FFI: IO reader callbacks now use AbstractMemory#put_bytes instead of …

…memcpy, per Wayne's advice. along the way, refactored callbacks. closes gh-43.

FFI-TODO

@@ -20,6 +20,7 @@
   - [X] XML::RelaxNG
   - [X] SAX::PushParser
   - [X] ProcessingInstruction
+* DONE refactor reader/writer/closer io callbacks
 * miscellaneous issues
 *** DONE blanks being escaped in output
     CLOSED: [2009-04-30 Thu 19:03]
@@ -60,9 +61,8 @@ RangeError: 0xdb387178 is recycled object
 *** TODO then remove the 'rake ffi' task and supporting functions
 
 * TODO open jira tickets: support varags in callbacks (needed for syntax error and sax error)
+* TODO rdoc documentation
 * figure out how to cache the ruby objects (nodes and documents) without using Objectspace.
 
 * use (new) nested struct support in FFI?
 * do we have string encoding issues?
-* i feel like we should refactor reader/writer/closer io callbacks
-* rdoc documentation? shit.

lib/nokogiri/ffi/html/document.rb

@@ -10,15 +10,7 @@ def self.new(uri=nil, external_id=nil)
 
       def self.read_io(io, url, encoding, options)
         wrap_with_error_handling(HTML_DOCUMENT_NODE) do
-          reader = lambda do |ctx, buffer, len|
-            string = io.read(len)
-            return 0 if string.nil?
-            LibXML.memcpy(buffer, string, string.length)
-            string.length
-          end
-          closer = lambda { |ctx| 0 } # coffee is for closers.
-
-          LibXML.htmlReadIO(reader, closer, nil, url, encoding, options)
+          LibXML.htmlReadIO(IoCallbacks.reader(io), IoCallbacks.closer(io), nil, url, encoding, options)
         end
       end
 

lib/nokogiri/ffi/libxml.rb

@@ -76,7 +76,6 @@ module LibXML # :nodoc:
     # libc
     attach_function :calloc, [:int, :int], :pointer
     attach_function :free, [:pointer], :void
-    attach_function :memcpy, [:pointer, :pointer, :int], :pointer
 
     # HTMLparser.c
     attach_function :htmlReadMemory, [:string, :int, :string, :string, :int], :pointer
@@ -282,7 +281,8 @@ def self.xmlFree(pointer)
 require 'nokogiri/syntax_error'
 require 'nokogiri/xml/syntax_error'
 
-[ "structs/common_node",
+[ "io_callbacks",
+  "structs/common_node",
   "structs/xml_alloc",
   "structs/xml_document",
   "structs/xml_node",

lib/nokogiri/ffi/xml/document.rb

@@ -29,15 +29,7 @@ def encoding
 
       def self.read_io(io, url, encoding, options)
         wrap_with_error_handling(DOCUMENT_NODE) do
-          reader = lambda do |ctx, buffer, len|
-            string = io.read(len)
-            return 0 if string.nil?
-            LibXML.memcpy(buffer, string, string.length)
-            string.length
-          end
-          closer = lambda { |ctx| 0 } # coffee is for closers.
-
-          LibXML.xmlReadIO(reader, closer, nil, url, encoding, options)
+          LibXML.xmlReadIO(IoCallbacks.reader(io), IoCallbacks.closer(io), nil, url, encoding, options)
         end
       end
 

lib/nokogiri/ffi/xml/node.rb

@@ -194,12 +194,7 @@ def add_previous_sibling(prev_sibling)
       def native_write_to(io, encoding, indent_string, options)
         set_xml_indent_tree_output 1
         set_xml_tree_indent_string indent_string
-        writer = lambda do |context, buffer, len|
-          io.write buffer
-          len
-        end
-        closer = lambda { |ctx| 0 } # coffee is for closers.
-        savectx = LibXML.xmlSaveToIO(writer, closer, nil, encoding, options)
+        savectx = LibXML.xmlSaveToIO(IoCallbacks.writer(io), IoCallbacks.closer(io), nil, encoding, options)
         LibXML.xmlSaveTree(savectx, cstruct)
         LibXML.xmlSaveClose(savectx)
         io

lib/nokogiri/ffi/xml/reader.rb

@@ -163,15 +163,7 @@ def self.from_memory(buffer, url=nil, encoding=nil, options=0)
       def self.from_io(io, url=nil, encoding=nil, options=0)
         raise(ArgumentError, "io cannot be nil") if io.nil?
 
-        reader = lambda do |ctx, buffer, len|
-          string = io.read(len)
-          return 0 if string.nil?
-          LibXML.memcpy(buffer, string, string.length)
-          string.length
-        end
-        closer = lambda { |ctx| 0 } # coffee is for closers.
-
-        reader_ptr = LibXML.xmlReaderForIO(reader, closer, nil, url, encoding, options)
+        reader_ptr = LibXML.xmlReaderForIO(IoCallbacks.reader(io), IoCallbacks.closer(io), nil, url, encoding, options)
         raise "couldn't create a parser" if reader_ptr.null?
 
         reader = allocate

lib/nokogiri/ffi/xml/sax/parser.rb

@@ -12,15 +12,7 @@ def parse_memory(data)
         end
 
         def native_parse_io(io, encoding)
-          reader = lambda do |ctx, buffer, len|
-            string = io.read(len)
-            return 0 if string.nil?
-            LibXML.memcpy(buffer, string, string.length)
-            string.length
-          end
-          closer = lambda { |ctx| return 0 }
-
-          sax_ctx = LibXML.xmlCreateIOParserCtxt(cstruct, nil, reader, closer, nil, encoding)
+          sax_ctx = LibXML.xmlCreateIOParserCtxt(cstruct, nil, IoCallbacks.reader(io), IoCallbacks.closer(io), nil, encoding)
           LibXML.xmlParseDocument(sax_ctx)
           LibXML.xmlFreeParserCtxt(sax_ctx)
           io