Crate cerniera 

A ZIP archive encoder that never copies your data.

Feed it file content through a Stream or write it directly with sendfile, mmap, or any I/O strategy you like - cerniera only encodes the ZIP framing around it.

Cerniera (/t∫erˈnjɛra/) is Italian for zipper.

Quick start

Feed a stream of ZipEntry items to ZipWriter and you get back a byte stream you can write to a file, use as an HTTP response body, or forward anywhere that accepts a Stream.

use std::{io, pin::pin};

use bytes::Bytes;
use cerniera::{MsDosDateTime, ZipEntry, ZipWriter};
use futures_util::{TryStreamExt, stream};
use tokio::{fs::File, io::AsyncWriteExt};

let modified = MsDosDateTime::new(2026, 3, 10, 12, 30, 0);

let entries = stream::iter([
    Ok(ZipEntry::File {
        path: "hello.txt".into(),
        modified,
        content: stream::iter([Ok::<_, io::Error>(Bytes::from_static(b"Hello, world!"))]),
    }),
    Ok(ZipEntry::Directory {
        path: "subdir/".into(),
        modified,
    }),
]);

let mut zip_stream = pin!(ZipWriter::new(entries));

let mut file = File::create("output.zip").await?;
while let Some(chunk) = zip_stream.try_next().await? {
    file.write_all(&chunk).await?;
}

Two API levels

• ZipWriter - high-level streaming builder. Give it entries, get a byte stream. Handles CRC-32 and all ZIP bookkeeping automatically. Files are stored (uncompressed).

• ZipArchive - low-level, sans-IO encoder. Gives you full control over buffering and compression (DEFLATE, Zstandard, etc.) at the cost of a more manual lifecycle. See the deflate_zip and sendfile_zip examples.

Features

• std (default) - enables runtime SIMD detection for faster CRC-32.
• jiff - adds From<jiff::civil::DateTime> for MsDosDateTime.

Re-exports

pub use self::archive::CompressionMethod;

pub use self::archive::MsDosDateTime;

pub use self::archive::ZipArchive;

Modules

archive

Structs

ZipWriter

High-level streaming ZIP archive builder.

Enums

ZipEntry

One entry (file or directory) passed to ZipWriter.