JezK
Edit File: dbm.rb
# frozen_string_literal: false require 'yaml' require 'dbm' module YAML # YAML + DBM = YDBM # # YAML::DBM provides the same interface as ::DBM. # # However, while DBM only allows strings for both keys and values, # this library allows one to use most Ruby objects for values # by first converting them to YAML. Keys must be strings. # # Conversion to and from YAML is performed automatically. # # See the documentation for ::DBM and ::YAML for more information. class DBM < ::DBM VERSION = "0.1" # :nodoc: # :call-seq: # ydbm[key] -> value # # Return value associated with +key+ from database. # # Returns +nil+ if there is no such +key+. # # See #fetch for more information. def []( key ) fetch( key ) end # :call-seq: # ydbm[key] = value # # Set +key+ to +value+ in database. # # +value+ will be converted to YAML before storage. # # See #store for more information. def []=( key, val ) store( key, val ) end # :call-seq: # ydbm.fetch( key, ifnone = nil ) # ydbm.fetch( key ) { |key| ... } # # Return value associated with +key+. # # If there is no value for +key+ and no block is given, returns +ifnone+. # # Otherwise, calls block passing in the given +key+. # # See ::DBM#fetch for more information. def fetch( keystr, ifnone = nil ) begin val = super( keystr ) return YAML.load( val ) if String === val rescue IndexError end if block_given? yield keystr else ifnone end end # Deprecated, used YAML::DBM#key instead. # ---- # Note: # YAML::DBM#index makes warning from internal of ::DBM#index. # It says 'DBM#index is deprecated; use DBM#key', but DBM#key # behaves not same as DBM#index. # def index( keystr ) super( keystr.to_yaml ) end # :call-seq: # ydbm.key(value) -> string # # Returns the key for the specified value. def key( keystr ) invert[keystr] end # :call-seq: # ydbm.values_at(*keys) # # Returns an array containing the values associated with the given keys. def values_at( *keys ) keys.collect { |k| fetch( k ) } end # :call-seq: # ydbm.delete(key) # # Deletes value from database associated with +key+. # # Returns value or +nil+. def delete( key ) v = super( key ) if String === v v = YAML.load( v ) end v end # :call-seq: # ydbm.delete_if { |key, value| ... } # # Calls the given block once for each +key+, +value+ pair in the database. # Deletes all entries for which the block returns true. # # Returns +self+. def delete_if # :yields: [key, value] del_keys = keys.dup del_keys.delete_if { |k| yield( k, fetch( k ) ) == false } del_keys.each { |k| delete( k ) } self end # :call-seq: # ydbm.reject { |key, value| ... } # # Converts the contents of the database to an in-memory Hash, then calls # Hash#reject with the specified code block, returning a new Hash. def reject hsh = self.to_hash hsh.reject { |k,v| yield k, v } end # :call-seq: # ydbm.each_pair { |key, value| ... } # # Calls the given block once for each +key+, +value+ pair in the database. # # Returns +self+. def each_pair # :yields: [key, value] keys.each { |k| yield k, fetch( k ) } self end # :call-seq: # ydbm.each_value { |value| ... } # # Calls the given block for each value in database. # # Returns +self+. def each_value # :yields: value super { |v| yield YAML.load( v ) } self end # :call-seq: # ydbm.values # # Returns an array of values from the database. def values super.collect { |v| YAML.load( v ) } end # :call-seq: # ydbm.has_value?(value) # # Returns true if specified +value+ is found in the database. def has_value?( val ) each_value { |v| return true if v == val } return false end # :call-seq: # ydbm.invert -> hash # # Returns a Hash (not a DBM database) created by using each value in the # database as a key, with the corresponding key as its value. # # Note that all values in the hash will be Strings, but the keys will be # actual objects. def invert h = {} keys.each { |k| h[ self.fetch( k ) ] = k } h end # :call-seq: # ydbm.replace(hash) -> ydbm # # Replaces the contents of the database with the contents of the specified # object. Takes any object which implements the each_pair method, including # Hash and DBM objects. def replace( hsh ) clear update( hsh ) end # :call-seq: # ydbm.shift -> [key, value] # # Removes a [key, value] pair from the database, and returns it. # If the database is empty, returns +nil+. # # The order in which values are removed/returned is not guaranteed. def shift a = super a[1] = YAML.load( a[1] ) if a a end # :call-seq: # ydbm.select { |key, value| ... } # ydbm.select(*keys) # # If a block is provided, returns a new array containing [key, value] pairs # for which the block returns true. # # Otherwise, same as #values_at def select( *keys ) if block_given? self.keys.collect { |k| v = self[k]; [k, v] if yield k, v }.compact else values_at( *keys ) end end # :call-seq: # ydbm.store(key, value) -> value # # Stores +value+ in database with +key+ as the index. +value+ is converted # to YAML before being stored. # # Returns +value+ def store( key, val ) super( key, val.to_yaml ) val end # :call-seq: # ydbm.update(hash) -> ydbm # # Updates the database with multiple values from the specified object. # Takes any object which implements the each_pair method, including # Hash and DBM objects. # # Returns +self+. def update( hsh ) hsh.each_pair do |k,v| self.store( k, v ) end self end # :call-seq: # ydbm.to_a -> array # # Converts the contents of the database to an array of [key, value] arrays, # and returns it. def to_a a = [] keys.each { |k| a.push [ k, self.fetch( k ) ] } a end # :call-seq: # ydbm.to_hash -> hash # # Converts the contents of the database to an in-memory Hash object, and # returns it. def to_hash h = {} keys.each { |k| h[ k ] = self.fetch( k ) } h end alias :each :each_pair end end