1 files changed, 75 insertions, 0 deletions
diff --git a/lib/json/pure.rb b/lib/json/pure.rb
new file mode 100644
index 0000000000..b86d905523
--- /dev/null
+++ b/lib/json/pure.rb
@@ -0,0 +1,75 @@
+require 'json/common'
+require 'json/pure/parser'
+require 'json/pure/generator'
+
+module JSON
+  begin
+    require 'iconv'
+    # An iconv instance to convert from UTF8 to UTF16 Big Endian.
+    UTF16toUTF8 = Iconv.new('utf-8', 'utf-16be') # :nodoc:
+    # An iconv instance to convert from UTF16 Big Endian to UTF8.
+    UTF8toUTF16 = Iconv.new('utf-16be', 'utf-8') # :nodoc:
+    UTF8toUTF16.iconv('no bom')
+  rescue Errno::EINVAL, Iconv::InvalidEncoding
+    # Iconv doesn't support big endian utf-16. Let's try to hack this manually
+    # into the converters.
+    begin
+      old_verbose, $VERBSOSE = $VERBOSE, nil
+      # An iconv instance to convert from UTF8 to UTF16 Big Endian.
+      UTF16toUTF8 = Iconv.new('utf-8', 'utf-16') # :nodoc:
+      # An iconv instance to convert from UTF16 Big Endian to UTF8.
+      UTF8toUTF16 = Iconv.new('utf-16', 'utf-8') # :nodoc:
+      UTF8toUTF16.iconv('no bom')
+      if UTF8toUTF16.iconv("\xe2\x82\xac") == "\xac\x20"
+        swapper = Class.new do
+          def initialize(iconv) # :nodoc:
+            @iconv = iconv
+          end
+
+          def iconv(string) # :nodoc:
+            result = @iconv.iconv(string)
+            JSON.swap!(result)
+          end
+        end
+        UTF8toUTF16 = swapper.new(UTF8toUTF16) # :nodoc:
+      end
+      if UTF16toUTF8.iconv("\xac\x20") == "\xe2\x82\xac"
+        swapper = Class.new do
+          def initialize(iconv) # :nodoc:
+            @iconv = iconv
+          end
+
+          def iconv(string) # :nodoc:
+            string = JSON.swap!(string.dup)
+            @iconv.iconv(string)
+          end
+        end
+        UTF16toUTF8 = swapper.new(UTF16toUTF8) # :nodoc:
+      end
+    rescue Errno::EINVAL, Iconv::InvalidEncoding
+      raise MissingUnicodeSupport, "iconv doesn't seem to support UTF-8/UTF-16 conversions"
+    ensure
+      $VERBOSE = old_verbose
+    end
+  rescue LoadError
+    raise MissingUnicodeSupport,
+      "iconv couldn't be loaded, which is required for UTF-8/UTF-16 conversions"
+  end
+
+  # Swap consecutive bytes of _string_ in place.
+  def self.swap!(string) # :nodoc:
+    0.upto(string.size / 2) do |i|
+      break unless string[2 * i + 1]
+      string[2 * i], string[2 * i + 1] = string[2 * i + 1], string[2 * i]
+    end
+    string
+  end
+
+  # This module holds all the modules/classes that implement JSON's
+  # functionality in pure ruby.
+  module Pure
+    $DEBUG and warn "Using pure library for JSON."
+    JSON.parser = Parser
+    JSON.generator = Generator
+  end
+end