rust.large_response_memory

Stability High

Detects loading entire HTTP responses into memory without streaming.

Why It Matters

Large responses in memory:

• OOM risk — Unbounded response sizes crash servers
• High latency — Must wait for entire download
• Memory pressure — Affects other requests

Example

// ❌ Before (entire response in memory)
async fn download_file(url: &str) -> Bytes {
    let response = client.get(url).send().await?;
    response.bytes().await? // Entire file in RAM!
}

// ✅ After (streaming response)
use tokio::io::AsyncWriteExt;
use futures::StreamExt;

async fn download_file(url: &str, path: &Path) -> Result<()> {
    let response = client.get(url).send().await?;
    let mut file = tokio::fs::File::create(path).await?;
    let mut stream = response.bytes_stream();

    while let Some(chunk) = stream.next().await {
        file.write_all(&chunk?).await?;
    }
    Ok(())
}

What Unfault Detects

• response.bytes() on unbounded responses
• response.text() for large payloads
• Missing content-length checks

Auto-Fix

Unfault can add streaming patterns or size limits.

Related Rules

• rust.unbounded_memory
• go.large_response_memory