HTTP Cache

HTTPX has no in-memory HTTP cache subsystem. HTTP caching is handled where it is actually implemented:

• Static files: server.static(mount, dir) serves with ETags and honors If-None-Match (304 Not Modified). See examples/staticFiles.zig.
• Downloads: .existing = .verifyExisting skips re-downloads, and .replaceIfChanged uses conditional headers. See examples/downloadExisting.zig.
• DNS: client-side cache via .dnsCache in the Client.init options.

Expected Output

Representative static-file conditional GET exchange (ports, sizes, and ETag values vary):

serving examples/static on http://127.0.0.1:54321/static
health endpoint on http://127.0.0.1:54321/healthz
GET /static/index.html -> 200 (1234 bytes)

GET /static/index.html HTTP/1.1
Host: 127.0.0.1:54321

HTTP/1.1 200 OK
ETag: "abc123"
Content-Length: 1234

GET /static/index.html HTTP/1.1
Host: 127.0.0.1:54321
If-None-Match: "abc123"

HTTP/1.1 304 Not Modified

Checklist

• [x] ETag generation and matching on static routes
• [x] Conditional GET (304 Not Modified)
• [x] Download resume and existing-file policies