1 files changed, 52 insertions, 0 deletions
diff --git a/lib/unicorn/trailer_parser.rb b/lib/unicorn/trailer_parser.rb
new file mode 100644
index 0000000..9431331
--- /dev/null
+++ b/lib/unicorn/trailer_parser.rb
@@ -0,0 +1,52 @@
+# Copyright (c) 2009 Eric Wong
+# You can redistribute it and/or modify it under the same terms as Ruby.
+require 'unicorn'
+require 'unicorn/http11'
+
+# Eventually I should integrate this into HttpParser...
+module Unicorn
+  class TrailerParser
+
+    TR_FR = 'a-z-'.freeze
+    TR_TO = 'A-Z_'.freeze
+
+    # initializes HTTP trailer parser with acceptable +trailer+
+    def initialize(http_trailer)
+      @trailers = http_trailer.split(/\s*,\s*/).inject({}) { |hash, key|
+        hash[key.tr(TR_FR, TR_TO)] = true
+        hash
+      }
+    end
+
+    # Executes our TrailerParser on +data+ and modifies +env+  This will
+    # shrink +data+ as it is being consumed.  Returns true if it has
+    # parsed all trailers, false if not.  It raises HttpParserError on
+    # parse failure or unknown headers.  It has slightly smaller limits
+    # than the C-based HTTP parser but should not be an issue in practice
+    # since Content-MD5 is probably the only legitimate use for it.
+    def execute!(env, data)
+      data.size > 0xffff and
+        raise HttpParserError, "trailer buffer too large: #{data.size} bytes"
+
+      begin
+        data.sub!(/\A([^\r]+)\r\n/, Z) or return false # need more data
+
+        key, val = $1.split(/:\s*/, 2)
+
+        key.size > 256 and
+          raise HttpParserError, "trailer key #{key.inspect} is too long"
+        val.size > 8192 and
+          raise HttpParserError, "trailer value #{val.inspect} is too long"
+
+        key.tr!(TR_FR, TR_TO)
+
+        @trailers.delete(key) or
+          raise HttpParserError, "unknown trailer: #{key.inspect}"
+        env["HTTP_#{key}"] = val
+
+        @trailers.empty? and return true
+      end while true
+    end
+
+  end
+end