Convert the image pointer to AutoPointer to avoid mem leaks

lib/gd2/cgd2.rb

@@ -18,4 +18,9 @@ def self.lib_path
 
   # void* gdImagePngPtr(gdImagePtr im, int *size) (FUNCTION)
   attach_function :gdImagePngPtr, [:pointer, :pointer], :pointer
+
+  # gdImageDestroy(gdImagePtr im) (FUNCTION)
+  attach_function :gdImageDestroy, [:pointer], :void
+
+  attach_function :gdFree, [:pointer], :void
 end

lib/gd2/image.rb

@@ -10,8 +10,14 @@ class Image::IndexedColor < Image
   end
 
   class Image::TrueColor < Image
+    def release(ptr)
+      CGD2::gdImageDestroy(ptr)
+    end
     def initialize(w, h)
-      @image_ptr = CGD2::gdImageCreateTrueColor(w, h)
+      @image_ptr = FFI::AutoPointer.new(
+        CGD2::gdImageCreateTrueColor(w, h), 
+        self.method(:release)
+      )
     end
 
     def png
@@ -20,7 +26,11 @@ def png
 
       size = size.get_int(0)
 
-      png_pointer.get_bytes(0, size)
+      png = png_pointer.get_bytes(0, size)
+
+      CGD2::gdFree(png_pointer)
+
+      png
     end
   end
 end

spec/image_spec.rb

@@ -1,9 +1,12 @@
 require File.expand_path(File.join(File.dirname(__FILE__), "spec_helper"))
 
 describe GD2::Image::TrueColor do
+  before do
+    CGD2.stub!(:gdFree)
+  end
   it "should generate png string" do
     image = GD2::Image::TrueColor.new(100, 100)
-    CGD2.should_receive(:gdImagePngPtr).and_return(mock("Pointer"))
+    CGD2.should_receive(:gdImagePngPtr).and_return(mock("Pointer", :get_bytes => ''))
 
     image.png
   end

spec/spec_helper.rb

@@ -3,4 +3,4 @@
 require 'spec'
 
 $: << 'lib'
-require 'gd2'
+require 'gd2-ffi'

test.rb

@@ -1,6 +1,5 @@
 $: << 'lib'
 require 'gd2'
-
 image_height = 100
 image_width = 200
 
@@ -35,25 +34,17 @@
   options[:offset_x] + options[:margin],
   options[:offset_y] + options[:line_spacing] * (0 + 1))
 
-10.times do |i|
-  image = GD2::Image::TrueColor.new(image_width * 2, image_height)
-  bg_rect.draw(image, white.to_i)
-  bg_rect_sprite.draw(image, yellow.to_i)
-
-  text = GD2::Canvas::Text.new(font, p_text, 0, line)
-  begin
-    text.draw(image, black)
-  rescue => e
-    puts e.message
-  end
-
+image = GD2::Image::TrueColor.new(image_width * 2, image_height)
+bg_rect.draw(image, white.to_i)
+bg_rect_sprite.draw(image, yellow.to_i)
 
+text = GD2::Canvas::Text.new(font, p_text, 0, line)
+begin
+  text.draw(image, black)
+rescue => e
+  puts e.message
 end
 
-GC.start
-
-gets
-
-#File.open("foo.png", "wb") do |file|
-#  file.write(image.png)
-#end
+File.open("foo.png", "wb") do |file|
+  file.write(image.png)
+end