Class: SpoolPool::Spool

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

Overview

This class manages the data storage and retrieval within a specific spool.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(pathname) ⇒ Spool

Uses the directory given in pathname as the directory for the subsequent spooling operations.

Will perform a simple check on the directory and throw an exception if the directory already exists but isn’t read- and writeable by the effective user id of the process.



19
20
21
22
 
# File 'lib/spool_pool/spool.rb', line 19

def initialize( pathname )
  @pathname = pathname
  validate_spool_directory
end

Instance Attribute Details

#pathname ⇒ Object (readonly)

Returns the value of attribute pathname.



9
10
11
 
# File 'lib/spool_pool/spool.rb', line 9

def pathname
  @pathname
end

Class Method Details

.deserialize(data) ⇒ Object

:nodoc:



91
92
93
 
# File 'lib/spool_pool/spool.rb', line 91

def self.deserialize( data ) # :nodoc:
  YAML.load( data )
end

.serialize(data) ⇒ Object

:nodoc:



80
81
82
 
# File 'lib/spool_pool/spool.rb', line 80

def self.serialize( data ) # :nodoc:
  YAML.dump( data )
end

Instance Method Details

#deserialize(data) ⇒ Object

Deserializes the data that has previously been serialized with serialize.



87
88
89
 
# File 'lib/spool_pool/spool.rb', line 87

def deserialize( data )
  self.class.deserialize( data )
end

#flush ⇒ Object

Retrieves and deserializes all the data in the spool, oldest data first. Each piece of spooled data will be yielded to the supplied block.

Ordering is based on the files ctime, but the ordering is non-strict. Data stored within the same second will be returned in a random order.



63
64
65
66
67
68
69
70
 
# File 'lib/spool_pool/spool.rb', line 63

def flush
  loop do
    data = get
    break if data.nil?

    yield data
  end
end

#get(&block) ⇒ Object

Reads and returns the deserialized data of the oldest file in the spool, yielding the deserialized data to an optionally passed block..

Deletes the file only if no exception was raised within the block.

Ordering is based on the filename (which in turn is based on the files creation time), but the ordering is non-strict.

Data stored within the same second will be returned in a random order.



45
46
47
48
49
50
51
52
53
54
 
# File 'lib/spool_pool/spool.rb', line 45

def get(&block)
  file = oldest_spooled_file
  return nil unless file
  data = if block_given?
          SpoolPool::File.safe_read( file ) { |data| block.call( deserialize(data) ) }
        else
          SpoolPool::File.safe_read( file )
        end
  deserialize(data)
end

#put(data) ⇒ Object

Serializes and stores the data.

Returns the path of the file storing the data.



29
30
31
32
 
# File 'lib/spool_pool/spool.rb', line 29

def put( data )
  @pathname.mkpath unless @pathname.exist?
  SpoolPool::File.write( @pathname, serialize( data ) )
end

#serialize(data) ⇒ Object

Serializes the data so that it can be deserialized with the deserialize method later on.



76
77
78
 
# File 'lib/spool_pool/spool.rb', line 76

def serialize( data )
  self.class.serialize( data )
end