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Diffstat (limited to 'jni/ruby/lib/yaml/dbm.rb')
| -rw-r--r-- | jni/ruby/lib/yaml/dbm.rb | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/jni/ruby/lib/yaml/dbm.rb b/jni/ruby/lib/yaml/dbm.rb new file mode 100644 index 0000000..24a68bf --- /dev/null +++ b/jni/ruby/lib/yaml/dbm.rb @@ -0,0 +1,279 @@ +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 |