https://github.com/billiegoose/cachecow

An on-disk cache for files with various garbage collection options.
https://github.com/billiegoose/cachecow

Last synced: 24 days ago
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An on-disk cache for files with various garbage collection options.

• Host: GitHub
• URL: https://github.com/billiegoose/cachecow
• Owner: billiegoose
• License: mit
• Created: 2016-07-04T02:40:12.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-07-04T04:01:04.000Z (over 8 years ago)
• Last Synced: 2024-10-06T03:24:07.341Z (3 months ago)
• Language: CoffeeScript
• Size: 7.81 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Cache Cow

All the caching modules I found on npm were for caching things in memory, or in an external service like Redis.

I couldn't find any cache modules on npm that fit my need, so I wrote this one.

# Motivation

 1. Do you have extra hard drive space?

 2. Store some of your files in the cloud or whatever?

 3. Want to save bandwidth or time by making fewer fetches to that cloud?

That is the use case this module is designed for.

I wanted to use the hard drive to cache files that are in remote storage like Amazon S3.

# Features

 - When cache reaches 90% of the defined `maxsize` it deletes files until the cache is 70% of `maxsize`.

 - Returns streams, not buffers, for faster requests.

 - How it chooses which files to delete can be customized

# Free support

Email me or create an issue if you need help! I'm throwing this up without a lot of documentation, and am very welcome to feedback and suggestions.

# Example

```coffee

# Hypothetical example using CacheCow with an HTTP proxy server

express = require('express')

request = require('request')

CacheCow = require('cachecow')

app = express()

cache = new CacheCow({

  maxsize: 1024*1024*1024*10 # 10GB

  # Define a function to deal with cache misses

  getter: (filename, callback) ->

    console.log "Not found in cache"

    stream = request("http://httpstat.us/#{filename}")

    callback(null, stream)

})

# Retrieve something from cache

app.get "/:filepath", (req, res) ->

  cache.get req.params.filepath, (err, stream) ->

    return res.status(404).send(err.message) if err?

    stream.pipe res

# This scans the cache directory to gather file size information for any files

# already present in the cache directory.

cache.init (err) ->

  console.log err if err?

  app.listen 8080, (err) ->

    console.log err if err?

    console.log "started"

```

# Options

```coffee

# Default values

cache = new CacheCow

  maxsize: 1024*1024*1 # 1MB

  dir: upath.join(os.tmpdir(), 'cachecow')

  getter: ->

    console.log 'You must define a getter function for cache misses!'

  # Weights used in garbage collection equation

  DeleteByFileSize: 0      # Delete big files first, keep as many files as possible

  DeleteByTotalReads: 0    # Delete rarely used files, keep file that are frequently fetched

  DeleteByLastAccess: 1    # Delete old files, keep files that have been recently fetched

```