#
# Copyright (C) 2009, 2010 Wayne Meissner
# Copyright (C) 2009 Luc Heinrich
#
# This file is part of ruby-ffi.
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
# * Neither the name of the Ruby FFI project nor the names of its contributors
# may be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
module FFI
# An instance of this class permits to manage {Enum}s. In fact, Enums is a collection of {Enum}s.
class Enums
def initialize
@all_enums = Array.new
@tagged_enums = Hash.new
@symbol_map = Hash.new
end
# @param [Enum] enum
# Add an {Enum} to the collection.
def <<(enum)
@all_enums << enum
@tagged_enums[enum.tag] = enum unless enum.tag.nil?
@symbol_map.merge!(enum.symbol_map)
end
# @param query enum tag or part of an enum name
# @return [Enum]
# Find a {Enum} in collection.
def find(query)
if @tagged_enums.has_key?(query)
@tagged_enums[query]
else
@all_enums.detect { |enum| enum.symbols.include?(query) }
end
end
# @param symbol a symbol to find in merge symbol maps of all enums.
# @return a symbol
def __map_symbol(symbol)
@symbol_map[symbol]
end
end
# Represents a C enum.
#
# For a C enum:
# enum fruits {
# apple,
# banana,
# orange,
# pineapple
# };
# are defined this vocabulary:
# * a _symbol_ is a word from the enumeration (ie. _apple_, by example);
# * a _value_ is the value of a symbol in the enumeration (by example, apple has value _0_ and banana _1_).
class Enum
include DataConverter
attr_reader :tag
attr_reader :native_type
# @overload initialize(info, tag=nil)
# @param [nil, Enumerable] info
# @param [nil, Symbol] tag enum tag
# @overload initialize(native_type, info, tag=nil)
# @param [FFI::Type] native_type Native type for new Enum
# @param [nil, Enumerable] info symbols and values for new Enum
# @param [nil, Symbol] tag name of new Enum
def initialize(*args)
@native_type = args.first.kind_of?(FFI::Type) ? args.shift : Type::INT
info, @tag = *args
@kv_map = Hash.new
unless info.nil?
last_cst = nil
value = 0
info.each do |i|
case i
when Symbol
raise ArgumentError, "duplicate enum key" if @kv_map.has_key?(i)
@kv_map[i] = value
last_cst = i
value += 1
when Integer
@kv_map[last_cst] = i
value = i+1
end
end
end
@vk_map = @kv_map.invert
end
# @return [Array] enum symbol names
def symbols
@kv_map.keys
end
# Get a symbol or a value from the enum.
# @overload [](query)
# Get enum value from symbol.
# @param [Symbol] query
# @return [Integer]
# @overload [](query)
# Get enum symbol from value.
# @param [Integer] query
# @return [Symbol]
def [](query)
case query
when Symbol
@kv_map[query]
when Integer
@vk_map[query]
end
end
alias find []
# Get the symbol map.
# @return [Hash]
def symbol_map
@kv_map
end
alias to_h symbol_map
alias to_hash symbol_map
# @param [Symbol, Integer, #to_int] val
# @param ctx unused
# @return [Integer] value of a enum symbol
def to_native(val, ctx)
@kv_map[val] || if val.is_a?(Integer)
val
elsif val.respond_to?(:to_int)
val.to_int
else
raise ArgumentError, "invalid enum value, #{val.inspect}"
end
end
# @param val
# @return symbol name if it exists for +val+.
def from_native(val, ctx)
@vk_map[val] || val
end
end
# Represents a C enum whose values are power of 2
#
# @example
# enum {
# red = (1<<0),
# green = (1<<1),
# blue = (1<<2)
# }
#
# Contrary to classical enums, bitmask values are usually combined
# when used.
class Bitmask < Enum
# @overload initialize(info, tag=nil)
# @param [nil, Enumerable] info symbols and bit rank for new Bitmask
# @param [nil, Symbol] tag name of new Bitmask
# @overload initialize(native_type, info, tag=nil)
# @param [FFI::Type] native_type Native type for new Bitmask
# @param [nil, Enumerable] info symbols and bit rank for new Bitmask
# @param [nil, Symbol] tag name of new Bitmask
def initialize(*args)
@native_type = args.first.kind_of?(FFI::Type) ? args.shift : Type::INT
@signed = [Type::INT8, Type::INT16, Type::INT32, Type::INT64].include?(@native_type)
info, @tag = *args
@kv_map = Hash.new
unless info.nil?
