Create and fork

CreateCopy Anchor Link

import { Effect } from "effect";
import { Notes } from "./streams.ts";

const ensure = Effect.gen(function* () {
  const notes = yield* Notes;
  const result = yield* notes.create({}, { ttlSeconds: 3600 });
  return result.nextOffset;
});

Both results carry nextOffset, contentType, and closed. A different configuration on the same id fails with CreateConflict.

Set ttlSeconds or expiresAt, not both.

ExpiryCopy Anchor Link

An expired stream answers StreamNotFound on the next access. On Cloudflare, the object alarm also sweeps expired streams. The Bun host has no sweeper.

A projection that stops reading can lose an expired input. It then stops with history-unavailable. See Faults.

ForkCopy Anchor Link

A fork is a child stream that starts with a prefix of a source stream. Appends to the child do not change the source.

import { Effect } from "effect";
import { Drafts } from "./streams.ts";

const branch = Effect.gen(function* () {
  const drafts = yield* Drafts;
  const head = yield* drafts.head({ draftId: "main" });
  return yield* drafts.fork(
    { draftId: "copy" },
    { draftId: "main" },
    { forkOffset: head.nextOffset },
  );
});

fork(params, source, options?) takes the child parameters, then the source parameters. Both are addresses of one stream class. The child gets every source message up to and including forkOffset. With no forkOffset, the child starts empty.

A fork never crosses two storage Layers.

See the upstream fork page.

RemoveCopy Anchor Link

remove(params) deletes the stream. Later calls on that id answer StreamGone. A source with live forks is kept until its last child is removed.

Over HTTPCopy Anchor Link

See Protocol routes.