[PATCH] avoid RARRAY_PTR usage for vmsplice

[Eric Wong <normalperson@yhbt.net>]

In case somebody finds vmsplice useful in Ruby, we avoid incurring
the performance loss from RARRAY_PTR under Ruby 2.1.0 and Rubinius.
However, I still haven't found a useful use of vmsplice under
Ruby (or any high-level languages).
---
 ext/io_splice/io_splice_ext.c | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/ext/io_splice/io_splice_ext.c b/ext/io_splice/io_splice_ext.c
index 1c938c3..9a838df 100644
--- a/ext/io_splice/io_splice_ext.c
+++ b/ext/io_splice/io_splice_ext.c
@@ -108,9 +108,6 @@ rb_thread_blocking_region(
 #ifndef RSTRING_LEN
 #  define RSTRING_LEN(s) (RSTRING(s)->len)
 #endif
-#ifndef RARRAY_PTR
-#  define RARRAY_PTR(s) (RARRAY(s)->ptr)
-#endif
 #ifndef RARRAY_LEN
 #  define RARRAY_LEN(s) (RARRAY(s)->len)
 #endif
@@ -416,20 +413,18 @@ static VALUE nogvl_vmsplice(void *ptr)
 /* this can't be a function since we use alloca() */
 #define ARY2IOVEC(iov,iovcnt,expect,ary) \
 do { \
-	VALUE *cur; \
 	struct iovec *tmp; \
-	long n; \
-	cur = RARRAY_PTR(ary); \
-	n = RARRAY_LEN(ary); \
-	if (n > IOV_MAX) \
+	unsigned long i; \
+	iovcnt = (unsigned long)RARRAY_LEN(ary); \
+	if (iovcnt > IOV_MAX) \
 		rb_raise(rb_eArgError, "array is larger than IOV_MAX"); \
-	iov = tmp = alloca(sizeof(struct iovec) * n); \
+	iov = tmp = alloca(sizeof(struct iovec) * iovcnt); \
 	expect = 0; \
-	iovcnt = n; \
-	for (; --n >= 0; tmp++, cur++) { \
-		Check_Type(*cur, T_STRING); \
-		tmp->iov_base = RSTRING_PTR(*cur); \
-		tmp->iov_len = RSTRING_LEN(*cur); \
+	for (i = 0; i < iovcnt; tmp++, i++) { \
+		VALUE cur = rb_ary_entry(ary, (long)i); \
+		Check_Type(cur, T_STRING); \
+		tmp->iov_base = RSTRING_PTR(cur); \
+		tmp->iov_len = RSTRING_LEN(cur); \
 		expect += tmp->iov_len; \
 	} \
 } while (0)
-- 
Eric Wong