Memcached Session Client

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bam.coffee memcached_session_client.coffee resource.coffee resource_service.coffee

¶

Memcached Session Client
¶

Imports
- bluebird is the promises library
- lodash is used as a general purpose utility library
- memcached is used to communicate with memcached
```
bb = require "bluebird"
_ = require 'lodash'
Memcached = require('memcached')
```
¶

Memcached Session Client

This class is used to store session and caller keys in memcached for use in authentication.
```
class MemcachedSessionClient
```
¶

constructor(options) The keys for the options are:
1. memcached_uri: the location of the memcached host
2. memcached_retries: the number of retries to attempt if writing or reading fails
3. memcached_session_namespace: the prefixed namespace added to session keys
4. memcached_caller_namespace: the prefixed namespace added to caller keys
5. memcached_ttl: the length of time that a key will exist in memcached
```
  constructor: (@options = {}) ->
    @options = _.defaults(
      @options,
      {
        memcached_uri: 'localhost:11211'
        memcached_retries: 2
        memcached_session_namespace: ''
        memcached_caller_namespace: ''
        memcached_ttl: 86400 # 24 hours for session to time out
      }
    )
```

connect created the memcached client and attempts to connect to the memcached host. It returns a promise that it has connected successfully.

  connect: () =>
    @_memcached = new Memcached(@options.memcached_uri, {
      retries: @options.memcached_retries,
      timeout: 200,
      remove: true,
      failures:2
    })

    @_memcached = bb.promisifyAll(@_memcached)

    @_memcached.statsAsync()
    .then( (data) =>
      @
    )
    .catch( ->
      throw "Error Connecting to Memcached"
    )

¶

disconnect deleted the connection to memcached and returns promise to disconnect
```
  disconnect: =>
    delete @['_memcached']
    bb.try( -> )
```

get_session returns a promise for the session from memcached using the session_id

  get_session: (session_id) =>
    @_memcached.getAsync("#{@options.memcached_session_namespace}#{session_id}")
    .then( (data) ->
      return null unless data?
      try
        return JSON.parse(data)
      catch e
        throw "Session is Corrupt (#{e})"
    )

get_caller returns a promise for the caller from memcached using the caller_id

  get_caller: (caller_id) =>
    @_memcached.getAsync("#{@options.memcached_caller_namespace}#{caller_id}")
    .then( (data) ->
      return null unless data?
      try
        return JSON.parse(data)
      catch e
        throw "Session is Corrupt (#{e})"
    )

set_session returns a promise to set the session to the session_id in memcached

  set_session: (session_id, session = {}) ->
    @_memcached.setAsync("#{@options.memcached_session_namespace}#{session_id}", JSON.stringify(session), @options.memcached_ttl)

set_caller returns a promise to set the caller to the caller_id in memcached

  set_caller: (caller_id, caller = {}) ->
    @_memcached.setAsync("#{@options.memcached_caller_namespace}#{caller_id}", JSON.stringify(caller), @options.memcached_ttl)


module.exports = MemcachedSessionClient

Memcached Session Client

Imports

Memcached Session Client