sbdb/lib/sbdb/environment.rb
2010-02-03 13:21:40 +01:00

89 lines
2.7 KiB
Ruby

require 'bdb'
require 'sbdb/weakhash'
require 'sbdb/db'
module SBDB
# Environments are for storing one or more databases and are important
# if you want to work with more than one process on one database.
# You needn't use Environment, but it's usefull.
class Environment
INIT_TXN = Bdb::DB_INIT_TXN
INIT_LOCK = Bdb::DB_INIT_LOCK
INIT_LOG = Bdb::DB_INIT_LOG
INIT_MPOOL = Bdb::DB_INIT_MPOOL
INIT_TRANSACTION = INIT_TXN | INIT_LOCK | INIT_LOG | INIT_MPOOL
LOCKDOWN = Bdb::DB_LOCKDOWN
NOMMAP = Bdb::DB_NOMMAP
PRIVATE = Bdb::DB_PRIVATE
SYSTEM_MEM = Bdb::DB_SYSTEM_MEM
TXN_NOSYNC = Bdb::DB_TXN_NOSYNC
# returns the Bdb-object.
def bdb_object() @env end
# Opens a Btree in this Environment
def btree file, name = nil, flags = nil, mode = nil, txn = nil, &e
Btree.new file, name, flags, mode, txn, self, &e
end
# Opens a Hash in this Environment
def hash file, name = nil, flags = nil, mode = nil, txn = nil, &e
Hash.new file, name, flags, mode, txn, self, &e
end
# Opens a Recno in this Environment
def recno file, name = nil, flags = nil, mode = nil, txn = nil, &e
Recno.new file, name, flags, mode, txn, self, &e
end
# Opens a Queue in this Environment
def queue file, name = nil, flags = nil, mode = nil, txn = nil, &e
Queue.new file, name, flags, mode, txn, self, &e
end
# Opens a DB of unknown type in this Environment
def unknown file, name = nil, flags = nil, mode = nil, txn = nil, &e
Unknown.new file, name, flags, mode, txn, self, &e
end
def initialize dir = nil, flags = nil, mode = nil
@dbs, @env = WeakHash.new, Bdb::Env.new( 0)
begin @env.open dir || '.', flags || INIT_TRANSACTION | CREATE, mode || 0
rescue Object
close
raise
end
return self unless block_given?
begin yield self
ensure close
end
nil
end
# Close the Environment.
# First you should close all databases!
def close
@dbs.each{|k, db|db.close}
@env.close
end
class << self
alias open new
end
# Opens a Database.
# see SBDB::DB, SBDB::Btree, SBDB::Hash, SBDB::Recno, SBDB::Queue
def open type, file, name = nil, flags = nil, mode = nil, txn = nil, &e
(type || SBDB::Unkown).new file, name, flags, mode, txn, self, &e
end
alias db open
alias open_db open
# Returns the DB like open, but if it's already opened,
# it returns the old instance.
# If you use this, never use close. It's possible somebody else use it too.
# The Databases, which are opened, will close, if the Environment will close.
def [] file, name = nil, type = nil, flags = nil, mode = nil, &e
@dbs[ [file, name, flags | CREATE]] ||= (type || SBDB::Unkown).new file, name, flags, mode, nil, self, &e
end
end
Env = Environment
end