Cache Stream

Streaming object cache controller

What Does This Do?

It's a non-blocking read-through cache, implemented with streaming interfaces. This means that all requests for an object are served in real-time, regardless of the state of the cache. While the cache is building, data will be streamed to new read requests first from the internal buffer, then as chunks are received from the upstream source.

API

Cache

Implements Stream.Writable

Instance Properties

Number Cache#length

The current size, in bytes, of the cached object

Boolean Cache#complete

true When object is fully cached (source stream has ended), and hashes have been calculated

String Cache#md5

MD5 sum of the cached object. Calculated after object is fully cached.

String Cache#sha1

SHA1 sum of the cached object. Calculated after object is fully cached.

String Cache#sha256

SHA256 sum of the cached object. Calculated after object is fully cached.

Instance Methods

Buffer Cache#chunk(position, length)

Return a slice of the cached object

CacheReader Cache#pipe(writable)

Create a new CacheReader, piped to writable

CacheReader

Implements Stream.Readable

Instance Properties

String CacheReader#id

Unique ID of the CacheReader instance.

Cache CacheReader#cache

Cache instance being read.

Boolean CacheReader#flowing

Buffer state of the read stream.

Number CacheReader#position

Position of the reader in the cache's payload.

Instance Methods

CacheReader#chunk(buffer)

Push chunk directly to read stream only if state is flowing.

License

The MIT License (MIT)

Copyright (c) 2014 John Manero

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.