Module compression 

Record-batch compression codecs.

The Compression enum is always available so crate::record::RecordBatch can read the compression type from attributes regardless of which codec features are enabled. Actual compress/decompress operations require the corresponding Cargo feature:

Feature	Codec	Backend	Pure Rust	HC mode
gzip	Gzip	flate2	yes	n/a
snappy	Snappy	snap	yes	n/a
lz4	Lz4	lz4_flex	yes	no
lz4-hc	Lz4	lz4 (C-FFI)	no	yes
zstd	Zstd	zstd (C-FFI)	no	n/a

compression is a meta-feature that enables gzip + snappy + lz4 + zstd (pure-Rust LZ4). Opt into lz4-hc explicitly if you need High-Compression mode — see the LZ4 section below.

LZ4 backend selection

• lz4 — lz4_flex block API behind a Kafka-compatible custom frame. Fast mode only; the level argument is ignored. Pure Rust, no C toolchain at build time, cross-compile clean.
• lz4-hc — lz4 crate (FFI to liblz4) behind the same frame format. Levels 3..=12 use HC mode; levels 0..=2 fall back to fast mode. Requires a C compiler at build time.

Both features are independent — enabling lz4-hc alone is sufficient (the C lib handles fast mode too). When both are enabled, lz4-hc wins at runtime; lz4_flex is linked but unused. Most users should pick one.

For high compression ratio in Kafka workloads, prefer zstd over lz4-hc — modern Kafka clients (Java, librdkafka) default to fast LZ4 when LZ4 is selected, and switch to zstd when ratio matters.

Re-exports

pub use self::error::CompressionError;

pub use self::error::CompressionErrorKind;

Modules

error

Error types for crate::compression.

gzip

Gzip codec (flate2 Rust backend).

lz4

Kafka-compatible LZ4 frame codec.

snappy

Snappy codec (snap Rust backend). Level is accepted but ignored.

zstd

Zstandard codec (zstd crate).

Enums

Compression

Kafka record-batch compression codec, encoded in bits 0–2 of the batch attributes field.

Constants

MAX_DECOMPRESSED_LEN

Hard ceiling on the decompressed size of a single payload.

Type Aliases

Result

Result alias for compression operations.