Stop one CDN host hanging up from failing a download

[beingsuz]

Requested by beingsuz · project thread

Before: downloading a Workshop item from haru on Windows failed with "fetch failed: malformed response: headers ended early". A CDN server accepted the connection and closed it without answering, and the manifest fetch asked exactly one host once, so that one server failed the whole download.

After: the manifest is fetched from up to four hosts, failing hosts are demoted, and the host list excludes servers that close the connection on requests they will not serve.

How:

• cdn_hosts builds the host list the way SteamKit and DepotDownloader do: drops ISP caches restricted to other apps (allowed_app_ids), Steam China servers, proxies, and types other than CDN/SteamCache, and addresses each server by its vhost (tapline recorded it but never used it). If the filter would leave nothing, it keeps every reachable server.
• fetch_manifest_from_pool replaces the three single-host manifest fetches.
• The HTTP pool discards connections idle for 15 s, and the client's retry always dials a fresh connection instead of popping another pooled one that may be just as dead.
• Fetch errors now name the host.

Verified: cargo clippy --workspace --all-targets clean and cargo test passes for tapline, tapline-cdn and tapline-rt-tokio on Linux, with new tests for the host filter. Not verified: no live download (Steam is unreachable from the sandbox), nothing run on Windows, and which of the three causes hit the reporter is inferred, not observed.

🤖 Generated with Claude Code

https://claude.ai/code/session_01JPbjRcr2kuhRi1wBhGk1ax

---

Generated by Claude Code

[coderabbitai]

Navigate logical layers of code changes, visualize relationships, and explore their blast radius.

Note

Currently processing new changes in this PR. This may take a few minutes, please wait...

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: 2cfe241c-aa5d-4b8f-8c0f-69d12d5b5494

📥 Commits

Reviewing files that changed from the base of the PR and between 3e638bf and 1b133b6.

📒 Files selected for processing (3)

• crates/tapline-cdn/src/lib.rs
• crates/tapline-rt-tokio/src/http.rs
• crates/tapline/src/session.rs

 ____________________________________________________________________________________________________________________
< Always design for concurrency. Allow for concurrency, and you'll design cleaner interfaces with fewer assumptions. >
 --------------------------------------------------------------------------------------------------------------------
  \
   \   (\__/)
       (•ㅅ•)
       / 　 づ

✨ Finishing Touches

📝 Generate docstrings

• Commit to this branch
• Create a new PR

🧪 Generate unit tests (beta)

• Commit to this branch
• Create a new PR

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}