whispeer 0.0.1

A plugin-based pub/sub messaging system
Documentation 
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use crate::plugins::plugin::Plugin;
use async_compression::tokio::write::ZstdDecoder;
use async_compression::tokio::write::ZstdEncoder;
use async_trait::async_trait;
use std::collections::HashMap;
use tokio::io::AsyncWriteExt;

pub struct CompressionPlugin;

impl CompressionPlugin {
  pub fn new() -> Self {
    Self
  }
}

#[async_trait]
impl Plugin for CompressionPlugin {
  fn name(&self) -> &str {
    "CompressionPlugin"
  }

  async fn on_publish(
    &self,
    _topic: &str,
    payload: &mut Vec<u8>,
    headers: &mut HashMap<String, String>,
  ) -> Result<(), anyhow::Error> {
    // Compress
    let mut encoder = ZstdEncoder::new(Vec::new());
    encoder.write_all(payload).await?;
    encoder.shutdown().await?;
    *payload = encoder.into_inner();

    headers.insert("X-Compression".to_string(), "zstd".to_string());
    Ok(())
  }

  async fn on_message_received(
    &self,
    _topic: &str,
    payload: &mut Vec<u8>,
    headers: &HashMap<String, String>,
  ) -> Result<(), anyhow::Error> {
    if let Some(method) = headers.get("X-Compression") {
      if method == "zstd" {
        let mut decoder = ZstdDecoder::new(Vec::new());
        decoder.write_all(payload).await?;
        decoder.shutdown().await?;
        *payload = decoder.into_inner();
      }
    }
    Ok(())
  }
}