Add bin and edit workflow

bin/gems/ffi-1.17.1-x86_64-linux-gnu/lib/ffi/managedstruct.rb

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+# Copyright (C) 2008 Mike Dalessio
+#
+# 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
+  #
+  # FFI::ManagedStruct allows custom garbage-collection of your FFI::Structs.
+  #
+  # The typical use case would be when interacting with a library
+  # that has a nontrivial memory management design, such as a linked
+  # list or a binary tree.
+  #
+  # When the {Struct} instance is garbage collected, FFI::ManagedStruct will
+  # invoke the class's release() method during object finalization.
+  #
+  # @example Example usage:
+  #  module MyLibrary
+  #    ffi_lib "libmylibrary"
+  #    attach_function :new_dlist, [], :pointer
+  #    attach_function :destroy_dlist, [:pointer], :void
+  #  end
+  #
+  #  class DoublyLinkedList < FFI::ManagedStruct
+  #    @@@
+  #    struct do |s|
+  #      s.name 'struct dlist'
+  #      s.include 'dlist.h'
+  #      s.field :head, :pointer
+  #      s.field :tail, :pointer
+  #    end
+  #    @@@
+  #
+  #    def self.release ptr
+  #      MyLibrary.destroy_dlist(ptr)
+  #    end
+  #  end
+  #
+  #  begin
+  #    ptr = DoublyLinkedList.new(MyLibrary.new_dlist)
+  #    #  do something with the list
+  #  end
+  #  # struct is out of scope, and will be GC'd using DoublyLinkedList#release
+  #
+  #
+  class ManagedStruct < FFI::Struct
+
+    # @overload initialize(pointer)
+    #  @param [Pointer] pointer
+    #  Create a new ManagedStruct which will invoke the class method #release on
+    # @overload initialize
+    # A new instance of FFI::ManagedStruct.
+    def initialize(pointer=nil)
+      raise NoMethodError, "release() not implemented for class #{self}" unless self.class.respond_to?(:release, true)
+      raise ArgumentError, "Must supply a pointer to memory for the Struct" unless pointer
+      super AutoPointer.new(pointer, self.class.method(:release))
+    end
+
+  end
+end