CoCalc provides the best real-time collaborative environment for Jupyter Notebooks, LaTeX documents, and SageMath, scalable from individual users to large groups and classes!

1
require 'redis'
2

3
module Anemone
4
  module Storage
5
    class Redis
6

7
      MARSHAL_FIELDS = %w(links visited fetched)
8

9
      def initialize(opts = {})
10
        @redis = ::Redis.new(opts)
11
        @key_prefix = opts[:key_prefix] || 'anemone'
12
        keys.each { |key| delete(key) }
13
      end
14

15
      def [](key)
16
        rkey = "#{@key_prefix}:pages:#{key.to_s}"
17
        rget(rkey)
18
      end
19

20
      def []=(key, value)
21
        rkey = "#{@key_prefix}:pages:#{key.to_s}"
22
        hash = value.to_hash
23
        MARSHAL_FIELDS.each do |field|
24
          hash[field] = Marshal.dump(hash[field])
25
        end
26
        hash.each do |field, value|
27
          @redis.hset(rkey, field, value)
28
        end
29
      end
30

31
      def delete(key)
32
        rkey = "#{@key_prefix}:pages:#{key.to_s}"
33
        page = self[key]
34
        @redis.del(rkey)
35
        page
36
      end
37

38
      def each
39
        rkeys = @redis.keys("#{@key_prefix}:pages:*")
40
        rkeys.each do |rkey|
41
          page = rget(rkey)
42
          yield page.url.to_s, page
43
        end
44
      end
45

46
      def merge!(hash)
47
        hash.each { |key, value| self[key] = value }
48
        self
49
      end
50

51
      def size
52
        @redis.keys("#{@key_prefix}:pages:*").size
53
      end
54

55
      def keys
56
        keys = []
57
        self.each { |k, v| keys << k.to_s }
58
        keys
59
      end
60

61
      def has_key?(key)
62
        rkey = "#{@key_prefix}:pages:#{key.to_s}"
63
        @redis.exists(rkey)
64
      end
65

66
      def close
67
        @redis.quit
68
      end
69

70
      private
71

72
      def load_value(hash)
73
        MARSHAL_FIELDS.each do |field|
74
          unless hash[field].nil? || hash[field] == ''
75
            hash[field] = Marshal.load(hash[field]) 
76
          end
77
        end
78
        Page.from_hash(hash)
79
      end
80

81
      def rget(rkey)
82
        hash = @redis.hgetall(rkey)
83
        if !!hash
84
          load_value(hash)
85
        end
86
      end
87

88
    end
89
  end
90
end
91

92