subcommands)

@spec bitfield(String.t(), [String.t()]) :: [String.t()]

Builds a BITFIELD command for multi-bit integer operations on a string key.

The subcommands list contains the raw BITFIELD subcommand tokens (GET, SET, INCRBY, OVERFLOW) as a flat list of strings.

Example

iex> Redis.Commands.Bitmap.bitfield("counters", ["SET", "u8", "0", "42"])
["BITFIELD", "counters", "SET", "u8", "0", "42"]

bitfield_ro(key, subcommands)

@spec bitfield_ro(String.t(), [String.t()]) :: [String.t()]

bitop(operation, destkey, keys)

@spec bitop(String.t(), String.t(), [String.t()]) :: [String.t()]

bitpos(key, bit, opts \\ [])

@spec bitpos(String.t(), integer(), keyword()) :: [String.t()]

getbit(key, offset)

@spec getbit(String.t(), integer()) :: [String.t()]

setbit(key, offset, value)

@spec setbit(String.t(), integer(), integer()) :: [String.t()]

Builds a SETBIT command to set or clear the bit at the given offset.

The value must be 0 or 1. Returns the command list; Redis will respond with the original bit value at that offset.

Example

iex> Redis.Commands.Bitmap.setbit("flags", 7, 1)
["SETBIT", "flags", "7", "1"]