stream-catcher

library1.0.5jsnpmunverified

A streaming wrapper around lru-cache that enables caching of readable streams and writing cached data to writable streams. Current version: 1.0.5 (unstable pre-1.0). Infrequently updated. Key differentiators: provides a simple streaming interface for caching, avoiding manual buffer management. Alternatives like `lru-cache` require manual serialization.

storage

npm install stream-catcher

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · STREAM-CATCHER

stream-catcher

storagejavascriptv1.0.5

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

StreamCatcher

✓ import StreamCatcher from 'stream-catcher'

✗ const StreamCatcher = require('stream-catcher').default;

Default export; CommonJS users can use `const StreamCatcher = require('stream-catcher')`.

StreamCatcher

✓ const StreamCatcher = require('stream-catcher')

CommonJS pattern; exports a constructor function directly.

StreamCatcher

✓ import StreamCatcher from 'stream-catcher'

✗ import { StreamCatcher } from 'stream-catcher'

Named import is incorrect; it is a default export.

Shows how to create a streamCache, cache a readable stream, and write cached data to a writable stream.

import StreamCatcher from 'stream-catcher'; import { createReadStream, createWriteStream } from 'fs'; const cache = new StreamCatcher({ max: 1024 * 100, // 100KB length: (n) => n.length }); const key = 'example.txt'; const writePath = './output.txt'; const readPath = './input.txt'; // Write to cache (read from a source and cache) const readStream = createReadStream(readPath); cache.read(key, readStream); // Later: Read cached data to a writable stream const writeStream = createWriteStream(writePath); cache.write(key, writeStream, () => { console.log('Cache miss, populate cache first'); });

Debug

Known issues

breakingIn version 1.0.0, the constructor options changed to match lru-cache v2 options. Older versions used different option names.

fix

Update constructor options to align with lru-cache v2: use `max`, `length`, `maxAge` etc.

affects: <1.0.0

gotchaDo not mutate streams after passing to `read` or `write` methods; behavior is undefined.

fix

Ensure streams are used only once and not modified externally.

affects: >=0.0.0

gotchaThe `length` option function receives data chunks, not file sizes. Ensure it returns a numeric value appropriate for cache size calculation.

fix

Define `length` as a function that returns `(n) => n.length` for buffer-like data.

affects: >=0.0.0

Errors

Common errors & fixes

TypeError: streamCatcher.write is not a function

Using named import `{ StreamCatcher }` instead of default import.

fix

Use `import StreamCatcher from 'stream-catcher'` or `const StreamCatcher = require('stream-catcher')`.

Error: options.length is required

Missing `length` option in constructor when `max` is set.

fix

Provide a `length` option function, e.g., `length: (n) => n.length`.

Error: Cannot read property 'on' of undefined

Calling `read` with a non-stream argument (e.g., string path).

fix

Pass a valid readable stream object to `cache.read(key, stream)`.

Upgrade

Version history

1.0.5latest on npm

Audit

Dependencies

lru-cacherequiredCore caching logic is delegated to lru-cache.

Agent activity

30 hits · last 30 days

node

Amazon

OpenAI (training)

Resources

githubhttps://github.com/KoryNunn/stream-catcher ↗

packagestream-catcher ↗

homepagehttps://github.com/KoryNunn/stream-catcher ↗