The fetcher is the SOLE writer of feed/episode metadata (D9). Three
files, no new deps (stdlib encoding/xml + net/http):
podcast_rss.go — RSS 2.0 + iTunes + Podcasting-2.0 structs. iTunes
fields are namespace-qualified in tags (local names collide with core
RSS: title/subtitle/author/summary/explicit/image/duration);
podcast:* fields match on local name (collision-free, tolerant of both
declared namespace URIs). Description/author fallback chains per §5;
itunes:duration parses seconds/HH:MM:SS/MM:SS/prose; pubDate accepts
the RFC-822/1123 spellings feeds actually emit.
podcast_http.go — the security boundary for user-supplied URLs:
https-only on every hop (CheckRedirect), private/loopback/link-local/
multicast IP ranges blocked at DIAL time (Dialer.Control sees the
RESOLVED address — DNS rebinding into 127.0.0.1 is refused at the
socket), 10-redirect cap, hard body caps (25MiB feeds / 20MiB artwork /
1GiB enclosures), no proxy.
podcast_service.go — fetch → parse → upsert. Episodes upsert
metadata-only keyed on (source_feed_id, episode_guid); rows for items
that vanish from the XML are NEVER deleted (D14 search covers
historical episodes). itunes:new-feed-url + permanent HTTP redirects
rewrite feed_url in place (row/subscriptions/episodes stay put);
podcast:guid dedupe reuses the canonical row instead of forking.
Artwork downloads feed-level under <feed-slug>/artwork.<ext>.
AddFeed authorizes ONLY on explicit arguments (library visible +
allow_member_feeds for non-admins — the D20 scoping model); detached
work runs under the first-admin identity via adminCtx (invariant 12).
Feed layout: <download-root>/<feed-slug>/<pos:04d>-<slug>.<ext> so
ServeFile/Range streaming resolve unchanged.
John O'Keefe
85a9873a75