OPFS for Resumable Large Files: Performance, Quota, and Cleanup
Compare OPFS with IndexedDB blobs across random writes, Worker sync handles, browser support, quota, export, and cleanup of sensitive temporary data.
uCopy Technical Blog
Clear explanations for connections that work in real life · Page 6
Practical uCopy guides to WebRTC, P2P file transfer, STUN and TURN, LAN discovery, resumable transfers, screen sharing, privacy, and security.
WebRTCP2P transferSTUN / TURNPrivacy & security
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Optimistic UI and Delivery Receipts: Defining What Sent Means
Separate local creation, queueing, channel write, peer receipt, persistence, and read using temporary IDs, monotonic status, retries, and refresh reconciliation.
Ordered Per-Peer Command Queues for Concurrent Connection Requests
Process connect, accept, reject, reconnect, and disconnect through per-peer serial queues while preserving parallelism across peers and enforcing global resource ceilings.
Accessible Orientation Controls Without Rotating Away Reading Order
Provide explicit rotation, orientation-lock fallback, keyboard operation, persistent preference, and visual transforms that preserve DOM reading order.
P2P vs Cloud File Transfer: Choose by File Lifecycle, Not Hype
Choose browser P2P, a cloud link, or a hybrid by asking whether both sides are online, how long the file must remain, who needs access, how recovery works, and which copies are acceptable.
Page Lifecycle in Real-Time Apps: Freeze, Resume, and Lost Timers
Handle visibilitychange, pagehide, freeze, resume, and system sleep by separating hidden, frozen, and offline states and reconciling connections after wake.
Permissions Policy for Embedded Real-Time Features
Control camera, microphone, display-capture, clipboard, and fullscreen with headers and iframe allow across cross-origin embeds, default denial, and capability messaging.
Requesting Persistent Browser Storage at the Right Moment
Request navigator.storage.persist after users create valuable resumable work, explain purpose and state, and provide export or cleanup when denied or eviction remains possible.
PostgreSQL Advisory Locks Coordinate but Do Not Constrain Data
Use transaction-scoped advisory locks for session rebuild, cleanup, and migration while handling key design, pools, deadlocks, timeouts, and database constraints.
Compressing Images Before Transfer Without Losing Control of Quality
Resize and encode with createImageBitmap, Canvas, or WebCodecs while handling EXIF orientation, alpha, color, private metadata, and low-end device cost.
Presence Is Not a Boolean: TTLs, Heartbeats, and Offline Decisions
Design leased presence, jittered heartbeats, grace windows, and explicit departure across background throttling, power loss, rolling deploys, and multiple tabs.
A Practical Privacy Review Using Data Flows and Abuse Cases
Review real-time features through data inventory, sources and destinations, purpose limits, retention, access, user control, and abuse scenarios.
Privacy-Safe Log Redaction Starts with Structured Fields
Classify log fields, enforce allowlists, wrap secret types, and sample safely so tokens, clipboard data, filenames, SDP, and full IP addresses never reach logs.
Diagnosing Frontend Failures Without Privacy-Invasive Session Replay
Replace DOM recording with bounded state transitions, interaction types, layout assertions, and performance summaries to preserve evidence without chat, clipboard, or screen content.
Prompt Injection in Support Intake and Diagnostic Text
When models analyze tickets, logs, and diagnostics, isolate untrusted content from instructions and restrict tools, retrieval, actions, and sensitive access.
Property-Based Protocol Testing Finds Unexpected State Sequences
Generate valid and hostile event sequences for connection and transfer state machines, asserting safety, invariants, liveness, and convergence with shrinking.
Protocol Version Negotiation Before Declaring a Connection Usable
Exchange supported versions, feature bits, and required capabilities during handshake, choosing a common version, explaining fallback, and rejecting unsafe combinations.
Real-Time Pub/Sub Fanout Under Subscription Changes and Reordering
Define channel subscriptions, sequence numbers, snapshot repair, and duplicate delivery so multi-instance signaling converges during migration and reconnect.
PWA Installability Beyond a Manifest, Icons, and Offline Shell
Configure manifest, scope, start URL, icons, theme, and display mode across iOS differences, updates, deep links, and post-install identity continuity.
Quota Messaging That Warns Early and Explains the Next Action
Explain TURN, storage, and send limits through accounting scope, period, estimated usage, early warning, reset time, and safe degradation.
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