class SdbmStore

The SdbmStore class manages access to all object storage.

db: is a handle to the database.
dbtop: stores the highest id used in the database.
cache: is a handle to the cache

Public Class Methods

new(dbfile) click to toggle source

# File lib/storage/sdbmstore.rb, line 29
  def initialize(dbfile)
    super()
    @dbfile = "#{dbfile}"

    # check if database exists and build it if not
    build_database
    log.info "Loading world..."

    # open database and sets @dbtop to highest object id
    @db = SDBM.open(@dbfile, 0666)
    @db.each_key do |o|
      @dbtop = o.to_i if o.to_i > @dbtop
    end

    @cache = CacheManager.new(@db)
    log.info "Database '#{@dbfile}' loaded...highest id = #{@dbtop}."
#    log.debug @db.inspect
  rescue
    log.fatal $!
    raise
  end

Public Instance Methods

check(oid) click to toggle source

Check if an object is in the database by its id.

oid: is the id to use in the search.
return: true or false

# File lib/storage/sdbmstore.rb, line 94
def check(oid)
  @db.has_key? oid.to_s
end

close() click to toggle source

Close the database

return: Undefined.

# File lib/storage/sdbmstore.rb, line 59
def close
  @db.close
end

delete(oid) click to toggle source

Deletes an object from the database.

oid: is the id to to be deleted.
return: Undefined.

# File lib/storage/sdbmstore.rb, line 80
def delete(oid)
  @cache.delete(oid)
end

each() { |get| ... } click to toggle source

Iterate through all objects This needs to have all the possible keys first. So we need to fetch them from the cache and from the database and and produce a list of unique keys.

yield: Each object in database to block of caller.

# File lib/storage/sdbmstore.rb, line 124
def each
  kys = @cache.keys
  @db.each_key {|k| kys << k.to_i}
  kys.uniq!
  kys.each {|k| yield @cache.get(k)}
end

get(oid) click to toggle source

Finds an object in the database by its id.

oid: is the id to use in the search.
return: Handle to the object or nil.

# File lib/storage/sdbmstore.rb, line 87
def get(oid)
  @cache.get(oid)
end

inspect() click to toggle source

inspect the store cache (only for caches)

return: string

# File lib/storage/sdbmstore.rb, line 65
def inspect
  @cache.inspect
end

makenoswap(oid) click to toggle source

Marks an object nonswappable

oid: is the object id
return: undefined

# File lib/storage/sdbmstore.rb, line 108
def makenoswap(oid)
  @cache.makenoswap(oid)
end

makeswap(oid) click to toggle source

Marks an object swappable

oid: is the object id
return: undefined

# File lib/storage/sdbmstore.rb, line 115
def makeswap(oid)
  @cache.makeswap(oid)
end

mark(oid) click to toggle source

Marks an object dirty

oid: is the id to use in the search.
return: undefined

# File lib/storage/sdbmstore.rb, line 101
def mark(oid)
  @cache.mark(oid)
end

put(obj) click to toggle source

Adds a new object to the database.

obj: is a reference to object to be added
return: Undefined.

# File lib/storage/sdbmstore.rb, line 72
def put(obj)
  @cache.put(obj)
  obj # return really should not be checked
end

save() click to toggle source

Save the world

return: Undefined.

# File lib/storage/sdbmstore.rb, line 53
def save
  @cache.sync
end

stats() click to toggle source

produces a statistical report of the database

return: a string containing the report

# File lib/storage/sdbmstore.rb, line 133
def stats
  stats = super
  stats << @cache.stats
end