Class: RubyFFDB::Index

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

Instance Method Summary collapse

Constructor Details

#initialize(type, column) ⇒ Index

Returns a new instance of Index.



3
4
5
6
7
8
9
10
 
# File 'lib/rffdb/index.rb', line 3

def initialize(type, column)
  @type = type
  @column = column
  FileUtils.mkdir_p(File.dirname(file_path))
  GDBM.open(file_path, 0664, GDBM::WRCREAT) do
    # Index initialized
  end
end

Instance Method Details

#delete(key, value) ⇒ Object

Remove a specific Document association with a key



35
36
37
38
39
40
 
# File 'lib/rffdb/index.rb', line 35

def delete(key, value)
  previous = get(key)
  GDBM.open(file_path, 0664, GDBM::WRCREAT) do |index|
    index[key.to_s] = Marshal.dump((previous - [value]).uniq)
  end
end

#file_path ⇒ Object 



12
13
14
15
16
17
18
19
 
# File 'lib/rffdb/index.rb', line 12

def file_path
  File.join(
    DB_DATA,
    @type.to_s.gsub('::', '__'),
    'indexes',
    @column.to_s + '.index'
  )
end

#get(key) ⇒ Object 



21
22
23
24
25
 
# File 'lib/rffdb/index.rb', line 21

def get(key)
  GDBM.open(file_path, 0664, GDBM::READER) do |index|
    Marshal.load index.fetch(key.to_s, Marshal.dump([]))
  end
end

#keys ⇒ Array

All keys (column data) in the index

Returns:

  • (Array) —

    An array of object ids



51
52
53
54
55
 
# File 'lib/rffdb/index.rb', line 51

def keys
  GDBM.open(file_path, 0664, GDBM::READER) do |index|
    index.keys
  end
end

#prune ⇒ Object

Evict keys (column data) with no associated Documents



70
71
72
73
74
75
 
# File 'lib/rffdb/index.rb', line 70

def prune
  GDBM.open(file_path, 0664, GDBM::WRCREAT) do |index|
    index.delete_if { |key, value| Marshal.load(value).empty? }
    index.reorganize # clear up wasted disk space
  end
end

#put(key, value) ⇒ Object 



27
28
29
30
31
32
 
# File 'lib/rffdb/index.rb', line 27

def put(key, value)
  previous = get(key)
  GDBM.open(file_path, 0664, GDBM::WRCREAT) do |index|
    index[key.to_s] = Marshal.dump((previous + [value]).uniq)
  end
end

#query(q, operator = '==') ⇒ Array

Complex queries of the index can be done with this method

Returns:

  • (Array) —

    An array of object ids matching the query



59
60
61
62
63
64
65
66
67
 
# File 'lib/rffdb/index.rb', line 59

def query(q, operator = '==')
  datum = []
  GDBM.open(file_path, 0664, GDBM::READER) do |index|
    index.each_pair do |key, value|
      datum += Marshal.load(value) if key.send(operator.to_sym, q)
    end
  end
  datum.uniq.compact
end

#truncate(key) ⇒ Object

Remove all associations with a specific key (column data)



43
44
45
46
47
 
# File 'lib/rffdb/index.rb', line 43

def truncate(key)
  GDBM.open(file_path, 0664, GDBM::WRCREAT) do |index|
    index.delete(key.to_s)
  end
end