Class: Bdb::Database
Instance Attribute Summary collapse
-
#name ⇒ Object
readonly
Returns the value of attribute name.
Attributes inherited from Base
Instance Method Summary collapse
- #[](key) ⇒ Object
- #close ⇒ Object
- #close_environment ⇒ Object
- #count(field, key) ⇒ Object
- #db(index = nil) ⇒ Object
- #delete(key) ⇒ Object
- #get(*keys, &block) ⇒ Object
-
#initialize(name, opts = {}) ⇒ Database
constructor
A new instance of Database.
- #set(key, value, opts = {}) ⇒ Object
- #sync ⇒ Object
-
#truncate! ⇒ Object
Deletes all records in the database.
Methods inherited from Base
#checkpoint, #config, #environment, #index_by, #master?, #path, #synchronize, #transaction
Constructor Details
#initialize(name, opts = {}) ⇒ Database
Returns a new instance of Database.
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# File 'lib/bdb/database.rb', line 4 def initialize(name, opts = {}) @name = name super(opts) end |
Instance Attribute Details
#name ⇒ Object (readonly)
Returns the value of attribute name.
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# File 'lib/bdb/database.rb', line 8 def name @name end |
Instance Method Details
#[](key) ⇒ Object
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# File 'lib/bdb/database.rb', line 148 def [](key) get(key).first end |
#close ⇒ Object
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# File 'lib/bdb/database.rb', line 53 def close return unless @db synchronize do @db.each {|field, db| db.close(0)} @db = nil end end |
#close_environment ⇒ Object
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# File 'lib/bdb/database.rb', line 61 def close_environment environment.close end |
#count(field, key) ⇒ Object
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# File 'lib/bdb/database.rb', line 65 def count(field, key) with_cursor(db(field)) do |cursor| k, v = cursor.get(Tuple.dump(key), nil, Bdb::DB_SET) k ? cursor.count : 0 end end |
#db(index = nil) ⇒ Object
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# File 'lib/bdb/database.rb', line 10 def db(index = nil) if @db.nil? @db = {} open_flags = master? ? Bdb::DB_CREATE : Bdb::DB_RDONLY transaction(false) do primary_db = environment.env.db primary_db.pagesize = config[:page_size] if config[:page_size] primary_db.open(transaction, name, nil, Bdb::Db::BTREE, open_flags, 0) @db[:primary_key] = primary_db indexes.each do |field, opts| index_callback = lambda do |db, key, data| value = Marshal.load(data) index_key = value.kind_of?(Hash) ? value[:field] : value.send(field) if opts[:multi_key] and index_key.kind_of?(Array) # Index multiple keys. If the key is an array, you must wrap it with an outer array. index_key.collect {|k| Tuple.dump(k)} elsif index_key # Index a single key. Tuple.dump(index_key) end end index_db = environment.env.db index_db.flags = Bdb::DB_DUPSORT unless opts[:unique] index_db.pagesize = config[:page_size] if config[:page_size] index_db.open(transaction, "#{name}_by_#{field}", nil, Bdb::Db::BTREE, open_flags, 0) primary_db.associate(transaction, index_db, open_flags, index_callback) @db[field] = index_db end end end @db[index || :primary_key] rescue Bdb::DbError => e # Retry if the database doesn't exist and we are a replication client. if not master? and e.code == Errno::ENOENT::Errno close sleep 1 retry else raise(e) end end |
#delete(key) ⇒ Object
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# File 'lib/bdb/database.rb', line 162 def delete(key) synchronize do key = Tuple.dump(key) db.del(transaction, key, 0) end end |
#get(*keys, &block) ⇒ Object
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# File 'lib/bdb/database.rb', line 72 def get(*keys, &block) opts = keys.last.kind_of?(Hash) ? keys.pop : {} db = db(opts[:field]) set = Bdb::ResultSet.new(opts, &block) flags = opts[:modify] ? Bdb::DB_RMW : 0 flags = 0 if environment.disable_transactions? keys.each do |key| key = get_key(key, opts) if key == :all with_cursor(db) do |cursor| if opts[:reverse] k,v = cursor.get(nil, nil, Bdb::DB_LAST | flags) # Start at the last item. iter = lambda {cursor.get(nil, nil, Bdb::DB_PREV | flags)} # Move backward. else k,v = cursor.get(nil, nil, Bdb::DB_FIRST | flags) # Start at the first item. iter = lambda {cursor.get(nil, nil, Bdb::DB_NEXT | flags)} # Move forward. end while k set << unmarshal(v, :tuple => k) k,v = iter.call end end elsif key.kind_of?(Range) # Fetch a range of keys. with_cursor(db) do |cursor| first = Tuple.dump(key.first) last = Tuple.dump(key.last) # Return false once we pass the end of the range. cond = key.exclude_end? ? lambda {|k| k < last} : lambda {|k| k <= last} if opts[:reverse] iter = lambda {cursor.get(nil, nil, Bdb::DB_PREV | flags)} # Move backward. # Position the cursor at the end of the range. k,v = cursor.get(last, nil, Bdb::DB_SET_RANGE | flags) || cursor.get(nil, nil, Bdb::DB_LAST | flags) while k and not cond.call(k) k,v = iter.call end cond = lambda {|k| k >= first} # Change the condition to stop when we move past the start. else k,v = cursor.get(first, nil, Bdb::DB_SET_RANGE | flags) # Start at the beginning of the range. iter = lambda {cursor.get(nil, nil, Bdb::DB_NEXT | flags)} # Move forward. end while k and cond.call(k) set << unmarshal(v, :tuple => k) k,v = iter.call end end else if (db.flags & Bdb::DB_DUPSORT) == 0 synchronize do # There can only be one item for each key. data = db.get(transaction, Tuple.dump(key), nil, flags) set << unmarshal(data, :key => key) if data end else # Have to use a cursor because there may be multiple items with each key. with_cursor(db) do |cursor| k,v = cursor.get(Tuple.dump(key), nil, Bdb::DB_SET | flags) while k set << unmarshal(v, :tuple => k) k,v = cursor.get(nil, nil, Bdb::DB_NEXT_DUP | flags) end end end end end set.results rescue Bdb::ResultSet::LimitReached set.results end |
#set(key, value, opts = {}) ⇒ Object
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# File 'lib/bdb/database.rb', line 152 def set(key, value, opts = {}) synchronize do key = Tuple.dump(key) value = Marshal.dump(value) flags = opts[:create] ? Bdb::DB_NOOVERWRITE : 0 db.put(transaction, key, value, flags) value end end |
#sync ⇒ Object
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# File 'lib/bdb/database.rb', line 176 def sync db.sync end |
#truncate! ⇒ Object
Deletes all records in the database. Beware!
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# File 'lib/bdb/database.rb', line 170 def truncate! synchronize do db.truncate(transaction) end end |