speedup of require

backported cached load path + custom loaded features index

array.c

@@ -295,6 +295,33 @@ rb_ary_frozen_p(VALUE ary)
     return Qfalse;
 }
 
+/* This can be used to take a snapshot of an array (with
+   e.g. rb_ary_replace) and check later whether the array has been
+   modified from the snapshot.  The snapshot is cheap, though if
+   something does modify the array it will pay the cost of copying
+   it. */
+VALUE
+rb_ary_dup_of_p(VALUE ary1, VALUE ary2)
+{
+    VALUE *p1, *p2;
+    long len = RARRAY_LEN(ary1);
+
+    if (len != RARRAY_LEN(ary2)) return Qfalse;
+
+    p1 = RARRAY_PTR(ary1);
+    p2 = RARRAY_PTR(ary2);
+
+    if (ARY_EMBED_P(ary1) && ARY_EMBED_P(ary2)) {
+        for (; len; len--, p1++, p2++) {
+            if (*p1 != *p2) return Qfalse;
+        }
+        return Qtrue;
+    }
+
+    if (p1 == p2) return Qtrue;
+    return Qfalse;
+}
+
 static VALUE
 ary_alloc(VALUE klass)
 {

file.c

@@ -149,40 +149,60 @@ file_path_convert(VALUE name)
     return name;
 }
 
-static VALUE
-rb_get_path_check(VALUE obj, int level)
+static rb_encoding *
+check_path_encoding(VALUE str)
+{
+    rb_encoding *enc = rb_enc_get(str);
+    if (!rb_enc_asciicompat(enc)) {
+	rb_raise(rb_eEncCompatError, "path name must be ASCII-compatible (%s): %s",
+		 rb_enc_name(enc), RSTRING_PTR(rb_str_inspect(str)));
+    }
+    return enc;
+}
+
+VALUE
+rb_get_path_check_to_string(VALUE obj, int level)
 {
     VALUE tmp;
     ID to_path;
-    rb_encoding *enc;
 
     if (insecure_obj_p(obj, level)) {
 	rb_insecure_operation();
     }
 
+    if (RB_TYPE_P(obj, T_STRING)) {
+	return obj;
+    }
     CONST_ID(to_path, "to_path");
     tmp = rb_check_funcall(obj, to_path, 0, 0);
     if (tmp == Qundef) {
 	tmp = obj;
     }
     StringValue(tmp);
+    return tmp;
+}
 
+VALUE
+rb_get_path_check_convert(VALUE obj, VALUE tmp, int level)
+{
     tmp = file_path_convert(tmp);
     if (obj != tmp && insecure_obj_p(tmp, level)) {
 	rb_insecure_operation();
     }
-    enc = rb_enc_get(tmp);
-    if (!rb_enc_asciicompat(enc)) {
-	tmp = rb_str_inspect(tmp);
-	rb_raise(rb_eEncCompatError, "path name must be ASCII-compatible (%s): %s",
-		 rb_enc_name(enc), RSTRING_PTR(tmp));
-    }
 
+    check_path_encoding(tmp);
     StringValueCStr(tmp);
 
     return rb_str_new4(tmp);
 }
 
+static VALUE
+rb_get_path_check(VALUE obj, int level)
+{
+    VALUE tmp = rb_get_path_check_to_string(obj, level);
+    return rb_get_path_check_convert(obj, tmp, level);
+}
+
 VALUE
 rb_get_path_no_checksafe(VALUE obj)
 {
@@ -3250,7 +3270,6 @@ rb_file_expand_path(VALUE fname, VALUE dname)
 VALUE
 rb_file_expand_path_fast(VALUE fname, VALUE dname)
 {
-    check_expand_path_args(fname, dname);
     return rb_file_expand_path_internal(fname, dname, 0, 0, EXPAND_PATH_BUFFER());
 }
 
@@ -5241,7 +5260,7 @@ rb_find_file_ext_safe(VALUE *filep, const char *const *ext, int safe_level)
 	rb_raise(rb_eSecurityError, "loading from non-absolute path %s", f);
     }
 
-    RB_GC_GUARD(load_path) = rb_get_load_path();
+    RB_GC_GUARD(load_path) = rb_get_expanded_load_path();
     if (!load_path) return 0;
 
     fname = rb_str_dup(*filep);
@@ -5306,7 +5325,7 @@ rb_find_file_safe(VALUE path, int safe_level)
 	rb_raise(rb_eSecurityError, "loading from non-absolute path %s", f);
     }
 
-    RB_GC_GUARD(load_path) = rb_get_load_path();
+    RB_GC_GUARD(load_path) = rb_get_expanded_load_path();
     if (load_path) {
 	long i;
 

hash.c

@@ -1087,7 +1087,7 @@ clear_i(VALUE key, VALUE value, VALUE dummy)
  *
  */
 
-static VALUE
+VALUE
 rb_hash_clear(VALUE hash)
 {
     rb_hash_modify_check(hash);

include/ruby/intern.h

@@ -56,6 +56,7 @@ VALUE rb_ary_tmp_new(long);
 void rb_ary_free(VALUE);
 void rb_ary_modify(VALUE);
 VALUE rb_ary_freeze(VALUE);
+VALUE rb_ary_dup_of_p(VALUE, VALUE);
 VALUE rb_ary_aref(int, VALUE*, VALUE);
 VALUE rb_ary_subseq(VALUE, long, long);
 void rb_ary_store(VALUE, long, VALUE);
@@ -441,6 +442,7 @@ VALUE rb_hash_lookup(VALUE, VALUE);
 VALUE rb_hash_lookup2(VALUE, VALUE, VALUE);
 VALUE rb_hash_fetch(VALUE, VALUE);
 VALUE rb_hash_aset(VALUE, VALUE, VALUE);
+VALUE rb_hash_clear(VALUE);
 VALUE rb_hash_delete_if(VALUE);
 VALUE rb_hash_delete(VALUE,VALUE);
 typedef VALUE rb_hash_update_func(VALUE newkey, VALUE oldkey, VALUE value);

internal.h

@@ -94,6 +94,8 @@ VALUE rb_home_dir(const char *user, VALUE result);
 VALUE rb_realpath_internal(VALUE basedir, VALUE path, int strict);
 VALUE rb_file_expand_path_fast(VALUE, VALUE);
 VALUE rb_file_expand_path_internal(VALUE, VALUE, int, int, VALUE);
+VALUE rb_get_path_check_to_string(VALUE, int);
+VALUE rb_get_path_check_convert(VALUE, VALUE, int);
 void Init_File(void);
 
 #ifdef _WIN32
@@ -119,6 +121,7 @@ VALUE rb_iseq_clone(VALUE iseqval, VALUE newcbase);
 
 /* load.c */
 VALUE rb_get_load_path(void);
+VALUE rb_get_expanded_load_path(void);
 
 /* math.c */
 VALUE rb_math_atan2(VALUE, VALUE);