Ruby C extension speedup: don't re-intern constant string needlessly.

Also fixed lines with > 80 char length.

1 files changed, 10 insertions, 0 deletions

diff --git a/ruby/ext/google/protobuf_c/protobuf.c b/ruby/ext/google/protobuf_c/protobuf.c
index 8ab518a5..d0625a10 100644
--- a/ruby/ext/google/protobuf_c/protobuf.c
+++ b/ruby/ext/google/protobuf_c/protobuf.c
@@ -64,6 +64,15 @@ rb_encoding* kRubyStringUtf8Encoding;
 rb_encoding* kRubyStringASCIIEncoding;
 rb_encoding* kRubyString8bitEncoding;
 
+// Ruby-interned string: "descriptor". We use this identifier to store an
+// instance variable on message classes we create in order to link them back to
+// their descriptors.
+//
+// We intern this once at module load time then use the interned identifier at
+// runtime in order to avoid the cost of repeatedly interning in hot paths.
+const char* kDescriptorInstanceVar = "descriptor";
+ID descriptor_instancevar_interned;
+
 // -----------------------------------------------------------------------------
 // Initialization/entry point.
 // -----------------------------------------------------------------------------
@@ -71,6 +80,7 @@ rb_encoding* kRubyString8bitEncoding;
 // This must be named "Init_protobuf_c" because the Ruby module is named
 // "protobuf_c" -- the VM looks for this symbol in our .so.
 void Init_protobuf_c() {
+  descriptor_instancevar_interned = rb_intern(kDescriptorInstanceVar);
   VALUE google = rb_define_module("Google");
   VALUE protobuf = rb_define_module_under(google, "Protobuf");
   VALUE internal = rb_define_module_under(protobuf, "Internal");