Class: Memcache::PGServer

Inherits:
Base show all
Defined in:
lib/memcache/pg_server.rb

Instance Attribute Summary collapse

Attributes inherited from Base

#prefix

Instance Method Summary collapse

Methods inherited from Base

#cas, #clear, #gets

Constructor Details

#initialize(opts) ⇒ PGServer

Returns a new instance of PGServer.



14
15
16
17
 
# File 'lib/memcache/pg_server.rb', line 14

def initialize(opts)
  @table = opts[:table]
  @db    = opts[:db] || ActiveRecord::Base.connection.raw_connection
end

Instance Attribute Details

#db ⇒ Object (readonly)

Returns the value of attribute db.



12
13
14
 
# File 'lib/memcache/pg_server.rb', line 12

def db
  @db
end

#table ⇒ Object (readonly)

Returns the value of attribute table.



12
13
14
 
# File 'lib/memcache/pg_server.rb', line 12

def table
  @table
end

Instance Method Details

#add(key, value, expiry = 0) ⇒ Object 



82
83
84
85
86
87
88
 
# File 'lib/memcache/pg_server.rb', line 82

def add(key, value, expiry = 0)
  delete_expired(key)
  insert(key, value, expiry)
  value
rescue PGError => e
  nil
end

#append(key, value) ⇒ Object 



96
97
98
99
100
101
102
103
104
 
# File 'lib/memcache/pg_server.rb', line 96

def append(key, value)
  delete_expired(key)
  result = db.exec %{
    UPDATE #{table}
      SET value = value || #{quote(value)}, updated_at = NOW()
      WHERE key = #{quote(key)} AND #{prefix_clause}
  }
  result.cmdtuples == 1
end

#decr(key, amount = 1) ⇒ Object 



62
63
64
 
# File 'lib/memcache/pg_server.rb', line 62

def decr(key, amount = 1)
  incr(key, -amount)
end

#delete(key) ⇒ Object 



66
67
68
69
70
71
72
 
# File 'lib/memcache/pg_server.rb', line 66

def delete(key)
  result = db.exec %{
    DELETE FROM #{table}
      WHERE key = #{quote(key)} AND #{prefix_clause}
  }
  result.cmdtuples == 1
end

#flush_all(delay = nil) ⇒ Object 



26
27
28
 
# File 'lib/memcache/pg_server.rb', line 26

def flush_all(delay = nil)
  db.exec("TRUNCATE #{table}")
end

#get(keys) ⇒ Object 



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
 
# File 'lib/memcache/pg_server.rb', line 30

def get(keys)
  return get([keys])[keys.to_s] unless keys.kind_of?(Array)
  return {} if keys.empty?

  keys = keys.collect {|key| quote(key.to_s)}.join(',')
  sql = %{
    SELECT key, value FROM #{table}
      WHERE key IN (#{keys}) AND #{prefix_clause} AND #{expiry_clause}
  }
  results = {}
  db.query(sql).each do |key, value|
    results[key] = value
  end
  results
end

#incr(key, amount = 1) ⇒ Object 



46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
 
# File 'lib/memcache/pg_server.rb', line 46

def incr(key, amount = 1)
  transaction do
    value = get(key)
    return unless value
    return unless value =~ /^\d+$/

    value = value.to_i + amount
    value = 0 if value < 0
    db.exec %{
      UPDATE #{table} SET value = #{quote(value)}, updated_at = NOW()
        WHERE key = #{quote(key)} AND #{prefix_clause}
    }
    value
  end
end

#name ⇒ Object 



19
20
21
22
23
24
 
# File 'lib/memcache/pg_server.rb', line 19

def name
  @name ||= begin
    db_config = db.instance_variable_get(:@config)
    "#{db_config[:host]}:#{db_config[:database]}:#{table}"
  end
end

#prepend(key, value) ⇒ Object 



106
107
108
109
110
111
112
113
114
 
# File 'lib/memcache/pg_server.rb', line 106

def prepend(key, value)
  delete_expired(key)
  result = db.exec %{
    UPDATE #{table}
      SET value = #{quote(value)} || value, updated_at = NOW()
      WHERE key = #{quote(key)} AND #{prefix_clause}
  }
  result.cmdtuples == 1
end

#replace(key, value, expiry = 0) ⇒ Object 



90
91
92
93
94
 
# File 'lib/memcache/pg_server.rb', line 90

def replace(key, value, expiry = 0)
  delete_expired(key)
  result = update(key, value, expiry)
  result.cmdtuples == 1 ? value : nil
end

#set(key, value, expiry = 0) ⇒ Object 



74
75
76
77
78
79
80
 
# File 'lib/memcache/pg_server.rb', line 74

def set(key, value, expiry = 0)
  transaction do
    delete(key)
    insert(key, value, expiry)
  end
  value
end