sbdb/lib/sbdb/db.rb

132 lines
2.5 KiB
Ruby

require 'bdb'
require 'sbdb/cursor'
module SBDB
TYPES = []
class DB
UNKNOWN = Bdb::Db::UNKNOWN
BTREE = Bdb::Db::BTREE
HASH = Bdb::Db::HASH
QUEUE = Bdb::Db::QUEUE
ARRAY = RECNO = Bdb::Db::RECNO
RDONLY = READLONY = Bdb::DB_RDONLY
CONSUME = Bdb::DB_CONSUME
CONSUME_WAIT = Bdb::DB_CONSUME_WAIT
attr_reader :home
include Enumerable
def bdb_object() @db end
def sync() @db.sync end
def close( f = nil) @db.close f || 0 end
def cursor( &e) Cursor.new self, &e end
def [] k
@db.get nil, k.nil? ? nil : k.to_s, nil, 0
rescue Bdb::KeyEmpty
return nil
end
def []= k, v
if v.nil?
@db.del nil, k.to_s, 0
else
@db.put nil, k.nil? ? nil : k.to_s, v.to_s, 0
end
end
class << self
def new *p, &e
x = super *p
return x unless e
begin e.call x
ensure
x.sync
x.close
end
end
alias open new
end
def initialize file, *args
info args: args
opts = Hash === args.last ? args.pop : {}
opts.update :name => args[0], :type => args[1], :flags => args[2], :mode => args[3], :env => args[4]
#type = BTREE if type == UNKNOWN and (flags & CREATE) == CREATE
@home, @db = opts[:env], opts[:env] ? opts[:env].bdb_object.db : Bdb::Db.new
opts[:type] ||= TYPES.index(self.class) || UNKNOWN
info opts: opts
begin
@db.open opts[:txn], file, opts[:name], opts[:type], opts[:flags] || 0, opts[:mode] || 0
@db.re_len = opts[:re_len] if opts[:re_len]
rescue Object
close
raise $!
end
end
def each k = nil, v = nil, &e
cursor{|c|c.each k, v, &e}
end
def reverse k = nil, v = nil, &e
cursor{|c|c.reverse k, v, &e}
end
def to_hash k = nil, v = nil
h = {}
each( k, v) {|k, v| h[ k] = v }
h
end
end
class Unknown < DB
def self.new file, *p, &e
dbt = super( file, *p) {|db| db.bdb_object.get_type }
TYPES[dbt] ? TYPES[dbt].new( file, *p, &e) : super( file, *p, &e)
end
end
class Btree < DB
end
TYPES[DB::BTREE] = Btree
class Hash < DB
end
TYPES[DB::HASH] = Hash
class Recno < DB
def [] k
super [k].pack('I')
end
def []= k, v
super [k].pack('I'), v
end
def push v
@db.put nil, "\0\0\0\0", v, Bdb::DB_APPEND
end
end
Array = Recno
TYPES[DB::RECNO] = Recno
class Queue < DB
def [] k
super [k].pack('I')
end
def []= k, v
super [k].pack('I'), v
end
def unshift
@db.get nil, nil, nil, Bdb::DB_CONSUME
end
def push v
@db.put nil, "\0\0\0\0", v, Bdb::DB_APPEND
end
end
TYPES[DB::QUEUE] = Queue
end