Class: Rufus::Tokyo::Dystopia::Core

Inherits:
Object
  • Object
show all
Extended by:
Openable
Defined in:
lib/rufus/tokyo/dystopia/core.rb

Overview

Tokyo Dystopia Indexed Database

tokyocabinet.sourceforge.net/dystopiadoc/#dystopiaapi

Defined Under Namespace

Classes: Error

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Openable

open

Constructor Details

#initialize(path, mode = "a+", locking = true) ⇒ Core

Opens/creates a new Tokyo dystopia database

The modes are equivelent to those when opening a file:

‘r’ : readonly ‘r+’ : read/write does not create or truncate ‘w’ : write only, create and truncate ‘w+’ : read/write, create and truncate ‘a’ : write only, create if db does not exist ‘a+’ : read/write, create if db does not exist

The third parameter ‘locking’ can be one of ‘true’, ‘false’ or :nonblocking

Raises:



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 84

def initialize( path, mode = "a+", locking = true )
  mode_bits = Core.mode_to_bits( mode )
  raise Error.new( "Invalid mode '#{mode}'" ) unless mode_bits
  lock_bits = Core.locking_to_bits( locking )
  raise Error.new( "Invalid Locking mode #{locking}" ) unless lock_bits

  @db = lib.tcidbnew()

  lib.tcidbopen( @db, path, mode_bits | lock_bits ) || raise_error
end

Class Method Details

.lib ⇒ Object 



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 39

def self.lib
  ::Rufus::Tokyo::DystopiaLib
end

.locking_to_bits(locking) ⇒ Object 



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 56

def self.locking_to_bits( locking )
  @locking_to_bits ||= {
    true  => 0,
    false => lib::NOLCK,
    :nonblocking => lib::LCKNB
  }
  return @locking_to_bits[locking]
end

.mode_to_bits(mode) ⇒ Object 



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 43

def self.mode_to_bits( mode )
  @modes_to_bits ||= {
    "r"  => lib::READER,
    "r+" => lib::READER | lib::WRITER,
    "w"  => lib::WRITER | lib::CREAT | lib::TRUNC,
    "w+" => lib::READER | lib::WRITER | lib::CREAT | lib::TRUNC,
    "a"  => lib::WRITER | lib::CREAT,
    "a+" => lib::READER | lib::WRITER | lib::CREAT ,
  }

  return @modes_to_bits[mode]
end

Instance Method Details

#clear ⇒ Object

Remove all records from the db



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 157

def clear
  lib.tcidbvanish( @db )
end

#close ⇒ Object

Close and detach from the database. This instance can not be used anymore



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 98

def close
  lib.tcidbclose( @db ) || raise_error

  lib.tcidbdel( @db )

  @db = nil
end

#count ⇒ Object Also known as: rnum

Return the number of records in the database



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 172

def count
  lib.tcidbrnum( @db )
end

#delete(id) ⇒ Object

Remove the given document from the index



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 116

def delete( id )
  lib.tcidbout( @db, id ) || raise_error
end

#fetch(id) ⇒ Object

Return the document at the specified index



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 123

def fetch( id )
  r = nil
  begin
    r = lib.tcidbget( @db, id )
  rescue => e
    # if we have 'no record found' then return nil
    if lib.tcidbecode( @db ) == 22 then
      return nil
    else
      raise_error
    end
  end
  return r
end

#fsize ⇒ Object

return the disk space used by the index



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 180

def fsize
  lib.tcidbfsiz( @db )
end

#lib ⇒ Object 



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 65

def lib
  Core.lib
end

#path ⇒ Object

Report the path of the database



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 164

def path
  s = lib.tcidbpath( @db )
  return File.expand_path( s ) if s
end

#search(expression) ⇒ Object

Return the document ids of the documents that matche the search expression

tokyocabinet.sourceforge.net/dystopiadoc/#dystopiaapi and scroll down to ‘Compound Expression of Search’



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 144

def search( expression )
  out_count = ::FFI::MemoryPointer.new :pointer
  out_list  = ::FFI::MemoryPointer.new :pointer
  out_list  = lib.tcidbsearch2( @db, expression, out_count )

  count = out_count.read_int
  results = out_list.get_array_of_uint64(0, count )
  return results
end

#store(id, text) ⇒ Object

Add a new document to the database



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# File 'lib/rufus/tokyo/dystopia/core.rb', line 109

def store( id, text )
  lib.tcidbput( @db, id, text ) || raise_error
end