Memory Cache Filter

Memory cache filter implementation for Clyde API gateway.

Implementation is based on node-cache module.

The filter works as an in memory <key, value> cache. For each request it caches response content, headers and status code as the value and using the url as the key.

If the property ignoreQuery=true the key will contain only the path part of the url and will ignore the query, for example, these URLs will be treated as the same: /some_path?param1=a&param2=b, /some_path?abc or /some_path.

• Memory Cache Filter
  • Installation
  • Configuration
  • Examples
    • Global cache with default configuration
    • Provider's cache ignoring URL query part and with a TTL of 5 minutes
  • Notes
• License

Installation

npm install clydeio-memory-cache --save

Configuration

The memory cache filter accepts the next set of configuration options. Note, with the exception of ignoreQuery property all the rest properties are the same as the node-cache module, because of this, the set of properties are passed directly to the internal module reference:

• ignoreQuery: (default: false) ignores the query part of the url when computing the cache key. Otherwise the full url is used.
• stdTTL: (default: 0) the standard ttl as number in seconds for every generated cache element.
  0 = unlimited
• checkperiod: (default: 600) The period in seconds, as a number, used for the automatic delete check interval.
  0 = no periodic check.
  Note: If you use checkperiod > 0 you script will not exit at the end, because a internal timeout will always be active.
• useClones: (default: true) en/disable cloning of variables. If true you'll get a copy of the cached variable. If false you'll save and get just the reference.
  Note: true is recommended, because it'll behave like a sever-based caching. You should set false if you want to save complex varibale types like functions, promises, regexp, ...

Examples

Global cache with default configuration

{
  "prefilters" : [
    {
      "id" : "memory-cache",
      "path" : "clydeio-memory-cache"
    }
  ],
  "providers": [
    ...
  ]
}

Provider's cache ignoring URL query part and with a TTL of 5 minutes

{
  "providers": [
    {
      "id" : "providerA",
      "context" : "/provider",
      "target" : "http://server_providerA",

      "prefilters" : [
        {
          "id" : "memory-cache",
          "path" : "clydeio-memory-cache",
          "config" : {
            "ignoreQuery" : true,
            "stdTTL" : 300
          }
        }
      ]
    }
  ]
}

Notes

• Memory cache filter must be configured as a prefilter. Its is required to capture the requests before sent to the provider.

License

The MIT License (MIT)

Copyright (c) 2015 Antonio Santiago (@acanimal)

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.