One HttpClient owns a small pool of workers, each with its own CURLM; an easy handle lives on one worker for its life. Public start/pause/resume/ cancel enqueue a command + curl_multi_wakeup(); callbacks (on_head / on_data / on_finished) run on the worker thread and return a DataAction (proceed / pause / abort). Covers redirects (final-response head only), ranges (inclusive ByteRange -> CURLOPT_RANGE), proxy/SOCKS5, basic/digest auth, cookies, verbatim headers, stall detection, a coarse recv-rate cap, and a curl_share DNS/TLS cache across workers. CURLcode + HTTP status -> vdm::Error in net/curl_error. A probe is on_head returning abort: it finishes successfully (head_complete), not canceled. Tests drive tools/testserver: full GET, ranged 206, redirect chain, 404 -> not_found, connection refused -> connect_failed, HEAD probe + ranged 0-0 probe (no body), cancel mid-transfer, pause/resume completes. Skip cleanly if testserver isn't in the tree. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01HPPSGhiArbvQgwC2DNiURS
Owner: lane CORE. See ../docs/agents/AGENT-CORE.md and ../docs/04-engine-design.md. No JSON, no SQL, no Qt, no RPC in this tree.