Class: CouchbaseStructures::Queue

Inherits:
Object
  • Object
show all
Includes:
CouchbaseDocStore
Defined in:
lib/couchbase_structures/queue.rb

Instance Method Summary collapse

Constructor Details

#initialize(key) ⇒ Queue

Returns a new instance of Queue.



7
8
9
10
11
12
13
14
15
16
 
# File 'lib/couchbase_structures/queue.rb', line 7

def initialize(key)
  @user_key = key
  @key = "#{key}::queue"
  @head_index_key = "#{@key}::head"
  @tail_index_key = "#{@key}::tail"
  initialize_document(@head_index_key, 0)
  initialize_document(@tail_index_key, 0)
  initialize_document(@key, { :type => "queue", :class => "CouchbaseStructures::Queue", :user_key => key } )
  self
end

Instance Method Details

#delete ⇒ Object 



54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
 
# File 'lib/couchbase_structures/queue.rb', line 54

def delete
  #head_index = get_document(@head_index_key)  # (not needed)
  tail_index = get_document(@tail_index_key)
  
  # delete all queued documents, including those that were before the current head (those aren't deleted as of now)
  1.upto(tail_index) do |i|
    delete_document("#{@key}::#{i}")
  end
  delete_document(@head_index_key)
  delete_document(@tail_index_key)
  delete_document(@key)
  @user_key = nil
  @key = nil
  @head_index_key = nil
  @tail_index_key = nil
  nil
end

#enqueue(value) ⇒ Object

Add an item to the end of the queue (tail)



32
33
34
35
36
 
# File 'lib/couchbase_structures/queue.rb', line 32

def enqueue(value)
  new_tail_index = increase_atomic_count(@tail_index_key)
  create_document("#{@key}::#{new_tail_index}", value)
  self
end

#inspect(html = false) ⇒ Object 



18
19
20
21
22
23
24
 
# File 'lib/couchbase_structures/queue.rb', line 18

def inspect(html = false)
  if html
    "<strong>key</strong> = #{@key}    <br /><strong>head_index</strong> = #{get_document(@head_index_key).to_s}  <br /><strong>tail_index</strong> = #{get_document(@tail_index_key).to_s}   <br /><strong>items</strong> = #{self.to_a(true)}"
  else
    "key = #{@key} head_index = #{get_document(@head_index_key).to_s} tail_index = #{get_document(@tail_index_key).to_s} items = #{self.to_a}"
  end
end

#peek(queue_index) ⇒ Object

peek at item at index (zero based)



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

def peek(queue_index)
  self
end

#pop ⇒ Object

Pop an item off the front of queue (head)



39
40
41
42
43
44
45
46
47
48
 
# File 'lib/couchbase_structures/queue.rb', line 39

def pop()
  head_index = get_document(@head_index_key)
  tail_index = get_document(@tail_index_key)
  if tail_index > head_index # if there is an item in the queue
    increase_atomic_count(@head_index_key) #incremented new_head_index is ignored, but we are incrementing and popping value
    return get_document("#{@key}::#{head_index + 1}")
  else # 
    nil
  end
end

#size ⇒ Object 



50
51
52
 
# File 'lib/couchbase_structures/queue.rb', line 50

def size()
  get_document(@tail_index_key) - get_document(@head_index_key)
end

#to_a(html = false) ⇒ Object 



72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
 
# File 'lib/couchbase_structures/queue.rb', line 72

def to_a(html=false)
  a = []
  head_index = get_document(@head_index_key) + 1
  tail_index = get_document(@tail_index_key)

  # delete all queued documents, including those that were before the current head (those aren't deleted as of now)
  head_index.upto(tail_index) do |i|
    a << get_document("#{@key}::#{i}")
  end
  
  if html
    str = "["
    a.each do |item|
      str += "<br />&nbsp;&nbsp;&nbsp;&nbsp;" + item.inspect
    end
    str += "<br />]"
    return str
  else
    return a
  end
end