Class: SBDB::Cursor

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/sbdb/cursor.rb

Constant Summary collapse

NEXT = 
Bdb::DB_NEXT
FIRST = 
Bdb::DB_FIRST
LAST = 
Bdb::DB_LAST
PREV = 
Bdb::DB_PREV
SET = 
Bdb::DB_SET

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ref) ⇒ Cursor

Returns a new instance of Cursor.



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# File 'lib/sbdb/cursor.rb', line 46

def initialize ref
  @cursor, @db = *case ref
    when Cursor  then [ref.bdb_object.dup, ref.db]
    when Bdb::Db::Cursor  then [ref]
    else [ref.bdb_object.cursor( nil, 0), ref]
    end
  if [Recno, Queue].any? {|dbt| dbt === @db }
    def get *ps
      key, val = @cursor.get( *ps)
      key.nil? ? nil : [key.unpack('I')[0], val]
    end
  end
end

Instance Attribute Details

#db ⇒ Object (readonly)

Returns the value of attribute db.



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# File 'lib/sbdb/cursor.rb', line 10

def db
  @db
end

Class Method Details

.new(*ps) ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 38

def self.new *ps
  ret = obj = super( *ps)
  begin ret = yield obj
  ensure obj.close
  end  if block_given?
  ret
end

Instance Method Details

#bdb_object ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 13

def bdb_object
  @cursor
end

#close ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 16

def close
  @cursor.close
end

#count ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 22

def count
  @cursor.count
end

#each(key = nil, val = nil, flg = nil, nxt = nil) {|ent| ... } ⇒ Object

Yields:

  • (ent) 


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# File 'lib/sbdb/cursor.rb', line 64

def each key = nil, val = nil, flg = nil, nxt = nil
  return Enumerator.new( self, :each, key, val, flg, nxt)  unless block_given?
  nxt ||= NEXT
  ent = get key, val, flg || FIRST
  return  unless ent
  yield *ent
  yield *ent  while ent = get( key, val, nxt)
  nil
end

#first(key = nil, val = nil) ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 25

def first key = nil, val = nil
  get key, val, FIRST
end

#get(key, val, flg) ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 19

def get key, val, flg
  @cursor.get key, val, flg
end

#last(key = nil, val = nil) ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 28

def last key = nil, val = nil
  get key, val, LAST
end

#next(key = nil, val = nil) ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 31

def next key = nil, val = nil
  get key, val, NEXT
end

#prev(key = nil, val = nil) ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 34

def prev key = nil, val = nil
  get key, val, PREV
end

#reverse(key = nil, val = nil, &exe) ⇒ Object 



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# File 'lib/sbdb/cursor.rb', line 60

def reverse key = nil, val = nil, &exe
  each key, val, LAST, PREV, &exe
end