hpack-html

High-performance .hpack HTML packet decompressor for Rust. Decodes binary packets produced by the hpack-html-js JavaScript compressor, decompresses the HTML body (DEFLATE/gzip via flate2), and verifies CRC32 integrity.

Pure Rust, no C dependencies.

Install

[dependencies]
hpack-html = "0.1"

Usage

use hpack_html::unpack;

fn main() -> Result<(), hpack_html::Error> {
    let packed: &[u8] = &std::fs::read("page.hpack")?;
    let result = unpack(packed)?;

    println!("URL: {}", result.url);
    println!("ETag: {:?}", result.etag);
    println!("HTML: {} bytes", result.html.len());
    println!("Checksum valid: {:?}", result.checksum_valid);

    Ok(())
}

API

unpack(data) -> Result<UnpackResult, Error>

Decompress and decode an .hpack packet with default options (verify checksum, decompress body).

unpack_with_options(data, options) -> Result<UnpackResult, Error>

Decompress with custom options:

let opts = UnpackOptions {
    verify_checksum: false,  // skip CRC32 check
    headers_only: false,     // set true to skip decompression
};
let result = unpack_with_options(data, &opts)?;

read_headers(data) -> Result<UnpackResult, Error>

Parse metadata without decompressing the body. Returns UnpackResult with empty html.

UnpackResult

pub struct UnpackResult {
    pub url: String,
    pub etag: Option<String>,
    pub signature: Option<String>,
    pub content_type: Option<String>,
    pub timestamp: Option<u64>,
    pub encoding: Option<String>,
    pub custom: HashMap<String, String>,
    pub html: String,
    pub version: u8,
    pub minified: bool,
    pub compression: CompressionAlgorithm,
    pub checksum_valid: Option<bool>,
}

Error Types

pub enum Error {
    InvalidMagic,
    UnsupportedVersion(u8),
    TruncatedPacket(String),
    DecompressionFailed(String),
    ChecksumMismatch { expected: u32, actual: u32 },
    InvalidUtf8(FromUtf8Error),
}

Dependencies

No C dependencies. Compiles on any target Rust supports.

Cross-SDK Compatibility

Tested against real web pages packed by the JavaScript compressor:

Byte-identical HTML output verified via SHA256 hash comparison between JS and Rust decompressors.

License

Apache License 2.0 — See LICENSE for details.