persist-compressed

name	persist-compressed
description	Compress a string-wire StateStorage with @stainless-code/persist/backends/compressed (gzip/deflate). Backend wrapper — compose with createStorage; stack compress-then-encrypt.
license	MIT
metadata	{"type":"composition","library":"@stainless-code/persist","library_version":"0.4.1"}
requires	["persist"]
sources	["stainless-code/persist:src/adapters/backends/compressed.ts"]

Compressed backend wrapper

Not a StorageCodec. Uses CompressionStream / DecompressionStream (default gzip); output is base64 on the string wire. Returns undefined if streams unavailable. Documented stack with encryption: compress → encrypt.

Minimal wiring

import { createStorage, jsonCodec } from "@stainless-code/persist";
import { createCompressedStorage } from "@stainless-code/persist/backends/compressed";

const storage = createStorage<Prefs>(
  () => createCompressedStorage(() => localStorage)!,
  jsonCodec(),
);

Richer graphs → persist-seroval as the codec.

Formats: gzip | deflate | deflate-raw (deflate-raw needs Node 20.12+).

Common mistakes

• Using as a codec.
• Encrypt-then-compress.
• Assuming streams exist in every runtime.

API surface

• createCompressedStorage(getStorage, { format? }) → StateStorage<string> | undefined

See also: persist-encrypted.