use crate::signature::SignedRequest;
#[cfg(feature = "encoding")]
use crate::signature::SignedRequestPayload;
#[cfg(feature = "encoding")]
use flate2::{write::GzEncoder, Compression};
#[cfg(feature = "encoding")]
use std::io::Write;
// Default compression level for gzip defined same as flate2
pub const DEFAULT_GZIP_COMPRESSION_LEVEL: u32 = 6;
#[derive(Debug, Clone)]
pub enum ContentEncoding {
/// Indicates the identity function (i.e., no compression or modification)
Identity,
/// Gzip encoding uses flate2 library's GzEncoder internally to compress request payloads.
/// Streaming requests are not supported yet.
///
/// First parameter is for minimum payload. If request payload length is lesser than it
/// no compression will be performed.
///
/// Second parameter is the compression level for gzip on a scale of 0-9 where 0 means
/// "no compression" and 9 means "take as long as you'd like".
#[cfg(feature = "encoding")]
Gzip(Option<usize>, u32),
}
impl Default for ContentEncoding {
fn default() -> Self {
ContentEncoding::Identity
}
}
impl ContentEncoding {
#[allow(warnings)] // Ignore request is not being used
pub fn encode(&self, request: &mut SignedRequest) {
match self {
ContentEncoding::Identity => {
// no compression or modification
return;
}
#[cfg(feature = "encoding")]
ContentEncoding::Gzip(min_payload_size, level) => {
match request.payload {
None => return,
Some(SignedRequestPayload::Buffer(ref payload)) => {
if let Some(min_payload_size) = &min_payload_size {
if payload.len() < *min_payload_size {
return;
}
}
let mut encoder =
GzEncoder::new(Vec::<u8>::new(), Compression::new(*level));
encoder
.write_all(payload)
.expect("Request payload was not written to encoder.");
let payload_compressed =
encoder.finish().expect("Failed to finish compression.");
// Don't compress if payload length isn't decreased
if payload.len() < payload_compressed.len() {
return;
}
let payload_compressed = bytes::Bytes::from(payload_compressed);
request.payload = Some(SignedRequestPayload::Buffer(payload_compressed));
}
Some(SignedRequestPayload::Stream(ref stream)) => {
// Stream compression is not supported yet
return;
}
};
request.add_header("Content-Encoding", "gzip");
}
}
}
}