Class: Higgs::Store

Inherits:
StorageManager show all
Defined in:
lib/higgs/store.rb

Overview

storage like pstore

tutorial

1. open a new store

% irb
irb(main):001:0> require 'higgs'
=> true
irb(main):002:0> st = Higgs::Store.new('foo')
=> #<Higgs::Store:0xb7cac7d8

2. write an object

irb(main):003:0> st.transaction{|tx|
irb(main):004:1*   tx[:foo] = Object.new
irb(main):005:1> }
=> #<Object:0xb7d18adc>

3. read an object

irb(main):006:0> st.transaction{|tx|
irb(main):007:1*   tx[:foo]
irb(main):008:1> }
=> #<Object:0xb7a3b1e8>

4. custom property

custom property name shuold be a string.

irb(main):009:0> st.transaction{|tx|
irb(main):010:1*   tx.set_property(:foo, 'list', %w[ apple banana orange ])
irb(main):011:1> }
=> nil
irb(main):012:0> st.transaction{|tx|
irb(main):013:1*   tx.property(:foo, 'list')
irb(main):014:1> }
=> ["apple", "banana", "orange"]

4. write a string with :string_only property

:string_only is system property. system property name should be a symbol.

irb(main):015:0> st.transaction{|tx|
irb(main):016:1*   tx['bar'] = "Hello world.\n"
irb(main):017:1>   tx.set_property('bar', :string_only, true)
irb(main):018:1> }
=> nil

5. read a string

irb(main):019:0> st.transaction{|tx|
irb(main):020:1*   tx['bar']
irb(main):021:1> }
=> "Hello world.\n"

6. :string_only property rejects an object

irb(main):022:0> st.transaction{|tx|
irb(main):023:1*   tx['bar'] = Object.new
irb(main):024:1> }
TypeError: can't convert Object (value) to String

7. read-only transaction

irb(main):025:0> st.transaction{|tx|
irb(main):026:1*   p tx[:foo]
irb(main):027:1>   p tx.property(:foo, 'list')
irb(main):028:1>   p tx['bar']
irb(main):029:1>   p tx.property('bar', :string_only)
irb(main):030:1> }
#<Object:0xb79dd764>
["apple", "banana", "orange"]
"Hello world.\n"
true
=> nil

8. shutdown

irb(main):031:0> st.shutdown
=> nil
irb(main):032:0> exit

9. unix TAR storage and some files

% ls -ln
total 20
-rw-r----- 1 1000 1000 1024 Sep 24 20:59 foo.idx
-rw-r----- 1 1000 1000 4096 Sep 24 20:59 foo.jlog
-rw-r----- 1 1000 1000    0 Sep 24 20:57 foo.lock
-rw-r--r-- 1 1000 1000   57 Sep 24 20:57 foo.log
-rw-r----- 1 1000 1000 5120 Sep 24 20:58 foo.tar

10. unix TAR contents

% tar tvf foo.tar
-rw-r--r-- 1000/1000        12 2007-09-24 20:58 foo
-rw-r--r-- 1000/1000       316 2007-09-24 20:58 foo.p
-rw-r--r-- 1000/1000        13 2007-09-24 20:58 bar
-rw-r--r-- 1000/1000       250 2007-09-24 20:58 bar.p
% tar xvf foo.tar
foo
foo.p
bar
bar.p

11. marshaled object

‘foo’ is marshaled object

% ls -ln foo
-rw-r--r-- 1 1000 1000 12 Sep 24 20:58 foo
% od -c foo
0000000 004  \b   o   :  \v   O   b   j   e   c   t  \0
0000014

‘foo.p’ is properties. "list" of custom property is defined.

% ls -ln foo.p
-rw-r--r-- 1 1000 1000 316 Sep 24 20:58 foo.p
% cat foo.p
# SUM16 21993
---
custom_properties:
  list:
  - apple
  - banana
  - orange
system_properties:
  hash_type: MD5
  modified_time: &id001 2007-09-24 20:58:03.568701 +09:00
  hash_value: 5490d172635c560daaff1de92779d605
  created_time: *id001
  changed_time: 2007-09-24 20:58:24.502465 +09:00
  string_only: false

12. string with :string_only property

‘bar’ is a string

% ls -ln bar
-rw-r--r-- 1 1000 1000 13 Sep 24 20:58 bar
% od -c bar
0000000   H   e   l   l   o       w   o   r   l   d   .  \n
0000015
% cat bar
Hello world.

‘bar.p’ is properties. :string_only of system property is true.

% ls -ln bar.p
-rw-r--r-- 1 1000 1000 250 Sep 24 20:58 bar.p
% cat bar.p
# SUM16 18034
---
custom_properties: {}

system_properties:
  hash_type: MD5
  modified_time: &id001 2007-09-24 20:58:45.420319 +09:00
  created_time: *id001
  hash_value: fa093de5fc603823f08524f9801f0546
  changed_time: *id001
  string_only: true

13. other operations

tx of block argument is an instance of Higgs::TransactionContext. see Higgs::TransactionContext for all operations of transaction.

sample script

sample/count.rb

:include: sample/count.rb

result of sample script.

% ruby count.rb
start - Tue Oct 02 00:50:14 +0900 2007
nil

1
70
134
200
256
318
382
446
508
554
620
685
751
796
862
927
992

last - Tue Oct 02 00:50:15 +0900 2007
1000
%

Constant Summary collapse

CVS_ID =

for ident(1)

'$Id: store.rb 841 2008-12-24 09:23:20Z toki $'
DECODE = 
proc{|r| Marshal.load(r) }
ENCODE = 
proc{|w| Marshal.dump(w) }

Instance Method Summary collapse

Methods inherited from StorageManager

open, #shutdown

Constructor Details

#initialize(name, options = {}) ⇒ Store

see Higgs::StorageManager.new for name and options.



227
228
229
230
231
232
 
# File 'lib/higgs/store.rb', line 227

def initialize(name, options={})
  options = options.dup
  options[:decode] = DECODE
  options[:encode] = ENCODE
  super(name, options)
end