Follow-up to #148: opening an already-cached message was still slow. Three fixes
on the cached-open critical path (issue #186).
Fix 1 - WebView renders once. The reader resolved cid: inline images AFTER the
first render, so the AndroidView update key (which included inlineImages.keys)
changed and reloaded the whole document a second time for any inline-image email.
ReaderViewModel now resolves inline images and folds them into the SAME state
update as the body, and HtmlBody drops inline images from the reload key, so the
WebView loads exactly once and a late inline-image change never reloads. The
WebView is also destroyed onRelease so it (and its Context) is not leaked.
Pool/pre-warm is left as a TODO (leak-prone; single-render is the dominant win).
Fix 2 - openMessage does no wasted work for a cached, already-read message. Added
a body-less MessageRouting projection (mirrors MessageSummary, no migration);
the routing/flag callers (openMessage's first read, downloadAttachment, setStarred,
deleteMessage, expunge, moveByRole/moveToFolder, buildReplyDraft, prefetchMessage)
route on it, and getById (SELECT *) is reserved for the single read that returns
the body. imapParamsFor (Keystore decrypt + DataStore read) is resolved lazily,
only in the fetch / SEEN-push branches; the cached+read path also skips the
account lookup. De-duped the inlineImages attachment N+1 via a shared
ensureAttachmentFile helper that takes the already-resolved account/folder.
Fix 3 - repository IO off the main thread. openMessage, inlineImages,
downloadedAttachmentParts, and downloadAttachment now run in
withContext(Dispatchers.IO), so their DB/file/crypto work no longer runs on the
Main.immediate viewModelScope during the open animation.
Reader behavior (content, read/SEEN semantics) is unchanged; does not touch the
async SEEN network push handled separately by #170.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
JMR-devandClaude Opus 4.8
aafb4f8f6a