last_cst = nil
value = 0
info.each do |i|
case i
when Symbol
raise ArgumentError, "duplicate bitmask key" if @kv_map.has_key?(i)
@kv_map[i] = 1 << value
last_cst = i
value += 1
when Integer
raise ArgumentError, "bitmask index should be positive" if i<0
@kv_map[last_cst] = 1 << i
value = i+1
end
end
end
@vk_map = @kv_map.invert
end
# Get a symbol list or a value from the bitmask
# @overload [](*query)
# Get bitmask value from symbol list
# @param [Symbol] query
# @return [Integer]
# @overload [](query)
# Get bitmask value from symbol array
# @param [Array<Symbol>] query
# @return [Integer]
# @overload [](*query)
# Get a list of bitmask symbols corresponding to
# the or reduction of a list of integer
# @param [Integer] query
# @return [Array<Symbol>]
# @overload [](query)
# Get a list of bitmask symbols corresponding to
# the or reduction of a list of integer
# @param [Array<Integer>] query
# @return [Array<Symbol>]
def [](*query)
flat_query = query.flatten
raise ArgumentError, "query should be homogeneous, #{query.inspect}" unless flat_query.all? { |o| o.is_a?(Symbol) } || flat_query.all? { |o| o.is_a?(Integer) || o.respond_to?(:to_int) }
case flat_query[0]
when Symbol
flat_query.inject(0) do |val, o|
v = @kv_map[o]
if v then val | v else val end
end
when Integer, ->(o) { o.respond_to?(:to_int) }
val = flat_query.inject(0) { |mask, o| mask |= o.to_int }
@kv_map.select { |_, v| v & val != 0 }.keys
end
end
# Get the native value of a bitmask
# @overload to_native(query, ctx)
# @param [Symbol, Integer, #to_int] query
# @param ctx unused
# @return [Integer] value of a bitmask
# @overload to_native(query, ctx)
# @param [Array<Symbol, Integer, #to_int>] query
# @param ctx unused
# @return [Integer] value of a bitmask
def to_native(query, ctx)
return 0 if query.nil?
flat_query = [query].flatten
res = flat_query.inject(0) do |val, o|
case o
when Symbol
v = @kv_map[o]
raise ArgumentError, "invalid bitmask value, #{o.inspect}" unless v
val | v
when Integer
val | o
when ->(obj) { obj.respond_to?(:to_int) }
val | o.to_int
else
raise ArgumentError, "invalid bitmask value, #{o.inspect}"
end
end
# Take two's complement of positive values bigger than the max value
# for the type when native type is signed.
if @signed && res >= (1 << (@native_type.size * 8 - 1))
res = -(-res & ((1 << (@native_type.size * 8)) - 1))
end
res
end
# @param [Integer] val
# @param ctx unused
# @return [Array<Symbol, Integer>] list of symbol names corresponding to val, plus an optional remainder if some bits don't match any constant
def from_native(val, ctx)
flags = @kv_map.select { |_, v| v & val != 0 }
list = flags.keys
# force an unsigned value of the correct size
val &= (1 << (@native_type.size * 8)) - 1 if @signed
# If there are unmatch flags,
# return them in an integer,
# else information can be lost.
# Similar to Enum behavior.
remainder = val ^ flags.values.reduce(0, :|)
list.push remainder unless remainder == 0
return list
end
end
end