Initial version 0.0.5

lib/sbdb.rb

@@ -0,0 +1,246 @@
+require 'bdb'
+
+module SBDB
+	CREATE = Bdb::DB_CREATE
+	AUTO_COMMIT = Bdb::DB_AUTO_COMMIT
+	INIT_TXN = Bdb::DB_INIT_TXN
+	INIT_LOCK = Bdb::DB_INIT_LOCK
+	INIT_LOG = Bdb::DB_INIT_LOG
+	INIT_MPOOL = Bdb::DB_INIT_MPOOL
+
+	class Environment
+		def bdb_object
+			@env
+		end
+
+		def initialize dir, flags = nil, mode = nil
+			flags ||= INIT_TXN | INIT_LOCK | INIT_LOG | INIT_MPOOL | CREATE
+			mode ||= 0
+			@env = Bdb::Env.new 0
+			begin @env.open dir, flags, mode
+			rescue Object
+				close
+				raise
+			end
+
+			return self  unless block_given?
+
+			begin yield self
+			ensure close
+			end
+			nil
+		end
+
+		def close
+			@env.close
+		end
+
+		class << self
+			alias open new
+		end
+
+		def open type, *p, &e
+			p[5] = self
+			type.new *p, &e
+		end
+		alias db open
+		alias open_db open
+	end
+	Env = Environment
+
+	class DB
+		UNKNOWN = Bdb::Db::UNKNOWN
+		BTREE = Bdb::Db::BTREE
+		HASH = Bdb::Db::HASH
+		QUEUE = Bdb::Db::QUEUE
+		ARRAY = RECNO = Bdb::Db::RECNO
+
+		attr_reader :home
+
+		include Enumerable
+		def bdb_object
+			@db
+		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, name = nil, type = nil, flags = nil, mode = nil, txn = nil, env = nil
+			flags ||= 0
+			type ||= UNKNOWN
+			type = BTREE  if type == UNKNOWN and (flags & CREATE) == CREATE
+			mode ||= 0
+			@home = env
+			@db = env ? env.bdb_object.db : Bdb::Db.new
+			begin @db.open txn, file, name, type, flags, mode
+			rescue Object
+				close
+				raise $!
+			end
+		end
+
+		def sync
+			@db.sync
+		end
+
+		def close f = nil
+			@db.close f || 0
+		end
+
+		def [] k
+			@db.get nil, k, nil, 0
+		end
+
+		def []= k, v
+			@db.put nil, k, v, 0
+		end
+
+		def cursor &e
+			Cursor.new self, &e
+		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 Cursor
+		NEXT = Bdb::DB_NEXT
+		FIRST = Bdb::DB_FIRST
+		LAST = Bdb::DB_LAST
+		PREV = Bdb::DB_PREV
+		SET = Bdb::DB_SET
+
+		attr_reader :db
+
+		include Enumerable
+		def bdb_object
+			@cursor
+		end
+
+		def self.new *p
+			x = super *p
+			return x  unless block_given?
+			begin yield x
+			ensure x.close
+			end
+		end
+
+		def initialize ref
+			obj = ref.bdb_object
+			@cursor, @db = *if Cursor === ref
+					[obj.dup, ref.db]
+				else [obj.cursor( nil, 0), ref]
+				end
+		end
+
+		def close
+			@cursor.close
+		end
+
+		def get k, v, f
+			@cursor.get k, v, f
+		end
+
+		def count
+			@cursor.count
+		end
+
+		def reverse k = nil, v = nil, &e
+			each k, v, LAST, PREV, &e
+		end
+
+		def each k = nil, v = nil, f = nil, n = nil
+			return Enumerator.new( self, :each, k, v, f, n)  unless block_given?
+			n ||= NEXT
+			e = @cursor.get k, v, f || FIRST
+			return  unless e
+			yield *e
+			yield *e  while e = @cursor.get( k, v, n)
+			nil
+		end
+
+		def first k = nil, v = nil
+			@cursor.get k, v, FIRST
+		end
+
+		def last k = nil, v = nil
+			@cursor.get k, v, LAST
+		end
+
+		def next k = nil, v = nil
+			@cursor.get k, v, NEXT
+		end
+
+		def prev k = nil, v = nil
+			@cursor.get k, v, PREV
+		end
+	end
+
+	class Unknown < DB
+		def self.new *p, &e
+			super *p[0...2], UNKNOWN, *p[2..-1], &e
+		end
+	end
+
+	class Btree < DB
+		def self.new *p, &e
+			super *p[0...2], BTREE, *p[2..-1], &e
+		end
+	end
+
+	class Hash < DB
+		def self.new *p, &e
+			super *p[0...2], HASH, *p[2..-1], &e
+		end
+	end
+
+	class Recno < DB
+		def self.new *p, &e
+			super *p[0...2], RECNO, *p[2..-1], &e
+		end
+
+		def [] k
+			super [k].pack('N')
+		end
+
+		def []= k, v
+			super [k].pack('N'), v
+		end
+	end
+	Array = Recno
+
+	class Queue < DB
+		def self.new *p, &e
+			super *p[0...2], QUEUE, *p[2..-1], &e
+		end
+
+		def [] k
+			super [k].pack('N')
+		end
+
+		def []= k, v
+			super [k].pack('N'), v
+		end
+	end
+end