tur-zlib

gzip + raw-deflate encode/decode for Turmeric, wrapping zlib. Binary-safe buffer in / buffer out, intended as the codec layer for HTTP compression middleware, log-file post-processing, and anywhere else gzipped or raw-deflate bytes need to flow through Turmeric.

Overview

tur-zlib is a cmake-dep spice that pins upstream zlib via :cmake-deps for reproducible builds. It exposes two encoder/decoder pairs:

• gzip-encode / gzip-decode -- standard gzip wrapper (magic bytes 1F 8B). What Content-Encoding: gzip over HTTP carries.
• deflate-raw / inflate-raw -- raw deflate streams, no wrapper.

Every encode/decode returns an opaque GzipBuf handle that bundles the produced bytes with their length in one allocation. Use gzip-buf-data + gzip-buf-len to read the payload, then gzip-buf-free to release it.

The GzipBuf shape -- length-prefixed, single allocation -- exists so that callers can safely move binary output (which may contain embedded NUL bytes) through pointer + length APIs without ever passing it through strlen.

Install

:spices {
  "zlib" {:url    "https://github.com/rjungemann/turmeric-spices"
          :ref    "zlib-v0.1.0"
          :subdir "spices/zlib"}
}

(import tur/zlib :refer [gzip-encode gzip-decode
                         gzip-buf-data gzip-buf-len gzip-buf-free])

(let [enc (gzip-encode src src-len)]
  (let [dec (gzip-decode (gzip-buf-data enc) (gzip-buf-len enc))]
    ;; (gzip-buf-data dec) ... (gzip-buf-len dec) bytes are the original
    (gzip-buf-free dec))
  (gzip-buf-free enc))

#lang sweet-exp
import tur/zlib :refer [gzip-encode gzip-decode
                        gzip-buf-data gzip-buf-len gzip-buf-free]

let [enc gzip-encode(src src-len)]
  let [dec gzip-decode(gzip-buf-data(enc) gzip-buf-len(enc))]
    gzip-buf-free(dec)
  gzip-buf-free(enc)

GzipBuf lifecycle

1. gzip-encode / gzip-decode / deflate-raw / inflate-raw return a fresh GzipBuf (or NULL on failure).
2. Read the payload with gzip-buf-data / gzip-buf-len -- the pointer is valid until you free the buffer.
3. Call gzip-buf-free exactly once when done.

The buffer keeps len + bytes in a single allocation, so there is no separate length to track and no double-free hazard between data and length.

See also

• API reference
• Source: https://github.com/rjungemann/turmeric-spices/tree/main/spices/zlib
• Upstream zlib: https://github.com/madler/zlib