Class: RRDSimple

Inherits:
Object
  • Object
show all
Defined in:
lib/rrdsimple.rb

Constant Summary collapse

VERSION = 
"0.0.1"

Instance Method Summary collapse

Constructor Details

#initialize(opts) ⇒ RRDSimple

Returns a new instance of RRDSimple.



8
9
10
11
12
13
 
# File 'lib/rrdsimple.rb', line 8

def initialize(opts)
  @buckets = opts[:buckets]
  @step = opts[:step]
  @debug = opts[:debug] || false
  @db = opts[:db] || Redis.new
end

Instance Method Details

#bucket(k, i) ⇒ Object 



43
44
45
 
# File 'lib/rrdsimple.rb', line 43

def bucket(k,i)
  @db.get(bucket_key(k,i)).to_i
end

#bucket_key(k, i) ⇒ Object 



39
40
41
 
# File 'lib/rrdsimple.rb', line 39

def bucket_key(k,i)
  "#{k}:#{i}"
end

#buckets(k) ⇒ Object 



56
57
58
59
60
61
62
63
64
65
 
# File 'lib/rrdsimple.rb', line 56

def buckets(k)
  a = []
  i = 0
  last_b = last_bucket(k)
  while (i < @buckets) do
    a.push bucket_key(k,relative_bucket(last_b,i))
    i += 1
  end
  a
end

#clear(k) ⇒ Object 



102
103
104
105
 
# File 'lib/rrdsimple.rb', line 102

def clear(k)
  @db.del(last_epoch_key(k))
  buckets(k){|b| clear_bucket(b)}
end

#current_bucket ⇒ Object 



19
20
21
 
# File 'lib/rrdsimple.rb', line 19

def current_bucket
  current_epoch % @buckets
end

#current_epoch ⇒ Object 



15
16
17
 
# File 'lib/rrdsimple.rb', line 15

def current_epoch
  Time.now.utc.to_i / @step
end

#epoch(k) ⇒ Object 



80
81
82
83
84
85
86
87
88
89
90
 
# File 'lib/rrdsimple.rb', line 80

def epoch(k)
  current_e = current_epoch
  last_e = last_epoch(k)
  if current_e != last_e
    [(current_e - last_e).abs, @buckets].min.times do |n|
      clear_bucket(epochs_ago(k, n))
    end
    set_last_epoch(k, current_e)
  end
  bucket_key(k, current_bucket)
end

#epochs_ago(k, num) ⇒ Object 



52
53
54
 
# File 'lib/rrdsimple.rb', line 52

def epochs_ago(k, num)
  bucket_key(k, relative_bucket(current_bucket,num))
end

#incr(k, val = 1) ⇒ Object 



92
93
94
95
 
# File 'lib/rrdsimple.rb', line 92

def incr(k, val=1)
  debug [:incr, epoch(k), val]
  @db.incrby(epoch(k), val).to_i
end

#last_bucket(set) ⇒ Object 



35
36
37
 
# File 'lib/rrdsimple.rb', line 35

def last_bucket(set)
  last_epoch(set) % @buckets
end

#last_epoch(k) ⇒ Object 



27
28
29
 
# File 'lib/rrdsimple.rb', line 27

def last_epoch(k)
  @db.get(last_epoch_key(k)).to_i
end

#last_epoch_key(k) ⇒ Object 



23
24
25
 
# File 'lib/rrdsimple.rb', line 23

def last_epoch_key(k)
  "#{k}:epoch"
end

#relative_bucket(value, i) ⇒ Object 



47
48
49
50
 
# File 'lib/rrdsimple.rb', line 47

def relative_bucket(value, i)
  b = value - i
  b = (b < 0) ? @buckets + b : b
end

#set(k, val) ⇒ Object 



97
98
99
100
 
# File 'lib/rrdsimple.rb', line 97

def set(k, val)
  debug [:set, epoch(k), val]
  @db.set(epoch(k), val)
end

#set_last_epoch(k, v = Time.now.utc.to_i) ⇒ Object 



31
32
33
 
# File 'lib/rrdsimple.rb', line 31

def set_last_epoch(k,v = Time.now.utc.to_i)
  @db.set(last_epoch_key(k), v)
end

#values(k) ⇒ Object 



67
68
69
70
71
72
73
74
75
76
77
78
 
# File 'lib/rrdsimple.rb', line 67

def values(k)
  a = []
  i = 0
  last_e = last_epoch(k)
  last_b = last_bucket(k)
  while (i < @buckets) do
    v = bucket(k,relative_bucket(last_b,i))
    a.push({:value => v, :epoch => last_e - i}) if v != 0
    i += 1
  end
  a
end